Marine Biological Laboratory

AUG :m1 1956 RAISING WOODS HOLE, MASS. BAIT FISHES

CIRCULAR 35

FISH AND WILDLIFE SERVICE UNITED STATES DEPARTMENT OF THE INTERIOR

RAISING BAIT FISHES

By John Dobie, O. Lloyd Meeheon

S. F. Snieszko, and George N. Washburn

CIRCULAR 35

Fish and Wildlife Service

John L. Farley^ Director

United States Department of the Interior Douglas McKay, Secretary

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • 1956

For sale by the Superintendent of Documents, United States Government Printing Office Washinston 25, D. C. Price 45 cents FOREWORD

At the second annual meeting of the Tri-State Fisheries Con- ference (Michigan, Minnesota, and Wisconsin) in 1946, a spe- cial committee was appointed to assemble information on bait culture and to assign research to the contributing agencies. In 1948, the results of that cooperative project were published in Circular 12, Propagation of Minnoios and Other Bait Species. The present publication is a revision of Circular 12 and adds the results of 5 years of pond investigations by research men in the Midwestern States.

The following persons contributed to this revision : Dr. John Dobie, Minnesota Fisheries Research Unit, revised the sections on production of fish in natural ponds, handling of minnows, and control of predators. Measurements, weights and volumes of minnows, and food habits of some minnows were added to the section on the life histories of important bait fishes. Dr. O. Lloyd Meehean, United States Fish and Wildlife Service, rewrote the sections on pond construction and control of aquatic vegetation. Dr. S. F. Snieszko, United States Fish and Wildlife Service, rewrote the section on control of diseases and parasites and added information on use of the new antibiotics. George N. Washburn, Ozark Fisheries, wrote the sections on methods of fathead-minnow, creek-chub, and golden- shiner propagation used by the large commercial hatcheries of Missouri. John Moyle, Iljalmar Swenson, and Fred Miller, Minnesota Bureau of Fisheries, reviewed the manuscript. Harold Condiff and L. N. Nelson generously provided ponds and field assistance for the Minnesota natural-pond studies. Ruth Aanes, Minnesota Fisheries Research Unit, typed and proofread the manuscript. CONTENTS

Page Foreword " Why bait-Fish propagation? 1 Establishing the hatchery 3 Economic considerations 3 Types of ponds 3 Artificial ponds 4 Natural ponds 21 Choosing the fish 23 Operating the hatchery 24 Fertilizing the pond 24 Stocking the pond with adult fish 26 Artificial feeding 27 Handling bait fish 28 Harvesting fish 29 Estimating production 37 Grading fish 39 Transporting and holding bait fish 40 Weed control in ponds 45 Chemical agents 46 Applying chemical agents 49 Spraying equipment 50 Controlling diseases and parasites 50 When to treat 50 Methods of treatment 51 Control of specific diseases 57 Disinfecting ponds and equipment 61 Controlling predators and pests 62 Some important bait fishes 66 White sucker 68 Fathead minnow 78 Creek chub 85 Golden shiner 94 Goldfish 100 Pearl dace 102 Hornyhead chub 103 River chub 104 Blacknose dace 1 05 Longnose dace 1 06 Finescale dace 1 07 Northern redbelly dace 108 Southern redbelly dace 109 Emerald shiner 110 Common shiner Ill Spotfin shiner 112 Brassy minnow 113 Bluntnose minnow 113 Stoneroller 115 Western mud minnow 116 Bibliography 118 Table of equivalents 121 Index 122

III

WHY BAIT-FISH PROPAGATION?

With the shortage of minnows fluctuations in the availability of in public waters now a reality and bait fishes are the rule; minnows strict regulations on minnow sein- are not found in the same pools or ing increasing each year, the bait over the same shoals in our lakes dealer is faced with the necessity and streams at all times of the of rearing his supply of bait fishes year. These changes in the supply in ponds or other private waters. of minnows are matched by in-

Most dealers will find the change verse fluctuations in demand : there from free-lance seining to propa- are fewer calls for bait during gation of minnows in ponds dif- spring and fall when minnows are ficult but worth while. This cir- plentiful, but a great demand ex- cular presents information on the ists during the warm summer culture of bait fishes and is in- months when the minnows are dif- tended as a guide for those inter- ficult to catch. Some dealers have ested in commercial propagation constructed outdoor ponds or in- of minnows. door tanks large enough to hold The growing number of fisher- over thousands of fish from tJie men each year has resulted in a time of their greatest availability greater fishing load and an in- to that of the greatest demand for creased demand for suitable bait them; but the losses are so great minnows. In an effort to satisfy that this method is not recom- this demand, commercial minnow mended as being either good busi- dealers have seined lakes and ness or good conservation. streams over wide areas and have The natural distribution of com- trucked their perishable commod- mercially important minnow spe- ity great distances. Consequently, cies sometimes does not coincide dealers, fish culturists, sportsmen, with the regions where these fish and biologists fear that the supply are most in demand, and expensive of bait fishes has been greatly de- trips must be made great distances pleted in many places, and that to collect them. Environmental the drain on this natural food of factors may also restrict the sup- game fishes may become a serious ply of minnows in an area where problem. demand for bait is often great. Several factors determine Frequently, the cooler, more-sterile whether seining minnow^s from waters in the northern fishing re- natural waters is a wasteful or gions do not support the needed profitable undertaking. Seasonal quantities or species of bait fishes.

1 WHY BAIT-FISH PROPAGATION?

The rearing of bait fishes is by sistent business, the sportsman is no means easy, but the advantages supplied a better bait fish, and the are many. The cost of raising fish State is aided in conserving its sup- may be less than the cost of seining ply of forage fishes. them in distant waters. Also, the Even though minnow propaga- dealer who raises his own fish can tion is desirable, dealers who plan have a nearly uniform supply on to engage in it should first consider hand at all times to meet the de- the problems involved. Fish prop- mands, and is freed from the com- agation is more than a simple propo- petition with other dealers for min- sition of combining fish and water nows in public waters. to produce a profit. Considerable Minnows raised in ponds are usu- skill and judgment are needed to fish from pub- ally better fed than select or construct good ponds. lic waters and are more hardy. Most dealers need years of practice Pond-reared fish also benefit from before they become proficient at being seined in smaller numbers and pond stocking, pond fertilizing, and from being in transit a shorter time. pond harvesting. Each pond is a So, the fisherman who buys these distinct problem, and conditions in fish will get better minnows for his it change from year to year. money and will be able to keep them may alive longer. The beginner in minnow propaga- Everyone benefits from minnow tion will do well to start on a small learn builds his propagation : the bait dealer is re- scale and as he up warded by a better and more-con- business. :

ESTABLISHING THE HATCHERY

ECONOMIC 4. Is there a natural supply of the popular species? In Minnesota, for ex- CONSIDERATIONS ample, fathead minnows are in great demand for crappie fishing, but these fish The bait dealer should consider are so abundant in the natural waters local economic conditions before he of the State that artificial propagation is not profitable. establishes a minnow hatchery. 5. Do any habits of a popular species The most important factor is the of bait fish make its propagation unprofit- retail price of the minnows. This able? price must be high enough to pay 6. How hardy are the popular species? production costs plus a fair profit. Those fish needed during hot weather must be able to stand seining and han- If artificial ponds have to be con- dling when water temperatures are high. structed, the price received for the In Minnesota, there is a demand for minnows must be high enough to golden shiners in the summer, but the pay off the principal and interest fish are too delicate to stand normal

on the investment. Topography handling in warm water ; consequently, the golden shiner is raised only for the and land values must be such as to use of winter fishermen. While it is allow the selection or construction possible for the dealers to use special of a sufficient number of ponds for methods of handling the shiners during a practical business. One small warm weather, the fisherman is still con- pond is not enough for a sound, fronted with a delicate minnow that re- quires special treatment in the minnow full-time business. pail. The successful dealer considers 7. What special handling do the fish the following points to avoid pro- require? Bait fishes raised for winter ducing fish that he cannot sell fishing require special holding facilities and suitable food for several months. 1. Which bait fishes are in greatest demand in the local market? 2. What size minnows do the fisher- TYPES OF PONDS men want? It is important to know A practical hatchery can be oper- whether the minnows to be raised arti- ated with either natural or artificial ficially will reach that size in one or two seasons. ponds—the choice depends to a

3. In which months do the fishermen la.rge extent on the location of the need minnows in the greatest number? hatchery. Artificial ponds are ex- The dealer must determine whether the pensive to build on sand and gravel pond minnows will be of commercial size soils and are rarely profitable be- in those months. Some species may be of added costs of ferti- too large and others may be too small cause the at the height of the fishing season. lizing and pumping. Fortunately, ESTABLISHING THE HATCHERY such areas usually abound in nat- tained for large-scale production of ural ponds that can be leased for a bait fishes (fig. 1). There will, of small fee and will be cheap to course, be differences in design for operate. Even though the yield each job, depending on local condi- from natural ponds is less than tions, so that only general recom- from artificial ponds, the margin mendations on construction can be of profit may be higher. On the made. Wherever possible, the serv- other hand, in areas of heavy clay ices of an enginer or of someone ex- soils, pond construction may be perienced in the construction of fish fairly cheap. On such soils, nat- ponds should be employed, to make ural ponds are usually scarce. the best possible use of the water While artificial ponds on clay soils supply, particularly if the construc- may require heavy fertilizing, the tion job involves a large investment. production Avill be high enough to Regardless of size, location, or provide a reasonable profit. number of ponds built, there are four essential requirements for suc- ARTIFICIAL PONDS cess in operating the ponds.

Artificial ponds for the produc- 1. The water supply must be dependa- ble at all seasons of the year, and of suflS- tion of minnows may be divided cient amount to exceed all requirements. into two categories : Single ponds, 2. The pond should be constructed on such as those which utilize runojff soil that will hold water. 3. Where a series is built, from the surrounding land, and a of ponds construction should, If at all possible, be series of ponds supplied by a much such that each pond can be handled in- larger source of water and main- dependently of the others.

Figure 1. — Series of ponds used in large-scale production of bait fishes. (Photo- graph courtesy of the Ohio Department of Conservation and Natural Resources.) WATER SUPPLY

4. Ponds should be constructed in such or baffles, and by storing it in a com- a way that they can be drained reservoir with a large surface area pletely, emptied of fish, and refilled to permit thorough aeration. when necessary. Spring and artesian water should Water supply be tested beforehand by placing fish in it. A temporary pond or A suitable and an adequate water trough may be employed for the supply is of primary importance, purpose. If possible, the fish and should be considered first in should be held in the pond or selecting a site for rearing ponds. trough for a whole season to ob- To be suitable, the water should be tain a good test ; however, a shorter only moderately hard and should period, perhaps a month, may be contain no other species of fish ; the sufficient. If the fish remain temperature of the water should be alive, the water can be considered high enough to promote rapid suitable. (see the hy- growth p. 69) ; pH, or Permanent construction should drogen-ion content, should be include a reservoir at or below the slightly on the alkaline side. spring itself. This reservoir may Springs and artesian wells are be of concrete, or riprapped with the most desirable source of supply stone or brick for protection. A because such water is dependable, way must be provided so that ex- easily controlled, permanently clear, cess w^ater from the supply can and generally free from pollution. be diverted around the pond or A water supply should be protected ponds. A sufficient flow should be from contamination by surface provided to compensate for seep- water, which may cause the supply age and evaporation from the to become turbid or polluted by ponds during the propagation drainage from stables, yard ponds, season. and like sources, as well as from con- Natural w^ater supplies, such as tamination iby insecticides, fungi- creeks, lakes, rivers, or ponds, may cides, and herbicides. be utilized as a source of water, Hard water may be undesirable but should be considered only because it generally contains nox- when springs or artesian supplies ious gases, such as carbon dioxide, are not available, or where the nat- nitrogen, hydrogen sulfide, and ural sources have all the necessary marsh gas. All of these gases are attributes of a good w^ater supply. injurious to fish by actually poison- These sources are subject to change ing or asphyxiating them. Other in volume, temperature, and tur- waters may contain excessive quan- bidity, and may be polluted. In tities of iron. In nearly all of addition, they generally contain these instances, the water can be undesirable species of fish which purified and made suitable for fish prey on minnows and reduce pro- by running it over a series of falls. duction in the ponds. No hatch- — ESTABLISHING THE HATCHERY ery operator has successfully control structure should be of con- screened undesirable fishes from crete and equipped at one side with ponds, except by using expensive an intake box from which the de- and elaborate gravel filters. sired amount of water may be ob- In selecting a stream to provide tained for the pond system. Dams water for rearing ponds, one should of low head provide no obstacle to take into consideration, primarily, flood wa.ters and allow debris to the fluctuations in volume and- the pass over readily without obstruct- amount of turbidity. Turbidity is ing flow. Where the flow is inter- particularly important because ex- mittent or becomes considerably cessive silt may gradually fill the reduced during the dry season, it ponds to which the water is sup- may be necessary to make a larger plied. Turbid water also reduces impoundment by constructing a productivity by restricting light higher dam. penetration and, as a consequence, The dam should be anchored in the development of food organisms. both banks of the stream with Where turbidity is periodic and of bulkheads as high as the banks short duration, the water should be to protect the banks. The spill- bypassed downstream. way should be built somewhat lower The volume of water must be kept than the bulkheads. A concrete within certain limits throughout apron should be provided to keep the year, depending on the num- the water flowing over the spillway ber of ponds operated. Fortu- from undercutting the dam. The nately, by building proper struc- intake box should be provided with tures, a suitable volume of water can a coarse grating to obstruct large be obtained. If the stream flow is masses of debris. It should have a constant or if the fluctuation in vol- slot in which a fine screen is in- ume is within narrow limits, suf- serted to keep out leaves and mate- ficient water may be obtained by the rials that might obstruct the flow building of a low dam (fig. 2). of water through the pipe to the This dam should be located so pond and to keep out other fishes. that water can be obtained for the So that the screen may be kept clear

ponds by gravity flow. The water of debris without too much diffi-

FiGURE 2.—A low dam with outlet for supplying water to ponds. POND SITE culty, the screening surface should source of water. This has the ad- be large in proportion to the amount vanta.ges of providing an adequate of water used. source of water as needed and of Where there is considerable de- removing noxious gases or minerals bris in the water, the operator may by aeration and storage. have difficulty in keeping the screens Water may be forced to a higher clean. In this situation, another level by means of a ram if conditions type of construction is often used. are satisfactory for its operation. This involves building a concrete When the source of water is a box in the bottom of the stream; spring, it must have a large capacity the box is slightly raised from the to justify the use of a ram, which bottom so that it does not become is wasteful of water. A maximum covered with gravel, and so that the of about one-seventh of the water current continually washes over the can be forced upgrade. A 1-foot surface and carries away leaves and fall from the spring to the ram is other debris. Information concern- required for every 10 feet that the ing a structure designed along these water must be forced vertically to lines is obtainable from a qualified the pond, and the flow is further re- civil engineer. duced in proportion to the horizon- Where water cannot be obtained tal distance the water must be by gravity, pumping is sometimes pushed. A large reservoir that per- justified. The pumping cost is a mits the use of water in the pond continuing and constant one, and system, as necessary, is preferable operations must be on a scale large to having a ram supply the ponds. enough to justify it. It is essen- Usually, obtaining water by use of tial to have a cheap source of power. u ram is inadequate and unsatisfac- To make operations as thrifty as tory. possible, the ponds must be tight A windmill can be used to supply enough to prevent too great a loss water to small ponds of i/i to 14 from seepage. Some operators ar- acre. Local conditions, such as the range construction in such a way amount of rainfall and evaporation, that when one pond is being drained help to determine the size of pond a portion of the water can be di- tliat can be tilled and maintained by rected into an empty pond and this method. The size of the pump- used again. This saves pumping ing equipment and other elements costs and fertilizer. involved in windmill operation will Where a series of ponds is oper- assist in deciding whether a wind- ated, the most satisfactory results mill should be used. are obtained by storing the water in Choosing the pond site a reservoir from which it may be taken as required. Generally, such Too much emphasis cannot be a reservoir is constructed by build- placed on the proper location of ing an earthen dike just below the ponds. The selection of a good site ESTABLISHING THE HATCHERY results in economical construction the porosity of the soil structure, and satisfactory operation. Time borings should be made to deter- spent in surveying possible sites be- mine the depth of the impervious fore a final selection has been made layer. Care should be taken that will pay dividends. Many failures there are no rock strata reaching the are traceable to a compromise in de- surface or beds of gravel anywhere sign features because of the cost dif- in the pond bottom, as water follows ficulties involved. Selection of a these formations readily with con- site on which favorable conditions siderable loss to the pond. can be utilized will avoid excessive Where an extensive pond system costs and impractical installations. is not desired, small impoundments After a suitable water supply has for the propagation of minnows been located, other details of site may be located in an area much selection may be considered. The more restricted than a hatchery- area must be relatively flat and large pond system would require. These enough to include the ponds, build- ponds may be located in a natural ings, and other structures required gully where the land slopes from for a modern hatchery. The ground three directions into the pond area should slope gently from the upper and where the dam will be neither end of the site, which is below the so long nor so high that the cost of source of water, to the lower end, construction will be excessive (fig. where water is drained from the in- 3). The shape of such a pond de- dividual ponds into a convenient pends entirely on the topography. watercourse. The main objective is It is not desirable under any cir- to select a site of suitable size for an- cumstances to dam a stream to make ticipated need and of such topog- a pond, or to locate the pond where raphy that ponds can be constructed it is subject to regular floods. The without moving or hauling an ex- best impoundments are supplied by cessive amount of dirt too far. Any just-sufficient spring water to main- good engineer can make a topo- tain the pond level, or are located graphic survey to determine the high enough on the drainage basin feasibility of constructing a pond that the water level is maintained system on a piece of land. by runofl^ from surrounding land. The most satisfactory ponds are In sections of the country where constructed on impervious soil. rainfall is relatively high, as in the Clay soils or soils with a high clay Gulf States as far west as Louisi- content are most desirable. The ana, the drainage area should be best material consists of approxi- about 5 acres for each acre-foot of mately two-thirds sand and one- water in the pond. In those sec- third clay, but generally some com- tions where rainfall is lower—as in promise in quality has to be made. southeastern AVisconsin and south- It is good practice to have the soil ern, central, and western Minne- tested. If there is any doubt as to sota—the proportion of drainage

8 POND CONSTRUCTION

FiGUBE 3.—Pond located in a natural gully, using runoff as a source of water. (Photograph courtesy of the U. S. Department of Agriculture.) area should be greater. It is par- Pond construction ticularly desirable that drainage be The da/in. Small impoundments from good pastureland, a stable for- — are generally made by building a est area, or other well-covered land. dam across a narrow gully where Eroded or improperly tilled soils the banks are of sufficient height to allow rapid runoff, which results provide water deep enough for fish in silty waters and gradual filling (luring winter. depth at the of the pond. Some operators who The must take waters from tilled land dam should be from 5 to 15 feet, de- construct a small settling pond or pending on the severity of winter silt basin above the regular pond. weather and the topography of the The lower end of the pond site pond bottom. In northern Illinois, should be of sufficient width to pro- the depth should be at least 10 feet; vide an adequate auxiliary spillway the farther north the pond, the more to carry off occasional floodwaters this figure should be increased.

(fig. 4). First consideration is given to POND

BAD

Figure 4.—A spillway with a flat design, as on the right, is less likely to wash out when heavy rains come than is the badly designed, V-shaped spillway on the left. ESTABLISHING THE HATCHERY laying out the dam and outlining normal water level of the pond the confines of the water level in the (fig. 5). pond. Because of the acreages of All trees and bushes should then water impounded, earthen dams are be removed from the dam site or used almost exclusively. Deter- stacked and burned. All stumps mining the desirable top width is sliould be removed from the pond the first step in the design of the site, particularly if the pond is to dam. Generally, the top of the dam be drained for the removal of min- is 8 feet wide, but if it is to be used nows, in which case it is also desira- as a road for automobile travel, it ble to grade the bottom so that no should be at least 11 feet wide. The low spots or water pockets will be equipment to be used in construct- left after the pond has been drained. ing the dam also influences the Every piece of root or stump should width of the top. If teams are used, be removed from the site where the the top of the dam should be 5 feet dam is to be located. If this is not wide ; if tractors, a width of at least done, the decaying wood may cause 10 feet is required. When the trouble. height of the dam and width of the The next step in construction of top are determined, the base can be the dam is to form a tight bond be- laid out. tween the dam and the base on Ordinarily, the upstream, or which the dam rests. If the surface pond, side of the dam is sloped at is covered with a layer of organic tlie rate of 3 feet for each 1 foot of matter, it should be removed and height. On the downstream side, stored for later use in covering sec- the slope is generally 2 to 1. If the tions of the dam which will be soil contains more than the recom- seeded with vegetation. The area mended amount of sand or gravel, covered by the base of the dam however, the slope should be in- should then be plow'ed. creased to as much as 5 to 1, de- No structure is better than its pending on the nature of the con- foundation. To assure a good pond, struction materials used. This a section of earth should be re- simply means that if the top of the moved, parallel to and directly un- dam is 8 feet wide and the height is der what will be the highest part of 10 feet, the base will be 78 feet wnde. (he dam, down to solid, mineral soil. Tlie site of the crest of the dam If clay soils are underlaid witli should be laid out first, then stakes sand or gravel, do not dig through set along the inside and outside toes, the clay into the sand, or the pond or limits, of the dam. Stakes will leak. Excavation for the clay should also indicate the limits of core may be accomplished with the water level in the pond. The ('(piipment commonly used, but un- dam should be high enough-to allow der certain conditions may he done

2 to 8 feet of freeboard ; that is, the more rapidly with dynamite. top should be 2 or 8 feet above the Dynamite is particularly efl'ective

10 POND CONSTRUCTION

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11 ESTABLISHING THE HATCHERY where the earth is saturated with maximum distance from the satura- water—the wetter, the better—and tion point of the water. where it would be impossible to use With small dams or pure clay other methods. Holes, 12 to 20 soil, it is unnecessary to construct inches apart, should be driven down a core through the dam. The same to solid earth (rarely more than 16 result may be effected, after the inches below the surface). These whole area of the base is plowed, by holes should be charjjed with dyna- removing the topsoil down to solid mite made of 50-percent nitro- earth on the upstream half of the glycerine, and set off \vith an elec- dam and properly placing it on the tric battery to obtain the greatest lower half. The solid earth should possible lifting power. The "prop- then be plowed so it will bind with agation" method may be used where new earth moved in. Thereafter, the soil is very wet. By this the builder should follow the method, one cap is used to set off same construction procedure rec- the first stick of dynamite, and the ommended for a dam in which a other sticks are exploded by the core is made. shock of the first charge. If the After the base has been properly soil is not Avet, a cap should be used prepared, the drain line should be for each charge. Less time is laid. A shallow excavation to solid needed to construct a ditch in this earth should be dug from the pro- way than is required for other posed pond outlet to a point below methods. the dam. Earth, the best clay avail- By now the soil types should be able, should be firmly packed known Avith some degree of ac- around the pipe, particularly on the curacy. Only pure clay or clay underside. Addition of water to soils should be used to fill the trench the soil to form a stiff mud will fa- that has been excavated. This cut- cilitate a firmer pack in the tamp- off wall, or core, shoidd be built up ing process. At some central point several feet through the center of in the dam, a concrete collar should the dam. The better, more im- be poured around the pipe. This I)ervious soils tliat are available for prevents water from following the construction should be used directly pipe and developing leaks; it also under the center of the dam and on prevents burrowing animals, such the upstream side. IjCSs desirable as crayfish, from following the or lower quality earths, such as pipe. After the pipeline has been sand, stone, or gravel may be used set up, construction of the dam may in the fill, hut they should be in- go forward. corjK^rated only on the downstream Earth from somewhere within side of the liighest [)oint in the dam the pond area can be used to pro- and extend to the toe. So placed, vide dirt for the dam. Most of the these poorei- earths provide weight soil should be obtained in the vi- to prevent slipping and are at the cinity to save labor. The whole

12 POND CONSTRUCTION bottom area of the pond should be somewhat different from building deepened and graded to drain prop- a dam, but the method of placing erly, and soil removed from all the and compacting the material is the pond edges so that the water has a same. The slopes on the dikes be- minimum depth of approximately tween the ponds should be uni- 2 feet. Earth taken from the edges formly 2 to 1. Where there is a and not used in the dam may be series of ponds, it will be necessary used for sloping the bottom of the to make only the dams or levee on pond so it will drain properly. the outside of the series water-tight Earth can be properly placed on by using a clay core. All levee bases the fill by keeping the fill higher should be properly prepared by on the edges than in the middle. clearing off organic debris and plow- If this is done, there will be no ing the entire area. tendency for equipment to spill The design of a hatchery is de- over and earth can be dumped the pendent on the size, shape, and proper distance from the edge. topography of the land on which Dirt should first be dumped about it is located. If the plot of land 2 feet from the upstream, or inside is properly sloped, ponds may be toe, stakes and about 18 inches from planned in such a way that suf- the lower, or downstream, stakes. ficient earth can be removed from This procedure will save labor by the pond site for the embankments. making a natural slope. Con- Ideally, the ponds should be from versely, all cuts with the scraper 1/4 to 1 acre in n^ea, but the topog- should be made deeper at the edges raphy of the land will dictate, to than at the center. This prevents some extent, the size of pond that the equipment from sliding away can be constructed most economi- from the banks, a possibility which cally. Under no circumstances might result in a ragged slope. should there be any large number Fill placed on the dam should be of ponds of an acre or more in size. properly compacted. Maximum Small ponds are handled more eas- compaction is effected by putting ily and are generally more pro- earth in place in thin layers and ductive (fig. 1). traveling the full length of the fill Plans for excavation and for the each time. On high dams, special placement of drains and waterlines compacting equipment, such as a should be made by a competent en- sheepsfoot roller, is needed, and the gineer. All elevation stakes for required density is obtained by the drain and waterlines and for the control of moisture content. Al- dikes should be placed before exca- though the compacting reduces the vation starts. The drainage lines amount of settling, allowance are generally placed in or through should always be made for it. the levees so that it is essential to The actual process of construct- have these lines in place before pond ing a series of hatchery ponds is construction starts. The drainage

367913 0—56- 13 ESTABLISHING THE HATCHERY

lines always lead from the deepest are used for longer distances, a part of the pond to a convenient four-horse-loaded, two-horse-trans- watercourse that will carry off the port wheeler should be used. drainage water. Maximum efficiency may be ob- Ponds should be so constructed tained with a 35-dhp (D-4) trac- that the minim\im depth at the tor bulldozer at distances from 100 shallow end is about 2 feet. Ponds to 150 feet and where the grade to be used for propa

Ponds used for holding fish through A self-loading, c a r r y i n g-type the winter must be at least 10 to 12 scraper should be used at distances feet deep in the Northern States; greater than 150 feet. On larger however, the size of the pond will, jobs, or where hauls are more than to some extent, determine the depth 500 feet, a 11-3-dhp tracktype trac- at the outlet. tor is more economical. Of course, The pond bottom should be sloped availability of equipment may be from the sides and ends toward the the decisive factor in most cases. center and the center sloped from Structures.—The types of struc- the shallow end to the outlet. The tures to be used in conjunction grade through the centerline of the with hatchery layouts are largely pond should be not less than 1 foot a matter of preference, but experi- for each 100 feet of pond length. ence has shown that adequate con- Where a series of hatchery ponds struction is highly advantageous. is being constructed, the ponds are Likewise, experience has demon- partly above and partly below nat- strated that adequate construction ural ground level. is more economical than skimping The type of equipment most on sizes and materials. Thus, pipe- economical to use for excavating lines of sufficient size are more eco- a series of ponds depends on the nomical than pipelines that are too size of the job and the distance small. In the past, tile drainlines, that earth must be moved. Horse- caulked with cement, have been drawn equipment is economical used extensively because the origi- only for small jobs and short nal construction cost is lower. Un- hauls, but may be used for larger fortunately, there have been many jobs if it is the only equipment failures with these lines on ac- available. With horses, a slip count of loose caulking, entrance scraper may be used economically of tree roots, pressure from the

for moving earth as much as 50 fill, and for other I'easons. feet, but for distances of more Great advances have been made

than 150 feet the cost is' so great in the last few years in pipeline that some other type of equipment fabrication. Among the types re- should be considered. If horses cently developed, the most suitable

14 POND CONSTRUCTION

for use as outlets and tlie most ature, suffocation, muddy water, easily installed are spiral-welded or other causes, in the draining steel pipe and asbestos-cement cast process). pipe. Spiral-welded pipe is light- Every pond should be equipped weifjht, lontj lasting if properly with an outlet structure of some installed, and comes in long type. This outlet, or kettle, serves lengths. Asbestos-c e m e n t pipe a number of purposes. It acts comes in shorter lengths but can as an o\'erflow Avhen rain or other be cut with a saw, and the joints inflow of water raises the pond have considerable flexibility. Not level above normal. In the proc- subject to corrosion, its period of ess of draining the pond, the out- utility is indefinite. Standard fit- let holds back the fish so that they tings can be used with both kinds can be removed when the water of pipe, and they can be utilized level has fallen to a depth that the for both drainage and waterlines. operator can wade. In ponds i/4 ^^^'^ or less in area, In small impoundments which the drainline should be not less than are to be drained infrequently, one inches in diameter; and in ponds of a number of outlets may be

of 1/4 to 114 acres, the line should used. The Canfield outlet is the be not less than 8 inches. Use of type most commonly used (fig. 6). large drainlines has a number of It consists merely of a pipe cut

advantages, including savings in to the proper length so that it will time and labor and frequently a act as an overflow and control the

saving in fish (which may be lost pond level. This pipe is inserted

otherwise because of high temper- in a 90° ell attached to the drain-

WoUr Surfoce

e Pischarc^t P>pc

Figure 6.—Canfield pond outlet. Commonly used in small impoundments that are drained infrequently.

15 ^

ESTABLISHING THE HATCHERY

at- line and can be tipped to the de- mend an adaptation which is 30° sired level to drain the pond. tached to a ell so that the gate Another outlet is merely a cement can be opened by pulling a wire on block laid around the outlet pipe, shore. This arrangement eliminates attached to which is one of a num- the need for a platform to the out- let, which must be located in the ber of gates ( fig. 7 ) . The most com- monly used gate is the usual irriga- pond beyond the toe of the levee and tion gate, the cost of which wnll at the low^est point in the bottom. vary according to size and type If the pond is to be drained fre- used. A homemade gate can be quently, however, one of the stand- made by bolting a channel iron to ard outlets for hatchery ponds the block on either side of the open- should be used. ing and inserting a piece of boiler Hatchery ponds should be plate that fits over the opening and equipped with an outlet to permit has a handle welded on it (fig. 8). ready drainage and removal of the It can be made by a blacksmith. fish that have been propagated. Eesearch workere at Alabama There are two general types of out- Polytechnic Institute, Auburn, lets which may be adapted to con- Ala., have designed an inexpensive ditions. One type has the outlet

gate which is attached to the bell of and water-control structure inside a piece of soil pipe. They recom- the pond and the catch basin for

Ovirflow slandpip* if dasired •— ^ POND CONSTRUCTION

Gole Lif4 4

OUD

4i>

GaU Plo4« ss^^^^^^^S! ^^S^^^

Z"^2"An<^i« Iron l^l Anqle Iron

Figure 8.—An inexpensive pond outlet gate that can be made from materials on hand.

collecting fish outside (fig. 9) . The The chimney usually has two sets other has the outlet kettle and catch of slots. The outer slots are pro- basin inside the pond. vided for a screen (.4), which pre- The plan of a conventional type vents fish from leaving the pond of catch basin and outlet is shown and debris from entering the pipe- in figure 10. Built of concrete, this line. The screen is made of hard- structure makes it possible to con- ware cloth on a wooden frame which trol the water level and to drain fits into the slots. The screen may the pond. The outlet is at the low be as fine as 8 meshes to the inch point in the bottom of the pond, or as coarse as 4, depending on the usually midway of one side. The use to which it will be put. catch basin should extend 6 to 10 The second set of slots is for inches above the bottom of the pond. dam boards, or stoplogs, which are

17 ESTABLISHING THE HATCHERY

FiGURK 9. —Catch basin constructed outside the pond. usually made of 2-inch by 8- or or stoplogs, can be removed at will 10-inch treated, finished lumber, and the water level kept at any de- and beveled on either end to fit. sired point in the pond. Also, if

The boards are placed one over the an irrigation or other gate is used, other up to the desired water level the total pressure of the water is in the pond, they serve aji and as against the screen when the pond overflow where rainfall or other is being drained, a.nd should the water may raise the pond above the gate become blocked with debris desired level. These boards may (as is generally the case) , the screen be kept ti

18 POND CONSTRUCTION no loss of fish from their being tom of the pond. Experience has forced against the screen. shown that most of the fish can be The kettle, or catch basin, which removed with a seine as the water is attached to every outlet .box, is being drained, but some recep- should be about 10 to 18 inches deep, tacle should be provided to capture and should extend above the bot- the last few fish. The catch basin

MH

SECTION THROUGH CENTERLINE MEASURE —

ESTABLISHING THE HATCHERY and outlet combination should be is most economical, because more set at the toe of the levee and half- than one pond can be drained into way down one side of the pond at the basin. If there is a large group the deepest end. of ponds, the situation may not lend An alternative type of construc- itself to this type of construction, tion involves the use of an outlet because only one pond can be box and the catch basin at some drained at a time. Where there is point outside the pond (fig. 9). a basin in each pond, more than one The outlet box is similar to that pond can be drained at a time designed for a natural pond and often a very desirable procedure. does not require the use of a screen. Waterlines supplying the ponds All the water is drained through should be of sufficient size to fill the the outlet to a catch basin outside ponds rapidly and to maintain the pond. water levels. At least 4-inch, and The outside seining, or catch, preferably 6-inch, pipes should be basin is a concrete tank constructed run to each 1-acre pond. The main in such a way that water from the supply lines from which these pipes pond outlet flows into it. Grooves lead off should be designed in ac- are provided for a screen and dam cordance with the number of ponds boards. "Where the outlet from the supplied, the amount of water pres- pond comes into the seining basin, sure, and other factors. Cements- it is provided with an irrigation asbestos pipe is ideal for the main gate or valve which may be shut supply lines. These lines should be when desired. laid in the dikes at the proper stage Most of the water from the pond of construction. is drawn through the seining basin There is some difference of opin- until a considerable number of min- ion regarding the proper location nows come into it from the pond. of the water-supply lines to the in- The outlet valve to the pond is dividual ponds. Where the seining, closed and the water in the basin or catch, basin is located in the lowered until the majority of the pond, the supply line should be lo- minnows can be removed to suitable cated at the basin. This permits the receptacles. This operation is re- use of fresh water when the pond is peated until all the water has been being drained and when the pond frequent agi- drained from the pond and all the water is muddy from provides a source of minnows have been removed from tation. It also fresh water to fill receptacles used the seining basin and placed in to transport fish from the pond. holding facilities. Except in those ponds used for the The type of construction with l)ropagation of stream-breeding ponds in a series along a water- species such as the creek chub, there course or in such grouped a way seems little in favor of having the that a number of pond outlets can water supply at the end opposite the bo brought into the seining basin outlet.

20 NATURAL PONDS

NATURAL PONDS and ponds on poor, rocky soils are infertile unless the runoff includes In some localities, the bait dealer such sources of fertility as barn- will have to use natural ponds for yard drainage. The type of soil on the production of minnows because the pond bottom has a definite effect of the lack of suitable locations for on pond fertility. Fine-textured artificial ponds. While natural soils that cloud the water easily and ponds often do not produce as many give up their fertility readily are minnows to the acre as do artificial usually found in fertile ponds. ponds, there are some points in their Soils that have most of their fer- favor. Natural ponds do not re- tility tied up in vegetation or or- quire expensive dams and control ganic matter give up that fertility structures, rentals are usually low, very slowly and ponds with such and little or no fertilizer is needed. soils tend to be moderately fertile. As these factors add up to low pro- The relative fertility of a pond can duction costs, the margin of profit be judged by how green it becomes is usually high. during hot weather: the greener Natural ponds available for the tlie water, the richer the pond. production of minnows vary A rich pond will contain a large greatly in size and shape, but me- amount of nutrients in the water dium-sized ponds are most practical and will produce good crops of wa- to operate. Large ponds are too ter fleas for fish food at various difficult to seine and small ponds times during the season. Such a cost more per acre to seine than do condition is desirable for the pro- medium-sized ponds. Deep ponds duction of large fish crops, but rich produce better in hot, dry years ponds also may produce great when shallow ponds become too amounts of algae. P]ven though al- warm and may even dry up, but in gae enter into the food chain, these cold, wet years, the shallow ponds microscopic plants are not readily come into their own. As it is diffi- eaten by most minnows, and when cult to predict a full season of they decompose the dissolved oxy- weather, the dealer should try to gen in the water is used up and operate both shallow and deep large amounts of ammonia are pro- ponds each year. While the type of duced. The fish need a fairly high pond most practical for production concentration of oxygen for respira- varies with the species of minnow tion, and ammonia in large concen- to be raised, Minnesota dealers have trations is toxic to them. Conse- found that natural ponds 3 to 5 quently, the decomposition of a acres in size and 5 to 8 feet deep are heavy algal growth may kill a large most profitable. number of fish. Algal blooms are Natural ponds vary greatly in likely to be more harmful in shallow fertility. Ponds located in rich ponds than in deep ponds. Some farmland are usually very fertile. species of minnows tolerate lower

21 ESTABLISHING THE HATCHERY oxygen and liigher ammonia concen- banks, soft bottoms, or brushy edges trations than others and are, there- should be avoided unless it has an fore, more successful in fertile open, firm-bottomed beach for good ponds. Each species has its limits seine landings. of tolerance that cannot be exceeded Fertile ponds covered with ice if the production of a pond is to be and snow will often run out of oxy- profitable. gen before spring, and the fish will The productivity of a pond is also smother unless the pond is at least related to the hardness of the water. 15 feet deep. During winters of no Medium-hard to very-hard water snow, the ice will transmit enough will usually produce more fish than light to keep the plants in the pond soft water. Sometimes it is possible actively supplying oxygen and the to increase the hardness of the water fish may survive in quite shallow- by the addition of lime, but fish pro- ponds. During winters of early will increase unless the duction not and heavy snow-s, fish will survive water contains sufficient nutrients, if the ice is kept clear of snow. Be- or a sufficient amount of these ele- cause of the difficulties encountered ments is added with the lime. in holding minnows over winter in Seining conditions in natural natural ponds, most dealers plan ponds must be considered before the their production so that all minnows pond is selected. While it is pos- can be sold the first year. When sible to trap minnows, they often do not move into the traps when this is not possible, holding ponds needed, and seines must be used to with running water are used and the get them out in time for the market. fish are fed artificially through the A pond with boggy shores, steep winter.

22 :

CHOOSING THE FISH

Many factors must be considered f. The fish should not be excessively cannibalistic. in choosino; a bait species to be g. The fish should be resistant to the raised. Several species should be more virulent fish diseases. sus- reared if the dealer expects a h. Those species lacking spines and tained income from his operations. hard parts are most suitable. If properly selected, they will pro- i. The minnow should be one that thrives under cultivation. vide suitable sizes through most of j. The fish should be suited to the ponds the year. As a general rule, a be- available. species ginner should raise only one k. Holding qualities are of the utmost in each pond. importance.

The following characteristics 1. Species that are hardy on the hook should be considered in selecting a sell the best. bait species for propagation None of the bait species will meet all of these conditions, but all the a. The fish should be reasonably tolerant to seining, handling, and points should be considered when transporting. choosing a species of fish to raise.

b. The fish should have a rapid rate of Often popular demand will dictate growth. Even then, some species must the kinds that can be sold. Among be held more than one winter in northern the most popular bait fishes for latitudes. propagation are the sucker, golden c. The adults must be large enough to shiner, creek chub, fathead minnow, be suitable bait for the predominant game and goldfish ; and specific informa- fish of the region. tion relative to their production is d. The species should have an extended spawning season. given in the section on Some Impor-

e. The fish should be prolific. tant Bait Fishes, pp. 68-102.

23 OPERATING THE HATCHERY

FERTILIZING THE POND A third method of providing crustacean (waterfleas) fish foods, The object of fertilizing a pond that is little used but offers great possibilities, is dry fallowing. Each is to produce foods in large quan- pond is drained and dried up pe- tities at the time they are needed riodically. When the pond bottom most by the fish. Several methods is dry enough to support farm ma- of supplying fish foods are in use chinery, it is disked, fertilized with at the present time. In the North- 10-10-10 fertilizer, and planted to ern States, organic fertilizers are rye. The rye is allowed to grow to added to the pond to produce a a height of 6 to 8 inches before the growth of bacteria protozoa and pond is refilled. As the rye decom- (fig. 11). These small forms are poses a growth of bacteria and pro- food for the waterfleas and rotifers, tozoans develops. In 7 to 10 days which in turn are the main source of the pond contains a crop of water-

food of the important bait fishes. fleas 8 to 10 times greater than that In most Southern States, the ponds obtained by fertilizing. Natural are fertilized with inorganic fer- ponds maintain their fertility by a tilizers, which release nitrogen and similar process. When the pond phosphorus into the water. Mi- level is low, the exposed bottom be- comes covered with a growth of hay. nute plants (algae) which often When the pond level is high, the give a greenish color, or bloom, to hay is flooded and decomposition pond waters utilize this nitrogen starts a new food cycle. and phosphorus. When they die For maximum growth of the fish and decay the food stored in them and maximum fish production, the becomes available to minute ani- food chain should be started early mals (i)rotozoa) in the water. and should be maintained through- These anima.ls are food for the wat- out the growing season. In north- erfleas and rotifers. The food cycle ern ponds, barnyard manure is gen- with algae in the primary stage is erally used in the spring because it dangerous to use in northern ponds decomposes rapidly and gets the because of the danger of an excessive food chain oft' to an early start. algal growth, which uses such a Manure should be applied at the large amount of oxygen from the rate of 400 to 1,000 pounds to an

water when it decomposes that the acre of water, depending on the fer-

fish suffocate. tility of the pond. Dried sheep

24 FERTILIZING THE POND

Figure 11.—Ponds often need to be fertilized to increase their productivity.

manure can be used at half the rate rule-of-thumb for liming ponds is of fresh manure. The proper time to add half as much limestone as of application is 2 weeks before the fertilizer. pond is to be stocked so that a In the Southern States, fertiliz- heavy food crop is ready for the ing should be started during the fish. first warm w^eather of spring, and During the growing season, the should be continued through the food supply is maintained by peri- summer and early fall. In the far odic applications of dried sheep South it may be advisable to fer- manure. The applications should tilize monthly during the winter. be made at 2- to 3-week intervals In fertilizing a pond, supply all summer. Ponds should be fer- enough nutrients to the water to tilized at the optimum rate rather induce the growth of microscopic than the maximum because an ex- plants, which give the water a cess is a waste of fertilizer and the green or brown tinge. It is neces- decomposition of a large quantity sary to apply the fertilizer fre- of fertilizer may reduce the oxygen quently enough to build up a sur- content of the water enough to plus of minerals. Applications

cause suffocation of the fish. should be made at weekly or 10-day AVhen soft-water ponds are fer- intervals and should be continued

tilized, it will be necessary to add until the water becomes so turbid agricultural limestone to the water (as a result of these microscopic to maintain proper alkalinity. A organisms) that the bottom cannot

25 : OPERATING THE HATCHERY be seen at a depth of more than 12 less phosphorus and soft waters less to 15 inches. Fertilizing should nitrogen and more phosphorus. then be stopped until the water be- Under acid conditions it may be gins to clear, when it should be re- advisable to use lime. At the pres- sumed. The objective is to main- ent time, there is insufficient knowl- tain a constant amount of turbidity edge to make specific recommenda- in the water. One should not over- tions for all conditions. One can fertilize, as the production of too obtain the desired results simply by many of certain microscopic or- increasing the amount of fertilizer ganisms will be detrimental to the per application, where a "water fish by removing too much oxygen bloom" is not obtained within a rea- from the water at night and on sonable time. Generally, 6 to 12 cloudy days. treatments are required through the Each application of fertilizer summer, depending on the fertility should consist of 100 pounds of fer- of the water, length of the season, tilizer of approximately an 8-8-4 amount of runoff, and other condi- formula for each acre of water sur- tions. face. This means that each 100 pounds of fertilizer contains 8 STOCKING THE POND pounds of water-soluble nitrogen, WITH ADULT FISH 8 pounds of phosphate, and 4 pounds of potash. If fertilizer of A very important step in op- this formula cannot be purchased, erating the pond is to stock it with regular garden or farm fertilizer the correct number of brood fish. may be supplemented with nitrate Adult fish seined from streams or of soda, ammonium nitrate, super- lakes in the spring before they have phosphate, or other chemicals. had time to spawn are commonly Any fertilizer dealer can give in- used as brood stock. Because of the formation for modifying regular uncertainty of the natural supply,

fertilizers to obtain the proper it is desirable for the dealer to hold formula. The 8-8^ formula was the brood stock from year to year. first worked out by Swingle and When selecting fish for brood Smith at Alabama Polytechnic In- stock, the dealer should attempt to stitute and is generally applicable. get an assortment of sizes. For ex- There is some variation in fer- ample, the male fathead and blunt- tilizer requirements, however, ac- nofre minnows are larger than the cording to the chemical content of females, while the male golden the water. For instance, in very shiner is smaller than the female. only largest specimens are hard water at the I^etown, W. Va., If the selected, the pond will have an un- station and surrounding territory, balanced sex ratio. In certain of it was found that a 12-5-5 mixture the Lake States, the following rates gave best results. In general, hard of stocking of adult fish have been waters require more nitrogen and found satisfactory

26 ARTIFICIAL FEEDING

Species stocked :

OPERATING THE HATCHERY be raised per acre of water by ar- duced by the decomposition of the tificial feeding; consequently, only feeding wastes. The costs of pro- lialf as many ponds are needed to duction were reduced under this produce a good supply of min- method. nows. Though the cost of produc- It should be remembered that tion is higher when the fish are water temperatures have a direct fed artificially, this may be offset effect on the amount of food eaten by a reduction in the original cost by fish. In cold-water ponds, the of the pond and in the annual consumption of food is low and maintenance. The artificial feed- growth is slow. Also, when the ing of heavy fish populations water becomes excessively hot, food (more than 2,000 pounds of fish consumption declines and growth per water acre) requires a con- becomes slow. stant flow of water through the pond for aeration and cleanliness. HANDLING BAIT FISH Only a small part of the natural While many species of fish can pond fertility and very little of be found in the tanks of the bait the fertility available from the dealers, certain species are more decomposition of food wastes are popular and are handled in greater used. Such concentrated popula- tions must be treated for disease at quantities. These fish require dif- frequent intervals. (See page 50). ferent methods of propagation, but The Michigan Institute for Fish- the handling techniques will be eries Research has developed a com- similar for all. The following bination method whereby creek table lists the kinds of bait fishes chubs are artificially fed and suck- in greatest demand in the Lake ers are raised on the bloom pro- States

Species HARVESTING FISH

HARVESTING FISH circular pond can be seined very effectively with two hauls of a 200- Seining foot net, at depths of 6 to 12 feet. A pond that can be drained to a Whether seining in public water seining pool can be seined much or in his own minnow pond, the bait more easily with a 30-foot net (fig. dealer should seine with the objec- 12). net that is too long for the tive of catchino; the maximum num- A job is cumbersome to use and in- ber of fish with a minimum of loss. creases the chance of injury to the The following- suggestions are pre- fish. For seining in public waters, sented to help the beginner avoid the net should be at least of ^- undue loss. inch mesh so that the minnows too Types of seines.—Minnow seines, small for use can escape for further generally speaking, can be classified growth. In a small production into three types depending on the })ond a bobbinet seine can be used kind of weave used in their con- to transfer the small fish to a win- struction. The most common min- tering pond (fig. 13). now net is made of woven threads, Good seining methods. and with prolonged or severe use —When possible the seine should be landed it will develop "runs" caused by on a firm, sandy bottom. silt thread breakage and separation. The stirred a soft to This type of netting can be ob- up on bottom adds the discomfort of the fish and may tained in mesh sizes of % to % inches (bar measurement). The cause suffocation. When there is danger of suffocation, smaller hauls second type of seining fabric is con- should be made and the fish should structed with a nonslip knot tie. be bagged and moved to deeper Each mesh is individually knotted, water as fast as possible (fig. 14). and it will not develop runs or When landed, the seine should thread separation under the most never be pulled onto the shore. As severe operating conditions. In this soon as the fish are in the net, it type of netting, mesh sizes ranging should be bagged loosely and floated from 14 inch upward can be ob- to deeper water. The fish should tained. The third of netting type then be dipped with a small hand material used by fish culturists and net, or scap net, into a floating live bait dealers is called, "bird's-eye,'' box (wooden box with a hardware- or bobbinet cloth. It is a fine- woven cloth bottom) for sorting (fig. 15). fabric and is excellent for use in Once in a while the bait dealer collecting small fish (fry). The will find it necessary to seine min- new nylon bobbinet is much better nows in large bodies of water with material for short seines than is a small net during a season when the old cotton "bird's-eye." the fish are too far from shore to be The net should be picked accord- taken by the usual method. In ing to the job to be done. A 1-acre such a case, two or three seiners put

367913 0—56- 29 OPERATING THE HATCHERY

Figure 12. — Seining minnows from an artificial pond. Drawdown has expo.sed the inside seining' well. (Photograph courtesy of the Michigan Department of Conservation.)

on waders and wade out as far as smd hoist it out of the w a t e r. possible. Two men take the seine Thouj^h the take by this method is brailles and a third keeps the float- not large, the roiling process in- ing live box in tow. The three men creases the harvest as much as 8 to stand with their backs together and 10 times. (See figure 16.) roil the water with their feet. When the water has been thor- Trapping bait fish oughly roiled for a few minutes, Wire and glass traps.—Wire and two seiners back off in opposite glass traps are commonly used by directions pulling the seine in a cir- minnow dealers to collect bait. cle. By going backward, they can Similar in design and differing only travel faster than if they went for- materia.ls, both con- ward. The third man turns and in construction entrance funnel backs out of tiie way splashing the sist of a pot and an water as he goes to drive the min- or funnels. The wire trap (fig. 17) nows into the net. AVhen the sein- is more variable in design, being ers liave completed the circle, thev round, rectangular, or square, and take up the slack in the net, bag it, having from one to four funnels.

30 HARVESTING FISH

FioTTBE 13.—A bobbinet seine is used to catch the fry in a small production pond. Good seining methods help to prevent fungused flsh. (Photograph courtesy of the Minnesota Department of Conservation.)

Glass traps usually are round and are usually found near the banks of have only one funnel entrance. the stream.) At this point a small Glass traps are used mainly in depression about the size of the glass streams. This type of collecting trap is gouged out of the bottom, gear has proved highly efficient ; not and the trap, baited with finely- only can a large number of minnows ground cracker crumbs, is placed in be taken in a relatively short time, the depression with the funnel open- but the fish can be collected with ing facing downstream. Within a little or no injury. Operation of a few minutes, by current action, glass trap is simple. The first step some of the food particles originally is to follow along the banks of a within the trap will be drifting stream until a school of minnows is downstream, attracting the fish be- located. The next step is to seek low. Immediately, the minnows an area upstream from the school will move upstream toward the

of minnows where the current is source of the food supply ; within a weak and the water depth does not half hour, the food supply in the

exceed 1 foot. (These locations trap will be exhausted and a num-

31 )

OPERATING THE HATCHERY

FiorRE 14.—Removing the fish from a seine in such a way as to avoid the roily water close to the shore of a shallow pond. (Photograph courtesy of the Minnesota Department of Conservation. ber of minnows will have been cap- baited with bread or cracker crumbs tured. and placed on the bottom of a The minnows should be removed stream or pond or suspended above from the trap as soon as the food the bottom at a desired depth by a is gone, as experience has proved stake. The traps should be at- that the mimiows will soon escape. tended daily and all fish removed On one stream in Michigan, four on each visit. If the minnows are glass traps took a total of 600 min- allowed to remain in the trap for nows, 21/2 to 51/2 inches long, in 1 any extended period, many become hour. The number of minnows injured by continued contact with captured per trap per set ranged the sides of the screen. In a pond from 10 to 70. The average dura- or lake where a good population of tion of a set (established by food minnows is known to exist, one \yire depletion) was about 20 minutes. trap, 2 feet long by 16 inches square Wire traps.—Wire traps are most and containing a funnel at each efficient when set in quiet waters end, wnll take as many as 500 min- iuul attended daily. They are nows in 1 day's operation.

32 HARVESTING FISH

Figure 15.—Transferring the fish from seine to floating live box. (Photograph cour- tesy of the Minnesota Department of Conservation.)

J^

Figure 16. — Seining in deep water after the tish have been attracted to an area of roily water. (Photograph courtesy of the Minnesota Department of Conservation.)

33 ) OPERATING THE HATCHERY

^ J

%

^^^^^^

Figure 17. —Wire trap couimonly used by bait dealers. ( I'hotograph courtesy of the Minnesota Department of Conservation.

Artificial ponds that are difficult instead of a rigid framework sup- to seine because of weeds or soft port, the netting is suspended from bottoms can be equipped with a flexible steel bands running diago- wire trap at the inlet (fig. 18). By nally across the net. "When the net running a current of water through is lowered, the bands tend to flatten the trap, the dealer can catch the en- out, and when lifted they bend in- tire population of a pond in 2 or ward, creating a pocket (fig. 19). 3 days. Whether the drop net is small (3 feet square) or large (8 to 10 feet Netting fish square), the principle of operation Drop nets.—One of the nets fre- is the same. The net is lowered to quently used in harvesting minnows the desired de})th by hand in the

from lakes and ponds is the lift, or case of the small net, and by rope

drop, net. This net is usually from a tripod and pulley or on the square in design, and it forms a end of a pole in the large net. pocket when lifted directly up- Bread and cracker crumbs or oat- wards. Sometimes the netting is meal are wetted and thrown into the supported by a rigid framework water inmiediately above the net to which prevents collapse when low- attract the fish. T^sually, as soon ering or lifting the net. Guy ropes as the bait has dropped to a depth are attached to each corner to en- ecpial to or nearly equal to that of able the operator to lift the net up- the set, the net can be lifted. When

ward on an even keel. On occasion. the small net is used, the fish can be

34 )

HARVESTING FISH

Figure 18. —A wire trap built Into the Inlet of an artificial pond. When the trap is

not in use the ends are left open, as in the photograph. ( Photograph courtesy of the Minnesota Department of Conservation.

Figure 19.—A drop net used to remove fish from the poiul. Feeding is done on the submerged net and from 2,000 to 3,000 minnows are raised at a time. (Photograph courtesy of the Ohio Department of Conservation and Natural Resources.)

35 OPERATING THE HATCHERY lifted in the net from the water and waters, dyeing would probably be of poured into tlie holding cans. no material value. Where fragile Where larger nets are employed, the minnows are being collected with a "lift" should not clear the water, drop net, the netting material but rise to a point where sufficient should be a soft fabric, such as water will be present for ample cheesecloth. When this material is movement of the captured fish. The used, some minnows which scale eas- fish in the net can then be trans- ily, such as the golden shiner, can ferred to the holding cans with a be harvested successfully during the long-handled dip net. hottest weather. Drop nets are operated success- Dip nets.—The so-called dip net fully in quiet waters on certain is frequently used in taking shiners species, such as the golden shiner, in the Great Lakes. This net is usu- fathead minnoM', and creek chub. ally of conical design, 1 to 2 feet in Minnows can be collected efficiently diameter at the opening, and 2 to with little or no injury by this ?) feet deep. The rigid hoop that method under the guidance of a forms the opening is fastened to a good operator. There are many ad- handle. The mesh size of the net- vantages in using a drop net, where ting material used in construction practicable, instead of a seine. In varies, depending on the size of the capture, the fish are not rolled, minnows to be collected (fig. 20). crowded, or crushed ; the bed of the Scap nets.—A scap, or hand, net pond is not broken, nor is the bot- is very useful in the handling, tom debris roiled to any extent. sorting, and transfer of fish. Gen-

Furthermore, minnows under sal- erally, the scap net is small, from able size can be returned to the () inches to 1 foot across, if square, Avaters, uninjured. and not more than 8 to 10 inches in

In clear waters, the drop net w ill diameter, if round. The netting work more efficiently for certain material is supported by a rigid species if the netting, ropes, and framework attached to a wooden frame support are dyed a neutral handle. These nets usually have color that harmonizes with the sur- shallow pockets. The netting ma- rounding water. In highly turbid terial is of small mesh and soft in

FiGUKK 20.—The dip net is used to handle bait fish in quantity.

36 ESTIMATING PRODUCTION

Figure 21.—The scap net has many uses about the hatchery. texture so as to prevent injury to organic materials or when exposed the fish being handled (fig. 21). to air, the bath must be strengthened about once a week by adding 13 Care of collecting gear ounces of cleanser. Once a month the entire solution should be dis- Nets should be carefully inspected carded and a new bath prepared. for holes, repaired when holes ap- A word of caution : chlorine is toxic pear, and thoroughly dried after to fish, and discretion should be each use. Nets should be stored used when disposing of old steril- in a cool, dry place with a good izing solutions. circulation of air. If they are fre- quently used in waters rich in or- ESTIMATING PRODUCTION ganic matter, it is well to have the nets treated occasionally with a pre- As soon as a tankload of fish has servative, such as tannin or copper been seined and transferred to the oleate. It is not desirable to use live box, the fish should be weighed tar as a preservative for minnow (fig. 22), and carried in a pail of nets because this substance has a water to the tank. The usual pro- tendency to harden the fibers, and cedure is to hang the scale from a tlius introduces conditions which tripod set in several feet of water. may be injurious to the fish being A half-bushel metal basket is partly handled. Nylon nets do not require filled with clean water. Ten pounds a preservative. of fish are weighed and carried to Small hand nets, such as dip nets the truck. By weighing 10 pounds and scap nets, used daily in and of fish at a time it is easy to keep about a bait dealer's establishment, account of the fish taken, or the when not in use, should be kept in production of a pond. Fish han- a sterilization bath consisting of a dled in these amounts will not be weak chlorine solution. In this too crowded or easily injured. If way, disease organisms will not be the operator is interested in know- carried from one tank to another by ing the number collected, he can the nets. One formula used in weigh and count the fish in 1 pound. Michigan hatcheries consists of 26 Another method of measuring fluid ounces of cleanser (3-percent minnows that is not destructive of available chlorine) to 30 gallons of the fish is the wet gallon measure. water. As chlorinated solutions de- A 5-gallon pail is marked off from teriorate rapidly in the presence of the li/^-gallon level to the top in

37 OPERATING THE HATCHERY

Figure 22.—Production should be determined by weijrhing rather than by volume. (I'hotograiih courtesy of the Minnesota Department of Conservation.)

V2-Sallon units. When the fish added until the level reaches the 2- are to be measured, the pail is filled gallon mark for half a gallon of with water to the n/a-gallon level Hsh and to the 2i/^-gallon mark for and minnows from a dip net are a full gallon. One gallon of min-

38 GRADING FISH

nows is counted when a large num- across the bottom of the grader, ber of minnows are to be sold by producing a sievelike structure. the dozen. By regulating the spacing between the tubes, fish of a desired size can GRADING FISH be retained in the box or permitted to pass through. If the fish are to The most practical method of be graded in several sizes, several sorting, or grading, fish—with the grading boxes will be necessary, one least amount of damage to the fish for each size group desired. involved—is by using a mechanical Periodic sorting of the fish grader. Similar to those used in the will trout culture, the bait-fish grader throughout growing season consists of a wooden box having a reduce the number of small fish that bottom of tubular grating (fig. 23). have to be held through the winter, The tubes, of lightweight metal of and will result in greater produc- about a i4"i'^ch diameter, extend tion of fish of a desirable bait size.

Figure 23.—Two sizes of slat sorting boxes used in grading minnows, ( Photograph courtesy of the Minnesota Department of Conservation.)

39 :

OPERATING THE HATCHERY

TRANSPORTING AND HOLDING 3. Water in nonaerated tanks should be kept at 65° F. or lower. BAIT FISH A popular practice when han- Aeration and temperature control dling minnows is to fill the truck factors in the success- are important tank at the bait store with cold ful operation of both carrying and water (often around 50° F.). holding tanks. series of experi- A While this water is being hauled ments was run in Minnesota to de- to the pond, it does not have time the effect of these factors termine to warm up very much. The min- on the mortality of fish. It was nows are seined from a warm- shown that fathead minnows ex- water pond and placed in the cold posed over a period of hours to non- water of the tank with only a few Avaters die with aerated increasing minutes of tempering. The shock rapidity at the higher temperatures. is not great enough to kill the fish The most rapid loss occurs at tem- at once, but within a few hours a peratures above 65° F. Fathead large percentage will be dead. minnows can be kept in well-aer- Those that survive this period ated water for several hours at rela- usually develop fungus and die tively high temperatures without within a few days. A minnow loss, and greater numbers of min- should not be subjected to more nows can be carried at all tempera- than a 10° F. change. A pocket tures in aerated water than in non- thermometer should be used to de- aerated water. termine temperature differences. These experiments showed that Likewise, bait fish that are to safe operation of minnow tanks re- be used locally should not be held quires close adherence to the follow- in very cold water unless the fish- ing limits erman travels far enough for the 1. When tanks are aerated by circu- water to warm up. Minnows that lating water, a continuous flow of not are taken from a cold minnow pail less than 1 gallon per minute for each and put into warm lake water will 25 gallons of water in the tank should be turn belly in a few minutes. maintained. The water should reach up the tank from pressure jets placed so Transporting minnows the water is sprayed toward the op- posite side of the tank. Each tank The hauling of minnows over should have a minimum of two pressure long distances during very hot Jets and at least one jet for every 25 gallons of water in the tank. weather presents a difficult prob- 2. When oxygen or other forms of lem. Success depends on close ob- aeration are used, the equipment should servance of the following impor- be operated so as to maintain a mini- tant requirements: mum of 3 p. p. m. of dissolved oxygen. 1. Harden the fish before they are When oxygen is used for aeration, it transported. Conditions such as crowd- should be dispensed into the water ing, excessive handling, and changing through carborundum tips or a per- water temperatures, encountered when forated oxygen-release tube. transporting minnows for long distances,

40 TRANSPORTING FISH

often prove fatal to many of the flsh. As ful tank is 6 feet long, 3 feet wide, and a n)eans of reducing this loss, a 24-hour iy

2. To prevent injury to the fish, the can be operated independently of each wooden sides of the tank should be other, in case one breaks down. An oxy- smooth. Several types of tanks have gen tank can be substituted for one pump proved satisfactory. One popular type in most cases. is a single-compartment tank, 4 feet Aeration is sometimes obtained from square and 3 feet deep, aerated with oxy- wind scoops and water pumps driven by gen dispersed through a perforated re- the truck motor. Both of these methods lease tube. This tank will carry 125 depend for their success on the ability of pounds of minnows for 300 or 400 miles the truck to maintain motion. When the with little or no loss. Another success- truck breaks down the fish are out of oxy-

FiGUBE 24.—An inexpensive fish-distribution tank truck. (Photograph courtesy of the Minnesota Department of Conservation.)

41 OPERATING THE HATCHERY gen in a short time. Such devices should loaded, especially during hot weather or only be used as auxiliary equipment or as on long trips. A load of 9 gallons of min- primary oxygen sources when supple- nows per 100 gallons of water, or 5.6 mented by other sources that are inde- pounds of minnows per cubic foot of pendent of the truck motor. water, has been found safe under severe 4. When the trip is unusually long and conditions. the weather extremely hot. the tempera- ture should be maintained between 65° Operating the holding tank and 70° F. by periodic icing. When pos- sible, long hauls should be made on cool The bait dealer encounters his days. Tanks that are constantly used greatest loss from handling and insulated with for long hauls .should be holding minnows in the holding a 4-ii;ch layer of cork. tank. Though much of the loss is Occasionally the dealer will find it nec- essary to temper minnows as they are attributed to fungus disease, the being transported from the lake or stream largest part is the direct result of where they were seined. For this pur- rough handling and careless opera- pose the truck must be equipped with a tion. There is no magic formula small box of ice. The minnow tank is for preventing minnow losses. Dis- filled with lake or stream water and the aeration pump is adjusted so the aerated ease-control treatments will not pre- water passes over the ice before it re- vent losses due to careless handling, turns to the tank. Periodically the op- but following the suggestions given erator will have to stop the truck and here will help to keep losses in bait take the temperature of the water in the fishes to a minimum. tank. When the water is of suitable tem-

perature, the water line to the ice box 1. Minnows should be handled carefully should be shut off. If the water in the during seining operations. Dealers who tank is cooled too much or too rapidly, buy their minnows should refuse to ac- the will minnows develop fatal "frost cept fish that have been handled roughly. bites." The water line to the ice box 2. The minnows should be carefully must be equipped with a valve so the rate tempered when they are transferred to of cooling can be adjusted. the truck tank and again when put in Some dealers cool the tank water by the holding tank (see p. 41 for "harden- using the live box as an ice tray. After ing" process). the truck tank is loaded with water and 3. The minnows should not be crowded. minnows the live box full of ice is placed 4. Holding tanks should be constructed over the top of the tank. The tank water of wood or smooth concrete, and painted is cooled as the ice melts and drips into heavily with asphaltum paint. Smooth the tank. The cooling rate cannot be sides in the tank help prevent disease controlled by this method and more fish and injury to the fish. The tank should suffer from "frost bite" from it than from be deep enough so that the fish are not the ice box. injured by the jets of water used for aera- 5. Salt is a tonic for fish and can be tion. The bottom should slope slightly used to help them over the rigors of trans- toward the outlet to facilitate cleaning portation. A salt bath should be given and draining. after the trip. When the aeration equip- 5. Each tank should be supplied with ment consists of a pump and water jets, plenty of filtered water—spring water is salt should not be u.sed in the tank be- filtered—and each tank should drain di- cau.se sodium chloride rusts' the ecjuip- rectly to the .sewer without passing inent. through other tanks. The water should 0. Truck tanks should never be over- enter the tank through pressure jets

42 HOLDING FISH placed well above the surface of the smaller nets will also produce injury and water. One overflow outlet should be at consequent loss of fish. or near the bottom to remove stagnant 12. Feed minnows that are held for water and waste material. more than a few days. A series of feed- 6. Well water containing more 'than ing experiments conducted by the Wis- 1 p.p.m. of iron will cause heavy minnow consin Fi.sh Management Division to de- mortality. Iron can be removed from termine the effect of food on the loss the water with the right kind of filter. of minnows in holding tanks, showed that Some water-softening filters will remove brassy minnows could be held for 63 days iron if the water is aerated before it at 46° F. with very little loss of weight is filtered. when fed all the canned carp they could Copper well points and copper water clean up. Fish that received half as pipes often give off enough copper to much carp survived nearly as well and kill minnows in holding tanks. This is showed only slightly more loss of weight. especially true in soft water or where Fish that received no food succumbed to the pH is high. In such cases, the of- heavy infestations of fungus, but those fending pipes must be replaced with iron receiving food had very little fungus. pipes. Minnows will eat a variety of foods, 7. Each tank should be small enough but the most practical foods are those that the complete contents can be sold that are easy to handle and ccmvenient in a few days. No more fish should be to store. The food should appeal to the added until these are sold, and the tank fish so that it is consumed fast enough should never be overloaded. The trans- to prevent undue contamination of the fer of fish from one tank to another will tank water. Oatmeal and cottonseed greatly aid the spread of disease. meal are satisfactory foods. Meal worms,

8. When the fish from one tank have ftour-weevil larvae, and similar worms been sold, the tank should be drained are very attractive to minnows and form and carefully cleaned. The sides and a substantial food ; but all must be raised bottom .should be thoroughly scrubbed for the purpo.se, As this takes quite a with a 1 : 10,000 solution of sodium hypo- bit of time and space, most bait dealers chlorite. This solution is mixed by add- do not use these organisms. Dry dog ing 1 quart of sodium hypochlorite or 3 foods or commercial fish foods can be to 5 quarts of any commercial bleach to used as a balanced diet that is easy to 250 gallons of water. The tank should handle and is reasonable in cost. be thoroughly sterilized at least once 13. Early treatment of diseased fish is a week. After an ample rinse the tank important. Epidemics of fungus disease can be filled with water and stocked with will produce a large loss of fish in hold- fish. ing tanks. While careful seining, trans-

9. All dead fish in the tanks should be portation, and holding of the minnows removed immediately and destroyed. will greatly reduce the chances of an

10. There may be considerable loss epidemic starting, it may happen even from the common practice of selling in the best-regidated establishments. minnows wholesale by the gallon. This At the start of the epidemic all dead procedure necessitates the measuring of fish should be removed and destroyed minnows in a nearly dry state. Such at once. The remaining fish should be measuring cannot be done without injury dipped in malachite green 1 : 15,000 solu- to the fish. tion (Ys ounce in 15 gallons of water) 11. Very large dip nets should not be for 10 seconds. The tank must be used for minnows. Lifting a half bushel drained and sterilized with sodium hypo-

of minnows in a dip net is likely to injure chlorite 1 : 10,000 solution. All tools and those on the bottom. Overloading dippers must be sterilized in the same

43 OPERATING THE HATCHERY solution and must be resterilized daily 14. Minnows that have not spawned until the epidemic is over. .should be placed in warm-water ponds Addition of some disinfectants and until they spawn. Then they can be put drugs to water in tanks holding fish is in cold-water tanks or iK)nd.s and held recommended by numerous investigators for long periods without heavy losses. for the control of various fish infections. When men of the Wisconsin Fish Man- Since a number of these methods are of agement Division were conducting feed- recent origin they have not been tried ing experiments with brassy minnows, vmder various conditions and with dif- they noticed an increased mortality dur- ferent species of fish. Therefore, it is ing May and June. Post-mortem exami- po.ssible that drugs listed in the section nations revealed that the majority were on diseases (p. 57) may be found toxic gravid, egg-bound females. That they to .some species of minnows or aquarium were ready to lay eggs but could not be- fishes and entirely harmless to other. cause of the cold water was interpreted All of these drugs are used in highly as the cause of their deaths. This may diluted forms and the fish should be able account for part of the heavy loss of min- to remain in such medicated water for nows in cold-water holding tanks during 2 to 3 days, or even longer, without any the warm summer months. apparent injury. If treatment should last more than a week, water in the tanks Holding minnows in ponds should be changed frequently, prefer- ably every 3 to 6 days. After each change In some States, lioldin^ ponds are of water, the required quantity of fresh a mucli debated subject. The bait drug should be added. Treatments dealers insist that they must have should not be carried on for more than 2 holding ponds to sta}^ in business, weeks at a time to reduce the possibility of devlopment of drug-resistant strains and the conservationists maintain (varieties) of the disease-producing that holding ponds are one of the organisms. chief causes of minnow losses. The Since some of these chemicals may be opponents to holding ponds point found to be toxic to some fishes under out that most ponds are used to hold all conditions or under special condi- tions like high temperature of water or lake shiners from early spring oxygen deficiency, all treatments should when they are abundant until sum- be made with great caution and tried mer when tliey are needed for bait, first with a small number of fish. The tliat the shiners do not thrive in medicated water should be replaced with holding ponds because most of the fresh water whenever fish show any signs of distress. ponds are too cold, and the fish be- Infected minnows should not be pur- come egg bound, and furthermore, chased or seined, as the danger from that fish held in ponds are not able loss and spread of disease to healthy fish to spawn that year and both the is too great. During times of scarcity adults and tlieii- reproduction are when only infected minnows are avail- lost from the lake. The problem is able, the fish should be dippe

44 WEED CONTROL dispensable to the hatchery opera- pond because different species and tor who wishes to produce a year- different sizes of minnows can be round bait supply from his produc- held separately in the small ponds. tion ponds. Minnows for the early This usually reduces losses and fishing season must be over-win- minimizes the sorting operations in tered in ponds that will maintain an the spring. ample supply of oxygen through the In areas where holding-pond con- longest winter. struction is not practical, minnows The most satisfactory ponds are can be overwintered in production those supplied with an ample ponds, if the ice is kept free of amount of oxygen-bearing, running snow all winter. There are several water from rivers, creeks, springs, ways to remove snow from the or flowing wells. There are advan- ponds, but the use of soot spread tages and disadvantages to all of thinly over the snow seems the most these sources. Water from unpol- practical. The soot absorbs enough luted rivers and creeks is usually heat from the sun to melt 6 to 9 high in oxygen and contains some inches of snow and ice. In areas natural minnow foods, but it may of light snow, plowing may be prac- not always be of the right tem- tical, but in regions of 3- to 6- perature. Water from springs and foot snowfalls plowing is very ex- flowing wells is usually cool and of pensive. Some operators use a uniform temperature, but it is often centrifugal pump to spray water low in oxygen and is always low over the snow ; the resulting slushy in natural minnow foods. Spring- condition usually freezes to clear w^ater must usually be run over a ice that transmits enough light to riffle before it enters the pond. This keep the plants producing oxygen. means that fish held in ponds sup- plied with stream water will not WEED CONTROL IN need as much artificial food, but PONDS they must be moved to growing ponds before the water warms up With good pond management, in the summer. Minnows held in weed control is generally not a prob- spring-water ponds can be left in lem. Ponds that are farmed inten-

the j)onds all year round, but they sively are heavily fertilized, either will require large amounts of artifi- directly by the use of fertilizers or cial food. indirectly by food that is not picked Holding ponds should be small up by the fish and by the heavy enough and shallow enough so that concentration of excretory products the fish can be readily removed that results from large populations. whenever they are needed. An acre Under these conditions, submerged

pond that is 4 or 5 feet deep is very vegetation will be controlled by the practical, and a number of small waterbloom produced, and emer-

ponds is preferable to one large gent vegetation such as cattails or

367913 0—56- 45 :

OPERATING THE HATCHERY pickerelweed, will invade the pond with a waterbloom will discourage emergent vegetation, as bulrush, arrow- rather slowly, and can be controlled head, and cattails. by hand or by the use of chemicals. .'{. Pond banks that can be mowed, Water quality and temperature with a good cover of hardy grasses, wall are controllin*; factors in the effec- discourage invader plants from the shore, tiveness of treatments to kill vege- such as wildmillet and parrotfeather. 4. If a bloom is kept on the pond, the tation and in the toxicity of the repeated cutting of emergents below the chemicals to fish. Each hatchery surface is an effective means of control- different situation with presents a ling undesirable vegetation in the pond. a new set of conditions, so that it In shallow ponds a scythe will be the is necessary at first to experiment most satisfactory tool, but in deep ponds on a small scale with control meas- one of the mechanical weed cutters is necessary. When iwssihle, the vegeta- ures, and modify them to fit the tion should be raked up on the banks to local situation. We can only give prevent an oxygen depletion when it general recommendations, which decomposes. must be adjusted to meet the specific conditions in an area. CHEMICAL AGENTS Many things can be done in pond Subject to local conditions, the management that will make the con- following table lists chemical agents trol of pond and emergent vegeta- which may be used to control the tion simpler. Among these are the various weed plants. Plants should following be treated while they are young and 1. A bloom heavy enough to shade out actively growing. Do not wait un- the rooted plants should be maintained til a nuisance, because throughout the season. A bloom that they become hides the pond bottom at a depth of 1 controls then may be only partly foot is heavy enough for this purpose. effective and a great deal of time The pond will have to be watched closely, and money will be lost. Always as there is danger that the bloom may kill the vegetation before the seed become heavy enough to cause an oxygen forms. The data in the three fol- depletion during warm nights. This lowing tables are taken from the method has the advantage of producing Fish-cultural Manual, Region 2, fish food while controlling the weeds. o^lbuquerque, N. Mex., U. S. Fish 2. Deep shorelines (at least 18 to 24 Inches) at the edge of the bank combined and Wildlife Service.

46 . - - 2 2

WEED CONTROL

Plant Chemical agent Application

Floating plants: Duckweed 2,4-D 1 % solution in oil.^ Filamentous algae. Copper sulfate 3 lbs. of crystals per 1,000 sq. ft. Water hyacinth 2.4-D 0.5% solution in oil.^ Emergent plants: Alligatorweed .do_ 1 % solution. Burreed .do-, Do. Cattail .do'. 0.5% solution in oil. Cow lily (yellow pond .do__ 1 % solution in oil.^ lily). Duckpotato -do- 1% solution. Giant cutgrass -do. 1 % solution in oil.^ Grass (most kinds). Sodium TCA. 7 oz. per 5 gal. of water (1% solution).

Johnson grass . 2,4-D. _ 1 % solution in oil. Lotus do. 0.5% solution in oil.^ Maidencane... Sodium TCA. 1 lb. dry powder per gal. of water.* Parrot feat her 2,4-D 0.5% solution in oil.^ Reed's canary-grass_ Sodium TCA. 1 lb. dry powder per gal. of water.* Smartweed 2,4-D_. 1 % solution. Softstem bulrush do. 1 % solution in oil. Squarestem bulrush do. 0.5% solution in oil.^ Water chestnut Sodium arsenite. 1 lb. powdered sodium arsenite plus 1 lb. sodium chlorate in 1 gal. of water to 150 sq. ft. Watercress 2,4-D.. 1 % solution. Weakrush do. Do. White waterlily -do. 2% solution in oil.^ Submerged plants: Bladderwort Sodium arsenite 2.5 p. p. m.5 Chara (muskgrass) Copper sulfate . _ 3 lb. of cry.stals per 1,000 sq. ft. Coontail Sodium arsenite. 2 p. p. m.5 Curlyleaf pondweed do 2.5 p. p. m.s Fineleaf pondweed do 2 p. p. m.8 Leafy pondweed do D0.5 Naiads .do. 2.5 p. p. m.5 Parrotfeather do. 3 to 4 p. p. m.5 Water crowfoot _do. 3 p. p. m.5 Water milfoil do. 3 to 4 p. p. m.5 Water purslane do. Do.* Water stargrass do. 2.5 p. p. m.5 Waterweed (Anacharis)_ do- 2 to 4 p. p. m.5 Woody plants: All species. 2,4,5-T_ 2.3 qt. of 44% esters per 100 gal. of water.'

1 In water solution, unless otherwise specified. 2 Refer to dilution table, p. 48. ' 3 oz. Esteron 44 in 1 gal. of kerosene or fuel oil, plus a detergent, is very effective on cattails and rushes. Highly volatile and should not be used if damage to adajacent croplands probable, in which case use instead Estericide D-4. * Effective if sprayed twice when pond is dry. * Liquid form is most convenient; for example, 5}i pt. of Atlas "A" (contains 4 lb. /gal. AS2O3, the active ingredient) per acre-foot equals 1 p. p. m. Do not treat more than one-third of pond area at a time because of danger of oxygen depletion. See table, p. 48, for concentrations. 8 Spray during active growing season and thoroughly wet the plants. Include a detergent in the solution.

47 OPERATING THE HATCHERY

The amounts of commercial solu- spray an acre of water are shown tions of 2,4-D that are required to in the following dilution table:

Acid content of 2,4-D (percent) WEED CONTROL

For 1 acre-foot (an acre of water gin to decay and remove oxygen

1 foot deep) use 5.3 gallons of from the water, it is advisable to i/^ sodium arsenite spray ; for acre- treat not more than one-third of foot, or for 4 p. p. m. on 1 acre-foot, the pond at one time. The re- use 2.65 gallons. mainder can be sprayed a few days If you are in doubt concerning later. This gives the fish an op- the type of vegetation in your pond, portunity to move into waters you should send samples of the where oxygen is available. questionable species with either the To hasten the effect of sodium blossoms or fruit to the nearest arsenite, it is helpful to fertilize the State University for identification. areas where the weeds are begin- Submerged vegetation should be ning to die. This will produce a thoroughly dried before mailing it. waterbloom and oftentimes will re- Preparation of the specimen is best sult in a complete kill of all vege- accomplished by spreading the tation in the pond, thus eliminat- plant flat on a piece of paper or be- ing the need for the use of chemi- tween the folds of a newspaper, and cals on the untreated areas. placing a weight on it until dried. Sodium arsenite is very poison- Attach a label to each sample giv- ous, and care should be taken when ing such information as you can applying it that the spray is not about the location and depth of inhaled and does not come in con- water where the plant was found. tact with the skin. Livestock should be kept away from sprayed APPLYING CHEMICAL AGENTS ponds for at least 2 days. Con- tainers in which the chemical has The best way to apply a weed been mixed should be thoroughly killer is in liquid form. It is neces- cleaned and removed from places sary that sprays be applied directly where livestock may have access to on the plants (in controlling emer- them. The water itself is not poi- gent vegetation), or to areas where sonous, since the amount of chemi- the plants cover the bottom of the cal used is not sufficient to provide pond (in submerged vegetation). a lethal dosage.

Sodium arsenite Copper sulfate

Sodium arsenite is heavy and Copper sulfate should be ob- sinks rapidly to the bottom. Con- tained in small crystals so that it sequently, the areas to be treated can be spread evenly over the area can be restricted by spraying only to be treated. As in the case of those places it is where intended to sodium arsenite, only part of the kill submerged vegetation. Some pond should be treated at one time, time will elapse before the effect of and copper-sulfate crystals should the chemical can be noticed. Since never be in excess of 0.5 p. p. m. for the vegetation that is killed will be- the pond as a whole. Also, fertili-

49 :

OPERATING THE HATCHERY zation of the treated area will as- cure. Moreover, diseased and ail- sist in producing a waterbloom, par- ing fish are often collected by un- ticularly if the vegetation is heavy. suspecting dealers, or the fish may become fungused from improper 2,4-D handling in the nets or tanks. The best method of disease con- In the use of 2,4-D, it is essential trol in a hatchery is prevention. that a uniform application be made Fish that are handled properly and on the treated area and that all that are adequately "tempered" be- plants be thoroughly wet. Under fore handling will usually be free these conditions, usually about an from disease. 80- to 90-percent kill results, and a Bait fishes are infested by several second application must be made kinds of parasites, and the follow- wherever new shoots appear. This ing numbers of species have been re- may be followed by an occasional ported from them shoot appearing that can be pulled Number of by hand. parasites White sucker 20 SPRAYING EQUIPMENT Golden shiner 14 Bluntnose minnow 9 Many sprayers are on the market Western mud minnow 4 Common shiner 3 that can be used to spread these Fathead minnow 2 chemicals. If considerable use is Silvery minnow 2 to be made of such equipment, it Most of these parasites will not probably would be ad\nsable to cause loss, and only a few are char- have a sprayer that can be mounted acteristic enough for the hatchery- in the back of a truck. There are man to recognize. Most likely to many pieces of equipment on the cause considerable loss in bait fishes market designed for specific jobs. are fungus diseases, fin or tail rot, Large dealers handling farm equip- black grub, and certain other dis- ment or garden supplies can recom- eases that are discussed in succeed- mend the proper piece of equipment ing pages. for your specific needs. WHEN TO TREAT CONTROLLING DISEASES In any method of treatment, time AND PARASITES is of vital importance. Disease rap-

When raised in ponds, minnows idly lowers the vitality of small fish, can be expected to suffer from many and although today they can with- of tlie diseases of hatchery fishes. stand the rigors of treatment, to-

For this reason, it seems wise to morrow may find them too weak. mention some of these diseases and The fish culturist must maintain parasites, and to outline briefly a strict watch on his stock. Early program for their prevention and warning of the presence of many

50 —

DISEASE CONTROL

external parasites is evidenced in detailed description of the condi- the fish refusing to eat, scratching tions existing in the pond or tank, themselves, or assuming a character- such as turbidity, presence of vege- istic bluish-gray sheen. Fungus is tation, waterbloom, water tempera- an excellent indicator of trouble, but ture, and any treatment of the pond it usually does not appear until after or fishes. The more accurate the de- the telltale rise in the daily losses scription of the symptoms and con- which is the surest proof that ditions that is given the more likely trouble is present. it is that the biologist will be able to Immediately upon any suspicion determine the cause of trouble and of trouble and always in the event recommend treatment. of increasing losses, the fish should be carefully examined for gross METHODS OF TREATMENT lesions, and all possible extraordi- Regardless of the concentration nary factors, such as bad food, silt, of the disinfectant used, the tech- and sudden fluctuations in water nique of application influences the temperature, should be checked. If success of any treatment to no small none of these is involved, the fish degree. It might, therefore, be ad- should be examined for parasites vantageous to briefly outline the and microscopic lesions. There are various methods of treatment in many diseases of fishes w^hich are common use and the recommended diiRcult to diagnose or treat, or both. techniques. When in doubt as to the cause of losses, the fish culturist should seek Salting the advice of a State fishery biolo- gist. Whenever it is necessary to Salting is good trough treatment, send the diseased fish to a diagnos- but it will not cure everything. In tic laboratory, the specimens se- troughs, it is extremely simple to lected should be fish with the most apply, is reasonably effective typical symptoms or signs of the against external protozoan para-

disease, but still living. It is very sites, is an excellent tonic for the difficult and often impossible to fish, and its application demands diagnose a disease from a dead fish. the least accuracy of any known If living fish cannot be brought to form of treatment. the laboratory, live fish with typical There are many w ays to treat fish symptoms should be placed in a jar by salting, and some methods are containing 1 part of commercial better than others. In the method formalin diluted with 3 to 4 parts recommended here, fish are treated of w^ater. A letter should accom- v/ith a known concentration of com- pany the specimen, giving as de- mon salt. Salt should be dissolved tailed information as possible re- in water in a quantity to give a 3- garding the progress of the disease, percent concentration when added percentage and rate of losses, and a to the water in which the fish will

51 OPERATING THE HATCHERY be treated. This can be done by de- ever be applied in the absence of termining the volume of water con- definite knowledge regarding the tained in a trough or tank at an cause of any mortality. Salting, arbitrarily predetermined depth, however, becomes progressively say 2 inches (5 cm.)- By multiply- more expensive, less effective, and ing the inside length of the trough more difficult to apply as the size by the inside width and the product of the body of water to be treated of these two numbers by the prede- increases. termined depth, all expressed in Flushing inches or centimeters, one can cal- Control of fish pathogens or para- culate how much salt to use. A sites by flushing does not have wide 3-percent concentration can be ob- use, but in certain instances it is tained by using 1 ounce of salt to quite effective. Flushing consists each 60 cubic inches of water, 30 in routinely adding a stock solution grams to the liter, 4 ounces to the of a disinfectant or drug of known gallon, or 30 ounces to the cubic foot strength to the upper end of a of water. To give fish a salting, trough and allowing it to flow down shut oflf the inflowing water, drain the trough and out. Most fre- the trought to the predetermined quently it is used with malachite depth, remove some of the water in green to control fungus infection a bucket and add the required quan- of fish eggs during hatching. Pre- tity of salt, dissolve the salt, and liminary experiments also indicate mix this strong solution with the that such treatment with malachite water in the trough. green may be of use in control of Fingerling trout will withstand a the external infection of fish by 3-percent concentration for 6 to 10 fungi belonging to the genus Sapro- minutes. Most minnows will prob- legnia. The most-frequently used ably stand this treatment for only 2 procedure is to make a stock solu- or 3 minutes. When several of the tion containing 0.5 gram of pure weaker fish have turned over, the malachite green per liter of water inflow is resumed at the maximum (2 grams to the gallon, 1 ounce to rate which the fish will withstand 14 gallons) and after the dye is and the drain is partially opened to permit a rapid replacement of the completely dissolved, 100 milliliters salt water. This method may be (3.5 fluid ounces) of the solution applied to fish as often as desired should be poured in at the head of without apparent injury and, in- the trough and half of that amount

deed, with a definitely tonic eflfect. in the middle of the trough. Bur- When repeated three times at 24- rows (1949) described a treatment

hour intervals, salting is quite ef- of eggs by a constant flow of mala- fective in curbing epidemics caused chite-green solution.

by external protozoans, and it is Malachite green also can be the only treatment which should added in powdered form to a fish

52 DISEASE CONTROL tank or concrete pond, and dis- a small number of fish as an ex- solved by mixing. In such cases periment. If the percentage loss it should be added at a rate of 1 in this experimental group does p. p. m. Water containing mala- not fall significantly below that of chite green should be gradually the rest of the affected fish within replaced with fresh water. If the 2 days after the experimental flow of water is such that the con- treatment w as given, hand dipping centration of the dye wnll be re- should not be used. duced in the pond by about 50 Hand dipping, in the opinion of percent during the first hour, no the authors, is best done in a dip- toxic effect on fish should be no- ping box. This apparatus con- ticeable. The use of malachite sists of a solidly constructed, water- green requires further investiga- tight, w^ooden box—in cross sec- tion. tion about 2 inches narrower than the hatchery troughs, about half Dipping again as deep, and approximately The third basic method of con- o feet long. The height reached trolling diseases and parasites in by a known volume of water is bait fishes, hand dipping, could be legibly marked on the box. In the the subject of several volumes. dipping box is slung an inner com- Suffice it to say that it is a danger- partment, with four ears which ous treatment, for the solutions are sufficiently wide to rest on the used are powerful and relatively top of the dipping box, yet suffi- concentrated. Hence, the differ- ciently narrow to permit the com- ence between an effective dose and partment to slip into the hatchery a killing one is exceedingly nar- troughs. This inner compartment row in view of our present lack has two wooden sides which round of knowledge concerning this very vertically at the ends, and the bot- common method of treatment. tom is covered with a galvanized, When applied with extreme care, coarse wire mesh. If a dip bath dipping undoubtedly may be of is used that contains copper sul- great value in controlling infesta- fate or acetic acid, the galvanized tions of external parasites and in- screen should be painted with as- fections caused by certain types of phalt, since even traces of dissolved bacterial diseases, such as fin rot zinc may be toxic to the treated and the eastern type of gill dis- fish. The galvanized mesh, in turn, ease. Certainly, hand dipping is covered on the inside with bob- should never be applied to any binet, that is caught to the wire large number of fish unless there mesh at a sufficient number of

is valid reason to believe that points to keep it from floating off. some external parasite is causing The desired quantity of disinfect-

the losses. In the absence of such ant is w^eighed out and dissolved reason, a dip should be applied to in the dipping box which has pre-

53 OPERATING THE HATCHERY viously been filled with water to a dilute solution of disinfectant is the calibration mark. The inner more effective and less toxic than compartment is then placed in the is the shorter, more-concentrated trough which contains the fish to hand dip. Furthermore, prolonged be treated, and a convenient num- treatment may be applied without ber of fish from the trough are liandling the fish, a factor which is placed in it by means of a scap not serious if the fish are carefully net. The compartment is then re- treated from troughs, but may be- moved to the dipping box and the come very serious when the fish are fish immersed in the disinfectant. in ponds or pools where a seine After the required time for the dip must be used and a large number of has elapsed, the inner compartment fish is involved. is carefully lifted from the dip- Prolonged treatment originally ping box and innnersed in the consisted of adding to the inflow- trough to which the treated fish ing water a sufficient amount of are being transferred. By slowly dissolved disinfectant at a uniform lifting the "upstream" end of the rate to maintain a constant concen- inner compartment, the fish slip tration of disinfectant over a defi- out into the trough. The solution nite period of time, usually 1 hour. in the dipping box should be aer- This method of treating the inflow- ated constantly and renewed fre- ing water is subject to an inherent quently. Differences in water tem- inaccuracy due to the diluting influ- perature between the infected ence of the residual water in the trough, the dipping box, and the pond at the time treatment is treated trough should at no time started. Although not serious in exceed 5° F. the case of troughs or small race- For treatment by dipping as ways which may be drained prac- used most frequently, the formula tically to dryness and which fill rap- for external parasites is glacial idly, the inaccuracy becomes pro-

acetic acid, 1 part dissolved in 500 gressively greater as the size of the

parts of water; for gill disease, it body of water to be treated is

is 1 part of copper sulfate (blue increased. stone) in 2,000 parts water; and For treatment of fish in larger for various external infections with water areas, such as circular pools,

animal ])arasites and fungi, it is a raceways, or ponds, the prolonged o-percent solution of salt. Fish treatments are identical in princi- are usually dipped for 1 minute in ple to salting, page 51. The volume acetic acid and copper sulfate, and of water in the pool (capacity of in salt for several minutes until the pool) to be treated must be the weakest fish begin to turn over. known ; then the required quantity Prolonged treatment of the disinfectant is weighed, or Prolonged treatments are based measured by volume if it is a liquid, on the theory that long exposure to and dissolved in a small quantity of

54 DISEASE CONTROL

water. This stock solution is mixed cent formaldehyde) to 4,000 parts thoroughly and quickly with the of water by volume. Pyridylmer- water in the pond. To ensure an curic acetate (P.M. A.) is used at a even distribution of the disinfectant rate of 2 parts per million. Treat- and to aerate the water dtiring ment with formalin is effective treatment, the w\ater should be re- against many of the external para- circulated in a closed system from sites, like Gyrodactyhis^ DaHyJogy- the lower end of the pond to the rus^ Chilodon., Costia^ Trichodina^ upper end b}' means of a centri- fin rot, and others. A 10-percent fugal pump. stock solution of P.M.A. can be Prolonged treatments can be car- easily prepared and kept on hand ried out easier if fish are not fed when needed. P.M.A. is used for 24 hours before treatment. This mainly for the treatment of gill reduces the fishes' metabolism rate diseases, but some of the external and oxygen requirement. Accord- parasites listed here are also af- ing to Fish (1947), for safe treat- fected by it. P.M.A. is toxic to ment, fish should not be too some fish, like rainbow trout. It crowded; there should be no more is not known how toxic it may be than that 1 part of fish by weight to minnows and other bait fishes. to 100 parts of water ( 1 pound of Antibiotics, such as chloram- fish per 12 gallons of water). If phenicol and terramycin, have been such a ratio is maintained, the flow found to be effective in the control of water or aeration can be cut off of ulcer disease and furunculosis in for 1 hour. trout and red-leg disease in frogs. Gammexajie has been described as Since the bacterium PseudoDionas an effective treatment for infesta- {Aeromonas) hydrophila^ which tion with ArguJus, a copepod. It causes red-leg disease is identical should be added at a rate of 1 part with that which causes infections in to 10 million parts of water to the many warm-water fishes, chloram- pond or tank holding the infested phenicol may be the choice in treat- fish. In tanks, the medicated water ment of infections of aquarium should be replaced with fresh water fishes. It sjiould be added to water after 2 to 3 days of treatment. in which fish are kept at the rate of How effective ganxmexane is for the 50 milligrams per liter (190 milli- treatment of infestations caused by grams per gallon of water ) . Water Lernea (another copepod) is not should be changed once a week and known at this time. fresh chloramphenicol added. The most-frequently used pro- Chloramphenicol is also available longed treatments are with formalin in capsules, each containing 250 and pyridylmercuric acetate, tech- milligrams of the drug (1 capsule nical (P.M.A.). Formalin is added per 5 liters or 1.3 gallons of water). to water at a rate of 1 part of If fish are kept in flowing water, formalin (containing about 40 per- flow should be stopped for 1 hour

55 OPERATING THE HATCHERY

( or for as lon^ as possible ) . Treat- antibiotics, calomel, carbarsone, and ments should be repeated at inter- kamala. vals of several days, if needed. Use Sulfonamides are most effective of antibiotics in treatment of exter- in treatment of furunculosis, which nal or internal diseases of fishes is is a disease predominantly affecting very recent, and the available in- the salmonid fishes. Sometimes, formation on this subject is scant. however, this disease may cause Caution, therefore, is advised when losses among warm-water fishes. usin^ antibiotics. They should not Of the great variety of sulfonamide be used for prolonged periods of drugs, those most frequently used time, (i. e. several weeks) be- are sulfamerazine and sulfametha- cause drug-resistant varieties of zine, with the possible addition of pathogens may appear, and in such sulfaguanidine. The effective dos- cases antibiotics will become use- age rate is 8 to 12 grams of sul- less against them. famerazine daily per 100 pounds of fish. Some workers have found Internal treatment that replacement of one-third of either of the first two sulfonamides, In internal treatment, drugs are with sulfaguanidine is somewhat given the fish by mouth with their more effective. For best results, food, or in certain instances they treatment should start as early as have to be introduced in capsules about directly to the stomach. Whenever possible and be continued for drugs are given with the food, it is 2 weeks. In a recurrence of the important to select a food of good disease, treatment should be re- cohesion (or use medicated pellets) peated. During the period of treat- which is readily taken by fish. This ment, only medicated food should is important, because if food is per- be fed to the treated fish. mitted to remain in the water even Calomel and carbarsone are effec- for a short time the drugs may tive in the treatment of intestinal leach out. Drugs must be mixed infections caused by one-celled ani- well with the food so that each fish mal parasites, like Octomitus. will get the ({uantity of drug pro- Either one of these drugs should portional to the amount of food be added at the rate of 1 gram to the taken. Food should be fed judi- pound of food. Feeding of the ciously in quantities exactly re- medicated food should be continued quired by the fish. If too much for H days, and repeated when food is given, both food and drug needed. Kamala is used for treat- will be wasted. If there is not ment of intestinal tapeworms in enough food given, the weakest fish, fislies. It can be added to food at a which may need the drug the most, rate of 1 to 1.5 percent, or given in will be deprived of it. Among the capsules to large brood fishes, the drugs given orally are sulfonamides. dosage being 0.1 gram for each 8

56 :

DISEASE CONTROL pounds of tish. Treatment with Here is a list of the chemicals and kamala should be continued for .3 drugs that are recommended for use days. in the treatment of bait fishes

Drug OPERATING THE HATCHERY

15,000 solution (Vs ounce in 15 gal- Superficially, the spots resemble lons of water) is very effective (see lesions produced by Saprolegnia., also Flushing, p. 52). but a close inspection shows that they lack the fuzzy appearance so Bacterial diseases characteristic of a fungus infection. C. columnaris can easily Fin rot.—This disease may be be identi- caused by several different bacteria. fied under the microscope by an ex- perienced person. The disease is cliaracterized by a Disease breaks out progressive degeneration of a fin or most frequently as a result of handling, the tail of a fish until the entire and this can be prevented by dipping the fish right appendage is destroyed. The infec- after han- dling for 1 minute in tion starts at the free end of the fin. a solution of copper sulfate. The diseased tissue is separated This chemical add- from the uninvaded tissue by a ed to pond water at a rate of 1 white line. Control of this disease p. p. m. may arrest the progress of the disease. is accomplished by dipping in a Infections dropsy.—Pseudomonas 1 : 2,000 solution of copper sulfate

for 1 or 2 minutes. If the water is {Aeromonas) hydrophila.^ a bac- hard, 10 milliliters of glacial acetic terium commonly present in water, acid should be added to 10 gallons causes this disease. Occasionally of water (1 fluid ounce to 30 gal- more infective races (mutants) of this bacterium appear, which are lons) . Fish on which the disease has progressed to a marked degree more destructive to fishes. The re- should be destroyed, as the dip can sistance of fishes is lessened by han- dling, crowding, do little for them. Bacterial fin rot or other unfavor- able conditions. has also been controlled with a Outbreaks of in- fectious dropsy occur most fre- 1 : 4,000 (8 ounces to 100 gallons of quently in spring water) solution of formalin (see when the tem- perature of water rapidly increases Prolonged Treatment, p. 54). Cohmmaris. — During recent and fish are still weakened by win- years, many outbreaks of infections ter. Sometimes up to 80 percent of the fish of warm-Avater pond fishes with a may die within several bacterium called Chondrococcus days. It is one of ihe most de- {C'ytophaga) columnarlH have been structive bacterial diseases of warm- water fishes. reported. This bacterium attacks fish mostly at higher water tem- The symptoms of this disease are peratures, like 25° to 30° C. (77° variable. Sometimes the diseased

to 88° F.). The infection is fish may have deep boils or shallow chai-acterized by the appearance of ulcers on their bodies. Frequently grayish-white spots on the head, the body is swollen and the abdo- gills, fins, or some part of the body, men filled with a watery fluid wliicli is usually surrounded by a (dropsy). Occasionally the skin zoiH' with a distinct reddish tinge. on the abdomen may become pink or

58 DISEASE CONTROL

red with some small hemorrhages. which belongs to the same group

The intestine also may show con- of drugs. Recommended dosage is gestion. Scales may stand out on 8 to 10 grams of sulfonamides daily the swollen fishes. Ps. hydrophila per 100 pounds of fish (see In-

can be isolated from the abdominal ternal Treatment, p. 56). fluid, blood, and lesions, and iden- Parasitic worms tified by a bacteriologist. Frogs also sometimes become infected Black grub.—Black grub, or with this bacterium, and the result- black spot, is caused by the larval

ing disease is called "red leg," form of the flatworm, Neascus sp. stressing the most characteristic The jiarasite occurs on fishes as a symptom of this disease in frogs. small black spot about 1^5 of an There is no known treatment for inch in diameter. This black cyst this disease. If fish are in an encloses a small worm which is usu- aquarium or a tank, addition of ally limited to the scales and in- chloramphenicol may be used. tegument, but wdiich may occasion- Also feeding food that contains ally be found in the flesh just below chloramphenicol or terramycin the skin. The life history of the may be effective (see Prolonged black grub is complicated, but is and Internal Treatments, pp. 54 typical of many of the parasitic and 56). flatworms. The adult worm oc- curs in Fmmnculosis.—Produced in fish the kingfisher. Eggs of the by Bactermm. salmonicida^ this is Vvorm are discharged into the water, a disease of salmonid fishes (sal- where they hatch into small, free- mon and trout), but whenever min- swimming organisms. These lar- nows or other warm-water fishes val forms swim about until they are kept in water which flows from come in contact W'ith a particular tanks or ponds holding infected species of snail. Then they bore trout, it may cause severe mortality into the snail and reproduce them- among them. Furunculosis has selves many times. Finally, num- variable symptoms. In minnows, bers of free-swimming forms break the most typical signs are boils or out in the water and move about bloodshot fins. Diagnosis can only until contact with a fish is made. be made with certainty by bacterio- They then bui-row in and encyst in logical examination of the diseased the scales or in the flesh. When fishes. Furunculosis, if correctly the fish is eaten by a kingfisher, the diagnosed, can be effectively treated encysted worm develops into an by feeding the infected fish with adult and the life cycle is com- food containing sulfamerazine, or pleted. It usually causes little dam- sulfamethazine. Some authors age to the fish, but may, at times, recommend replacement of one- be jn*esent in numbers large enough third of either of these two sul- to cause death. fonamides with sulfaguanidine. Klak (1940) reports a heavy

59 OPERATING THE HATCHERY

Neascus infection of fathead min- be found in the intestinal tract of nows in a pond at Leetown (W. warm- or cold-water fishes. Heav- Va.). The encysted worms were ily infested fish become sterile, found in the abdominal cavity in therefore, the removal of tape- such numbers that the abdomen Avorms is important in the case of was greatly distended. Mortality brood stock. Several drugs given was so high that a change to golden orally may be effective. McKernan shiners, a more resistant species, (1940) found that the addition of was recommended. 1 to 1.5 percent of kamala to their The only control for this para- food rids fish effectively of tape- site is draining the pond long worm. One contributor to this pub- enough to kill the snails and con- lication (Snieszko and Powell, un- trolling the kingfisher population. published ) successfully cured adult Snails in ponds can be killed largemouth black bass by treating rapidly by disinfection of the pond the fish for 3 days with kamala in with chlorine (see Disinfecting capsules. Each adult bass received Ponds and Equipment, p. 61). daily one capsule containing 0.1 to Tapeworm.—Ligula intestinalis 0.2 grams of kamala, dosage being is a tapeworm whose last larval about 0.1 gram for each 3 pounds stage is commonly found in the of fish. The treated fish eliminated body cavity of suckers and min- great masses of tapeworms with the nows, and rarely in perch, darters, feces. and bass. Infested fish are easily External animal parasites recognized by their swollen bellies. Worms 6 inches long have been Here are included such proto- taken from minnows, and worms as zoans as Costia, Chilodon, Tricho- long as 12 inches have been taken diim^ Scyphidia, Epistylis^ Ichthy- from suckers. The adult stage lives ophthinus, and external trematodes in the intestines of water birds. such as Dactylogyrus and Gyrodac- Minnows and suckers reared in tylu^. All of these parasites except ponds or taken from shallow waters Ichthyopkthirius live on the surface along lake shores may be infested. of the fish's body and gills and are The parasite is known to be of wide readily removed by salting, dipping occurrence in the Great Lakes and in glacial acetic acid, or by using adjoining areas. Because the para- prolonged treatments with forma- site's eggs are spread by water lin. Ichthyophthirius differs from birds, and early larval forms live the other external parasites listed in the natural food organisms of here, since in its adult stage it buries fish, tliere is little chance for perma- in the epidermis of the fish; there- nent control, although drying and fore, these treatments are not effec- freezing of pond bottoms may re- tive against it unless they are re- duce infestation. peated daily until the desired Other tapeworms can frexjuently results are attained. Where water

60 DISINFECTING flows through the pond, increasing produced a mild current. The the rate of flow is considered the young that hatched did not reinfect most eft'ective means of controlling the fish, and the adult parasites this parasite. If fish are held in dropped off after they reproduced. tanks or aquariums, the addition of Infected goldfish could be healed in hydrochloride or sulfate of quinine about 10 days. to the water at the rate of 1 : 50,000 Recently a chemical, gammexane, has been for treat- to 1 : 100,000 is recommended. recommended Water containing quinine should be ment of fish infected with the cope- replaced by fresh water when the pod Argulus sp. It may also be fish are cured. Recently Schaper- effective against other copepods. claus (1954) recommended using It should be added to water contain- acriflavine in the same way as qui- ing infected fish at a rate of 0.1 nine. Acriflavine is believed to be p. p. m. and mixed well. It is rec- even more effective than quinine in ommended that after 2 to 3 days of the treatment of Ichthyophthirius treatment, the water containing and other external protozoans. gammexane should be replaced Copepods.—Suckei-s and min- with fresh water. Since this is a nows held in sluggish or warm new and little-known treatment, it waters may develop raw circular should be carried out with great wounds with what appears to be a caution. slender bonelike splint projecting from the center of each lesion. The DISINFECTING PONDS AND white splint actually is a copepod EQUIPMENT parasite, Lernea sp., which has The incidence of disease can be burrowed head first into the flesh, greatly diminished or even entirely usually beneath the dorsal fin. This avoided by observation of certain parasite is common in southern por- sanitary measures. Some of them tions of the Lake States and is more will be listed here. For more detail, abundant southward. see publications by Davis (1947 The projecting i>ortion of the and 1953) and O'Donnell (1947). parasite contains reproductive or- If disease recurs frequently, the gans which scatter eggs into the hatchery must be carefully exam- water as the host fish swims about. These eggs hatch into tiny free- ined to determine the source of in- swimming larvae. The larvae, in fection. Most frequently the source time, attach themselves to another of infection can be found in not- fish, transform their body shape to completely cured fish or in older fish a great degree, and burrow in. (brood stock), which may serve as Meehean was able to cure the infec- a reservoir of infection without any tion on fancy goldfish by reducing visible symptoms of a disease. the pond level to a point wiiere Since frequent treatments are costly water flowing in and out of the pond and time consuming, it is often bet-

367913 O—5€ 61 OPERATING THE HATCHERY ter to kill the diseased fish, disinfect gaseous chlorine, to water. The the ponds, and start over with concentration of free chlorine healthy stock. should not fall below 100 p. p. m. In case of an outbreak of a disease during disinfection, which should in one part of a hatchery, the in- last at least for 1 hour. Water con- fected part should be isolated and taining chlorine is very toxic to fish quarantined. All of the equipment and other life. If water with chlo- used in this part of the hatchery rine is kept in ponds for 2 or 3 days, should be disinfected. Ponds, also, all chlorine will disappear. If, should be disinfected as soon as the however, water with chlorine must fish are removed. be released sooner to a stream with fish, the free chlorine should be

Disinfecting equipment neutralized w i t h photographer's hypo (sodium thiosulfate). Chlo- For disinfection of tools and rine will also kill fish parasites pres- utensils, any good disinfectant can ent in water, as well as snails which be used. Chlorine in the form of often act as intermediary hosts to hypochlorite is generally available, some fish parasites. inexpensive, and easy to use. The Drying and liming of ponds are concentration used in hatcheries is also good practices; however, ponds 200 p. p. m. of free chlorine. The so treated must remain completely quantity of hypochlorite that has to dry for several months to make this be used to obtain this concentration practice entirely effective. can be calculated from the contents of available free chlorine as indi- CONTROLLING PREDATORS cated on the product's label. Hypo- chlorite in open containers and ex- AND PESTS to moisture and light loses its posed INSECTS strength rapidly. Roccal, another widely used dis- Minnow ponds may become over- infectant, is recommended for dis- populated with aquatic insects that infection of hands, boots, nets, and prey on fish fry. Of these, the bee-

other equipment. It is sold as a 10- tle larva called the water tiger and percent solution. The disinfecting the adult insect known as the back- solution can be obtained by diluting swinnner {Nofonecta) are the most 1 part of commercial roccal with 100 destructive. As both come to the yjarts of water. is Roccal colorless, surface of the water for air, they can odorless, and harmless, if not taken be controlled by covering the ponds internally. with a film of oil. Kerosene, fish

oil, No. 2 fuel oil, and cod-liver oil Disinfecting ponds can be used for this purpose, as they Ponds can be disinfected by the are not injurious to fish. The cod-

addition of hypochlorite, or liquid liver oil must be mixed with gaso-

62 PREDATOR CONTROL line before use. Meehean (1937) some garter snakes consists of fish. recommended using 10 to 12 gallons The water snake has a preference of kerosene to an acre of water sur- for streams but frequents fish face. The same result can be ob- ponds. tained with 4 or 5 gallons of com- Snakes can be controlled by kill- mercial fish oil. The fish oil is ing all that are seen around the sprayed on the surface to control ponds. The grass and weeds at the thickness of the film. Kerosene the edge of the pond should be becomes too thin to be effective when cut short at all times so as to de- sprayed, so it is best poured along prive the snake of much-needed the windward side of the pond. cover. Logs, tree roots, and boul- ders should be removed for the BIRDS same reason. Ponds that are fenced Herons and kingfishers may cause to keep out herons should be pro- a heavy loss of fish from ponds. vided with pits at intervals along Occasionally, the entire production the outside of the fence to catch of a pond has been taken by birds. snakes and turtles. Water-snake The private hatcheryman is not al- traps are now advertised for sale lowed to shoot or trap these birds; in some communities. so he must depend on scares, wires, TURTLES and fences to keep them from the ponds. Some species of turtles are known Herons do not usually alight in to be fish eaters and, consequently, the water, and a low chicken-wire are predators if given access to a fence close to the edge of the pond, minnow pond. As a safeguard, or very steep banks around the all turtles frequenting a pond of pond, will keep them out. Some- minnows should be considered pre- times, several wires around the dators and controlled. Turtles can pond will work as well. be captured with baited hooks or Kingfishers are attracted to turtle traps (fig. 25). posts that overlook the water. Re- PREDATORY FISH moving all posts and dead trees near the ponds should help to dis- Predatory fish and the adults of courage these birds. cannibalistic minnows must be con- The hatchery operator should trolled in minnow ponds. As men- try to keep predatory birds from tioned before, lake and river water his pond, as the heron spreads the should be filtered to keep preda- yellow grub, and the kingfisher is tory fish fry from entering a pond. host to the black grub. When possible, the minnow pond should be drained dry during the SNAKES winter to kill any predatory fish A large percentage of the food that may have escaped notice. of the common water snake and Ponds that cannot be drained

63 OPERATING THE HATCHERY

lines about 50 feet apart for good distribution of the poison.

SALAMANDERS

The tiger salamander (fig. 26) is abundant in many minnow ponds and is often considered an important predator of minnows. Salamanders grow fast enough to keep ahead of most minnows and could be fish predators during the entire period of pond life. Stud- ies on Minnesota sucker ponds Figure 25.—Floating turtle trap. Tur- tles seeking a sunning spot are tipped show that the salamander is more into the net or wire bag. important as a competitor of the sucker, than as a predator. The should be treated with rotenone stomach contents of 133 salaman- before minnows are introduced and ders of all sizes from 8 sucker whenever there is an indication ponds was only 2.3 percent min- tliat predatory fish have become n o w s . Copepods and cladocera established. which are important sucker foods procedure is to apply The best made up 29.6 percent of the total 1.5 to 3 pounds of 5-percent rote- food of the salamander. Corixid none powder to an acre- foot of water bugs which are little used by water, depending: on the hardness suckers made up 28.9 percent of of the water. Ponds with hard the salamander diet. water, very cold water, or contain- ing bullheads require a heavier dosage. Emulsifiable rotenone can be used at the rate of 1 gallon for each 3 acre-feet of water. The emulsifiable rotenone can be ap-

plied as it comes from the can but the powder must be mixed with water to form a thin batter. The

poison is usually spread evenly over the pond with a boat and out-

b o a r d motor. The rotenone is Figure 26.—The tiger salamander is poured over the edge of the boat abundant in many streams and is an important predator of into the propeller wash at a steady considered bait fishes. (Photograph courtesy of rate. The pond should be criss- the Minnesota Department of Conser- crossed in a good pattern with vation.)

64 PREDATOR CONTROL

Salamanders can be controlled in CRAYFISH artificial ponds by keeping the pond In dry until after they have deposited many places the crayfish (fig. is considered their eggs. Because the salamander 27) a predator or a nuisance in ponds, but in returns to the pond to lay its eggs regions where crayfish are shortly after the ice melts, the pond used extensively for bait, they be can be safely filled in late spring. may an important byproduct In natural ponds the salamanders of minnow production, or may rate can be controlled by removing the separate ponds. In areas large gelatinous egg masses before where crayfish are a nui- sance in ponds, they hatch. The egg masses are they can best be con- trolled at usually formed on sticks or weeds harvest time when they in shallow water, so they are easy can be removed at no extra cost. to find. Every haul of the seine will bring Salamanders do so little harm in in large numbers of crayfish that sucker ponds that control is usually should be separated from the min- not necessary. At seining time, the nows as soon as possible to prevent dealer should sort out the sala- damage to the minnows from their possible manders as soon as because claws. If crayfish removal is to be they will gulp large down numbers effective, the crayfish must be car- of minnows when held in such ried away from the pond or buried, crowded conditions. as those thrown up on shore will MUSKRATS crawl back to the pond in a short time. The only appreciable damage done by these animals results from their burrowing in the dikes of ponds. At times they can be seri- ous pests, causing abnormal bank leakage and slipping that result in expensive maintenance costs. If a minnow producer has difficulty with these animals, he should con- sult his Stat« conservation depart- ment as to methods of control. Figure 27.—The craylish is considered Most States have specific laws pro- an important predator in some areas. tecting the muskrat because of its ( Photograph courtesy of the Minnesota value as a fur-bearing animal. Department of Conservation.)

65 SOME IMPORTANT BAIT FISHES

Knowledge of the life history and attain weights of 40 to 80 pounds. behavior of the bait fishes he is rais- Young game and food fishes, such ing helps the operator achieve max- as perch and pike, and which should imum production in his ponds. be called fry or fingerlings, are This knowledge aids him in select- often improperly called minnows. ing the species for each type of Of the fishes used for bait, the pond, in choosing the spawning fa- true minnows are most important. cilities to be supplied, and in de- They can be distinguished from termining the amount and kind of other fishes by the following char- fertilizer to use. acters: No teeth in the jaw^s; no The name "minnow" is commonly scales on the head but over re- but erroneously applied to small mainder of body; no spiny rays in fishes of all species. The true min- any of the fins ; one dorsal fin ; less nows are members of a family of fin pelvic than 10 rays in the dorsal ; fresh-water fishes, the Cyprinidae, fins abdominal in position ; size usu- and have definite characteristics ally small, under 6 inches (fig. 28). that separate them from other fam- Fish have definite food prefer- ilies. Most bait fishes are true min- ences. Many species feed entirely nows, but some important species on the tiny, drifting plants of the like the mud minnow and the sucker plankton, others on animals, and belong to other families. Most bait fishes are small, but some, like the some on both; some prefer insects, carp, an introduced "minnow," and and others take whatever comes the Colorado River white salmon. along (figs. 29-32).

DORSAL FIN LATERAL

BARBEL PECTORAL FIN ANAL FIN PELVIC FIN

Figure 28.—A typical minnow, showing the parts used in identification.

66 ——

LIFE HISTORY

extended spawning seasons and oth- ers have short ones. Adequate fa- cilities for spawning are a neces- sity in good pond management. To comply with natural habitat

requirements is important. Those normally living in bog streams or swift currents might not readily Figure 29. Daphnia, a pond organism adapt to life in ponds or holding

used by bait fish as food ; greatly mag- nified. (Photograph courtesy of the Minnesota Department of Conserva- tion.)

SpaAvning requirements, like feeding habits, differ for different species. Some bait fish require flowing waters; others do not. Some lay their eggs on vegetation; some lay their eggs on open gravel shoals or under debris. Some have Figure 31.—The rotifler, Karatella; greatly magnified. (Photograph cour- tesy of the Minnesota Department of Conservation.)

tanks. In general, however, most stream or lake minnows can be reared in ponds, and with proper food may grow faster than in their natural environment. There are many species of bait

Figure 30. Cyclops, another minute fishes, but the following pages in- crustacean used by bait fish greatly ; clude some of the more important magnified. (Photograph courtesy of species. The culture of several the Minnesota Department of Con- servation.) "minnow" species that are of wide

67 SOME IMPORTANT BAIT FISHES f\ rt f

• % ) L

O "n

Figure 32.—Some common aquatic insects and worms and their relation to bait fish. Top row: Stonefly (food), mayfly (food), dragonfly (predator). Middle row: Water tiger (predator), whirl-a-gig beetle (predator), canefly (food), chironomid-fly larvae (food). Bottom row: Leech (competitor), annelid worm (food). distribution and that have been sue- parts of the country is treated in cessfully introduced in various detail.

WHITE SUCKER Cafosfomus commersonnii' Also called Common Sucker.

68 SUCKER

LIFE HISTORY pods, 17 percent ; ostracods, 2.4 per- cent; chironomid larvae, 26.4 per- Description.—Sucking m o u t h cent; miscellaneous insects, 1.5 per- with thick fleshy lips on underside cent; rotifers, 10 percent; protozo- of head; fine scales near head and ans, 0.8 percent ; nematodes, 0.6 per- coarse ones on tail ; small specimens cent; and miscellaneous organisms, have three large dark blotches on 10.7 percent. This list suggests each side of body ; more than 10 rays that the planktonic crustaceans are in dorsal fin (true minnows have the preferred food of the sucker, but less than 10) ; no spiny rays in any a closer study reveals that chirono- of the fins. mid larvae are eaten whenever they Range.—This fish is widely dis- are available irrespective of crusta- tributed in the United States, oc- cean abundance. Very small suck- curring east of the Great Plains ers prefer small organisms but can from northern Canada, Hudson exist on larger forms when neces- Bay drainage, to Labrador, and sary. south to Georgia, Arkansas, and Importance.—The common, or Oklahoma. It thrives under a va- white, sucker is a popular minnow riety of conditions, but prefers for propagation because it is easy to clear-water lakes and streams. raise in large numbers, grows rap- Breeding habits.—The sucker idly, is very hardy in the minnow runs upstream to spawn early in the pail, and is preferred by fishermen spring. It prefers swift water and as a bait for walleyed pike. Suckers gravel bottoms, scattering its eggs are raised more cheaply in natural freely in the current. It will spawn ponds than in artificial because the to some extent in lakes if there are sucker needs a large amount of no outlets and inlets. Work done growing space that can be provided in New York indicates that temper- more cheaply in natural ponds. atures from 57° to 68° F. are best for hatching eggs. In this temperature PRODUCTION range, the incubation period was 5 to 7 days. At 70° F., mortality was The white sucker is naturally a high and the incubation period was fish of clear waters, so ponds ^ for 40° about 4 days. At F., none 1 Many Minnesot.a dealers have had no re- hatched in more than 14 days. As turns from Slicker fry planted in natural ponds. There are four pobable reasons for many as 47,800 eggs were taken this : 1. There may not have been ample food from one female. for the fry at the time of planting. A question- able pond should be fertilized with barnyard Food.—The sucker has diversified manure about 2 weeks before the fry are feeding habits. It seems to feed on planted. 2. There may have been a large pop- ulation of aquatic insects in the pond at plant- any food that may appear in the ing time. The back-swimmer and the water water. A study of 1,080 suckers tiger prey heavily on fish fry and should be killed off 2 days before the fish are planted In from Minnesota natural ponds the pond (p. 62). 3. The natural pond may shows the average food content to have had a population of predatory fish or minnows at planting time. 4. The ponds may be cladocera, 30.6 percent; cope- not have been stocked with free-swimming fry.

69 :

SOME IMPORTANT BAIT FISHES

its production must be selected more chironomid-fly larvae, or blood worms, in the bottom muds will produce good sucker carefully than those used for other crops more consistently year after year bait species (fig. 33). Experience than ponds that do not have an ample has shown that the following points supply of these larvae. are important in choosing sucker 3. The texture of the pond soil is very ponds important. Ponds with loam and sandy- loam soils produce best, peat and peat- 1. Ponds of moderate fertility usually loam ponds are average producers, and Sterile ponds produce the most suckers. silt and clay loam ponds are poor. The fish do not produce enough food for the pond soil is imiwrtant in its effect on and very fertile ones often produce water fertility and the production of enouKh algae to cause summer kill. Any chironomid-fly larvae. pond that becomes pea-soup green should 4. Ponds with heavy, mosslike growths with suckers because pro- not be stocked of filamentous algae over the bottom do will very small. If the pond duction be not produce good crops of suckers. One feet and the algal bloom is over 10 deep Minnesota pond always produced large heavy, the byproducts of is moderately sucker crops until the filamentous algae algal decomposition will be dispersed got started and covered the entire bot- widely enough to make a fair sucker pro- tom. Since then production has been duction possible. almost zero. This is possibly because

2. Ponds with large populations of filamentous algae decompose readily and

FiGUBE 33.—A profitable sucker pond in Minnesota. (Photograph courtesy of the Minnesota Department of Conservation.)

70 SUCKER produce toxic ammonia just as the water- available, however, if the fish are bloom does, and because the algal mat caught as they run up the stream on the bottom may interfere with the and are put into a suitable holding feeding activities of the sucker. pond until needed for stripping op- Collecting the eggs erations. In any event, eggs should not be taken unless a ripe male is im- Suckers and minnows that spawn mediately available for fertilizing in running water are usually them. stripped and the eggs are hatched The female is held over a damp- in jars. Taking eggs from the ened pan into which the eggs are ex- sucker and fertilizing them is not pressed (fig. 34). Immediately difficult, but considerable strength after the eggs are taken, a male is is required. The sucker not only is

stripped of his sperm ; the milt and large, but it is one of the most active eggs are thoroughly mixed by and powerful fish for its size native gently swirling the pan. Four or to our waters. On the upper Missis- five pairs of fish may be stripped sippi and its tributaries, suckers lit- into one pan providing each batch erally swarm during May and June of eggs and milt are thoroughly over the shallow, rocky stream bot- mixed immediately after stripping. toms in swift water, as well as along After a lapse of 2 or 3 minutes, the rocky, wind-driven shores of water may be slowly added to the many of the northern lakes. pan and the stirring continued at The fish in these spawning runs intervals by rocking the pan gently are caught with seines or traps and to and fro, swirling the water. are sorted. The ripe males and fe- The milt can now be washed out males are carefully put in separate by frequent changes of water (fig. tubs of water and the unripe fish are

35) . If the eggs have a tendency to released for another day. If those stick together in clumps, a cup of selected for stripping do not give muck or corn starch of the consist- their eggs and milt freely under ency of bean soup should be added light pressure, with the thumb and as the eggs are stirred (fig. 36). forefinger moved downward over The muck or cornstarch is then the abdomen toward the vent, they washed out with the milt. should also be released. Eggs After being washed, , the green forced from the fish by heavy pres- fertilized sucker eggs are trans- sure will not prove fertile. The ferred to a tub to harden (fig. 37). males mature somewhat earlier in The tub is placed in cold creek water

the season than the females, and the and is shaded from the sun. Peri- bulk of them may have moved odically the eggs are stirred gently higher up stream than the point at and the water is changed. After 2 w^hich the bulk of the females are hours the eggs are hard enough to taken, resulting in a local scarcity withstand the rigors of transporta- of males. Both sexes would be tion to the hatchery.

71 SOME IMPORTANT BAIT FISHES

all in water colder than 50°. Min- nesota hatchery operators prefer to start the eggs at 50° to prevent clumping, and then increase the temperature to 55° or 60° for hatch- ing, if possible. In some States, the water from lakes and streams reaches optimum temperature in time to be used in the hatching battery. Fortunately, sucker fry stay in the jars after hatching, and do not swim out with the water until they are about 5 to 10 days old. Conse-

I'^iGURE 34.—A female sucker is stripi)ed of its eggs. (Photograph courtesy of the Minnesota Department of Con- servation.)

Artificial hatching

At the hatchery, the eggs are transferred to Meehan hatching jars (fig. 38) , Usually 2 or 3 quarts of eggs are placed in eacli jar, and the water is adjusted so the eggs are in constant hut gentle movement tliroughout the lower portion of the jar. For best results, the water shoukl contain sufficient dissolved oxygen for the eggs, but should be free of air bubbles because the bub- bles adliere to tlie eggs and carry them up and out of the jar. Lengtli of hatching time depends on tem- perature of the water. Eggs will FiGURK Hry. —The milt is washed away hatch in 4 to 6 days in water warmer with frequent changes of water. than 65° F., in 10 to 15 days in ( Photograph courtesy of the Minnesota water of 50° to 60°, and not at Department of Conservation.)

72 SUCKER

quently, the fry can be held in the jars until they are free swimming, and are not put in the pond until they are strong enough to search for food. Because the suckers stay in the jar and settle to the bottom

when the water is turned off, it is very easy to determine the number

Figure 36.—A eup of muck is added to keep the eggs from clumping. (Photo- graph courtesy of the Minnesota De- partment of Conservation.)

Figure 38.—Hatching sucker eggs.

( Photograph courtesy of the Minnesota Department of Conservation.)

on hand and the number to be used in each pond. The fry can be poured into a glass measure gradu- ated in ounces and measured after they settle. Counts made in Minne- sota indicate that there are 2,720 5-day-old sucker fry per ounce. Suckers grow rapidly in ponds. In Figure 37.—The fertilized eggs are trans- 60 days they average 2.8 inches and ferred to a tub to harden. (Photo- in graph courtesy of the Minnesota De- may reach a length of 3,5 inches partment of Conservation.) that time. The following table

73 SOME IMPORTANT BAIT FISHES shows the rate of growth of young suckers in ponds:

Number of days SUCKER wishes to raise and stock accord- ingly. The following table shows the relation between the number of fish produced in some Minnesota sucker ponds and the size of the fish at 60 days:

Number of fish produced per acre SOME IMPORTANT BAIT FISHES

ern natural ponds because the and continues until September. pliosphorus tends to produce heavy The only ponds that have not been algal blooms that may result in harvested by that time are those fish kills. In very fertile ponds, producing fish to be held over win- the control of algae with copper ter. In areas where winter spear- sulfate may be more important ing is allowed, the cash return from than fertilization (see table, p. a poor pond can be improved by 47, for amount to use). holding the fish until October or November, when they can be sold as Harvesting the fish decoys for spearing. Higher prices can be obtained for them at that Natural ponds can be harvested time than if they were sold as pike- most efficiently with a large seine bait-sized minnows in the summer. that is set out in a semicircle from While the production of sucker a boat and pulled in slowly to a ponds varies with pond conditions good landing beach. When the and pond-management methods, the net reaches the shore, it is bagged average production of sucker ponds and moved quickly to deeper water in Minnesota was 10,000 nsh per so the minnows will not smother acre for 26 pond-seasons, with a or choke on silt. The minnows are transferred to a floating live box high of 25,000 and a low of 1,500. us soon as possible, and all turtles, The average was 165 pounds to the salamanders, and crayfish are acre, with a high of 490 pounds and thrown out. If the minnows are a low of 6 pounds. These produc- uniform in size and are large tion figures are far below the yield enough for pike bait, they are goals set in some publications on loaded into a tank of fresh water minnow propagation, but the ponds hauled and to the bait shop. If still are considered very practical. the haul produces large numbers The cost of operation was low and of undersized minnows, the fish the margin of profit was high. are put in a slat grader (fig. 23) In most sucker ponds, the pound- and the small ones returned to the age of fish produced can be greatly pond for further growth. The increased by cropping and grading pond is then reseined at periodic the fish periodically. On the aver- intervals until further hauls are age, the production of Minnesota not practical. The minnows that have been missed can be trapped sucker ponds was increased 75 per- under the ice during the early part cent by cropping. When the ponds of the winter. were cropped twice in a season, the The time of harvest for each pond poundage increase was only 5 or 6 will depend on the seasonal market percent, but when the ponds were and the size of the fish being raised. cropped 6 to 8 times, the poundage In Minnesota, the sucker harvest increase was as high as 140 percent.

starts during the last week of July This means that if the dealer har-

76 SUCKER vests all of the minnows from a ponds are not practical for over- pond the first day he seines, large wintering suckers. The fish must numbers of the suckers will be small be seined or trapped and moved to and will have to be sold as crappie holding ponds supplied with run- bait. If the dealer removes only ning w^ater (fig. 39). River- w^ater the pike-bait size each time and al- ponds are preferable to those fed lows the small fish to stay in the Avith spring water, because the river pond and grow, he will be able to water supplies some natural food sell the entire production as pike and the minnows are in better condi- bait. The number of times a pond tion in the spring. In either type can be cropped will depend on the of pond, the fish must be fed arti- cost seining the value of pike of and ficial food, but less food is needed in bait versus crappie bait. river-water ponds than in spring- fed ponds. Suckers feed readily Holding suckers over winter on moist meat scrap or fish-meal In the Northern States, where 3 mash thickened with middlings and feet of snow and 20° -below-zero formed into fair-sized balls. The weather are common, propagation balls are dropped to the bottom of

Figure 39.—A winter holding pond supplied with river water. ( Photograph courtesy of the Minnesota Department of Conservation.)

367913 0—56- 77 SOME IMPORTANT BAIT FISHES

the pond and left until consumed. them is to place the fish in shallow Additional food should not be added natural ponds that have a good sup- until tlie tirst lias been cleaned up. ply of natural foods. Fish that are Even with good artificial feeding, about 2.5 inches long will soon grow suckers held over winter in hold- to pike-bait size and those that are ing ponds will be thin the following 3.5 inches will increase to bass-bait spring. The best way to fatten size by June or July.

FATHEAD MINNOW Pimephales promelas Also called Tuffy Minnow.

MALE

.^,.'«f'"^''"'?***^*' # .-4^m^ FEMALE

LIFE HISTORY cavity black ; intestine two to three Description.—First obvious ray times body length. of the dorsal fin thickened so that The males are larger than the fe- it stands out; mouth small, termi- males and reach a maximum length nal, and upturned; scales small and of 31/^ inches. crowded behind the head; back Range.—The fathead is generally rounded and arched; lateral line distributed throughout southern only on anterior half of body. Canada and in the Ignited States Breeding male with black head; from Lake Champlain west to the soft swollen pad on top of neck re- Dakotas and south to Kentucky and gion ; bleeding tubercles on snout the Kio Grande River. In north- and under the chin. Lining of body ern AVisconsin and Michigan, it

78 FATHEAD MINNOW

Length of fish (inches) SOME IMPORTANT BAIT FISHES

minnow ranges in length from 1^/2 Intensive culture of fatheads to 4 inches, the male being con- To practice intensive fish culture, sistently larger than the female. it is necessary to have a source of The life span of the hatchery- flowing, cool water from a spring or reared fathead minnow is from 12 well. The ponds should not be to 15 months, depending on the size larger than 1 acre or smaller than of the fish at maturity. It is quite 1/4 acre. The depth of water should certain that during the early range from 2 feet at the shallow end spawning season a large majority to 6 feet at the drain, and average of the males die within 30 days after about 3 feet deep. The pond the onset of spawning activities, should be equipped with a control- and that a large percentage of the lable inlet and similar bottom gravid females die within 60 days. drain. To raise fatheads profit- Immature fatheads, ranging in ably, it is necessary to have at least length from 1 to 2 inches, even 6 ponds available for propagation, though a year old will die shortly and it is more economical, as after they become gravid at the much far as production costs are con- age of about 15 months. It has cerned, to have 12 to 15 ponds. In been noted that a small percentage every unit of 6 ponds, it is desirable of the adult hatchery-reared fat- to use only 2 for reproductive pur- heads are sterile, and also, that poses, leaving the remaining 4 for these fish live longer and grow growing ponds. The ponds to be larger than the fertile fish. used for reproductive purposes In Missouri, the fathead is com- mercially produced by two types of should be ballasted along two banks with rocks in size culture: intensive and extensive. ranging from 6 Intensive culture refers to the op- to 12 inches in diameter, or with eration of hatcheries where large tile (fig. 40). This construction should extend from about 6 inches populations of fish are fed artifi- cially. Extensive culture refers to above the planned normal water hatchery operations where smaller level to a depth where the rocks fish populations are fed natural will be covered by about 2 feet of foods produced by fertilization. water. The purpose of this instal- Both methods have merit, depend- lation is to provide adequate ing on the type of water available spawning facilities for the fat-

at the hatchery site. Intensive fat- heads; at the same time, it offers head culture requires much more considerable protection to the levees labor and initial capital expendi- against pond erosion. ture than does extensive; however, The brood ponds should be fish may often be produced in stocked in the early part of April, greater numbers and at lower cost and the breeders should consist of

by the intensive type of fish farm- both mature and immature fat- ing. heads in ratio of about 00 percent

80 )

FATHEAD MINNOW

Figure 40.—Four-inch tile used for spawning devices. (Photograph courtesy of the Ohio Department of Conservation and Natural Resources.

adult to 40 percent immature fish. conditions or by an increase in the Both adults and juveniles are used flow of spring water into the pond. as breeders because of the short life Sometimes, during the warm span of the fathead. Since the summer months when the surface larger fish will die shortly after the water temperatures rise above the onset of spawning, it is necessary 80° to 85° F. range, the breeding to provide immature, developing fatheads will conduct their spawn- fish to have spawners later. In this ing activities at lower depths than way, one can be sure of a continu- normally to attain a cooler stratum ous, uninterrupted supply of newly of water. The water at this level hatched fry. The brood ponds (2 to 8 feet below the surface) fre- should be stocked at the rate of 15,- quently is low in the concentration 000 to 25,000 fish to the acre of of dissolved oxygen. Even though water. the breeder fatheads can tolerate Spawning.—In Missouri, fat- the low oxygen content, the develop- heads normally start spawning ac- ing eggs cannot; and subsequently, tivities during the latter part of they all will die before the incuba- April or at a time when the pond- tion period is completed. To coun- water temperature reaches 65° F. teract this condition, the fathead They spawn intermittently minnow grower must keep his throughout the summer, providing brood ponds free from rich organic the water temperature does not rise deposits, either by reducing the above 85°. When this temperature amount of artificial food supplied is reached, spawning ceases, and is to the breeders, by reducing the not resumed until the temperature amount of fertilizer, by increasing is lowered by prevailing weather the incoming spring- water supply.

81 SOME IMPORTANT BAIT FISHES

or by using a combination of all seining or by draining the pond, three. Fathead brood ponds aver- and transfer the fry to another aging an acre in size should have a pond or destroy them. The other minimum incoming flow of 25 gal- solution is to introduce predacious lons of water a minute during the species, such as the creek chub or warm summer months. the golden shiner, to forage on the During the latter part of April small fatheads. This method when the water temperature ap- should not be used unless a minnow proaches 65° F., spawning activity propagator has had a number of can be observed. AYithin a few years of experience in fish-cultural days, small fry will be seen swim- work, because he may find that his ming near the surface, a few feet introduced predators are too effi- out from shore. As soon as these cient at control, resulting in nearly small fish become numerous, they a total loss of fathead production can be captured by a small bobbinet for the pond. If it becomes neces- seine and transferred to the grow- sary to resort to this method of ing ponds. The stocking rate in a population control, a successful growing pond should range between stocking rate is 50,000 feeder (1- to 300,000 and 600,000 fry for each 2-inch) creek chubs or golden shin- acre of water. At this rate of ers for each acre of water. stocking, the successful operator Intensive culture of fatheads re- will harvest a minimum of about quires many daily tasks. The water 150,000 salable fathead minnows level should be checked each day in annually for each acre of water. the ponds assuring the operator Growing-pond operatimi.—Dur- that both the inlet and outlet valves ing the first few weeks of life after are in operation. It is necessary to the fry is transferred to the grow- feed the fish each day and to fer- ing pond, its rate of growth is very tilize the pond when food alone rapid, and sometimes individual will not maintain a desirable plank- fish attain a length of li/^ inches. ton bloom. A productive pond Within 8 to 12 weeks, many of these should have a plankton turbidity in first-generation fish will mature and the water sufficient to blank out a begin to spawn. When this occurs, white surface at 12 inches. A feed-

and it frequently does, the propa- ing ratio demonstrated as success-

gator is confronted with a major ful for fatheads consists of 6 parts problem: If he allows this repro- gray shorts, 1 part low-grade flour, ductive activity to progress unat- and 1 part cottonseed meal. This tended, he will soon find that the diet is fed at the rate of 1 pound of

growing pond is overstocked and food for every 20 pounds of fish in that all of the fish are stunted. the pond. By feeding only a few When this situation arises, there are pounds of feed at first to a pond con- two corrective measures available. taining fatheads, an observing fish One is to remove the excess fry by culturist can easily determine each

82 FATHEAD MINNOW day how much food is to be applied risk of losing most of the fish by to eacli pond. If the plankton trying to get them all out. bloom remains about the same in the water from day to day and the fish Extensive culture of fatheads are growing, then the amount of The extensive culture of fathead food is sufficient. If the plankton minnows employs the use of much bloom becomes too intense and the larger ponds than are used in in- fish continue to grow, then he is tensive culture. Locating the site feeding too much; or if the fish are for a hatchery of this type is rela- not growing, the amount of food is tively easy, since the water supply too small. At the end of the grow- is not too important ; however, it is ing season, a successful propagator necessary to locate the hatchery on should not have used more than 1 soil that is composed of a tight clay pound of food for each 20 pounds loam capable of holding water. The of fish in any 1 day during the peak source of water is provided by rain- of growth. Also, if his operations fall, and the ponds are strategically were successful, he should not have located to pick up surface runoflf. used more than 6 pounds of food to The design of the hatchery usually produce 1 pound of salable fat- follows a characteristic pattern. It heads. consists of one or more large (20 to When about 50 percent of the fat- 30 acres in surface area) reservoir heads (by weight) in a growing ponds having a maximum depth of size inches pond attain salable (11/2 15 to 20 feet, surrounded on the or more in total length), it is de- lower-gravity side by several small sirable to remove as many as pos- (14- to 1-acre) ponds. sible by trapping, seining, or by The smaller ponds, in turn, are draining the pond, and to place the filled with water acquired by grav- fish in a pond by themselves. To ity flow from the larger pond above. drain a fathead pond during the hot In instances when the annual rain- sufficient to fill the reser- summer months, it is necessary to fall is not voir ponds, some operators resort to pull the water level down to about the use of a pumping system, ob- 1/5 of its original volume and to taining their water from a nearby triple the incoming flow of cool stream. The large reservoir ponds water, or, at least, to increase the usually have a bottom drain and an flow until all of the w^ater remain- emergency high-water overflow\ ing in the pond has a temperature The small ponds are supplied w4th 80° below F. If the water tempera- water from the large ponds by ture in a pond cannot be lowered to means of a series of contour ditches. this extent, it is better to seine or Very few of the smaller ponds have trap out as many of the salable fish bottom drains, and the operator as possible and to leave the others must cut a hole in the levee to drain in the pond, rather than to run the the pond, siphon the water out, or

83 SOME IMPORTANT BAIT FISHES

resort to a mechanical pump. in the growing pond has to be About the only advantage of this quite restricted. The same rule type of hatchery construction is its applies to fertilizing the ponds. relatively low initial cost and the During the midsummer period in ease with which the site can be ob- Missouri, the water temperatures tained. The disadvantages are that of reservoir-type ponds usually are during the warm summer months too high for continued fathead re- the operator must supply the ponds production. At this season, it is with cold water from a deep well or desirable to fertilize both the provide a holding station where brood ponds and the growing cold water is available to store his ponds with a combination of su- salable minnows. perphosphate and cottonseed meal

In the actual operation of an ex- ill equal proportions at the rate tensive type of minnow hatchery of 25 pounds an acre every 10

for fathead production, it is not days, or until a plankton turbidity necessary nor is it desirable to bal- colors the water sufficiently that a last the banks of the pond with white object cannot be distin- rocks for the breeding fish. Usually guished at 114 feet. If the pond the large reservoir pond is used for becomes too rich in organic mat- this purpose, and the water level ter, it is quite possible that all of may fluctuate as much as 10 feet the fatheads will die from oxygen during a season. Also, these large depletion. At best, it is more ponds usually contain enough rocks, practical to fertilize sparingly, and roots, and other debris to provide allow the natural fertility of the sufficient spawning structures for soil to determine the productivity the number of breeders introduced. of the pond. In stocking a pond with breeders, about 4,000 fish per acre are used, Harvesting and storing the fish consisting of about 60 percent If some of the fathead minnows adults and 40 percent juveniles. attain a salable size during the When the water temperatures in summer months, they can be re- the reservoir pond reach 65° F. moved by trapping or seining. In spawning occurs, and within a the fall or at any time during the week or 10 days fry appear on cooler seasons of the yeai-, the pond the surface. Within 8 to 4 weeks, can be drained and the entire pop- the fry should be sufficiently large ulation removed. These fish in and abundant enough to warrant turn can be graded as to size and transfer, by trap net or bobbinet stored for future sales, or they can seine, to the smaller growing be placed in different ponds for ponds. Since there is no assur- additional growth. The drained ance of an incoming supply of ponds can again catch the surface fresh water, the artificial feeding runoff, thus storing the next year's of both the breeders and the fish water supply.

84 CREEK CHUB

A minnow producer, using in- excessive icing during transit in tensive techniques, should be able warm weather. to harvest from 200 to 300 pounds Grading of salable minnows from each acre of water in production. This In grading the fathead minnow poundage converted into numbers for sale in Missouri, a box con- of fish would represent from 40,- structed of %6"ii^ch aluminum bars 000 to 70,000 fish. has proved satisfactory. The When removed from ponds, fat- mechanical graders are made in head minnows should be placed in two sizes: One, constructed to al- cool water for hardening before low the small unsalable fatheads to pass through the openings, has they are sold. The w^ater temper- a clearance between the aluminum ature in the storage vats should bars of i%4 inch; the other, to not be allowed to rise above 70° F. separate the larger size from the during the summer months, and smallest salable size, has a spacing the fish should not be confined at of i%4 inch between the bars (see this temperature for more than a fig. 23). In using these graders, v/eek. If the operator needs to two size groups of salable fish are for longer store the fatheads a obtained. The first group ranges period, it is desirable to reduce the in length from li/^ to 2 inches and water temperature to 65° F. Fat- averages about 325 fish to the head minnows can tolerate a 20° pound. Fish of the second size temperature change within a few group are from 2 to 31^ inches in minutes without any harmful ef- length and average about 225 to

fects. Also, these fish can stand the pound.

CREEK CHUB Semofi'/us atromaculatus Also called Horned Dace.

LIFE HISTORY hidden just above corners of mouth Desenption.—Blsick spot at base in groove behind underjaw; scales crowded at front of dorsal fin ; mouth large, extend- smaller and more on ing back to below eye ; small barbel end of body ; color, olive green

85 SOME IMPORTANT BAIT FISHES top, steel blue on sides, white on Though it spawns in moving wa- belly; size of females to 5 inches, ters, it grows very well in ponds and males to 11 inches. slow-moving streams. The adults Range a/tid breeding hahifs.— strip easily and the number of eggs This minnow is found most often is relatively large. This fish is ex- in creeks and rivers from Montana ceptionally suited to production in and Xew Mexico east to the Atlan- large numbers in artificial ponds. tic coast and south to Florida. The creek chub, sometimes called the PRODUCTION the tuber- horned dace because of The tenacity of life of the creek males develop during the cles the chub makes it a good minnow for breedino; season, spawns during handling, holding, and transport- in small April, May, and June ing. It can tolerate, to a consider- creeks, on gravel beds at the base able degree, exposure to sudden of pools, or at the head of riffles. changes in water temperature, but prepares and guards the The male the culture of this species is not an the breeding season. nest during easy task. A suitable spawning fish an excellent The young make area (running water in a gravel- growth in the first year, reaching bottomed stream) must be provided 3I/2 a length of inches by Septem- where natural spawning can occur, late in the ber. Those maturing or the breeders must be stripped fall the following season. spawn and the fertilized eggs incubated Food. The creek chub seems to — in a hatchery. eat anything that comes its way. It has been known to feed on algae, Preparing the spawning raceway vegetable matter, aquatic insects, When selecting a location for a terrestrial insects, crayfish, small creek-chub hatchery, it is most im- fish, fish eggs, chub eggs, snails, portant to formulate plans for the and small mollusks, and it oft^n number of minnows to be raised, so rises to a trout lure. Sometimes a as to determine whether a sufficient chub stomach will contain only sur- volume of water is available at the face drift. A study of 37 stom- location to operate the needed num- achs taken from fish collected in ber of raceways and rearing ponds. the eastern and midwestern United The general layout of an area States showed the average percent- for the culture of creek chubs con- age of the various food items to be sists of a stream emptying into a as follows: Insects, 51.3; mollusks, pool. The stream provides the

; crustaceans, ; fishes, cray- 3 0.8 5.4; spawning space, and the pool acts fish, annelids, 3; 2.1; surface drift, as a refuge area for the breeders 26; algae, 2.8 plants, 4.6; vegetable ; during the spawning season and debris and plant seeds, 1. ~ later as a collecting basin or a rear- Importance.—The creek chub is ing pond for the newly hatched fry. excellent bait for pike and panfish. In Ohio, a successful raceway pre-

86 CREEK CHUB pared for the propagation of creek netting over the stream bed for con- chubs consisted simply of a gravel- trol of predatory birds. bottomed stream and a base pool The main channel (6 feet wide, 1 confined within the basin of a pond foot deep, and 300 feet long) was covering an area 143 feet long, 13 dug within the basin of a 1.8-acre feet wide, and from 1 to 3 feet deep. pond. Starting at the inlet—fol- Starting at the inlet, the upper 24 lowing along the base of one of the feet of the pond was filled with fine dikes—the excavation gradually de- soil to create a steeper slope on scended (an 8-inch fall per 100 which a meandering channel (27 lineal feet) into the basin of the feet long, 27 inches wide, and 2 to pond. The materials removed from 10 inches deep) was prepared. At this ditch were placed on both sides places in the dirt fill where there of the channel, forming 1.5-foot was likely to be some washing by banks. At intervals of 25 feet current action, heavy reinforcing along the course, rectangular pits, material was used. The banks and 2 feet deep, 3 feet wide, and 8 feet bottom of the channel were covered long, were prepared. These pools, with a heavy layer of gravel. referred to as refuge zones, crossed Water supplied by an 8-inch inlet the streambed and extended into one passed down the stream channel of the banks for a distance of a.bout and into the base pool below that 4 feet (fig. 41, upper). That por- was formed by impounding the tion of the refuge zone extending water in the remaining portion of into the bank was curbed to prevent the original pond basin. its filling by erosion. In Michigan, a successfully used At this point of construction the creek-chub spawning raceway was entire stream, including those por- built within the basin of a pond, and tions of the refuge zones lying likewise consisted of a stream and within the channel and both banks, base pool ; however, the design of was surfaced with a 6-inch layer the stream was radically different of washed gravel (l^- and 3^-inch from that used in Ohio. The se- screened stones in equal propor- quence of the Michigan construction tion). About 38 cubic yards of 300- was as follows : (1) Excavating the gravel were used to surface the main channel; (2) installing refuge foot raceway. Immediately after zones at 25-foot intervals along the the spreading of the gravel, splash stream; (3) surfacing the entire boards (fig. 41, lower) were in- raceway with gravel; (4) installing stalled across the channel at each splash boards (check dams) at 25- refuge zone. These boards were foot intervals; (5) regulating the driven into the bottom soil to a stream flow, height of the splash depth of 1.5 feet and were exposed boards, and the water level of the about 3 inches above the gravel. base pool; (6) placing covers over The purpose of the splash boards a break the refuge pits; and (7) erecting was twofold : (1) To act as

87 —

SOME IMPORTANT BAIT FISHES

COVER OVER

^iLji'2Z:!:^Jf!li: ^OjMBM

- '''' y >^r^>V:*"<' ^W'^-^^;^-*?*' *^^' * **"f^

25 —

Figure 41. —Typical raceway construction for spawning creek chubs. Upper : Dia-

grammatic view of streambed and shelters. Lower : Cross section of spawning area. (Diagrams courtesy of the Michigan Department of Conservation.)

against the continuous current raised to the desired height. The resulting in the formation of areas outlet valve was then closed and the of slow and fast-moving water and water allowed to accumulate within thus simula.ting conditions i n the basin of the pond until it spawning areas in natural waters; reached a level even with the lower and (2) to prevent the refuge pools end of the stream (fig. 41, lower). from being filled by washing gravel. After the sluice boards had been To determine to what degree these installed in the outlet to maintain splash boards were accomplishing this height, the outlet valve was their purpose, the inlet valve of the opened and the overflow water al- pond was opened to allow 1.5 cubic lowed to pass through. Finally, feet of water per second to flow the refuge zones were covered with down the stream channel as a test. lids made of tarred paper and strips Some splash boards projecting too of lath and netting was stretched high above the streambed (forming over the stream. barriers) were lowered; others, too Anyone contemplating the propa- low to be effective in checking the gation of creek chubs need not con- current and preventing wash, were struct a raceway exactly duplicating

88 CREEK CHUB either of the two just described. cate that it is advisable to use 6- When constructing a spawning to 8-inch males and 5- to 6-inch stream, it is important to take into females for breeders. If larger account the ecological conditions males (7 to 10 inches in length) are affecting the breeding habits of the available and the total stock of creek chub, such as currents, pools, breeding males could be represented hiding places, and types of bottom by fish of this size, results should soil. As life-history studies show" prove satisfactory. Likewise, if that the creek chub prefers a certain larger females (6 to 8 inches in type of habitat (p. 86), it is desir- length) are available, they could able to provide these conditions as also be used. completely as possible. Raceway It is not advisable to mix small streams can be made any length de- (5-inch) mature males with larger (10-inch) males in the same race- sired ; the width does not necessarily have to be confined to 4 or 5 feet, way, because mortality occurs as a provided that a sufficient volume of result of fighting. Where small (3- water is available to operate effec- inch) females are mixed with larger tively a wider channel. Most im- (8-inch) females in the same race- portant is the water supply. The way, a prolonged spawning season water should be clear in color, have occurs, resulting in a loss of fry. a temperature range of 55° to 60° The larger females mature about 2 F. during the spawning season, and weeks earlier than the smaller ones, be free of other species of fish. and by the time the smaller females are through spawning, many fry Stocking the raceway have hatched and emerged from the earlier-formed nests. The presence the brood stock. Selecting —An of fry in the raceway and base pond operator selecting brood stock must before the brood stock is removed bear in mind that the male chub naturally complicates removal of the female; that grows larger than the fry. the mature male is distinguishable One more suggestion concerns the from the female by the presence of age of adult fish. Normally, only bony protuberances (horns) on the a few pond-reared creek chubs can head immediately before and dur- be expected to mature in their first ing the spawning season; and that year and be used as breeders. In the male is usually highly colored the second year, possibly 50 percent during the spring, having tinges will mature (depending on the rate of red on the paired fins and abdo- of growth, the larger fish being the men. In contrast, the adult female favored) as a result, most of is generally smaller and more drab more ; in color and has a swollen abdomen the brood stock will have to be se- during the spawning season. lected from older fish. In natural Results of Michigan studies in waters, female creek chubs nor- the selection of brood stock indi- mally do not mature until their

89 SOME IMPORTANT BAIT FISHES

fourth year and males their fifth. about 266 males if a 3 to 2 ratio were Creek chubs are not long-lived fish, followed. If 4- to 8-inch females rarely exceeding 6 or 7 years. were used, 300 would be needed Stocking rates.—Recommended with the corresponding ratio of stocking rates calculated on a the- males. The mortality rate of adult oretical basis derived from observa- creek chubs during the spawning tions and studies conducted in season has been exceptionally high, Michigan may not be entirely sat- sometimes amounting to as much as isfactory for all types of raceways. 75 percent. To be assured that an

It is believed, however, that a brood adequate supply of adult fish will stock should contain more females be available each spring, provision than males (approaching a ratio of should be made whereby a new 2 to 1 or 3 to 2). Furthermore, group of fish will be maturing each each female in stock composed of year. 3.5- to 7-inch fish should be pro- Results from creek-chub studies vided with 1.5 square feet of spawn- in Michigan indicate that with a ing area for egg deposition, and fair amount of success in fish cul- each female from a gi'oup composed ture, about 800 fry may be expected of 4- to 8-inch chubs, 2 square feet for every female creek chub intro- of area. In calculating the square duced in a spawning raceway. In feet of available spawning area in Ohio, each female introduced into a raceway, the margins along the a spawning raceway in 1941 gave a banks (about 3 inches on each side return of about 400 salable fish, and of the stream) and any areas used in 1942 about 450. Since we have for refuge zones or current deflect- some idea as to the spawning needs ing structures should be omitted. of the female chub and can roughly Generally, about one-fourth of the calculate the number of females total area will be taken up by these which will satisfactorily stock a structures. specified raceway, a crude estimate To illustrate, let us suppose that can be made as to the number of an operator had a raceway 200 feet females and the size of the raceway by 4 feet, and wished to determine necessary to realize a predeter-

the number of breeders it would ac- mined production. commodate. Assuming that one- There was considerable difference fourth of the total area would be in the size range of the fish pro- occupied by the banks, refuge zones, duced in individual ponds. Ponds and other structures, he would have that had a high production con- to make his calculations on the re- tained smaller fish than those of low maining 600 scjuare feet of stream- production. In ponds where the bed. If 3- to 7-inch females were average length of the chubs was used, about 400 of these and 200 about 2 inches, the number of fish males would be required if a sex per pound was 300. In other ponds

ratio of 2 to 1 were established, or where the fish averaged about 31/^

90 CREEK CHUB inches in length, the number per pound was reduced to 100 fish. In some ponds where overstocking had occurred, the minnows at the end of the growing season had an Average length of 11/2 inches. It was learned that when these unsalable fish were returned to growing ponds the next year, it took several weeks before growth was resumed. It seems that these fish had been stunted the previous year by the crowded condition. From this ex- perience it is suggested that an op- erator should be careful and not stock his ponds at the maximum rate. The following table presents the number of creek chubs of various lengths to the pound and gallon-

Length of fish (inches) :

SOME IMPORTANT BAIT FISHES number of breeders removed from and stored under refrigeration until needed. the pond each fall for the 4-year Whole glands were used in all experi- period, it was calculated that at nients, no attempt to separate the lobes least 30 percent of the males and 15 being made. Just before use, dried percent of the females die each year. glands were i)ulverized in a mortar and

mixed with distilled water ; frozen Stripping creek chubs glands were macerated to form a thick suspension in distilled water. No dif- In regions where natural ponds ference between the effects of frozen and dried pituitaries on fish was noted are used for minnow culture, creek- in any experiments. chub raceways are not practical be- cause of the lack of running water. Each ripe female received one- Fry for these ponds can be obtained fourth of a pituitary from a 2- more easily by stripping the adults milliliter glass hypodermic syringe of their eggs, fertilizing the eggs, supplied with a No. 19 needle. The and hatching them in jars. Until tip of the needle was placed under recently, ripe creek chubs were diffi- a scale, pushed through the belly cult to obtain and the green fish wall into the body cavity, and di- would not ripen in the ponds that rected parallel to the ventral sur- were available. face. Two men were required for

Michigan workers (Ball and the job : one to hold the fish ajid the Bacon, 1954) have been successful other to handle the needle. After in injecting creek chubs with carp injection, the chubs were held in pituitary to ripen them. The fish tanks in which water varied from then are stripped of their eggs, 46° to 64° F. At the end of 48 which are hatched in Meehan jars. hours, the fish were stripped and The pituitary Avas obtained from nearly all gave up their eggs. Fer- 6- to 8-pound carp by the following tilization of the eggs by the usual procedure hatchery method produced nearly a 100 -percent hatch. The head of the carp was removed, and the brain was exposed by removal of the Growing-pond operation dorsal surface of the brain case. The broad white ophthalmic nerve, attached As soon as the fry concentrating to the fore of the brain, was picked up in the base pool become conspicuous with a pair of tweezers and the entire and are grouped in schools along brain lifted up and laid back. The pitu- the shore, they can be collected with itary gland, a small organ resembling an

acorn, is located underneath the largest, a bobbinet seine and transferred to rounded portion of the brain. Occasion- rearing ponds. The removal of the

ally the gland will remain on the floor fry from the brood pond is a simple of the brain case. task. The creek-chub fry tend to The glands were either imme

92 CREEK CHUB

seine, one operator can collect up The records show that in the to 500,000 fry in a day. In collect- transfer of fry from the brood ing the fry, the operator carries a ponds to the growing ponds a high floating container tied to his wader survival can be expected. It also strap. In this manner, the small seems, according to the informa- fish are transferred from the hand tion available, that the rate of sur- net to the container without injury. vival is in direct proportion to the As soon as a sufficient number of stocking rate. Ponds stocked at fry is collected, the fish are trans- the rate of 50,000 to 200,000 fry per ferred in cans to the growing ponds. acre of water had about a 90-per- It is almost impossible to make an cent survival; those stocked at the accurate count of the number of rate of 250,000 to 400,000 gave a fry collected other than by hand return of about 80 percent sur- counting, which wovdd be an endless vival; and those ponds in which a job. About the only method for nuiximum transfer was made gave estimating numbers of fish would be a return of about 60 percent. to concentrate the fry in a container, Artificial feeding.—During the such as a tub, and remove them first 6 weeks of life, development with a quart dipper in which the of the chub fry is rapid in ponds estimated number per dipper had having a prevailing water tem- already been determined. Natu- perature of between 70° and 75° rally, there would be considerable F. In this period the fry readily error involved. eat fine-grained artificial food. By Stocking the groicing ponds.-— the end of the 6 weeks, most of The stocking rate of chub fry in these small fish will have reached growing ponds can be varied con- a length of about 11/4 inches, and siderably. In ponds where an op- there is a marked change in their erator can supply an incoming diet demands : they are no longer flow of about 150 gallons of spring interested in the fine food, but seek water a minute for each acre of larger food particles. The oper- Avater, he can stock at the rate of ator must now provide a pellet 600,000 fry to an acre and obtain type of food ranging in diameter a very satisfactory return. If the from i/i6 to i/g inch, or introduce incoming water supply is limited a small forage minnow, such as to about 25 gallons a minute for fathead fry. each acre of water, then it is de- A considerable amount of study sirable to reduce the stocking rate has been conducted on diets for to about 300,000 fry to an acre of the creek chub at commercial water. In ponds that do not have hatcheries, and at present the an incoming supply of water, the most satisfactory diet mixture con- operator should not stock heavier sists of 4 parts of gray shorts or than 50,000 fry to an acre of ground whole wheat, 3 parts of water. meat scraps or some comparable

367913 O—5e 93 SOME IMPORTANT BAIT FISHES animal protein, 1 part of cotton Harvesting and storing the fish seed meal or soya-bean meal, 1 The production of creek chubs percent of brewers yeast or wood in pounds or in numbers of salable yeast, and 1 percent of a mineral fish per acre of water has consid- supplement, such as that used in erable variation. The records livestock feeds. The small fish are from one commercial hatchery, given this formula in a dry, pow- covering a 4'year period starting dered form, and the larger fish are in 1949, show that the annual pro- provided with the same food pre- duction of salable creek chubs per pared in pellet form. acre of water varied from a low In feeding creek chubs, care must of 500 pounds to a high of 3,000 be taken not to overfeed. The op- pounds. It was found that when erator should watch the plankton only a portion of the fish are to turbidity of the water and be sure be removed and these are to be that the bloom will not mask a removed by trap or seine, then it w^hite disk at a depth of 24 inches. is not too important whether the The food can be fed to the fish water is cool or warm; but if the once each day or, in reduced pond is to be drained, it is very amounts, several times a day. desirable to lower the water tem- Usually, an acre pond with a good perature to about 70° F. before flow of spring water and a large any fish removal attempts are population of growing chubs will made. require about 50 pounds of food When chubs are removed from daily during the minnows' maxi- the growing pond to be placed in mum growing season. At the end storage vats for sale, they should of a growing season, a successful be held in water having a temper- operator should be able to realize ature of 60° to 65° F. By using a food conversion whereby 2 cool water in the storage tanks, the pounds of food has produced 1 chubs can be kept for a 2- or 3- j)ound of salable minnows. In week period without any ill effect. heavily stocked ponds where the Also, when chubs are in storage average length of the minnows will for any extended period of time, be smaller than those in lighter they should be fed the same type stocked ponds, the conversion ratio of food daily that they received will be about 4 to 1. in the growing pond.

GOLDEN SHINER Notemigonus crysoleucas Also called Roach.

LIFE HISTORY scales loose and easily visible; mouth small upturned, with no Description.—Body thin and flat and from side to side, deep from top to barbels; base of anal fin long, con- bottom; adult golden in color. taining many more than the cus-

94 GOLDEN SHINER

Length of fish (inches) ;

SOME IMPORTANT BAIT FISHES extending from the time the water man uses suckers for summer pike reaches 68° F. tlirough the rest of fishing. tlie summer. The eggs, which are adhesive and stick to plants, are PRODUCTION commonly scattered over filamen- The propagation of the golden tous algae and less frequently over shiner is conducted in extensive rooted aquatic plants. and intensive artificial ponds and Food. The golden shiner is — extensive natural ponds. Intensive omnivorous. The young feed on ponds are operated on the principle algae and entomostracans. The that greater production can be ob- adults have been known to eat young tained if the brood fish are main- fishes, insects, plankton, crusta- tained in a pond with ideal ceans, protozoans, algae, diatoms, spawning conditions and the fry and mollusks. Some stomachs con- are transferred to growing ponds as tain nothing but insects; some, soon as they are free swimming. nothing but plankton; others, 95 In an extensive hatchery, the fry percent algae ; a few had more than remain in the same pond with the 75 percent amphipods; and three brood fish until harvest time. contained 5 percent arachnids. The An intensive golden-shiner hatch- food percentages in golden-shiner ery should be made up of units that stomachs examined by a number of contain one large pond for spawn-

workers are as follows : Insects, 35 ing and three smaller growing plankton, 28.5; algae, plants, 13.8; ponds. When the ponds are sup- 5.3; amphipods, 0.4; mollusks, 1.9; plied with spring water, the grow- arachnids, 1.4; bryozoans, 1.4; ing ponds do not have to be adjacent rotifers and protozoans, 0.2; and to the brood pond. If the ponds crustaceans, 12. are maintained by surface runoff, Importance.—In Minnesota, this the growing ponds sliould be located shiner reaches a size for pike bait so the water from the brood pond in the fall of its first year. In can be used in the growing ponds. Michigan and Iowa, it has been pro- duced at a rate of more than 200,000 The brood pond used in intensive a water acre in fertilized ponds. operations should be free of vege-

The golden shiner is a popular tation so that the fry can be re-

m i n n o w with fishermen every- moved without difficulty. An ex- where. Tlie light color and general tensive production })on(l should

activity make it a good minnow to contain enough vegetation to i)ro- use for wa.lleyes. The greatest de- tect the fry from the cannibalistic mand for this minnow comes in the adults.

winter time when the Avater is cold. In the Northern States where

In warm weather, the golclen shiner pond construction is expensive,

is very delicate and is hard to keep golden shiners are raised in natural

alive in the bait ])ail so the fisher- l^onds (fig. 42). Usually they are

96 GOLDEN SHINER

raised in ponds that are too fertile Stocking the ponds for suckers, because the golden shiner can stand more adverse con- Golden-shiner breeders should be least 1 ditions. It is also desirable because at -year-old fish, ranging in most of the fertile ponds contain size from 31^ to 8 inches in length. masses of filamentous algae which About 50 percent of the brood stock provide plenty of places where the should be less than 5i/^ inches in shiners can deposit their eggs. The length ; or otherwise, the total stock best natural pond for the propaga- wnll be predominantly females, tion of golden shiners is 2 to 3 acres since the males are consistently the in size and 4 to 5 feet deep. The smaller. The stocking rate in large pond must be free of fatheads or ponds, where the fry will remain the spawning success of the shiners with the adults (extensive culture) will be poor. should range from 2,000 to 3,000 fish

ItJk.

Figure 42.—A productive golden-shiner pond in Minnesota.

97 SOME IMPORTANT BAIT FISHES for each surface acre of water. In of the pond. At this stage of de- ponds where fry removal is planned velopment, an operator can collect (intensive culture), the stockinfr these small fish with a fine-mesh rate of breeders should be 4,000 to net and transfer them to the grow- 8,000 adults per surface acre of ing ponds. By transferring the fry water. In Minnesota n a t u r a 1 to other ponds, he can realize about ponds, the stocking of 500 adults to twice the production of those ponds the acre has proved satisfactory. where the adults and fry are left to- gether. The reason for this in- Spawning creased production is due to the fact that the adults prey on the In Missouri, the golden shiner smaller fish throughout the season, starts spawning activity when the thus reducing the total population. temperature of the pond water rises If the minnow producer decides to above 70° F. If the temperature transfer the golden-shiner fry to exceeds 80° F., spawning ceases. growing ponds, the recommended In this State, the spawning activity rate is from 200,000 to 800,000 for of the golden shiner starts during each acre of water. Undeo" this the latter part of April or the fore- progi'am, a successful propagator part of May, and usually terminates can realize a production of 75,000 in early June. During this period, to 150,000 salable fish per acre of at least 4 or 5 distinct spawning water. In ponds w here the fry re- cycles have been observed. The main with the adults, 60,000 salable cycles are separated by periods of minnows for each acre of water is about 4 or 5 days. During the considered good production. summer months w^hen the water temperature in the brood ponds ex- Artificial feeding ceeds 80° F., there is no spa.wning Golden-shiner production ponds activity unless a cool rain reduces that contain only small fish intro- the water temperature sufficiently duced at the prescribed stocking to shock the fish into further spawn- rate (see above) can be fed daily a ing activity. diet of 8 parts of gray shorts, 1 part The spawning act usually starts of cottonseed meal, and 1 part of early in the morning and terminates tankage or meat scraps. In ponds before noon. The females deposit where there is no incoming fresh their eggs on any type of sub- water, the daily feeding, regardless merged debris. With a water tem- of the number of fish within the perature ranging between 75° and pond, should not exceed 10 pounds 80° F., the fertilized eggs will hatch for water. within 4 days after deposit. of food each acre of At A few days after the eggs are this rate, the operator should not fertilized very small fry can be ob- feed more than 4 days each week. served swimming in schools near In ponds supplied with an incoming the surface along the shore margin flow of fresh water, a daily food

98 GOLDEN SHINER

quota of up to 25 pounds to an acre dling. While it is possible to han- of water can be supplied. In all dle golden shiners in summer with instances, regardless of the feeding, special nets, the fish are too delicate the plankton turbidity of the water for the fisherman to carry in the should not be allowed to become minnow pail. Most of the fish dense enough to obscure a white ob- seined in the fall will have to be ject at a depth of less than 12 inches. held in large tanks or holding ponds supplied with running water Harvesting and storing the fish until they are needed for winter The harvesting of the golden fishing. shiner in Missouri and surrounding Production in g o 1 d e n-shiner

States is an exacting task, otherwise ponds varies more than that in severe injury will result in a high sucker ponds because shiner pro- mortality. When golden shiners duction not only is dependent on are to be seined from a pond during the rate of stocking and the amount warm weather, the seine should be of food available, but is primarily made of either a cotton netting or determined by spawning conditions

bobbinet m a t e r i a 1. The fish and spawning success. A pond trapped in the seine should not be with poor spawning conditions will rolled or crowded while bringing produce a small crop of fish, while them in near shore. When the a pond with good spawning condi- golden shiner is removed from the tions will produce a large crop. Of seine by a hand net made of a soft course, the fish from the last two or fabric, the fish should be trans- three spawnings will not grow ferred with a considerable amount large enough to be used the first of water. year, but most of the others will be

When the entire population is to suitable for winter fishing the first be removed by draining the pond, it winter. Optimum production in is necessary to lower the tempera- natural ponds probably can be ob- ture of the pond water to about 75° tained by removing the adults F. before undertaking the task. If from the pond after the fourth or the pond is such that the water can- fifth spawning. The production of not be cooled to this degree, the op- eight Minnesota golden-shiner erator should wait until weather ponds averaged 145 pomids an acre, conditions are favorable for the re- and the maximum was 390 pounds moval. In the reservoir type of an acre. AVhen the production was culture, many operators have to over 300 pounds to the acre, about wait until fall. 5 percent of the fish were pike-bait In Minnesota, natural shiner size minnows. When the produc- ponds should be harvested in the tion was around 150 pounds, 70 per-

fall when the weather is cool. The cent of the fish were pike-bait size. fish will .be of pike-bait size then When golden shiners are re- and hardy enough to stand han- moved from the ponds to the stor-

99 SOME IMPORTANT BAIT FISHES age vats, the storage water should tion and to approach the storage not exceed 70° F. During the first tanks quietly when attempting to 24 hours of storage, the fish are handle the fish. If he plans to con- highly excitable and react violently fine the salable golden shiners for to any sudden jar or fast-moving a 2- or 3-week period in holding object. It is well for the operator tanks, it is desirable to maintain a to take these factors into considera- water temperature of about 60° F.

GOLDFISH Carassius auratus Also called Indiana, Baltimore, and Missouri Minnow.

LIFE HISTORY well-meaning persons who tired of their care. Description}.—Mouth small but Goldfish normally start spawn- not sucker shaped; no teeth in the ing when the water reaches 60° F., jaws; dorsal fin with more than 10 and continue to spawn throughout rays; a smooth spine at the leading the summer if the temperature re- edge of the dorsal and anal fins; mains above 60° and the fish are scales large; no scales on the head, not overcrowded. The favorite cheeks, or gill covers. The male de- spawning time is right after sun- velops tiny tubercles on the sides of I'ise on sunny days. The female the head and front edges of the pec- lays the eggs on grass, roots, leaves, toral fins during the mating season. or similar objects. The eggs are In natural waters, goldfish grow to adhesive and stick to any object a weight of 3 to 5 pounds. they touch. The male fertilizes the Range and hreeding habits.—The eggs innnediately. The eggs are goldfish was originally imported clear when laid and turn brown as from Eurasia as an ornamental t hey develop. Dead eggs are cloudy aquai-ium lisli, but has since been and opaque. The eggs hatch in 6 introduced into ii:itui'al waters by to 7 (lavs in water of 60° ^. A fe-

100 GOLDFISH male goldfish may lay 2,000 to 4,000 sliould be repeated at 2- or 3- week eggs at one time and may spawn intervals until the pond is drained. several times during the season. Food.—Goldfish feed largely on Stocking the pond plankton, but will take insects and Medium-sized, uncolored goldfish very small fish. should be used for brood stock, be- Importance.—Many States pro- cause fish of that size reproduce well hibit the use of goldfish for bait and fish of that color are preferred because of the danger of intro- for bait. Brood stock that is over- ducing them into valuable game- wintered in crow^ded ponds will not fish waters. Experience in some of spawn in the holding ponds. Maxi- these States has shown the goldfish mum egg production is obtained by to be as vigorous as carp in destroy keeping the brood fish in the over- ing game-fish habitats. wintering pond until after the last The goldfish is a good bait fish spring frost. Then the fish can be to raise in the States where it is put in the production ponds with- legal. It is hardy and lives well out danger of frost damage to eggs in crowded pails even during hot or fry. weather. It reproduces in large The production ponds should be numbers and grows rapidly. Gold- stocked with 200 to 300 adults per fish of various sizes can be used as water acre. As the males can be rec- bait for most of the fish-eating game ognized by their tubercles, it is pos- fish. sible to stock equal numbers of PRODUCTION males and females.

In the southeastern United Spawning States, where the goldfish is legal Spawning is encouraged by plac- bait, it is perhaps the best bait fish ing a row of spawning mats near to raise. Even in the South, a (he shore of the pond. Spawning hatchery operator who plans to mats are wire-bottom frames filled propagate goldfish for bait should with moss, excelsior, or grass, that check the State laws that regulate fioat on the surface of the pond. minnow use and transportation. The fish lay their eggs on the bot- The best type of pond for gold- tom side. When the mats are fish is less than I/2 acre in size and moved to clean ponds to hatch 4 or 5 feet deep. Small ponds can the eggs, the sides of the spawning be harvested before the water be- with boards comes too warm and the oxygen pond should be covered the supply becomes too low for the fish. so the fish cannot spawn on Production ponds should be filled grass. If the eggs are allowed to early in March and fertilized at the hatch in the ponds where they are rate of 200 pounds of 8-8-6 ferti- laid, the adults will stop spawning lizer per acre. Similar applications when the pond becomes crowded

101 ;

SOME IMPORTANT BAIT FISHES

with yoiin^ fish. When the eggs fed all of the food they can con- aie moved to clean ponds to hatch, sume in 2 hours. the uncrowded adults will spawn all summer. Harvesting the fish Goldfish production will vary Artificial feeding according to the size and condition of the brood stock, number of dis- Goldfish pioduction can be in- ease organisms affecting the adults creased in most ponds by supple- and the young, amount and kind menting the natural food produced of fertilization, and the quantity by fertilizing with artificial food. and kind of su])plementary feed- Soybean meal, peanut meal, poul- ing. In general, ponds containing try mash, and cottonseed meal are both young and adults will pro- good supplementary foods for duce up to 100,000 fingerlings to goldfish. The food should be fed the acre. Intensive hatcheries at the same time each day and where a heavily stocked brood should be thrown into shallow pond provides fry for 8 or 10 water in the same place each day growing ponds, the production will so the fish become familiar with reach 200,000 to 300,000 bait fish the routine. The fish should be to the acre.

PEARL DACE Margariscus margarita Also called Leatherback Minnow,

LIFE HISTORY Range.—The pearl dace prefers cool lakes, bogs, and creeks. Its Description.—Robust minnow I'ange is through all Canada east snout blunt and head rounded; of the Kockies and the northern small but visible scales; mouth not I'nited States to New York. extended behind eye; color a dusky Hireding hahff.s.—]h: T. H. silver mottled by darker scales; no Laiiglois (V.yii)) reports that— large nui)tial tubercles, no black tlu' Xortheni Dace were .seen spawning pigment si)ots on Hus. The i)earl in a dear water stream of 1 V^ to 2 dace grows to a length erf at least feet deptli and !."» feet widtli, in or out ^1^ inches in 1 year, and reaches of the current, on sand or gravel bot- ;i maxiinuni of 7 inches. tom, witli the water temperature from

102 HORNYHEAD CHUB

63° to 65° F. * * * Each adult male ies rapidly * * * and * * the eggs maintains a small area of the stream and milt are * * * extruded * * bottom as his private spawning ground, since each female repeats the act many guarding it against intrusion by other times during the breeding season she males, and apparently restricting his must extrude but a few eggs each time. own spawning to it the major share Food.—The food habits of the of the time. * * * his brief perio'ds at pearl dace have received little at- home are spent nosing over the bottom as if seeking eggs to eat. The moment an- tention. From the studies avail- other dace reaches his vision he is .off in able, it seems probable that insects pursuit, but seldom ranges farther than are preferred, but the fish has been 4 feet from his home. If the stranger known to feed on phytoplankton, proves to be a male he is promptly es- mollusks, surface drift, and water corted away * * * * If the stranger should be a female, mites. and if she permits the male to drive her Importance.—It is possible that into his holding instead of fleeing, and the pearl dace can be reared suc- if, once there, she stays and permits cessfully in artificial ponds, and the male to pair with her, the process that bait sufficiently large for occurs in this manner. The two flsh come to a position side by side, close catching panfish could be raised to bottom, and, if there is a current, in one season. Because it makes a heading upstream. The oversized tu- fine growth in northern boggy bercle-roughened pectoral fin of the waters, this fish could be raised in male is slipped beneath the anterior northern areas in places where part of the body of the female, and his land is cheap. For dealers with tail is crossed over her back, just be- little working capital, this species hind her dorsal fin. * * * When this position has been reached both fishes seems to oifer excellent opportuni- vibrate the posterior parts of their bod- ties.

HORNYHEAD CHUB Nocomis b/guffafus Also called Redtail Chub.

LIFE HISTORY young (accounting for some call-

ing it the redtail chub) small Description.—Heavy, robust ; minnow; blunt nose; large scales barbels at corners of mouth; body olivaceoiis; large clearly outlined ; large diffuse black color usually spot at base of tail, tail fin red in tubercles on top of head and orange-

103 SOME IMPORTANT BAIT FISHES

red spot behind eye of breeding probably spawns with several fe- males. males. These nest piles are often Range.—The hornyhead chub is used by common shiners at the same a minnow of hirge creeks and small time, the males of both species rivers, preferring swift waters and guarding the nest. The male at- gravel bottoms. It is found in the tains a maximum length of about United States from North Dakota 10 inches and the females are smal- and Colorado east to the Great ler. This minnow requires several Lakes and the Hudson River, and years to reach maturity. south to Oklahoma and the Ohio Food.—The food of the horny- River valley. head chub is mostly insect larvae Breeding habits.—This chub and crustaceans. A summary of spawns late in May and early in several food studies made in New June on gravelly riffles in 1 to 2 feet York showed an average percentage of water at 65° F. or warmer. The of the following food items : Cray- nest is either a natural cavity in the fish, 5.6 ; mayflies, 11.1 ; caddisflies, stream bottom or one fanned out by 2.8; chironomid larvae and pupae, the fish. Mating activities and 29.4; miscellaneous insects, 7.8; stone carrying into the nest by

small beetles, 23.9 ; algae, 13,9 ; and males are alternated so that the peb- silt, bles and eggs are mixed in the nest. 5.6. Iniportance. The nest pile is large, often cover- —The hornyhead is ing several square feet of bottom, an excellent bait fish for pike, hardy and 2 to 6 inches deep. Each nest on the hook or in storage tanks, is occupied by a single male who and attains large size.

RIVER CHUB Hybop/s (Nozomis) m/cropogon

LIFE HISTORY of young sometimes amber but not

'"^^^ "" ''^'^ ^^ehind eye several Description.—hody robust, nose ' «P"^ ; blunt, scales large and easily seen, ''^I'Se tubercles on swollen forehead

similar to liornyhead chul), p. 103; oi breeding mules. It difl'ers from black spot at base of tail iiulistinct thelioinyliead chub in having an in- and of no definite shape; tail fin distinct black spot of no definite

104 —

BLACKNOSE DACE

shape at the base of the tail, no red 3 inches high, is accumulated all on the caudal fin, and in its prefer- in 2 to 5 days. Small spawning ence for larger rivers. troughs are then made by the male Range.—The river chub is found in the surface of this stone pile to in the eastern United States from receive eggs and milt as they drop New York to Virginia and in the from the spawning fish above. The Tennessee River drainage in troughs are filled again with peb- Georgia and Alabama, and north- bles immediately after spawning. ward to southern Michigan. Common sliiners, hornyhead chubs, Breeding habits.—The life his- and stonerollers may use the stone tory of the river chub is similar to pile for a spawning place at the that of the hornyhead chub. Ex- same time. cellent descriptions of the breeding Food.—The feeding habits of the habits of this chub have been writ- river chub are probably very simi- ten by Michigan investigators. Ac- lar to those of the hornyhead chub. cording to their observations, the The two species were thought to be male first digs a pit 12 to 15 inches the same for many years and very in diameter and 3 to 6 inches deep little work has been done on them in the streambed in water less than separately. 2 feet deep. Stones are removed by Importance.—The river chub is being carried away in the mouth. [)robably as important a bait fish

The male then fills the pit again as the hornyhead chub, and most with other stones until a heap of dealers do not distinguish between large pebbles, 30 inches across and them.

BLACKNOSE DACE Rh/nichf/iys atratulus Also called Slicker.

m^,m

LIFE HISTORY of body; black streak on side of body, extending forward through Description.—A c t i v e , stream- lined minnow, usually under 3 eye and snout; scales small but inches in length; color dusky or easily seen; small barbel clearly black above with pronounced freck- visible at each corner of moutli espe- les or dark spots over top and sides cially when the mouth is opened;

105 —

SOME IMPORTANT BAIT FISHES

fins short and rounded; dorsal set up over the female's tail to her dorsal fin, when vibrations cease. Occasionally behind pelvics. the pair remains in place and spawns Rcmge. This (hice is found in — again immediately, but usually they sep- clear, rocky streams from Virginia arate, the male darting forward while northward to the St. Lawrence the female relaxes limply onto one side, River, westward through the Ohio remaining there sometimes for several River system and Great Lakes' seconds. basin, to Nebraska, Iowa, and The milt and eggs may be

North Dakota. It is most abundant stripped from ri})e males and fe- in small, cool streams, and is rarely males, and artificial fertilization is taken from lakes or ponds. practical. The eggs are about i/^g Breeding hahit^.—The blacknose inch in diameter when spawned, dace spawns in April and May but quickly swell to about y^ of an when the water temperature of the inch. creek reaches about 75° F. The Food.—The food of the black- spawning site is located at the head nose dace varies according to what

of riffles. It frequently occupies the is available. Some workers have same riffles used by creek chubs found the diet to be 100 percent when the chubs are absent. Lang- insects while others have found it lois (1941a) comments on the to be at least '24 percent filamentous spawning activities: algae. Crustaceans, diatoms, and Avater mites are eaten when avail- Each male oct-upies a "holding" thouf^h able in large enough numbers. shifting around considerably. When a female enters a "holding:," the male goes I ni portanee.—The blacknose dace

to her and sometimes passes several is a fairly important bait fish in to times around her before coining a Minnesota where it is sold along lateral parallel position for spawning. with the longnose dace under the When side by side, the female vibrates name of slicker. It is a hardy min- her tail, sometimes nearly burying it can used in pike, bass, while doing so, and at the same time the now that be male's tail starts vibrating and curling and catfish fishing.

LONGNOSE DACE Rhini'chfhys cafaracrae

106 LONGNOSE DACE

LIFE HISTORY ern Mexico. It is found in small to moderate-sized streams, and is Description. The lonfjiiose dace — scarce or lacking in lakes. Usually lias an elongate and cylindrical found with the blacknose dace, its body. color is olive <;reen to The habitat preferences may be consid- above, with dark blotches on brown ered similar to that species. the sides, an indistinct lateral band, The longnose dace breeds in pale beneath. The upper jaw and A])ril and May over sand or gravel extends considerably beyond the bottom in clean, swift streams. lower one. In this fish, the air During this period the males have is or not fully bladder rudimentary considerable red on head, sides, developed. and fins. While the lontifnose dace reaches Food.—The food of 186 long- 5 inches, the .4 at the end of the fourth, and iiisects. 0.2 percent ; annelid worms, 0.9 inches at the end of the fifth 1 percent; algae, 0.8 percent; and this were year. The fish for study debris, 5.8 percent. collected in southern Minnesota Importance.—Like the blacknose trout streams. — dace, the longnose dace is used by Ranije and hreeding habits. anglers for bass and catfish bait. This species ranges from coast to This minnow has been propagated coast in northern North America, at least once in Minnesota and and southward in the interior to seems to do well in long, narrow Iowa, and along the mountains to ponds supplied with a very small North Carolina, and also to north- amount of running water.

FINESCALE DACE 9U\\\e neogaea Also called Rainbow Chub.

107 SOME IMPORTANT BAIT FISHES

LIFE HISTORY sippi Valley, and northern parts of noi'theastern Xnited States. Description.—R o b u s t minnow Food.—The limited food studies growing- to 5 inches in len,

NORTHERN REDBELLY DACE Chrosomus eos Also called Yellowbelly Dace and Leatherback.

LIFE HISTORY has been called "'leatherback" by sportsmen and minnow dealers. Description.—S m a 1 1 minnows Range.—Though their ranges averaging H inches in length; two slightly overlap, the bait dealer dusky lateral bands from head to can best distinguish the northern tail ; dark bronze color except for southern forms of the redbelly silvery belly of females, scarlet in and males; mouth small and pointing dace by the location of their cap- uj)ward at end of snout; lining of ture. The northern form is found body cavity black, intestine more connnoidy in bog ponds and slug- than twice as long as body. The gisli creeks from British Columbia scales are minute, and this species east to Nova Scotia, southward to

108 REDBELLY DACE southern Michigan, southern Wis- revealed the simultaneous matura- consin, southern Minnesota, the tion of several hundred eggs and Dakotas, Montana, and Colorado; the presence of at least two size and in portions of northeastern groups of maturing eggs. This United States to Potomac River suggests that one female has no drainages of Maryland. In Min- fewer than two distinct spawning nesota, it seems to j)refer acid bog periods during a season. The lakes; in Michigan, in addition to young, hatching early in the sum- its occurrence in bog lakes, it has mer, attain nearly adult size by the been found in small ponds show- end of the first growing season and ing a heavy growth of chara and spawn early the next summer. a rapid deposition of marl. Those hatching late in the season Breeding habits.—In the spawn- pass the first wnnter as small fish ing season, the males are brilliantly and require most of the next sum- colored. The abdomen is a beauti- mer to reach maturity, often not ful red, and the fins are highly col- spawning until their third summer. ored with red and yellow. Food.—Studies made in the St. The spawning habits, rate of Lawrence watershed of New York growth, and age at maturity have indicate that the northern redbelly

been carefully studied in Michigan. dace is mainly herbivorous, that it The eggs are deposited entirely feeds almost entirely on diatoms upon filamentous algae. One fe- and other algae, the remains of seed male lays from 5 to 30 nonadhesive plants, and only to a limited degree eggs scattered through and entan- on insects and animal plankton.

gled among the filaments. The fe- I rrvportanc e.— Experimental male darts from one algal mass to propagation of this species in Mich- another, laying eggs in each new igan has shown that 128,000 fish can mass. The eggs hatch in 8 to 10 be raised per acre of water surface. days at water temperatures of 70° The redbelly dace is best suited to to 80° F. Spawning takes place cool waters. This species does not from the latter part of May into reach a length of more than 21/^ August in southern Michigan. inches and is valuable only as bait Adult females, when dissected. for panfish.

SOUTHERN REDBELLY DACE Chrosomus eryfhrogasfer

LIFE HISTORY southern redbelly dace is more southern in range than its northern Description.—The southern red- relative, and has a decided prefer- belly dace differs from the northern ence for cool, gravelly creeks from form in its more horizontal mouth, Iowa, southern Minnesota through longer snout, and narrower caudal southeastern Michigan eastward to peduncle. Ohio River drainages of Pennsyl- Range and hreeding habits.—The vania and West Virginia, and south-

.S67913 O—56- 109 SOME IMPORTANT BAIT FISHES

ward in the Mississippi River valley major differences seem to be a pref- to the Tennessee River system in erence by this species for spawning Tennessee and northern Alabama, on gravelly bottoms and sele^-tion

tlie northern Ozarks in Arkansas of a more insectivorous diet. and Oklahoma, and the Missouri Importance.—In Minnesota, this River drainage in Kansas. dace is not as hardy as the northern The feeding and spawning habits species, but is frequently used as of this form are believed similar to bait for crappies in the southern those of the northern species. The part of the State.

EMERALD SHINK Nofroph oHierino/des

LIFE HISTORY year and 3 inches at the end of the second. Description. B o d thin and — y Food.—The food of the emerald streamlined, snout blunt; scales sil- shiner consists largely of insects, very colored, with no black pig- most of which are terrestrial. This ment, loose and easily removed; shiner has been known to feed on mouth large with thin black lips entomostracans, algae, small fish, running to tip of nose; dorsal fin fish eggs, terrestrial insects, aquatic behind point of pelvic-fin attach- insects, and oligochaete worms. ment; anal fin pointed (as is dor- The studies of several workei^s with sal) and containing about 9 rays. the lake emerald shiner show that, Range and breeding habits.—The in general, the food percentages are lake emerald shiner is found in as follows: Water fleas, 26.8; algae, large lakes and rivers, usually in 7.}); water boatmen, 1.0; nuiyflies, large schools in open waters. Its l.;^>; caddisflies, 2.1; chironomids, lange includes the larger glacial miscel- lakes in Hudson Bay, the Great 0.7; terrestrial insects, 7.9; Lakes drainages, and the larger laneous insects, 26.3; fish eggs, 2.9;

tributaries of the Mississippi River. crustacean debris, 10.7 ; and miscel- The emerald shiner spa\yns over laneous, 3.2. gravel shoals from the middle of Importance.—The emerald shiner May to early June. The fish aver- is often used for bait despite the

age 1% inches at the end of the first fact that it dies quickly and its

110 COMMON SHINER

scales come oft' easily. It is a jrood pike. Hardy in cold weather, this bait for bass, perch, and walleye fish is a favorite for winter fishing.

COMMON SHINER Notropls corn ufus Also called Skipjack.

LIFE HISTORY spawning on gravel shoals in quiet waters. The spawning season is silvery on Description.—Color short in Michigan, extending from belly alive; sides, white on when the latter part of May into June; scales large, high, and narrow on it begins somewhat earlier in Min-

; ; dorsal side of the body no barbel nesota's western w^aters. Studies pel vies; a fin inserted directly over in Michigan have shown that the size of 8 inches, or more, attained common shiner grows about 2 inches males. by the first year and requires 2 or 3 Range.—This minnow is common years to reach maturity. in nearly all cool creeks and lakes Little or no success has been ob- of northeastern United States. It tained in stripping the eggs from occurs from southern Canada along this fish. To raise this species, the Atlantic coast to Virginia ; cen- rearing ponds should be arranged trally, southward to northern Ala- to allow adult fish to swim up- bama, and westward from Ozark stream from the ponds to lay their to Arkansas region of Missouri eggs. The young will then drift River system in Arkansas and downstream and grow in the ponds, Oklahoma. as do other species. Breeding habits.—B r e e d i n g Food.—Only in the most recent males have large tubercles over the food studies have the subspecies of top of the head, and body and fins this minnow^ been considered sepa- are brightly colored orange and rately. Here, the food habits of pink. It spawns on stream riffles {frontalis) and the over gravelly bottoms, but its the northern con- abundance in some inland lakes southern (chrysocephalus) are may mean that it is successful in sidered together.

111 SOME IMPORTANT BAIT FISHES

The common shiner is omnivor- The studies of several workers show ous in its feeding habits. It has that, in general, the food percent- been known to eat algae, insects, ages are as follows: Insects, 37.2; plants, plank- fish, phxnts, entomostracans, hy- algae and other 39.9 ; drachnids, protozoans, and des- ton, 11.8; fish, 7.1; sand and silt, mids. Stomachs of this species 1.1; and miscellaneous foods, 2.9. have contained in some instances Importance.—It is used widely 100 percent insects; in other, 100 as bait for bass and pike, but is percent algae and other plants. one of the less-hardy bait fishes.

SPOTFIN SHINER Nofrop/s spifopferus Also called Blue Minnow.

LIFE HISTORY Breeding habits.—The spotfin shiner spawns from May to August Description. — Body thin from on gravelly riffles or over sandy side to side, deep from top to bot- shoals. The adhesive eggs are

tom ; dorsal fin with black pigment often laid on logs and dock pilings, on one or two membranes between in crevices of submerged tree

posterior rays ; breeding males often trunks, and even in old pails. steel blue wdth orange fins and Food.—The food of this shiner small, pointed tubercles snout; on consists mostly of insects. It has females and young fish silvery blue been knowni to eat both aquatic and in color. terrestrial insects, small fishes, vege- Range.—The spotfin shiner pre- table matter, small crustaceans, fers rapid-running streams, but is plankton, and carp eggs. Food sometimes found in clear, weedy studies by several workers show percent- lakes. It occurs from the eastern that in general, the food ages are as follows: Midge larvae, part of the Dakotas to New Eng- 17.5; mayfly nymphs, 6.2; insects, land, except in Lake Superior and 64.7; and miscellaneous, 11.5. its tributaries, and south in the cen- Importance.—The spotfin is a tral Mississippi basin to the Ten- good bait species for crappies and

nessee River drainage of Alabama, pike; it is active, and is hardy on and to central Missouri. the hook and in the live box.

112 ;

BRASSY MINNOW

BRASSY MINNOW Hybognathus hankinsoni Also called Grass Minnow.

LIFE HISTORY commonly in bog streams, and sometimes in lakes. Description. — Small minnow Breeding.—Little is known of its with large, easily removed scales; spawning habits, but adhesive eggs scales not small and crowded be- probably are scattered over bottom liind head ; brassy sheen on sides of sand, mud, or debris early in the rounded, body; snout blunt and spring when water temperatures mouth small; fins short, rounded reach 50° to 55° F. Growth is on tip and free edges; lining of slow and maturity probably is body cavity black, intestine (coiled reached at the age of 2 years with like a watch spring) more than a length of 2% to 3 inches. Larger twice as long as body. specimens may be raised in ferti- Range. One of the most com- — lized ponds. mon and widespread bait fishes of Food.—The food of the brassy the Great Lakes region, except minnow is varied. A summary of Lake Erie in Ohio; ranges from food studies made by two investi- Montana to southern Ontario, and gators indicates the following per-

the Lake Champlain region, south- centages : Zooplankton, phyto- 25.9 ; ward to Missouri, Nebraska, and plankton, 31.6; aquatic insects,

Colorado in the West. This min- 21.3 ; plants, 3.4 ; surface drift, 16.1 now is often found in small creeks, and silt, 1.7.

BLUNTNOSE MINNOW Hyborhynchus notatus

113 ;

SOME IMPORTANT BAIT FISHES

LIFE HISTORY head in the large, clearer lakes and firm-bottomed streams. In First obvious ray Descriptio7i.— Michigan, the bluntnose has been of the dorsal fin thickened, stand- called tlie most conmion minnow in ing out from followino; rays; scales inla.nd waters. Spawning begins small and crowded behind the head the latter part of May and continues mouth small, horizontal, a.nd under through August in Michigan, but tlie snout; back flat and straight; may begin 1 month earlier in west- lateral line complete from head to ern Minnesota. Water tempera- tail ; breeding male with a tiny tures of 70° F. or higher are neces- blisterlike swelling of skin at each sary before spawning takes place. corner of mouth, tubercles on snout A female may spawn a.t least twice only; spot at base of tail dark but in one season, and eggs are laid diffuse; body ca.vity lined with under any flat object on the bottom

black ; intestine less than twice body in water as deep as 8 feet (fig. 43), length. The males grow larger A depth of 6 inches to 3 feet is pre- females, attaining a maxi- than the ferred. A count of eggs in 10 mum length of 4 inches. females averaged 2,005 eggs per Range and breeding habits.— fish. The eggs hatch in 7 to 15 days. This minnow resembles the fathead The young reach marketable size minnow (p. 78) in appearance, by fall and spawn the following breeding ha.bits, and distribution. spring. The maximum age is about

It is more abundant than the fat- 4 years.

FiouBE 43.—Spawning boards strung in pond for bluntnose minnow.

114 ;

STONEROLLER

Food.—Because good keys for workers shows that, in general, the the separation of minnow species food percentages are as follows : In- were not available until recent sects, 15.9; crustaceans, 3.5; ento- years, much of the literature and mostracans, 2; surface drift, 10.7; the records of stomach contents for annelids, 0.5 ; zooplankton, 6.9 the bluntnose minnow has probably phytoplankton, 35; plants, 8.7; been confused with those of the fat- algae and diatoms, 4,9; and silt and head minnow. More recent studies debris, 11.8. indicate that the feeding habits of Importance.—T h i s minnow is these two species are similar; so the easily propagated and has been records, general as they are, could widely introduced. It has been apply to either species. propagated in Michigan at the rate bluntnose minnow is known The of 104,800 fish (250 pounds) an to eat diatoms, algae, aquatic in- acre. In general, this species seems sects, entomostraca.ns, fish eggs, fish less prolific than the fathead min- fry, and oligochaete worms. Oc- now, but in Ohio, 473,350 to an acre casionally this minnow will eat its of water have been raised. This young. Some stomachs of the species will not withstand crowding blunt-nosed minnow contain only in minnow containers so well as the phytoplankton ; others, only sur- fathead minnow. It is important face drift ; and others large percent- ages of insects, higher plants, zoo- as a food for game fish, because of plankton, debris, or silt. A sum- its preference for large lakes where mary of food studies by several jrame fish are abundant.

STONEROLLER Camposfoma anoma\Mm Also called Racehorse Chub.

LIFE HISTORY black crescent on dorsal fin of adults; large tubercles on top of DeHcription..—I'lump, sturdy males; lining of mrnnowTundersiung suckerlike li^ad of breeding mouth with horny ridge forming abdominal cavity black, intestine spirally the lower lip; scales large, some- very long and wound times flecked with black pigment; around air bladder.

115 ; :

SOME IMPORTANT BAIT FISHES

Range.—The stoneroller is a min- to eat algae, diatoms, small amounts now of creeks and small rivers, and of zooplankton, a few aquatic in- prefers rocky, shady streams with sects, and plant tissue. Sand and swift water. Of very wide distribu- clay are often found in the intes- tion, it is common in southern Mich- tinal tract, but are probably taken Minnesota, Wisconsin, igan, and along with the various foods. A is found from the St. Lawrence and study of 20 specimens from the southward to northern Alabama ex- Oswego River system (New York) cluding the extreme southeastern showed food percentages as follows United States, and westward from Midge larvae, 10; diatoms, 50; Wyomino: to Texas. algae, 10 ; and sand and silt, 80. Breeding hahits.—T his fi s h ImportaTice.—The stoneroller is spawns from May to June 15. tenacious of life, and is regarded as (yreat numbers ascend streams, where the bright-colored males ex- one of the best baits for bass. In cavate funnel-shaped cavities sev- Minnesota, it is widely sold under eral inches deep and guard these the name of racehorse chub. One and the eggs for a short time. The dealer has experimented with prop- stoneroller minnow reaches matur- agation of this minnow in shallow

ity during its second or third sum- ponds supplied with a slow-moving mer. Males attain a size of 6 inches current. The first attempts were

and females less than 5. moderately successful, but were not Food.—The stoneroller is chiefly on a large enough scale to be a bottom feeder. It has been known practical.

WESTERN MUD MINNOW Umbra llmi

LIFE HISTORY is not a true minnow, but is re- lated to the northern pike. It Description.—Tail tin rounded grows to a length of 5 inches. dorsal fin far back on body with hahits.— iibout 12 rays; dark vertical bar Range and, breeding at base of tail; scales on Head (no This species is distributed from other fish described in this section Manitoba through the Great Lakes l)ossesses scales there). This fish region to Quebec and Lake Cham-

116 :

WESTERN MUD MINNOW

pliiiii, southward in tlie central ach contents of others has been basin to the Upper Oliio River plant food. More than 50 percent system, and in northwestern Ten- of the food of some stomachs has nessee, nortlieastern Arkansas, and been mollusks, and in one collec- Kansas. It prefers sprino;-fed, tion 40 percent of the stomach con- soft -bottomed pools, and weedy tents was surface drift. streams and ponds. It is common Stomach analyses by various in bo^ijy or stagnant places. workers show^ed that the digestive Spawning- takes place in early tracts of mud minnows contained spring, usually upstream in small the following average percentages brooks. Insects, 45.6; amphipods, 11.1; en- hibernates in The mud minnow tomostracans, 16.3; mollusks, 12.3; the mud and will go dow^n 4 to 9 arachnids, 0.16; plants, 7.1; surface inches. It may be found in the drift, 4.6; algae, 1.4; miscellane- mud in a horizontal position or in ous, 1.24; and silt, 0.2. a vertical position with the head Importance.—The mud minnow upward. When alarmed, it usu- is very hardy, but is not a popu- ally buries itself in the mud. lar bait species, except in Wiscon- Food.—The food of the mud sin, as it is not very active. minnow is mostly of an animal nature. It has been known to eat Evermann (1901) had the fol- insects, spiders, mites, amphipods, lowing to say regarding this fish: entomostracans, snails, leeches, So pei'sistently do they cling to life

that it is really difficult to kill them. oligochaete w o r m s , nematodes, * * * Its unexcelled tenacity of life is, earthworms, rotifers, protozoans, however, about the only thing it has to and algae and other plants. A recommend it as a bait minnow. Its of the records indicates summary somber, unattractive color prevents it that mud minnows will take as being readily seen by game fishes, and much as 80 percent of their food its tendency to pull down or get to the also militates against it. But from insect fauna, some have taken bottom bass and pickerel and pike do some- 90 percent amphipods, others have times take it and, in spite of its de- 50 ])ercent entomostracans. taken ficiencies, the Mudfisli is a good thing to More than 20 percent of the stom- have in one's minnow pail.

117 BIBLIOGRAPHY

Allan, Philip F. 1952. How to grow minnows. Published by the author. Fort Wcjrth, Tex. 63 pp. Ambeus, J. L., C. M. Ambrus, and J. W. E. Harrisson. 1951. Pi-evention of Proteus hydrophilus infection (red leg disease) in frog

colonies. American Jour. Pharmacy, vol. 123, No. 4, p. 129. April. AMERICAN Fisheries Society.

1954. SympcjsiunL Research on tish diseases : A review of progress during the past 10 years. Trans. American Fisheries Soc, vol. 83, part II, pp. 217-349. Ball, Robert C, and Edward H. Bacon. 1954. U.se of pituitary material in the propagation of minnows. U. S. Fish

and Wildlife Service, Progressive Fish-Ciilturist, vol. 16, No. 3, pp. 108-113. July. Bauman, Aden C.

1946. Bait minnow production in ponds. Missouri Conservationist, vol. 7,

No. 6, pp. 2-5. June. Burrows, Roger E. 1949. Prophylactic treatment for control of fungus (f^aprolec/nia pnrasilica) on salmon eggs. U. S. Fish and Wildlife Service, I'rogressive Fish-Culturist,

vol. 11, No. 2, pp. 97-103. April. Cooper, Gerald P. 1935. Some results of forage fish investigations in Michigan. Trans. American Fisheries Soc, vol. 65, pp. 132-142. 1936. Age and growth of the golden shiner (Notemigotius cnjsolcucas auratuH), and its suitability for propagation. Papers Michigan Academy Science, Arts and Letters, vol. 21 (1935), pp. 587-597.

Davis, Herbert S. 1947. Care and di.seases of trout. U. S. Fish and Wildlife Service, Research Report 12. 98 pp. [Reprint.] 1953. (^ulture and diseases of game fishes. University of California I'ress, Berkeley and Los Angeles. 332 pp. DoDiE, John. 1948. Minnow propagation. Minnesota Department of Conservation, Bull. No. 13. 24 pp. EvEHtMANN, B. W. 1901. Bait minnow.s. Sixth Annual Report of New York Forest. Fi.sh and Game Commission (1900), pp. 307-356. Fish, Frederic F. 1938. Treat—think—and be wary, for tomorrow they may die. Some advice on the prevention and treatment of fish diseases. U. S. Bur. Fisheries, Pro-

gressive Fish-Culturist, No. 39. \)\i. 1-9. June-July. lf>47. A technique for controlling infectious di.sease in hatchery fish. Trans. American Fisheries Soc, vol. 74 (1944), pp. 209-222.

118 BIBLIOGRAPHY

Hasler, Arthur D., Hans P. Thomsen. and John Neess. 1946. Facts and comments on raisinfr two common bait minnows. Wisconsin Conservation Department, Bull. No. 210. 14 pp. HuBBS, Carl L., and Gerald P. Cooper.

1936. Minnows of Michigan. Cranbrook Institute Science, Bull. No. 8. 95 pp., illus. November. Irwin, W. H.

19— . Commercial production of bait minnows. Oklahoma A. and M. College, 4 pp. [Mimeographed.] Klak, George E. 1940. Neascus infestation of black-head, blunt-nosed, and other forage min- nows. Trans. American Fisheries Soc, vol. 69 (1939), pp. 273-278. Langlois, T. H.

1929. Breeding habits of the northern dace. Ecology, vol. 10, No. 1, pp. 161- 163. January. 1941 a. Bait culturists guide. Ohio Division Conservation and Natural Re- sources, Bull. 137. 18 pp., 5 figs. 1941 b. Observations on bait culture. Ohio Division Conservation and Natural Resources, Bull., pp. 18-19. August. Markus, Henry C. 1934. Life history of the blackhead minnow {Pimephalcs inomelas). Copeia

1934, No. 3, pp. 116-122. 1939. Propagation of bait and forage fish. U. S. Bur. Fisheries, Fishery Cir- cular 28. 19 pp., 10 figs. McKernan, Donald L. 1940. A treatment for tapeworms in trout. U. S. Bur. Fisheries, Progressive Fish-Culturist, No. 50, pp. 33-35. May-June. Meehean, O. Lloyd. 1934. The role of fertilizers in pondfish pro

RIellen, Ida M., and Robert J. Lanier.

1935. 1001 questions answered about your aquarium ; toy fishes—fresh, brackish and salt water, also your garden pool and terrarium. Dodd, Mead and Com- pany, New York. O'Donnell, D. John. 1947. The disinfection and maintenance of trout hatcheries for the control of disease, with special reference to furunculosis. Trans. American Fisheries Soc, vol. 74 (1944), pp. 26-34.

Prather, E. E., J. R. Fielding, M. C. Johnson, and H. S. Swingle. 1953. Production of bait minnows in the Southeast. Alabama Polytechnic In- stitute, Agricultural Experiment Station, Circular No. 112. 71 pp. January. Raney, Edward C. 1940. The breeding behavior of the common shiner, Notropis cornutus

(Mitchill). Zoologica, vol. 25, part I, pp. 1-14. 4 plates. 1941. Pond propagation of the silvery minnow, Hybof/nathiis rcgiiis Girard. U. S. Fish and Wildlife Service, Progressive Fish-Culturist, No. 55, pp. 43-44. November. [Abstract.] SCHAPEBCLAUS, WiLHELM. 1954. Fischkrankheiten. 3d edition. 708 pp. Akademie Verlag, Berlin.

119 BIBLIOGRAPHY

Spoor, William A. 1938. Age and growth of the sucker, Catostomus commersonnii (Lacepede), in Muskellunge Lake, Vilas County, Wisconsin. Trans. Wisconsin Academy Science, Arts, and Letters, vol. 31, pp. 457-505. Stewart, Norman H. 1926. Development, growth, and food habits of the white sucker, Catostomus comnnersatmii LeSueur. U. S. Bur. Fisheries, vol. 42, Document 1007, pp. 147-184. Svrber, Thaddeits. 1940. Propagation of minnows. Minnesota Department of Conservation, Divi- sion of Game and Fish. 22 pp. January 10. Van Cleave, Harley J., and Henry C. Markus. 1929. Studies on the life history of the blunt-nosed minnow. American Nat- uralist, vol. 63, No. 689, pp. 530-539. November-December. VioscA, Percy, Jr.

1987. Pondfish culture ; a handbook on the culture of warm water game fishes of the United States. Pelican Publishing Company, New Orleans, La. 260 pp., illus. Wascko, Harold. 1946. Notes on bait propagation. Ohio Division of Conservation and Natural Resources, Leaflet 156. 2 pp. [Mimeographed.] Wascko, Harold, and Ci^arence F. Clark. 1948. Pond propagation of bluntnose and blackhead minnows. Ohio Division of Conservation and Natural Resources, Wildlife Conservation Bull. No. 4. 16 pp. March. Washburn, George N. 1948. Propagation of the creek chub in ponds with artificial raceways. Trans. American Fisheries Soc, vol. 75 (1945), pp. 336-350. Wynne-Edwards, V. C. 1933. The breeding habits of the black-headed minnow {Pimephales promelas Raf.). Trans. American Fisheries Soc, vol. 62 (1932), pp. 382-383.

120 TABLE OF EQUIVALENTS

1 liter =1,000 milliliters or 1,000 grams. 1,000 liters =1,000,000 grams.

1 : 1,000 =0.1 percent.

1 : 10,000 =100 parts per million.

1 : 100,000 =10 parts per million. 1 part i^er mil-

1 i o n ( p. p. m.) — 1 gram in 1,000 liters of water. =1 gram in 264 gallons. = 1 gram in 35.5 cubic feet. =1 ounce (avoir.) in 28,350 liters. =1 ounce (avoir.) in 7,480 gallons. =1 ounce (avoir.) in 1,000 cubic feet. =8.34 lbs. per million gallons.

1 part per thousand (p. p. th.) = 1 gram per liter. =1 ounce (avoir.) per cubic foot. 1 part per 100 (1%) =1 gram in 100 grams of vi^ater. = 10 grams in 1,000 grams (1 liter). =37.8 grams in 1 gallon. =283 grams in 1 cubic foot. = 1 ounce in 100 ounces (avoir.) or 0.75 gallon. =10 ounces in 1 cubic foot. 0.5% solution-. =0.7 ounce per gallon. 1% solution__.=1.3 ounces per gallon of water. 2.5% solution-. =3.3 ounces per gallon.

121 INDEX

Aeration, 40, 41-42, 54, 55 Disinfecting, 37, 43-44, 61-62 Antibiotics, 55-56, 57 Dropsy, 58 Bacterial disease, 53, 55, 57, 58-59 Dry fallowing, 24 Baltimore minnow, 100 Emerald shiner, 110 Birds, control, 63, 87 Equivalents, table, 121 Black grub, 59-60, 63 External parasites, 52, 53, 54, 55, 57, Blacknose dace, 105-106 59-61, 62 Black spot, 59-60 Fathead minnow, 27, 78-85 Blue minnow, 112 Feeding, 27-28, 43, 45, 75, 77-78, 82-83, Bluntnose minnow, 113-115 93-94, 98-99, 102 Brassy minnow, 43, 44, 113 Fertilizing, 24-26, 49, 75-76, 82, 84, 101 Campostoma anornalum, 115 Finescale dace, 107-108 Carassius auratus, 100 Fin rot, 53, 55, 58 Catostomus commersonnii, 68 Flatworms, 59-60 Chrosomus eos, 108 Flushing diseased fish, 52-53 Chrosomus erythrogasler, 109 Fungus disease, 40, 42, 52, 54, 57-58 Chub: FuruncuJosis, 55, 56, 59 Creek, 85-94 Gear, care, 37, 43, 62 Hornyhead, 103-104 Gill disease, 53, 54, 55 Racehorse, 115 Golden shiner, 27, 94-100 Rainbow, 107 Goldfish, 100-102 Redtail, 103 Grading fish, 39, 76, 85 River, 104-105 Grass minnow, 113 Columnaris, 58 Hardening eggs, 71 Common shiner, 111-112 Hardening fish, 29-37, 76-77, 84-85, 94, Common sucker, 68 99, 102 Copepods, 55, 57, 61 Hatching eggs, 72-73, 92 Counting fish, 37-39, 73-74, 79, 91, 95 Herbicides, 46-50 Crayfish, 27, 65 Holding fish, 42-45, 77-78, 84-85, 94, Creek chub, 85-94 99-100 Dace: Horned dace, 85 Blacknose, 105-106 Hornyhead chub, 103-104 Finescale, 107-108 Hyhognathus hankinsoni, 113 Horned, 85 Hybopis (Nocomis) micropogon, 104 Longnose, 106-107 Hyborhynchus noiatus, 113 Northern, 102 Indiana minnow, 100 Northern redbelly, 108-109 Insect control, 62-63 Pearl, 102-103 InternaUtreatment, 56-57 Southern redbelly, 109-110 Intestinal infections, 56, 57 Yellowbelly, 108 Lake shiner, 44 Dams, 9-13 Leatherback, 108 Dipping diseased fish, 43, 44, 53-54, 57, Leatherback minnow, 102 58, 60 Live box, 29, 76 Diseases and parasites, 50-61 Longnose dace, 106-107 122 —

INDEX

Margariscus margarita, 102 Salamander, 64-65 Minnow: Salt treatment, 42, 51-52, 57. 60 Baltimore, 100 Seines, 29-30, 76 Blue, 112 Semotilus airomaculatus, 85 Bluntnose, 113-115 Shiner: Brassy, 43, 44, 113 Common, 111-112 Fathead, 27, 78-85 Emerald, 110 Grass, 113 Golden, 27, 94-100 Indiana, 100 Lake, 44 Leatherback, 102 Spotfin, 112 Missouri, 100 Silvery minnow, 27 Silvery, 27 Skipjack, 111 Tuffy, 78 Slicker, 105 Western mud, 116-117 Snakes, 63 Missouri minnow, 100 Sorting fish, 39, 76, 85 Muskrat damage, 65 Southern redbelly dace, 109-110 Nets, 34-37, 43 Spawning raceway, 86-89 Northern dace, 102 Spotfin shiner, 112 Northern redbelly dace, 108 109 Stocking: Notemigonus crysoleucas, 94 Adults, 26-27, 80-81, 84, 89-90, 97-98, Notropis atherinoides, 110 101 Noiropis cornutus, 111 Fry, 74-75, 80-81, 82, 93, 98 Notropis spilopterus, 112 Stoneroller, 115-116 Parasites, 50-56, 57, 59-61 Stripping, 71, 86, 92, 106, 111 Pearl dace, 102-103 Sucker, 68-78 Pfrille neogaea, 107 Sulfa drugs, 56-57, 59 Pimephales promelas, 78 Tanks, 40-44, 85, 94 Pituitary injection, 92 Tapeworm, 56, 57, 60 Plant control, 45-50 Tempering. See Hardening fish. Ponds: Transporting fish, 40-42 Artificial, 4-20, 103 Traps, 30-34 Growing, 45, 80, 82-83, 92-93, 96, 98 Tuff}' minnow, 78 Holding, 44-45, 71, 77 Turtles, 63 Natural, 21-22, 75, 76, 78, 92, 95, 96-97, Ulcer disease, 55 98, 99 Umbra limi, 116 Predacious fish, 63-64, 82, 87 Water supply, 5-7 Predator control, 62-65 Water temperature, 40, 42, 44, 54, 58, 69, Prolonged treatment, 54-56, 60, 61 71, 72, 79, 81, 83, 84, 85, 89, 91, Racehorse chub, 115 93, 94, 96, 98, 99, 100, 103, 104, Raceway, 86-89 106, 109, 113, 114 Weed Control, 45-55 Rainbow chub, 107 Weighing fish, 37-39 Redtail chub, 103 Western mud minnow, 116-117 Rhinichthys atratulus, 105 White sucker, 68-78 Rhinichthys cataractae, 106 Worms, parasitic, 56, 57, 59-60 River chub, 104-105 Yellowbelly dace, 108 Roach, 94 Yellow grub, 63

123 NOTES

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