165. Food Habits of Georges Bank Haddock

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FOOD HABITS OF GEORGES BANK HADDOCK

Marine Biological Laboratory

MAR 26 labS

WOODS HOLE, iViASS.

SPECIAL SCIENTIFIC REPORT- FISHERIES No. 165

UNITED STATES DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE EXPLANATORY NOTE The series embodies results of investigations, usually of restricted scope, intended to aid or direct management or utilization practices and as guides for administrative or legislative action, it is issued in limited quantities for official use of Federal, State or cooperating agencies and in processed form for economy and to avoid delay in publication United States Department of the Interior, Douglas McKay, Secretary Fish and Wildlife Service, John L. Farley, Director

FOOD HABITS OF GEORGES BANK HADDOCK

Roland L. Wigley Fishery Research Biologist

Special Scientific Report- -Fisheries No 165

Washington, D. C. January 1956

ABSTRACT

Stomach contents of 1, 287 haddock, each major food group in the diet was as - Melanogrammu s aeglefinu s, from Georges follows: Crustaceaiisracfa 33.1oo.i percent; Mol-i\ Bank were analyzed qualitatively and quan- lusca - 17 5 percent; Echinodermata - titatively. These specimens were caught 14 6 percent; Annelida - 9.9 percent; and by means of otter trawls during the period Pisces - 1.9 percent. April 1953 to February 1954. Canadian biologists have reported that The haddock's diet consisted principally haddock on the offshore Nova Scotian banks of sedentary or slow moving invertebrate fed predominately on fish. On Georges animals; benthic and epi-benthic forms pre- Bank crustaceans were found to be the pri- dominated. Small organisms were especially mary food; fish constituted less than 2 common in the food, presumably because the percent of the food volume . Other notable haddock's rather small mouth precludes tak- differences were disclosed in the dietary ing large items The percentage volume of composition of specimens collected from various parts of Georges Bank itself.

CONTENTS Page Introduction 1 Methods ...... 2 Results ...... 6

Food-type areas , 11 Georges Basin 11 Northeast Peak 13 Southeast Part 16

Evaluation of foods , . 16 Seasonal variation ,.,,,,.... 18 Size of food organisms ,.,...... ,.,,.: 21

Acknowledgments , . . 21 Summary ...... :...... ,...,.,.... 22

Literature cited , ...... ,...,. 22 Appendix: A list of organisms found in stomachs of Georges Bank haddock during this report period ...... 24

LIST OF ILLUSTRATIONS

Figure 1 . Collection stations and food-type areas on Georges Bank 3

Figure 2 . Regression of body length on stomach weight 7

Figure 3 . Composition of haddock stomach contents expressed as

percentage volume . . 9 Figure 4. Histograms of haddock stomach contents for each food-

type area , ..,..,....,.....,....., 14

. . . .

FOOD HABITS OF GEORGES BANK HADDOCK

invertebrate fauna in The Georges Bank haddock ( Melanogrammus sampling the bottom aeglefinus Linnaeus) fishery yields approximate- the areas where stomach samples are ly 94 million pounds o± fish annually. Production taken in order to relate the food captured of this weight of fish requires many more times by haddock with the presence of food organ- as much weight m food organisms . The fact isms. that the total production of haddock does not vary widely from year to year indicates a This report presents the results of the fairly reliable and constant supply of food. Is first year's study of haddock food habits. this food supply reliable? Is it always composed of the same species of organisms? Does European biologists Jmve long been in- it vary from season to season? Does it differ terested in the food habits of haddock and from one part of the bank to another? Is it they have carried out many investigations consistent from one year to another or are on this subject. Food studies of haddock there violent changes which affect the abundance taken from waters surrounding the British of new year classes as they begin their demer- Isles have been particularly numerous. sal existence? Are the movements of the had- Macintosh (1874), Trechman (1888), Smith dock over the bank influenced by variations in (1892), Scott, A. (1896), Scott, T. (1902), the available food supply? Are the haddock Todd (1905, 1907), Carr (1907, 19D9), selective in their food habits or do they take Bowman (1923), Ritchie (1937), and Jones anytking they can catch? (1954) are the most important contributors. They found echinoderms, moUusks, Georges Bank haddock are the fastest crustaceans, annelids, and fish to be the growing m the world. Is this the result of common foods of haddock in that area more abundant or more nutritious food? Some Ritchie (loc. cit.) made quantitative analyses of year classes grow faster than others . Is this of the stomach contents from thousands related to variations in available food? What haddock . His work is the most thorough species of fish compete with haddock for the study of haddock food habits that has been same foods and how detrimental is this com- made . Haddock from Scandinavian waters, petition? as xenorted by Idelson (1929), Blegvad (1917), and Poulsen (1928), were found to These are some of the questions which subsist largely upon mollusks, echinoderms, the food habits project of the North Atlantic annelids, and crustaceans . Food of haddock Fishery Investigations is attempting to answer from Icelandic waters has been reported by The initial work m this study is the examina- Thompson (1929), Brown and Cheng (1946), tion and analysis of stomach contents collected and Fridriksson and Timmermann (1950) primarily on commercial trawlers. No ex- Echinoderms and annelids were the pre- perimental design could be followed during dominant food Items; crustaceans, mollusks, this stage of the study when observers were and fish occurred less frequently. collecting stomachs wherever the fishermen happened to fish North American biologists have carried out comparatively few investigations per-

The second stage of this study calls for taining to haddock food habits , Haddock (1) sampling according to plan using the from Nova Scotian waters have been exam- Albatross in to fill in where samples from ined by Willis (1890), Needier (1929), -commercial trawlers are lacking; and (2) Vladykov (1933), and Homans and Needier . .

(1944). The-principal foods were fish, ech- of Cape Cod, Massachusetts, known as inoderms, moUusks, and annelids . The work Georges Bank. Most of the samples were by Homans and Needier (loc cit.) is the most taken from the northern and eastern parts complete food habit study of haddock from of the bank, which are the areas most heavily North American waters. Specimens from the fished by the commercial haddock-fishing coastal waters of Maine were found by Atwood fleet . The location at which each collection (1865) and Kendall (1898) to feed chiefly on was made is plotted on the chart shown in brittle- stars, sea urchins, andmollusks. figure 1 . Specific information concerning

From haddock taken in coastal waters of each collection is listed m table 1 . All southern New England, Verrill (1871, 1873 = specimens were collected with standard otter Baird 1889) reported moliusks, echinoderms, trawl gear operated from commercial fishing crustaceans, and annelids trawlers and the research vessel Albatross lU.

Bigelow and Schroeder (1953), in refer- This report is based upon the content ence to haddock inhabiting the Gulf of Maine analysis of 1, 287 haddock stomachs from 38 (Georges Bank included), state that large collections taken during the 1 1 -month period crustaceans, a great variety of gastropods April 1953 to February 1954. An attempt and bivalve moliusks, worms, starfish, sea was made to collect stomachs regularly urchins, sand dollars, brittle -stars, and sea throughout the year . However, samples are cucumbers all enter regularly into the had- lacking for August and November because dock's dietary, Homans and Needier (1944) commercial fishing"within the study area was examined 179 small (10 - 30 centimeters) too light to afford an opportunity to obtain haddock from Georges Bank. The stomach samples contents consisted entirely of the shell-less gastropod Aeolis papillosa Stomach contents Haddock utilized m this study ranged in of 1, 500 haddock, also taken fiom Georges size from 14 to 75 centimeters In length. The

Bank, were examined by Clapp (1912) . Sixty- length -frequency distribution of these fish is eight species of moliusks are the only items listed in table 2 . Most of the specimens were listed. Clapp also observed that in certain between 30 and 75 centimeters, which is the parts of the noithwest portion of Georges same size range of haddock captured by com-

Bank the haddock feed heavily upon annelid mercial trawlers . Inasmuch as the smaller worms o specimens, those between 14 and 30 centimeters, were not commonly caught by It is apparent from the foregoing litera- standard gear, few specimens within that ture review that a comprehensive study of size range are represented. the food habits of haddock from Georges Bank - one of the greatest haddock producing areas Because detailed analysis of the stomach

- in the world has never been undertaken . It contents was required, the stomachs were is the purpose of the present report to record collected at sea and brought to the laboratory

the kinds of orgamsms Georges Bank haddock for examination . Aboard ship, stomachs prey upon and, more specifically, to evalu- were removed from haddock and placed in a ate the relative importance of various groups plastic bag containing 10 percent formalin. of organisms in the dietary. All stomachs from one collection were placed

in the same container , A label bearing the METHODS date, location, water depth, time of capture, and cruise number was attached to the con-

This study was geographically restricted tainer . Since the procedure for collecting to that portion of the continental shelf east stomachs from haddock on commercial vessels 72° Table 1. —List of haddock stomach collections Table 1.—List of hi ......

did not include measuring the body length of of marine invertebrate animals were repre- each fish, an alternative method had to be sented in their diet A large majority of employed. Several methods for estimating the organisms in the haddock's dietary were body length from the size of stomach were sedentary or slow -moving benthic animals. tested. Body length estimates based upon Crustaceans were the primary food, Moi linear measurements of the stomach proper lusks, echinodeims, and annelids comprised were lejected because rather large errors a substantial, but secondary, share of the

resulted from their use. Gravimetric meas- diet . Fish were a minor component in the urements were found to be fairly accurate, haddock's diet The major categories of because even though the stomach dimensions the stomach content components for all varied according to the quantity of food with- specimens examined in this study are listed

in It, the weight of the empty stomach re- in table 4 and illustrated in figure 3

mained constant . The relationship between body length and stomach weight was deter- Items of subordinate status in the had- mined from measurements on 325 haddock dock's dietary were grouped together under (table 3). A regression of this relationship the heading Miscellaneous. These items is plotted in figure 2 and the standard devia- consisted of 5 food categories and 2 non-food

tion from regression (or standard error of categories . The food categories were: the estimate) is indicated by the dashed lines. Brachiopoda, Coelenterata, Nemertea, The regression formula is log Y = - 0.0498 Turbellaria, Urochorda, and unidentified / 0.3557 log X and the correlation coeffic- animal flesh. Non-food categories were: ient is 0.972. It was possible to estimate parasitic nematodes and sand and stone the body length of a haddock by simply weigh- Individually these miscellaneous groups were ing the empty stomach and referring to the not especially abundant in the diet, but to-

graph . Since only approximate body lengths gether they constituted a significant share were required for this work, the method worked out very satisfactorily Mucus was designated a major classifica- tion heading because of the large quantities

In the laboratory the stomachs were (9 . 4 percent) encountered in the stomach

opened and all contents removed for exam- contents. It was usually yellow in color and ination. The food mass in each stomach was its consistency varied from cream- to jelly- measured volumetrically by water displace- like . Inasmuch as fish are known to possess ment. Food items were sorted to the lowest mucus -producing glands in the mouth and category to which they could be identified. pharynx, to provide a food lubricant, it They were then counted and the volume of seems likely that most of the mucus recovered each item was estimated. The volume of from haddock stomachs originated in their large items was measured in order to obvi- mouth and pharyngeal region and was swal- ate large errors due to estimation. When lowed with their food. numerous amphipods and small annelids were encountered, estimated totals were The unidentified material encountered in arrived at from counting a small sample the stomach contents was composed of approximately equal parts of relatively undigested RESULTS fragments of invertebrate organisms and rather well macerated matter of undeter- Georges Bank haddock were found to be mined origin exceedingly omnivorous in habit. Three species of fish and nearly all major groups One outstanding feature of the food 80

tr 60

50 oUJ

X 40 o z UJ

30 >- Q O CD

10 15 20 25 30 35 STOMACH WEIGHT (GRAMS)

Figure 2. --Regression of liody length on stomach weight. (Standard deviation from regression, which includes approximately two-thirds of the observations, are indicated by the dashed lines.) Table J. —Body (for':) length and empty stomach weight of 325 haddock

Bod;' Stomach Body Stomach Body Stoniach Body Stomach Body Stomach Body 3toniach length weight length weight length weight length weight length weight length weight

(centi- , , (centi- . / , , . , (oenti- , ^ (centi- (centi- (centi- , (S'^^^'^^ ^^^^^^^^ ^Srams) (grams) (grams) (gramas) meters) meters) meters) ^^^^^^^ ^^^^^^^ ^^^^^^^^

14 Figure 3. --Composition of haddock stomach contents expressed as percentage voliome. —

Table 4. Stomach content composition of Georges Bank haddock ......

habits of Geoiges Bank haddock levealed by or (2) because they have been encountered this study was the noticeably small quantities in haddock stomachs from only one area, of fish in the diet. In view of the finding of even though present in small quantities . The Homans and Needier (1944) that haddock on location and delineation of each food-type the Nova Scotian banks feed heavily upon fish, area is diagrammed m figure 1 , A modifica it was more or less expected that Georges tion of these areas will no doubt be necessary Bank haddock would have a somewhat similar when the food habits of haddock inhabiting the diet . The food of haddock from the Nova central and western parts of the bank become Scotian banks was reported to consist of 53 .0 known percent (by weight) fish, nearly all of which was made up by one species, the sand launce, Georges Basin

Ammodytes americanus DeKay . In contrast to this, fish made up only 1 9 percent (by Adjacent to the northwestern perimeter volume) of the diet of Georges Bank haddock, of Georges Bank the ocean bottom forms a and the sand launce constituted only a small channel-like depression known as Georges part of this amount. The explanation for such Basin. Its depth is approximately 125 fathoms diverse food habits of haddock on these adja- and the substrate is composed mostly of gray cent offshore banks will not be forthcoming mud and sand. Food habits of haddock from until more information is obtained on the ben- this area are known from the stomach analysis thic fauna. of 1 16 specimens from 4 collection stations Mean body length of the specimens was 57 FOOD-TYPE AREAS centimeters; mimmum and maximum length were 45 and 75 centimeters, respectively. Haddock collection stations were cluster- Their average stomach content volume was ed in three more or less separate geograph- 3.33 cubic centimeters. Stomach contents ical areas of CJeorges Bank (figure 1) . From of the Georges Basin samples are itemized stomach analyses made so far, the foods in table 5 eaten by haddock m each area were sufficient- ly distinctive and consistent enough to warrant Georges Basin haddock ingested enor- the establishment of three food-type areas. mous quantities of ophiuroids (brittle- stars). These areas and the orgamsms characteristic Annelid worms and urochordates were taken of each are as follows: in moderately small quantities , Relatively minor amounts of crustaceans, moUusks, Georges Basinl': Parathemisto (amphipod) fish, and echmoderms other than the Cuspidaria (pelecypod) Ophiuroidea were eaten by haddock in this particular area Northeast Peak: Hyas (toad crab)

Eunice (annelid) The food items of outstanding importance ^ to the Georges Basin haddock., both in number Southeast Part: Echinarachnius (sand dollar) and volume, were the Ophiuroidea. They con-, Byblis (amphipod) stituted 47.2 percent of the total volume and were present in 43 percent of the specimens These index organisms were representative of Species of brittle-stars most frequently en- the specific area either (1) because of their countered were: Ophiura lobusta Ayers, occurrence in large quantities in haddock Ophiura sarsi Lutken, and Ophiopholis stomachs from one particular aiea, even aculeata (Linnaeus). Other groups of echmo- though found in small quantities in other areas. derms, namely, the echinoids, asteroids,

V -Names applied to areas of Georges Bank were taken from U.S. Coast and Geodetic Survey Chart number 71 11 Table ......

and holothurians, made up less than 5 per- 100 fathoms, although most of it is between cent of the stomach contents 40 and 50 fathoms . Sand with gravel and shell fragments aie the predominant sub-

Unusually small quantities of crusta stiate components . Food habits of haddock ceans were found in the diet of Georges from this food-type area were determined Basin haddock. In samples from the iNjorth- from the stomach analysis of 639 specimens east Peak and Southeast Part, crustaceans from 15 collection stations . Mean body constituted 30 to 40 percent of the food, in length of these haddock was 46 centimeters; contrast to 5 percent found in the Georges extremes m length were 14 and 75 centi-

Basin samples. Euphausiids were represent- meters . Their average stomach content ed by a single species, Meganyctiphanes volume was 1 . 93 cubic centimeters norvegica M. Sars. Although this species was found in haddock from the Northeast Crustaceans were the primary food of Peak, it was much more common in Georgps haddock in this aiea, followed closely in im-

Basin samples . Hyperiid amphlpods were portance by the mollusks and echinoderms comparatively abundant in Georges Basin had- Annelids, fish, and the miscellaneous animal dock, and one species, Parathemisto com- groups made up only a small portion of the pressa (Goes), was one of the animals dis- diet o In table 6 the frequency, number, and tinctive to this food-type area. volume of the food organisms are enumerated.

Pelagic tunicates, listed under the head- Decapod crustaceans were an especially ing Urochorda in the miscellaneous group, common food of haddock from the Northeast were rather common food items in diis area Peak . They alone accounted for 22 . 1 per- They provided 8.2 percent of the food for cent of the total stomach -content volume.

Georges Basin haddock . The aggregate form The toad crab, Hyas coarctatus Leach, was of Salpa zonaria (Pallas) was the predominant the decapod taken in the greatest quantity species Because of the large amount of toad crabs eaten, and because their occurrence in the Even though haddock from this food-type diet was restricted to the Northeast^eak, area were large and thereby better adapted this species was selected as one of the index for engulfing fish, only an insignificant organisms characteristic of this food-t3?pe quantity of fish or fish remains, 0.5 percent area . Cancer irroratus Say, Pandalus by volume, was present in their diet. borealis Kroyer, Dichelopandalus leptocerus (Smith), and several species of Pagurus were

Histograms illustrating the percentage other crustaceans prominent in the diet , volume of the stomach contents of haddock from each food-type area are presented in Among the mollusks that were preyed figure 4. Differences in stomach -content upon by haddock, the squid, Illex illecebrosus composition of Georges Basin haddock as Lesueur, made up the greatest volume but compared with other areas are readily appar- were taken by relatively few haddock . Gastro ent. pods and pelecypods occurred in approximately equal amounts, with each providing slightly Northeast Peak more than 5 percent of the food. Anachis haliaeeti Jeffreys, Cerastoderma pinnulatum The most easterly portion of Georges Conrad, Astarte undata Gould, and Placo- Bank, including nearly one -fifth the total pecten magellanicus Qmelin were some of the bank area, is designated the Northeast Peak. species frequently eaten. It was interesting Water depths in this area range from 30 to to note that the only portions of the sea scallop,

13 50r

40-

GEORGES BASIN 30-

so-

50r

30- NORTHEAST PEAK

t^ 50

PART 30 SOUTHEAST

LM-^^'JI

c^^ ^> .^^^ .tv^ ?^^ .ov^ a^^ .^^^ .v^\ J" ^' i<^

Figure ^4-.- -Stomach contents of haddock from three food-type areas.

. . . . . -. -,

p. magellamcus , found in the haddock's diet quency of occurrence as well as in volume were the soft body parts with the notable ex- One particular species of amphipod that ception of the adductor muscle. There is occurred in enormous numbers was Byblis heavy fishing for sea scallops in riie North- gaimardii (Kr5yer). Other species frequent- east Peak area . And on board ship the ad- ly encountered were: Monoculodes edwardsi ductor muscle IS removed and the remainder Holmes, Leptocheirus pmguis Stimpson, and thrown overboard. Apparently it was the re- Unciola irrorata Say mains of scallops discarded by scallop fishermen that were eaten by the haddock. Mollusks commonly eaten by haddock in this part of Georges Bank were: Colus

Fish constituted 2 . 6 percent of the diet pygamaeus Gould, Yoldia thraciaeformis and were present in 4 percent of the speci- Storer, Y, sapotilla Gould, and Solemy velum mens . This quantity of fish in the diet is Say (and/or S . borealis) . Very few living slightly greater than the average for Georges gastropods were eaten by haddock . In nearly Bank as a whole all instances the gastropod shells were in-

habited by hermit crabs . Invariably all shell Southeast Part bearing mollusks found in haddock stomachs were of small size Most specimens were A large area in the south central portion less than 5 and 15 millimeters in height and of Georges Bank has been designated the length, respectively. Southeast Part. Most of this area lies between the 30 and 50 fathom isobaths. Sand The sand dollar^ Echinarachnius parma is the major substrate constituent with admix- Lamark, was the predominant echinoderm tures of shell fragments and gravel from in the food of haddock from this area . This place to place . The food habits of haddock in species was most abundant in the samples this portion of Georges Bank were determined from the western end of the Southeast Part. by stomach analysis of 532 specimens from Again, only the small (3 - 20 millimeters in

19 collection stations . Mean body length of diameter) specimens were taJcen by haddock these specimens was 39 centimeters; ex- Large specimens or pieces of large speci- tremes were 16 and 75 centimeters. Their mens were not observed m the stomach average stomach content volume was 2 . 41 contents cubic centimeters. EVALUATION OF FOODS Crustaceans were the major foods of pad- dock in this area . Mollusks and annelids Three criteria were employed for deter were of secondary importance and echino- mimng the importance of the various food derms, fish, and miscellaneous groups were items that were found in stomachs of haddock of minor valu6 . The number, frequency, They were as follows: (1) Percentage volume and volume of each group of stomach contents the volume calculated from the total stomach are recorded m table 7 contents of all haddock representing the particular area or season under discussion, and

Amphipods and decapods were the pri- expressed as a percentage . (2) Frequency of mary crustacean forms preyed upon by occurrence - determined by counting the num- haddock in this area. The amphipods pro- ber of stomachs in which the item occurred - vided 34.0 percent of the total stomach in the area or season . (3) Number of organ content volume and the decapods 5.3 per- isms - a summation of the number of speci- cent . Considering all food groups, the mens of each item found in the stomachs-. ampkipods ranked first m number and fre- In the calculation of averages and percentages

16 Fable StoiTiach contents of 532 haddock from the Southeast Part of leorf^os Canlc . . . . .

all stomachs were included. Some authors SEASONAL VARIATIONS have omitted empty or nearly empty stomachs m their calculations Haddock captured during the spawning period exhibited a pronounced decrease in

The percentage volume method is undoubt- stomach content volume . Because of the edly the best single criterion for evaluating conflicting evidence on this subject it has the relative importance of foods . It was the been uncertain whether or not haddock abstain only method employed in this investigation from feeding during the season for spawning. which gave a measure of the bulk or mass of Information gathered by Welsh (Bigelow and the various items. "The frequency of occur- Schroeder, 1953) in 1913 indicated that had- rence and number of organisms yielded a dock are apt to fast during the spawning useful indication of the availability and quan- season. This contention was supported by tity of the orgamsms eaten. A well-rounded Homans and Needier (1944). The opposite assessment of the comparative value of each situation was found by Needier (1930). He food item can be gained by taking into consid- reported spawning haddock of both sexes with eration all three methods described above well filled stomachs . Studies conducted by Vladykov and Homans (1935) and Ritchie Certain species of animals were much (1937) found an intermediate situation to exist, more prevalent in the diet than others . No in that only a decline in feeding took place doubt the abundance and availability of particu during the spawning period rather than a com- lar orgamsms to the haddock were important plete cessation. This last view is corrobo- factors contributing to the quantity eaten rated by the data obtained in this investigation Possibly the haddock's preference for particu- (table 8) lar Items was another factor affecting the quantity taken . Evidence to resolve this Distinct seasonal trends in diet composi- question of species abundance has not been tion weie not evident although some rather ascertained and must await further investiga- wide variations occurred from month to tion. And, as explained previously in this month . An insist to seasonal trends in di^- report, there was considerable variation in ary components was gained by comparing the dietary components from one location to an- stomach content composition of specimens other, but considering the entire area studied taken during six different months from the 11 species of ammals were especially import- Northeast Peak, namely, duiing April, July, ant in the diet. Judged aocording to the num- September, October, January, and February. ber, frequency of occurrence, and volume the Data from this analysis are presented in following species were considered to be the table 9 most important foods of Georges Bank haddock: Four of the more obvious monthly iriegu- Byblis gaimardii Kr6"yer Amphipod larities were the mollusks in the July samples, Monoculodes edwardsi Holmes Amphipod miscellaneous items in the January samples, linciola irrorata Say Amphipod and mucus in the January and Febiuary Cancer irroratus Say Rock Crab samples. The unusually large percentage of Hyas coarctatus Leach Toad Crab Mollusca in the July samples was due to sev-

Clymenella torquata (Leidy) Annelid eral squid of large volume . A few pelagic

Eunice pennata (O . F . MflUer) Annelid tunicates (Salpa) in the January specimens Nereis pelagica Linnaeus Annelid resulted in the unusuaUy high percentage for Echinarachmus parma (Lamarl^Sand Dollar miscellaneous Items. The quantity of mucus Ophiopholis aculeata (Linnaeus) Brittle -Star was found to be especially high in January and Ophiura lobusta Ayers Brittle-Star February samples. These months are the

18 —

Table 8. Avera,(^e volume of food per haddock by months —

?able 9. nnmpoy^it.ion of stomach contents of haddock fxx>m. the Tortheast Peak, compiled by months and expressed as percentag:e volume

Item April July September October January February

Crustacea . . . . .

period during which haddock spawn, or im- were common in large haddock . In fact mediately prior to it, when the fish slacken the predominant food in some collections of off in their feeding. The decrease in foods large haddock were organisms whose great- resulted in a disproportionately high percent- est lengths were less than 1 centimetei age of mucus This information suggests that the upper limit in size of food organisms is dependent EWfferences in diet of specimens cau^t upon the haddock's size, but through either during the same month but from different preference or necessity small items con- locations within the food-type area were suf- stituted the bulk of the food of both large and ficiently large to overshadow any seasonal small haddock dietary changes that may have existed. From the data at hand, it appears that seasonal Many species of groundfish with which variations in diet composition of Georges haddock associate and with which they must Bank haddock are relatively minor in compari- compete for food, such as the cod, pollock, son to the variations associated with geo- hake, skates, etc., have proportionately graphical distribution. larger mouths . This puts the haddock at a disadvantage in competing for the larger SIZE OF FOOD ORGANISMS food items, but the haddock, because their lips are muscular and somewhat prehensile, Haddock have a rather small, subterminal are better adapted than most of their associ- mouth and consequently are prevented from ates for pulling worms and other soft-bodied taking large articles of food. Most of the creatures out of the ocean floor. food organisms were small - between 1/2 and 3 centimeters in length - and the major- ACKNOWLEDGMENTS ity were narrow, elongate forms. Exceptions occurred, of course, but in general the food The writer wishes to express his appre- Items with two dimensions greater than 1 or ciation to fellow staff members and to Messrs.

2 centimeters in length were taken only by Allan M . Barker, Robert L . Cory, Jim W the very largest haddock. McKee, and David Miller, formerly of the Woods Hole Oceanographic Institution, for Differences in the size of food organisms their assistance with the collection of study were, to some extent, correlated directly materials . Mr . Wendell Patton tabulated with the size of haddock . Small organisms much of the numerical data . The author is such as amphipods, phyllodocid worms, cuma- also indebted to Dr . Marion H . Pettihone, ceans, and isopods were dominant in the food University of New Hampshire, and Drs of small (14 - 30 centimeters) haddock. Fenner A. Chace, Jr. and Clarence R. Shoe- Large haddock (40 - 75 centimeters) con- maker, and their associates at the Smithson- tamed the greatest share of fish, sipunculids, ian Institution, U. S. National Museum, for holothurians, asteroids, cephalopods, and the identification of many invertebrate animals other comparatively large items . The largest creature found in the haddock's diet was a squid, (Illex) whose body measured 20 centimeters in length and whose volume was 103 cubic centimeters. The predator of this squid measured 52 centimeters in body length. Food items as large as this are rarely encountered in the stomach contents of haddock. It is important to note, however, that small organisms

21 . . . . .

SUMMARY LITERATURE CITED

1 . A quantitative analysis of the stomach Atwood, N. E. contents of 1, 287 haddock from Georges Bank, 1866 . On the habits and distribution of captured by means of otter trawls, form the the haddock, Proc. Bost. Soc. Nat. basis of this study. Hist., 10: 322-323.

2 . The average body length of all haddock Baird, Spencei F. examined was 44 centimeters . Minimum and 1889. The sea fisheries of eastern maximum lengths were 14 and 75 centimeters, North America . Rpt.U.S. respectively. Calculated body wei^ts aver- Comm. Fish and Fisheries, aged 2 . 1 pounds, with extremes from 0. 1 to 1886, 14, App. A: 33-34, 73-80.

9 . 2 pounds Bigelow, Henry B. and William C. Schroeder.

3 . Stomach content volume varied from 1953 , Fishes of the Gulf of Maine .U.S. to 110.0 cubic centimeters; average volume Fish and Wildlife Service, was 2.2 cubic centimeters. Fishery Bull. 74 (Vol. 53).

4 . Considering the entire area sampled, Blegvad, H. the primary food groups in decreasing oidei 1916. On the food of fish in the Damsh of importance were: crustaceans, mollusks, waters within the Skaw. Rpt. echinoderms, annelids, and fish. Dan. BioL Sta., 24: 63-65,

5, Distinct differences in food of haddock Bowman, Alexander. from several parts of Georges Bank warranted 1923 . Spawny haddock: The occurrence the establishment of three food type areas of the "spawny" haddock and the These areas and the predominant food of had- locus and extent of herring spawn- dock in each are as follows: Georges Basin - ing grounds. Fisheries, Scot- brittle -stars. Northeast Peak - decapod land, Sci. Invest., 1922, IV. crustaceans, and Southeast Part - amphipods Brown, W. W andC. Cheng.

6, Most of the food organisms were small, 1946 . Investigations into the food of the

animals, Gadus callarias L ) off sedentary or slow-moving benthic cod ( . Bear Island, and of the cod and

7 , Differences in the food habits between haddock (G_. aeglefinus L.) off large and small haddock were of a minor Iceland and the Murman coast. nature HullBuU. Mar. Ecol., 3 (18): 35-71,

8 . During the spawning season, February May, the haddock contained smaller quantities Carr, A. M,

of food than fish taken at other seasons of the 1908. Food of fishes . Northumberland year. Sea Fish. Comm. Rpt., Sci. In- vest., 1907: 68-71. 9. Seasonal trends in diet composition were not apparent. 1909. The food and condition of fish obtained from the noith-east coast. 10. In this study more than 173 species of Northumberland Sea Fish, Comm, food organisms were observed m the haddock's Rpt., Sci. Invest., 1908:41-50. diet; only 11 species were present m large quantities

22 . . , . . .

Clapp, W. F. Poulsen, Erik M.

1912 . Collecting from haddock on the 1928 . The haddock in the Belt Sea and

George ' s Bank . Nautilus, 25: the western Baltic during the 104-106. years 1926-28. Rpt. Dan. Biol. Sta., 34: 99-121. Fridriksson, A. andG. Timmermann.

1950 . Notes on the food of haddock Ritchie, Alfred. (Gadus aeglefinus L.) at Iceland. 1937. The food and feeding habits of Ann. Biol. Cons. Int. Explor. the haddock (Gadus aeglefinus)

Mer., 7: 34-36. in Scottish waters . Fisheries, Scotland, Sci. Invest,, 1937, II. Homans, R. E.S. andA.W.H Needier.

1944 Food of the haddock . Proc.N.S. Scott, Andrew

Inst. Sci., 21, Pt. II: 15-49. 1896 Examination of food in fishes'

stomachs . Proc . Lpool Biol Idelson, M.S. Soc, 10: 108-114.

1929 . On the nourishment of the food fishes in the Barents Sea. Russk. Scott, Thomas

gidrobiol. Zh., 7: 269-285. 1902. Observations on the food of fishes . Fisheries, Scotland,. 20th Rpt: Jones, R. 486-538. 1954. The food of the whiting, and a com- parison with that of the haddock Smith, W. R.

Mar. Res. Scot., 1954 (2). 1892 . On the food of fishes . Fisheries, Scotland, 10th Rpt: Kendall, William Converse. 211-231.

1898 . Notes on the food of four species

of the cod family . Rpt .U.S. Thompson, Harold. Comm. Fish and Fisheries, 1896, 1929. General features in the biology of 22: 177-186. the haddock (Gadus aeglefinus L.) in Icelandic waters in the period Macintosh, W. C 1903-1926- Rapp. Cons. Int. 1874. On the invertebrate marine fauna Explor. Mer., 57, 1926-27: 48-50, and fishes of St. Andrews, Ann. Nat. Hist, Mag., 13: 204. Todd, R. 1905, Report on the food of fishes col-

Needier, A. W. H. lected during 1903 . Mar . Biol

1929. Unpigmented elvers ( Anguilla Ass. U. K., Inter. Fish. Invest., ro strata Lesueur) in haddock Rpt. I (S. Area) 1902-1903: 227- stomachs at Ingonish, Cape Breton 287. COPEIA, 171: 41-42, 1907. Food of fishes (North Sea). Mar. 1930. The migrations and interrelation- Biol. Ass. U. K., Inter. Fish ships of haddock populations in Investi., Rpt. II (S. Area) 1904-

North American waters . Contrib. 1905: 49-87. Canad. Biol. Fish., N S., 6(10): 241-314.

23 .

Trechmann, Charles O. Vladykov, V. D.

1888 . Voracity of tfie haddock . Nature 1933. High temperature stops haddock (London) 39: 9. fishing. Prog. Rpt. Atlant.

Biol. Sta. 7: 10-11. Verrill, A. E.

1871 . On the food and habits of some of Vladykov, V. D. and R. E.S. Homans. our marine fishes. Amer. Nat. 1935. Do haddock feed during the spawn-

5: 397-400. ing period? Prog Rpt . Atlant Biol. Sta., 15: 10-11. 1873. Lists of species found in the stomachs of fishes - food of Willis, John R.

fishes. Rept. U.S. Comm. 1890. Nova Scotia shells , Proc N.S. Fish and Fisheries, 1871-1872, Inst, Sci., 7: 419-428.

1: 514-521.

APPENDIX

A List of Organisms Found in Stomachs of Georges Bank Haddock

COELENTERATA ANNELIDA (cont'd.) Cerianthus borealis Verrill Lumbrinereis fragilis (O.F. MUller) Epizoanthus americanus Verrill Marphysa sp. Nephthys incisa Malmgren PLATYHELMINTHES Nereis pelagica Linnaeus Planocerca Sp. Northria opalina Verrill Odontosyllis sp. NEMERTEA Owenia fusiformis Delle Chiaje Micrura sp. Pectinaria gouldii (Verrill) Phyllodoce mucosa Oersted ANNELIDA Polydora sp. Ampharete arctica Malmgren Rhodine loveni Malmgren Amphitrite sp. Sabella crassicornis Sars Aphrodita aculeata Linnaeus Sabellaria vulgaris Verrill Arabella sp Samythella elongata Verrill Clymenella torquata (Leidy) Scalibregmia inflatum Rathke Drilonereis filum (Claparede) Stylaroides arenosa (Webster) Ephesia gracilis Rathke Travisia carnea Verrill Eteone longa (Fabricius) Eualia sp. Phascolion strombi (Montagu) Eumida sanguinea Oersted Phascolosoma gouldii Ehesing Eunice pennata (O.F. MUller) Glyceria capitata Oersted CRUSTACEA Glyceria dibranchiata Enlers Balanus sp. Goniada maculata Oersted Lumbrinereis acuta Verrill Neomysis sp.

24 .

CRUSTACEA (cont'd.) CRUSTACEA (cont'd.) Diastylis sculpta CO.. Sars Phoxocephalus holbblli (Krbyer)

Lamprops quadriplicata S , L Smith Podoceropsis nitida (Stimpson) Leptocuma minor Caiman Pontharpima spmosa (Holmes) Pontogeneia inermis (K.r5yer) Aega sp. Protomedia fasciata Krbyer Calathura branchiata (Stimpson) Stenothoe cypris Holmes Chiridotea tuftsi (Stimpson) Stenothoe minuta Holmes? Cirolana polita Harger Stegocephalus inflatus Kr5yer Cirolana concharum (Stimpson) Stenopleustes graciis (Holmes) Cyathura carinata (Krbyer) Sympleustes glaber (Boeck) Edotea montosa (Stimpson) Tiron acanthurus Lilljeborg Janira sp. Tmetooyx cicada (Fabricius) Rocelina americana Schioedte &Melnert Unciola irrorata Say Sphaeroma quadridentatum Say Unciola obliquua Shoemaker

Hyperia medusarum (MUller) Aegiriina longicornis (Kr5yer) Themisto abyssoram (Boeck) Capreila geometrica Say Parathemisto compressa (G5es) forma compressa Meganyctiphanes norvegica (M. Sars) Parathomisto compressa (G5es) forma bispmosa Axius serratus Stimpson Amphithoe rubricata (Montagu) Cancer irroratus Say Ampelisca spinipes Boeck CaridioR gordoni (Bate) Anonyx mugax (Phipps) Crago septemspinosus (Say) Argissa hamatipes (Norman) Dichelopandalus leptocerus (Smith) Byblis gaimardii (Kr5yer) Hyas coarctatus Leach Calliopius laeviusculus (Krbyer) Pagurus bernhardus (Linnaeus) Corophium crassicorne Bruzelius Pagurus kr5yeri Stimpson Corophium volutator (Pallas) Pagurus pollicaris (Say)

Ericthonius hunteri (Sp . Bate) ? Pandalus borealis KrOyer Erichthonius rubricornis (Stimpson) Pandalus montagui Leach Eusirus c'jspidatiis Krbyer Pontophilus norvegicus (M. Sars) Gammareilus angulosus (Rathke) Eualus pusiola (Krbyer) Gammarus locusta (Linnaeus) Gammaropsis melanops G. O. Sars PYCNOGONIDA Haustorius arenarius (Slabber) Nymphon stromii Kroyer Hippomedon serratus Holmes Ischyroceras anguipes Kr5yer MOLLUSCA Lembos smithi (Holmes) Ishnochiton sp Leptocheims pinguis (Stimpson) Melita dentata (KrOyer) Astarte undata Gould Monoculodes edwardsi Holmes Cardium sp. Neopleustes pulchellus (KrOyer) Cerastoderma pmnulatum Conrad Orchomenella mmuta (KrOyer) Crenella decussata Montagu Orchomenella Pinguis (Boeck) Ouspidaria pellucida Stimpson Photis sp. Ensis directus (Conrad) Photis macrocoxa Shoemaker Lyonsoa arenosa (M511er)

25 MOLLUSCA (cont'd.) ECHINODERMATA Macoma sp. Asterias sp„ Nuculana tenuisulcata (Couthuoy) Ciossaster papposus (Linnaeus)

Petricola pholadiformis Lamarck Henricia sangumolenta (O . F . MUUer) Placopecten magellaiucus Gmelin Hippasteria phrygiana (Parelius) Solemya velum Say Leptychaster arcticus (M. Sars) Venericardia borealis (ODnrad) Poraniomorpha sp. Yoldia limulata (Say) Yoldia sapotilla Gould Amphiopholis squamata (Delle Chiaje) Yoldia thraciaeformis (Storer) Amphioplus sp. Amphiura denticulata Koehler Heatahum pffalf Linnaeus Echinarachnius parma (Lamarck) Ophiacantha bidentata (Retzius) Amauropsis islandica (Gemlin) Ophiopholis aculeata (Linnaeus) Anachis haliaeeti Jeffreys Ophiura robusta Ayres Colus pygmaeua (Gould) Ophiura sarsi Lutken Epitomum sp. Strongylocentrotus droehbachiensis Lora sp. (O.F MUller) Margarites groenlandicus (Gmelin) Margarites sp. Chirodota laevis (Fabricius) Nassarius trivlttatus Say Thyone scabra Verrill Natica sp. Pohnlces sp. BRACHIOPODA Puncturella noachina Linnaeus Terebratulina septentrionalis Couthuoy Pyramidella sp. Retusa obtusa Montagu ASCIDIACEA Separatista cingulata Verrill Molgula arenata Stimpson Trophon clathratus Linnaeus Salpa zonaria (Pallas) Salpa sp. Illex illecebrosus Lesueur PISCES Ammodytes americanus De Kay Clupea harengus Linnaeus Melanogrammus aeglefinus (Linnaeus)

26 92U21