Food and Feeding Habits of the Western Blacknose Dace, Rhinichthys Atratuius Meleagris Agassiz, in Doe Run, Meade County, Kentucky

Food and Feeding Habits of the Western Blacknose Dace, Rhinichthys atratuius meleagris Agassiz, in Doe Run, Meade County, Kentucky

DONALD C. TARTER

Reprinted from THE AMERICAN MIDLAND NATURALIST

Vol. 83, No. 1, January, 1 970, pp. 1 34-159 University of Notre Dame Press

Notre Dame, Indiana Food and Feeding Habits of the Western Blacknose Dace, Rhinichthys atratulus meleagris Agassiz, in Doe Run, Meade County, Kentucky'

DONALD C. TARTER Department of Biological Sciences, Marshall University, Huntington, West Virginia 25701

ABSTRACT: Analyses were made of the stomach contents of 934 blacknose dace, Rhinichthys atratulus meleagris Agassiz, from three stations in the upper 3.1 miles of Doe Run, Meade County, Kentucky. Dipteran larvae ranked either first or second in percentage frequency of occurrence in the diet of individuals of Age Group 0 dace at all stations. Dipteran larvae were replaced by amphipods in percentage frequency of occurrence in stomachs of dace in the older age groups at and 2 miles below the source of the stream. Stomach contents reflected a difference in feeding habitat between younger and older dace, the younger feeding in quiet, shallow water over soft, silty bottoms, and the older in progressively rapid riffles with some vegetation, and deep, eddying pools of vegetation. Gastropods, isopods, and oligochaetes reflected some seasonal differences in feeding by western blacknose dace. Stomach contents of western blacknose dace indicated some selectivity with respect to a few groups of benthic organisms. This dace in Doe Run is almost entirely carnivorous in its feeding habits. INTRODUCTION Many studies involving food habits of fishes are based solely on analyses of stomach contents. The present study is an attempt to supplement such data by analyzing the bottom fauna available to the western blacknose dace, Rhinichthys atratulus meleagris Agassiz, in Doe Run. The relative abundances of various food items in the benthic fauna, collected at the same time as the fish, were compared with those food items in the stomach contents of the dace. Hess and Swartz (1941) reported that the "kind and amount of food eaten by a fish is a result of interactions between the fish and its environment, and in order to understand this result we should study both units of interaction." They suggested that when the numerical percentages are the same (forage ratio 1), food is selected at ran- dom. A greater percentage of food items in stomachs than in benthic fauna (forage > 1) indicated that food was readily available or actually selected. A smaller percentage of food items in stomachs than in benthic fauna (forage < 1) indicated that food was unavailable or avoided. Available organisms are capable of being eaten by the fish

1 Part of a dissertation submitted to the Graduate School, University of Louisville, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, June 1968. It was supported in part by the U .S. Atomic Energy Commission, under Contract No. AT-(40-1)-3540 with the University of Louis- ville, Louis A. Krumholz, Principal Investigator. 2 Contribution No. 121 (New Series) from the Department of Biology, University of Louisville, Louisville, Kentucky 40208. 134 1970 TARTER: FEEDING HABITS OF DACE 135 if it so desires, and preference indicates a definite choice by the fish. I am sincerely grateful to Louis A. Krumholz for advice and encouragement throughout this study and for criticism and suggestions in the preparation of this manuscript.

DESCRIPTION OF THE STUDY AREA A detailed description of Doe Run (Minckley, 1963) has been summarized by Krumholz (1967) as a torrent spring that rises near Ekron, in eastern Meade Co., Kentucky. The stream flows north- northeast for about 3.5 miles and empties into Doe Valley Lake, a recent impoundment of more than 500 acres (200 ha) and about 4 miles long. As it leaves the lake, Doe Run flows over the floodplain of the Ohio River for about 2 miles and empties into the Ohio River 3.5 miles E of Brandenburg, Kentucky, about 36 miles downstream from Louisville (Fig. 1) .

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Fig. 1.—Doe Run, Meade Co., Kentucky, showing locations of collecting stations, stream miles, extent of Doe Valley Lake, and other features. The broken line through Doe Valley shows the course of the stream prior to impoundment (after Krumholz, 1967). 136 THE AMERICAN MIDLAND NATURALIST 83(1)

MATERIALS AND METHODS From October 1965 through September 1966 dace were collected semimonthly at three stations for a study of food habits. Regurgita- tion of food following fixation was observed only once during the collecting period. Of 934 stomachs analyzed, 734 (78.6%) contained food and 200 (21.4%) were empty. The breakdown by stations of the number of stomachs with food was: Station I, 220; Station II, 386; and Station III, 128; the numbers of empty stomachs were 63, 103, and 34, respectively. In the laboratory, stomachs were excised and the contents were sorted under a binocular dissecting microscope into various taxonomic categories. Representatives of each taxon were weighed as a unit to the nearest milligram on a Mettler electric, single-pan balance, after blotting dry on paper toweling. The number of individuals in each taxon was counted and recorded for each stomach. The following calculations were made on the stomach contents of each age group of dace at each station: (1) the percentage of stomachs in which a certain taxon occurred (percentage frequency of occurrence), (2) the average of the percentages of volume of each stomach containing a particular taxon (average of volume percentages), (3) the average number of individuals in all stomachs containing any taxon (X) and in stomachs containing the particular taxon (X1), and (4) the percentage of the total volume (by weight) of all taxa made up by the total weight of each particular taxon (percentage of total volume). In areas from which the fish were seined a series of benthic samples was collected with a Surber sampler during each season, from each station. Each object in the sampled area was washed care- fully into the net. The samples were preserved in toto in 10% for- malin while in the field and were returned to the laboratory for separation and identification. Organisms were sorted primarily by handpicking with small forceps, but a flotation technique using a saturated solution of salt (Lyman, 1943) was helpful occasionally. The organisms in each taxon were counted and placed in 70% ethanol. Histograms were prepared to compare the numerical percentages of the taxa in the benthic samples with the numerical percentages of the taxa in the stomachs. The data from each station were arranged for each of four seasons —winter (December, January, February), spring (March, April, May) summer ( June, July, August), and autumn (September, October, November)—to determine if food habits varied seasonally. Percentage frequency of occurrence ( %F0), average of volume percentages (X—V%), and percentage of total volume (.70TV) were used in analyzing the data. On three occasions during the summer, attempts were made to determine daily feeding periods of the dace. Each series contained fish captured between 0600 and 0700 hours, 1200 and 1300 hours, and 1800 and 1900 hours. On one of those occasions, samples were 1970 TARTER: FEEDING HABITS OF DACE 137 taken also between 0300 and 0400 hours and between 2300 and 2400 hours. Data from each collection were compared with respect to the percentages of empty stomachs taken at the designated times.

AVAILABILITY AND USE OF FOODS Gerald (1966) reported that abundance and availability of benthic fauna appeared to be the main factors which determined the diet of fish. In Doe Run, the stomach contents of dace reflected the availability of food items most of the time, but the dace did show some selectivity with respect to a few groups of organisms.

TABLE 1.—Categories of stomach contents of western blacknose dace at each of three stations ANNELIDA OLIGOCHAETA Nais spp. II "Lumbricus" sp. I, II, III ARTHROPODA ISOPODA Asellus bivittatus Walker I, II, III AM PHIPODA Garnmarus minus (Say) I, II, III Gammarus bousfieldi Cole and Minckley I, II, III EPHEMEROPTERA Pseudocloeon sp. II Ephemerella sp. II Baetis vagans Traver II, III Stenonema sp. III Paraleptophlebia spp. I COLEOPTERA Stenelmis sp. I, II Terrestrial beetles II TRICHOPTERA Glossosoma sp. I Hydro psyche sp. II, III Cheumatopsyche sp. II, III Psychomyia sp. I, II, III Agraylea multiplicata Curtis I, II LEPIDOPTERA I, II HYMENOPTERA I, II, III DIP TERA Simu/ium sp. II Tipula sp. II Antocha sp. I, II, III Chironomids I, II, III ARACHNIDA Terrestrial species I, II, III MOLLUSCA PELECYPODA I, II GASTROPODA Goniobasis senzicarinata group I, II CHRYSOPHYTA Vaucheria sp. I CHLOROPHYTA Cladophora sp. II DETRITUS AND UNIDENTIFIED I, II, III 138 THE AMERICAN MIDLAND NATURALIST 83(1)

The categories of food items found in the stomachs of the dace from the three stations in Doe Run are listed in Table 1. Three groups, Arachnida, Hymenoptera, and Lepidoptera, were combined as terrestrial organisms in the graphic presentations. In addition to those categories, representatives of Plecoptera, Megaloptera, Turbel- laria, and Decapoda were taken in the benthic samples. Of all categories listed, representatives of Plecoptera, Megaloptera, Turbel- laria, Decapoda, Oligochaeta, Coleoptera, Pelecypoda, and Ter- restrial Organisms were not common in either the bottom fauna or in the stomach contents (Fig. 2).

STATION I Data depicting the food habits of dace at Station I are presented in Figs. 3, 4, and 5. Oligochaeta.—Only six specimens were found in stomachs of all fish examined, and oligochaetes were not considered abundant in the diet of any group, nor were they abundant in the benthos (Fig. 2) . Isopoda.—Isopods were most abundant in bottom samples at Station I in most seasons, but, for the most part, were absent or scarce in stomach contents of dace during most seasons. Their small size and concealment in beds of Fissidens rendered the isopods somewhat unavailable as food for dace, but it may also be that they were selected against. The highest percentage frequency of isopods, mostly Asellus bivittatus, was 13.3% in Age Group III (Fig. 3). Amphipoda.—Amphipods were the most numerous benthic organisms at Station I in all seasons. That abundance was reflected in the stomach contents during winter and spring but in summer and autumn the amphipods ranked second to dipterans, which were less numerous in benthic samples. Gammarus bousfieldi was more abundant than any other item in the stomachs of dace of Age Groups I, II, and III, and occurred in 71.4, 79.4, and 46.7% of the stomachs, respectively. In Age Group 0 they ranked second in frequency of occurrence to chironomid larve. The greatest number of amphipods, 167, was found in Age Group II. In the above age groups only lepidopteran larvae, in Age Group III, outranked amphipods in total volume of food. On the basis of average volume percentages, amphipods were first only in Age Group I, and followed caddisfly larvae and mayfly nymphs in Age Group 0. Gammarus minus was the only other amphipod found with any regularity. Ephemeroptera.—Mayfly nymphs were rare (1.0% or less) in the bottom fauna at Station I in all seasons, and were only slightly more numerous in the stomach contents, although only one species, Para- leptophlebia sp. was found. Fish of Age Groups II and III did not eat this species frequently, but the larvae comprised the highest average volume percentages (25.0) in Age Group 0, and were present in 17.2% of those stomachs. Coleoptera.—Larvae of the elmid beetle, Stenelmis sp., were found - -

1970 TARTER: FEEDING HABITS OF DACE 139

in 3.2% of the stomachs of fish in Age Group II (Fig. 3) but in no other age group, and they were not common in the bottom samples. Trichoptera.—Caddisfly larvae were more numerous in stomach contents than in benthic samples in all seasons except autumn at Station I. Inadvertent sampling errors may be partly responsible for this discrepancy since the primary trichopteran at this station was the very small caddisfly Agraylea multiplicata. There was a high percent-

o- f Plecoptera 01 — •■• Mepaloptera 0-1 — — — 101 Turbellaria 0 — M ME OM IN ■ ME ■ 10 -1 Decapods OJ — — 10i T ...... trials_o 0 —• — — —__= 10 _1 Oli oochaetes ,.. 0 _1 — __,— _- ■_. _ _ O Isopods 2° 0 4 •_11.1 .....• ELI._ _ ....__ _In

i 60: AmI] hipi °.• 40:_ • 20- o_ - 0- 60- _ 40 - _ 20- Ephemeroptera O - D. O- .11.014 cdlil 10d Coleoptera 111111 am. ° — — ▪ Trichoptera 20 0 =0, 1111 • • 80 a) _ o- 60- Diptera 40-

20- .1] 0- ill Pelecypoda c_E ioj 0

40- Gastropoda 20- 0- C.= 1111 BS •BS BS BS BS BS BS BS BS BS BS BS F WSS FWSSFWSS Station 1 Station 11 Station III

Fig. 2.—Seasonal differences in percentages of benthic organisms (solid columns) and stomach contents (open columns) of western blacknose dace at three stations.

140 THE AMERICAN MIDLAND NATURALIST 83(1)

age frequency of occurrence of Agraylea multiplicata in stomachs of fish in Age Groups I (23.8%), II (20.6%), and III (40.0%) but it amounted to only 7.6, 7.0, and 4.2%, respectively, of the total volume. The 40.0% in Age Group III was second only to amphipods. Like mayfly nymphs, Agraylea multiplicata composed 25% of the average volume percentages in stomachs of fish in Age Group 0. Larvae of Glossosoma nigrior and Psychomyia sp. rarely were found in the stomachs of any dace. Diptera.—Chironomid larvae were abundant in the benthic samples

Terrestrials 0 58 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Age Group 0 Coleoptero Trichoptera Diptera Pelecypoda Gastropod° Detritus Other I

Terrestrials 84 Specimens Oligochaeta lsopoda Amphipodo Ephemeroptera Age Group I Coleoptero Trichoptera Diptera Pelecypoda Gastropoda Detritus Other

Terrestrials 63 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Age Group II Coleoptera Trichoptera Diptera Pelecypoda Gastropod° Detritus Other

T eeeee trials 15 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Age Group 111 Coleoptera Trichoptera Diptera Pale cypoda Gastropoda 1 Detritus Other

0 20 40 60 80 100 PERCENTAGE FREQUENCY OF OCCURRENCE Fig. 3.—Percentage frequency of occurrence of various food items in stomachs of western blacknose dace of Age Groups 0, I, II, III at Station I.

1970 TARTER: FEEDING HABITS OF DACE 141 most of the time at Station I and apparently were captured quite easily by the dace. Chironomids ranked first in numbers (1208), frequency of occurrence (67.2%), and total volume (67.9%) in stomachs of dace of Age Group 0. In fish of Age Groups I and II, where the numbers were considerably smaller, the total volumes were only 4.9 and 8.7% respectively. An average of 33 larvae was found in stomachs of fish' in Age Group 0 that contained dipterans. They ranked second in percentage frequency (28.6%) to amphipods in fish of Age Group I, third (19.0%) to amphipods and caddisfly larvae in Age Group II, and fifth (13.3%) in Age Group III. Antocha

80- 60: 40: 20: o= E Terrestrials

0° 80: 60-_ o 40 - E 20- 0- Oli g oc ha et a 20- 0: 1=1-- I sopoda

11 rm Amphipoda

Ephemeroptera Cole opt era

Trichoptero

Diptera

Pelecypoda Gastropoda EL_ Detritus 20- 0: Other 0 1 II III 0 1 II III 0 I II 111 Station 1 Station II Station III Fig. 4.—Averages of volume percentages of various food items in stomachs of western blacknose dace of Age Groups 0, I, II, and III at three stations.

142 THE AMERICAN MIDLAND NATURALIST 83(1) sp. was the only other dipteran occasionally found in the stomach at Station I. Pelecypoda.—Sphaeriid clams were rare in bottom samples (Fig. 2) and occurred only in fish of Age Group I (1.2%) and Age Group III (6.7%) (Fig. 3). Ten clams in the stomach of one fish in Age Group III are responsible for the percentage frequency given above. Those clams made up 11.6% of the total volume of stomach contents in fish of Age Group III. Gastropoda.—Only eight snails (all Goniobasis semicarinata?) were found in stomachs of dace at Station I. They occurred in Age Group I (1.2%) and Age Group III (13.3%) and only made up 0.6

60- 40- 20-_ 0 Terrestrials 40- 20- Oligochaeta 10- 0 Isopoda 60- 40- 20- 0 Amphipoda 40- 20- Ephemeroptera 10- 0- Coleoptero 40- 20: 0- Trichoptera 60: 40:

0 - Diptera 20- 0- — Pelecypodo io- o- Gastropod° io- o- Detritus 20- Other 0 I II III 0 I II III Station I Station III Fig. 5.—Percentages of the total volume of various food items in stomachs of western blacknose dace of Age Groups 0, I, II, and III at three stations. 1970 TARTER: FEEDING HABITS OF DACE 143 and 0.7% of the total volume, respectively. Although gastropods were abundant at all times in Doe Run, there usually were none in the stomachs of dace, and it is obvious that dace did not select them as a food item. Terrestrial organisms.—Lepidopteran larvae ranked first in total volume of food and average volume percentage in fish of Age Group III. They occurred in that age group in 33.3% of the stomachs and made up 76.8% of the total volume; the average volume percentage was 81.4. They were found in fish of Age Groups I and II to a much lesser degree, but comprised 51.0% of average volume in Age Group II. Other terrestrial organisms of lesser importance in the diet were spiders and ants. Spiders were found only in fish of Age Groups I (7.1%) and II (1.6%). Ants ranked third in the average volume percentages of Age Group 0, but made up only 0.9% of the total volume. Algae.—Vaucheria sp., a filamentous alga, occurred in the stomachs of fish in Age Groups I (12.4%), II (15.7%), and III (11.8%) but represented only trace amounts in volumes. Detritus.—Detritus was found in about 10% of the stomachs in all age groups and contributed very little to total or average volume percentages. Other and unidentified.—Digested and unidentified materials were fairly high in frequency of occurrence in stomachs of fish in Age Groups I (21.4%) and III (26.7%). These materials in the stomachs of dace in Age Group II showed an average volume percentage of 25.3, but composed only 14.9% of the total volume.

STATION II Data on food habits of dace at Station II are presented in Figs. 4, 5, and 6. Data for fish of Age Group III are represented by only two individuals. Oligochaeta.—"Lumbricus" sp. and Nais sp. were found occasionally in fish of Age Groups 0 (0.8%), I (0.9%), and II (2.6%). However, they made up a larger part of the average volume, 28.4 and 23.3%, respectively, in Age Groups I and II. As at Station I, oligochaetes were not common in bottom samples. Isopoda.—Isopods, mostly Asellus bivittatus, did not abound in the diet of any age group, but followed a trend similar to that at Station I. They comprised only 0.4% of the total volume in Age Group 0 but the average volume percentage was 12.7. Amphipoda.—Amphipods were the most numerous category, or next to it, in the benthic samples during all seasons except spring. Stomach contents reflected the abundance of amphipods in autumn and lesser numbers during other seasons. Amphipods, usually Gam- marus bousfieldi, ranked first in frequency of occurrence in fish of Age Groups 0 (46.5%) and I (53.2%) and, like mayfly nymphs, made up 59.0% in Age Groups II. They also ranked first in per- 144 THE AMERICAN MIDLAND NATURALIST 83(1) centage of total volume in Age Groups I, II, and III, where they made up 38.7, 30.0, and 50.0%, respectively. In fish of Age Group I amphipods (304) ranked first in number of individuals of any food item taken. G. minus also was found in some stomachs. Ephemeroptera.—Mayfly nymphs, mostly Baetis vagans, were more abundant in stomach contents and benthic samples in summer than at any other season and were more abundant in the diet of most age groups than at Station I, both in frequency of occurrence and

Terrestrials 1 27 Specimens Oligochaeta Isopoda Amphi pods Ephemeroptera Coleoptera Tri eh optera Age Group 0 Mote ra Pel ecy pod a Ga stropod a Detritus Other

T eeeee trials 218 Specimens Oligochaeta Isopoda Amphipodo Ephemeroptera Coleoptero Trio hoptera Age Group 1 Diptera Pelecypoda Gastropoda Detritus Other

Terrestrials 39 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Coleoptera Trichoptera Age Group 11 Diptera Pelecypoda Gastropoda Detritus Other

Terrestrials 2 Specimens Oligoc ho eta Isopoda A mphip ad a E p he mar optera Age Group III Cole optera Trichoptera Di pte ra Pelecy pod a Gastropod a Detritus Other

0 20 40 60 80 101 0 PERCENTAGE FREQUENCY OF OCCURRENCE

Fig. 6.—Percentage frequency of occurrence of various food items in stomachs of wcstern blacknose dace of Age Groups 0, I, II, and III at Sta- tion II. 1970 TARTER: FEEDING HABITS OF DACE 145

percentage of total volume. The percentage frequency ranged from 42 to 59 in fish of Age Groups 0 to II. At that station mayfly nymphs composed the highest percentage of the total volume (28.7) of all food items in dace of Age Group 0. Ephemerella and Pseudocloeon sp. were found occasionally in stomachs at Station II. Coleoptera.—Larvae of elmid beetles occurred in small but consistent percentage of stomachs below Age Group III, and in somewhat greater numbers than at Station I. They comprised 9.4% of the total volume in fish of Age Group 0; the average volume percentage was 12.7. Coleopteran larvae were more abundant in bottom samples at Station II than at either of the other stations (Fig. 2) . Trichoptera.—Caddisfly larvae, primarily Hydro psyche sp. and Cheumato psyche sp., were relatively scarce in most seasons both in benthic samples and stomach contents. The relative scarcity of net- building caddisflies in the stomach contents at the downstream stations may have been due, in part, to their concealment in the vegetation and their protection by the net. Caddisfly larvae occurred in progressively increased percentages in stomachs of dace in Age Groups 0 (12.6), 1(17.4%), II (53.9%), and III (100.0%). The only two stomachs of fish in Age Group III contained trichopterans. In the stomachs of individuals of Age Group II there was an average of 5.6 larvae per stomach. This was the highest average for any food item in all age groups except for gastropods in Age Group I. In total volume, trichopterans ranked second to amphipods in Age Group II (28.0%) and third (11.0%) in Age Group I. Larvae of four genera were found and identified: Hydro psyche sp., Cheumato psyche sp., and Psychomyia sp. were about equally abundant in the stomachs; Agraylea multiplicata, most abundant at Station I, was uncommon at Station II. Diptera.—Dipteran larvae were less abundant in bottom samples during all seasons at Station II than at Station I, but were present in large numbers in the stomachs of dace in the former area. While they occurred with the highest percentage frequency at Station I in Age Group 0, they were replaced at that level by amphipods and caddisfly larvae at Station II. They were found in decreasing percentage fre- quencies, 40.9, 24.3, and 20.5, as well as percentages of total volume, 24.5, 6.4, and 1.9, in fish of Age Groups 0, I, and II, respectively. Stomachs in Age Group 0 contained an average of 3.6 dipteran larvae at Station II compared with 33 at Station I. Larvae of chironomids and Simulium sp. were found most often in stomachs at Station II. Larvae of Antocha sp. and Tipula sp. were uncommon. Pelecypoda.—Only two sphaeriid clams were found. One clam made up 20.7% of the average volume percentage in a fish of Age Group II. Here again, bivalve mollusks were rare in bottom samples. Gastropods.—Thirty-two snails (all Goniobasis semicarinata?) were found in two stomachs of Age Group I. This is the only instance in the entire study in which snails contributed significantly to the diet of dace in Doe Run, even though they were very abundant in the bottom fauna at all times. 146 THE AMERICAN MIDLAND NATURALIST 83(1)

Terrestrial organisms.—Ants, spiders, and lepidopteran larvae made up a small but consistent part of the diet of dace in Age Groups 0 and I at Station II. Algae.—Cladophora sp., a filamentous alga, was present only in fish of Age Group II (7.3%) and was limited to a trace amount. At Station I, Vaucheria sp. was found in 12 to 15% of the stomachs in dace of Age Groups I, II, and III. Detritus.—Similar to Station I, at Station II detritus was found in no more than 15.0% of the stomachs of dace. Other and unidentified.—Digested and unidentified materials occurred in greater percentages in stomachs of all age groups than at Station I. STATION III Data depicting the food habits of dace at Station III are presented in Figs. 4, 5, and 7. Data recorded for individuals of Age Groups II and III were probably less representative than those for other age groups, since fewer stomachs, 8 and 5, respectively, were available for analyses. Oligochaeta.—Only one oligochaete ("Lumbricus" sp.) was found in the stomachs examined. This oligochaete ranked first in average volume percentages (97.0) and percentage of total volume (50.3) in fish of Age Group I, even though members of that category were rare in bottom samples. Isopoda.—Although 13% of the stomachs in Age Group II analyzed contained isopods, they made up only 4.3% of the total volume. However, the average volume percentage was 25.6. Isopods were scarce in benthic samples from Station III, probably because of the scarcity of Fissidens or other suitable habitat. Amphipoda.—Amphipods, both G. minus and G. bousfieldi, were much less numerous in benthic samples at Station III than at the other stations and, similarly, were not common in the diet of dace there. They occurred in the stomachs of dace of all age groups, and made up more than 25.0% — which ranked fourth among the food items — in fish of Age Group II. The highest percentage of total volume was 9.3 in dace of Age Group III. Ephemeroptera.—Ephemeropterans reached their greatest abundance in the benthos of Doe Run at Station III in spring and summer, and were somewhat less abundant in autumn and winter. Usually, stomach contents reflected the availability of mayfly nymphs, which are very active and exposed during most seasons in Doe Run. Mayfly nymphs, primarily Baetis vagans, ranked second to dipterans in all age groups in percentage frequency of occurrence. The range was from 45.8 to 62.5%. They ranked first in percentage of total volume in fish of Age Groups II (34.8) and III (51.9) . Except for Age Group III, the pattern was about the same as that of Station II. Stenonema sp. was uncommon in stomach contents. Coleoptera.—No beetle larvae were found in the stomachs of any 1970 TARTER: FEEDING HABITS OF DACE 147 dace from Station III, and they were rare in the bottom samples from that area. Trichoptera.—Caddisfly larvae, principally Hydro psyche sp. and Cheumato psyche sp., reflected the same trend as at Station II, except in fish of Age Group III. They ranked third to dipterans and ephemeropterans in percentage frequency of occurrence in Age Groups 0-II. Psychomyia sp. was rarely found in the stomachs of dace at Station III. Trichopterans were not common in bottom samples at Station III at any time.

Terrestrials 67 Specimens Oligochaeta lsopoda Amphipodo Ephemeroptera 1 Coleoptero Trichoptera Diptera Pelecypoda Gastropoda Age Group 0 Detritus 1 Other

Terrestrials 48 Specimens Oligochasta Isopoda Amphipada Ephemeroptera 1 Coleoptera Trichoptera Diptera Pelecypoda Gastropod° Ago Group I Detritus Other

Terrestrials 8 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Coleoptera Trichoptera Diptero Pelecypoda Gastropoda Age Group II Detritus Other

Terrestrials 5 Specimens Oligochoeto Is aped Amphipoda 1 Ephemeroptera Coleoptera Trichoptera Dieter° Pelecypoda Gastropod° Age Group HI Detritus Other

0 20 40 60 80 1 00 PERCENTAGE FREQUENCY OF OCCURRENCE Fig. 7.—Percentage frequency of occurrence of various food items in stomachs of western blacknose dace of Age Groups 0, I, II, and III, at Sta- tion III. 148 THE AMERICAN MIDLAND NATURALIST 83(1)

Diptera.—Except in summer following emergence, dipteran larvae were the most abundant organisms at all seasons both in the benthic samples and in the stomach contents. Chironomid larvae usually were the most abundant food in stomachs of dace. They ranked first in total numbers, 506, 813, 103, and 137 in Age Groups 0-III, respectively. They occurred with the highest frequency in all age groups, ranging from 71.6 to 89.6%. The range for the average number in stomachs containing them was 10.5 (Age Group 0) to 34.3 (Age Group III) . They also ranked first or second in percentage of total volume in fish of all age groups, ranging from 30.4 to 40.3%. They were more abundant in the diets of more age groups at Station III than at Sta- tions I and II. Mollusca.—No snails or clams were found in the stomachs. Snails were common in the bottom samples but clams were rare. Terrestrial organisms.—Only two terrestrial organisms, one ant and one spider, were found present in stomachs. Algae.—No alga was found in the stomach contents. Detritus.—Detritus occurred in a small percentage of stomachs in Age Groups 0 and I, and contributed very little to the percentage of total volume. Other and unidentified.—Digested and unidentified materials were found in varying percentages (12.5 to 32.8) in stomachs of dace of each age group. Such material contributed only 2.0% to the total volume except in Age Group 0 where the percentage was 13.8. From the above data, several conclusions were reached concerning the food habits of the different age groups of dace collected from Doe Run. Dipterans, principally chironomid larvae, ranked first or second in percentage frequency of occurrence in the diet of dace of Age Group 0 at all stations, which reflects in part the food available in their habitat over soft, silty bottoms. They occurred in the highest frequency of any food category in all age classes at Station III, where they made up a consistently high percentage of the total volume of food. There was a progressive decrease in frequency of occurrence of dipterans with each increasing age group of fish at Stations I and II. Amphipods usually replaced dipterans as the most frequently oc- curring organism in stomachs of dace in the older age groups at Sta- tions I and II. Amphipods were uncommon at Station III both in benthic samples and stomach contents. Amphipods made up large percentages of the total volume of food in most age groups at Stations I and II. Ephemeropterans ranked behind dipterans in percentage frequency of occurrence in the diet of fish of Age Group 0 at all stations, and ranked second to dipterans in all age groups at Station III. Ephemer- opterans made up fairly high percentages of the total volume of food in fish of Age Group 0 at Stations II and III. Generally, trichopterans and ephemeropterans, along with amphipods, occurred in a higher percentage frequency in fish of Age Groups II and III at all stations. Stomach contents of dace, involving the four most abundant food 1970 TARTER: FEEDING HABITS OF DACE 149 organisms, reflected a change in feeding habitat from quiet, shallow water over soft, silty bottoms for younger dace, to progressively rapid riffles with some vegetation, and deep, eddying pools with vegetation, for older dace. Terrestrial organisms made up a relatively high percentage of the total volume of food in fish of Age Groups II and III at Station I, a pattern also reflected in the average volume percentages. As indicated by the percentages of occurrence and volume, algae and detritus did not constitute a major part of the over-all diet.

Terrestrials 77 Specimens Oligochoeta leopoda Amphipoda Ephemeroptera Coleoptera FALL Trichoptera Diptero Pole cypoda Gastropoda Detritus Other

Terrestrials 57 Specimens 011gochaeta Isopoda Am phipoda Ephemeroptera Coleoptera WINTER Trichoptera 1 Diptera Pete cy pods Gastropod° Detritus Other

Terrestr ials fl Oligochoeta 35 Specimens Isopoda 1 Amphipoda Epherneroptera Coleoptera SPRING Trichoptera Diptero Pelecypodo Gastropod° Detritus Other

Terrestrials 42 Specimens Oligochoeto Isopodo Amphipoda Ephemeroptero li Coleoptero SUMMER Trichoptera Water° Pele cy pod o Gastropoda Detritus Other , 1 1 1 1 I 1 1 1 1 1 0 20 40 60 80 100 PERCENTAGE FREQUENCY OF OCCURRENCE

Fig. 8.—Seasonal differences in percentage frequency of occurrence of various food items in stomachs of western blacknose dace at Station I. 150 THE AMERICAN MIDLAND NATURALIST 83(1)

SEASONAL DIFFERENCES IN FOOD HABITS Seasonal differences in food habits of the western blacknose dace, from three stations in Doe Run, are presented in Figs. 2 and 8 through 12. Oligochaeta.—Oligochaetes, primarily"Lumbricus"sp. were present in a small percentage of stomach contents at Station III in winter, but made up 57.8% of the total volume and 97.4% of the average volume percentage. They occurred in small percentages at Stations I and II in autumn but comprised only 5% or less of the total volume. Isopoda.—Isopods, mostly Asellus bivittatus, reached their maximum percentage frequency (11.4) in spring at Station I. They were found in small percentages during different seasons at some of the other stations. Amphipoda.—Amphipods, mostly Gammarus bousfieldi but with some G. minus, were found in consistently high frequency in stomachs at all seasons at Stations I and II, reaching the highest frequency (94.3%) in spring at Station I. They were least abundant at those stations in summer, and much less numerous during all seasons at Station III. Dace fed on amphipods in all seasons if they were available, and apparently selected for them on occasion. The percentage of total volume (70.2) was greater for amphipods than for any other food item in spring at Station I. Ephemeroptera.—At Station III, mayfly nymphs, mostly Baetis vagans, occurred in a larger percentage in stomachs in winter (56.9) and spring (55.6) than in any other season, although they were abundant in summer and autumn. During the winter and spring they comprised 41.2 and 43.5% of the average volume percentage and percentage of total volume, respectively. At Station II, they were more abundant in stomach contents and benthic samples in summer than at any other season, when the greatest number (292) and percentage frequency (79.4) of mayflies occurred. They were somewhat less abundant during the other seasons. They were abundant in benthic samples at Station II in spring but apparently unavailable or not selected for by dace since relatively few were found in the stomachs. In autumn and winter, however, the numerical percentages of mayfly nymphs in stomachs were at least twice those in benthic samples. This may indicate some selection on the part of dace for mayfly nymphs. Ephemeropterans of the genus Paraleptophlebia were present in stomachs during all seasons of the year but were eaten in greatest numbers during autumn and winter. This occurrence of mayfly nymphs as a major food item may indicate that dace in Doe Run are primarily bottom feeders during the colder months of the year. Coleoptera.—Larvae of the elmid beetle, Stenelmis sp., were not abundant in the diet of dace at any time. They were not found in the stomachs of dace at Station III and only during the fall (1.3%) at Station I. At Station II they occurred in summer (8.7%), but made up 12.2% of the total volume. Trichoptera.—At Station I, larvae of the microcaddisfly Agraylea

1970 TARTER: FEEDING HABITS OF DACE 151 multiplicata were found consistently (15.6 to 22.9%) in stomachs in all seasons. Larvae of Hydro psyche sp., Cheumato psyche sp., and Psychomyia sp. occurred in all seasons, with the highest frequency (42.9%) in summer at Station II, where they constituted 22.9% of the total volume. They were less abundant downstream at Station III, especially during the spring and summer. Diptera.—Dipterans, primarily chironomid larvae, were the most numerous food item in fall at Stations I (N=1,104) and III (N= 873). The following total numbers of dipterans at three stations during each season reflected their over-all abundance: autumn 2,034; winter,

Terrestrials Oligochaeta 154 Specimens Isopoda Amphipoda Ephemeroptera Coleopter° FALL Trichoptera Diptera Pelecypoda Gastropod° Detritus Other

Terrestrials Oligochasta 56 Specimens Isopoda Amphipoda Ephemeroptera Coleoptera WINTER Trichoptera Diptera Pelecypoda Gastropod° Detritus Other

Terrestrials 30 Specimens O lig ochart a Isopoda A mphipoda II Ephemeroptero Coleoptera Trichopte r a SPRING Di pt era Pelecypo do Gostropoda Detritus Other

Terrestrials 126 Specimens Olipochosta Isopoda Amphipoda Ephemsroptaro — Coleoptera 1 SUMMER Trichoptera Diptera Pelecypoda Gastropodo Detritus Other I I I I 0 20 40 60 80 100 PERCENTAGE FREQUENCY OF OCCURRENCE Fig. 9.—Seasonal differences in percentage frequency of occurrence of various food items in stomachs of western blacknose dace at Station II.

152 THE AMERICAN MIDLAND NATURALIST 83(1)

627; spring 162; and summer, 320. They were most numerous on a yearly basis at Stations I (N=1,400) and III (N=1,483) . They were present in more stomachs at Station III in autumn (98.0%) than at any other season, although the lowest occurrence was 44.8% in summer. About 50.0% of the total volume of food at Station III consisted of dipteran larvae in autumn and spring. They were found in the most stomachs at Station II in winter (48.2%) and in the least in autumn (18.2%) . The percentage frequency of occurrence at Station I ranged from 47.2 in summer to 22.9 in spring. Pelecypoda.—Sphaeriid clams were found in stomachs only during

Terrestrials 50 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera Coleoptera FALL Trichoptera Diptera Pelecypoda Gastropod° Detritus Other 1

T eeeee trials 58 Specimens Oligochoeto Isopoda Amphipoda Ephemeroptera Coleoptera WINTER Trichoptera Diptera Pale cypoda Gastropoda Detritus Other 0

Terrestrials 18 Specimens 011gochasta Isopodo Amphipoda Ephemeropter a Coleoptera SPRING Trichoptera Diptero Pelecypoda Gastropod° Detritus Other

Terrestrials 9 Specimens Oligochaeta Isopoda Amphipoda Ephemeroptera 1 Coloopier° SUMMER Trichopter a Diptera 1 Pelecypodo Gastropoda Detritus Other 1

20 40 60 80 1 00 PERCENTAGE FREQUENCY OF OCCURRENCE Fig. 10.—Seasonal differences in percentage frequency of occurrence of various food items in stomachs of western blacknose dace at Station III. 1970 TARTER: FEEDING HABITS OF DACE 153

the summer (2.4%) at Station I and were not found at Station III. They occurred only in 1.8% of the stomachs at Station II in winter and 0.8% in summer, but comprised 21.3 and 44.4% of the average volume percentages in winter and summer, respectively. Gastropoda.—Gastropods were not found in any stomachs at Station III, and were limited to small percentages in autumn and spring at the two upstream stations. Terrestrial organ isms.—At Stations I and II lepidopteran larvae and hymenopterans were only present in stomachs examined in summer and autumn. Lepidopterans reached their greatest frequency (21.4%), percentage of total volume (71.7%), and average volume percentage (79.3%) in summer at Station I. Hymenopterans occurred in 13.5% of stomachs in summer at Station II, but made up only a small percentage of the total volume. Spiders were found only rarely in stomach contents of dace during most seasons and only at Stations I and II. Algae.—Vaucheria sp. was the only alga found in stomachs of dace at Station I, and reached the highest percentage (40.0) in spring. Cladophora sp. was present occasionally in summer and autumn at Station II. Only trace amounts of algae were identified from either station. Detritus.—Detritus was present in more stomachs in summer and autumn than in other seasons at all three stations. The highest frequen- cies of occurrence, 18.3 and 22.2%, occurred in summer at Stations II and III, respectively, and contributed only small percentages to the total volume of food at any station. Other and unidentified.—At Stations I and II, digested and unidentified materials were most abundant in summer. However, they composed a small but consistent percentage of the diet throughout the year at all stations. On a seasonal basis, amphipods made up the highest percentage of total volume and occurred with the highest frequency in the foods of dace at all seasons, except summer, at Stations I and II in Doe Run. They were not abundant in stomach contents or benthic samples at any time at Station III, although they made up the highest average volume percentages there in autumn and spring. Amphipods were replaced by dipterans as the most abundant food item in summer at Station I. That abundance of dipterans reflected the very high percentages in stomachs of young-of-the-year dace (Age Group 0) which fed primarily over soft, silty bottoms. At Station II, amphipods were replaced as the most abundant food item by mayflies. Dipteran larvae were found in greater percentages of stomachs in winter and spring than at any other season at Station II. They reached their greatest abundance and percentage of total volume in the diet of dace during most seasons at Station III. Ephemeropterans occurred most frequently in summer at Stations II and III, and ranked second or third during the other seasons at that station. They made up a high percentage of total volume of food during all seasons at Station II. Trichopterans were common in stomachs in spring at Station I. Terrestrial organisms were 154 THE AMERICAN MIDLAND NATURALIST 83(1) never very numerous, but made up large percentages of the total volume of food in summer at Station I. The average volume percentages of terrestrial organisms were high in summer at Stations I and II. Algae were found most frequently in the stomachs of dace at Station I and reached their highest frequency in spring. In summary, a few food items occasionally reflected seasonal feeding by dace in Doe Run. Gastropods entered the diet only in autumn and spring at Stations I and II, and made up only a small percentage of the total volume of food. Isopods were most numerous in the stomach contents in spring at Stations I and II, and in summer at Station III. Iso- pods reached their highest percentage (10.0) of total volume of food in summer at Station III. Coleopterans were not abundant in the diet of dace in any season. Oligochaetes were eaten primarily in autumn at 80- 60- 40 - 20: - 0: 17 1 Terrestrials

o 80: 60: f, 40: ; 20- 0- = Oli g ochaeta 20- IS 0: Isopoda 40- 20:417 0 Amphipoda 40- 20- a. 0- Elb Ephemeroptera 10- 0- = Coleoptera 20- - Fl 0 •=imi= Trichoptera 10- 0- Diptera . 40- : 20: 0: Pelecypoda > 20-

0- II= • • ■• • Gostropoda l g - Th =0= 0 Detritus 10- p7:1== 11 1-1 1 Other 0 FWSS F WSS F WSS Station 1 Station II Station III Fig. 11 .—Seasonal differences in average of volume percentages of various food items in stomachs of western blacknose dace at three stations in Doe Run. 1970 TARTER: FEEDING HABITS OF DACE 155

Stations I and II, but comprised 5% or less of the total volume of food. Oligochaetes made up 57.8% of the total volume of food in the winter at Station III, but occurred only in 1.7% of the stomachs. Amphipods occurred with high frequency in all seasons at Stations I and II, but were much less numerous in all seasons at Station III. Amphipods made up 37.8 to 70.2% of total volume of food in stomachs in all seasons, except summer, at Stations I and II. Larval chironomids, the most abundant food item in stomach contents at certain stations, are very numerous in the stream most of the time, and are easily captured and digested by dace.

SEASONAL OCCURRENCE OF EMPTY STOMACHS Seasonal patterns of feeding also may be indicated by the numbers

so- 60: 40: 20:

1 Pl■• Terrestrials 0 60-

40:

20- 01 i goch seta 0- 1 0 - 0 0-- 111 Isopoda

60- - 40-

20- — 1 Amphipoda 0 40-

20 - Ephemeroptera 0 10 - 0 - Coleoptera 20- Trichoptera 0 of 40-

20- - , r I Di pte ra 0 1- 1 0- Pelecypoda 0 -

Percentage 1 0- Gastropoda 0 - — - 10 o Detritus 0 .■1■■■11= 20- Other 0 F W SS FWSS F WS S Station I Station II Station III Fig. 12.—Seasonal differences in percentages of total volume of various food items in stomachs of western blacknose dace at three stations. 156 THE AMERICAN MIDLAND NATURALIST 83(1) of dace stomachs that contained no food. The numbers of empty stomachs for each season at each station in Doe Run (Table 2) indicate that there was marked decrease in the percentage of empty stomachs (7.9%) at Station I in the spring, a reflection of increased feeding activity by dace during that season. It may be that increased feeding activity can be correlated, at least in part, with the very high frequency of amphipods (94.3%) in stomachs at that location. At Station II, the percentage of empty stomachs was almost twice as great in winter (38.5%) as at other seasons. The decreased feeding activity at that time may be a reflection of colder water temperatures with resultant lower metabolism, but there were relatively few empty stomachs at Stations I (28.8%) and III (10.8%). It is possible that the scarcity of preferred food items was manifested by an increase in the number of empty stomachs. Larimore (1957) suggested that a high percentage of empty stomachs in winter, when digestion was slow, indicated that the fish had long waiting periods between feedings. The extremely high percentage of empty stomachs (55.0%) in summer at Station III probably resulted, at least in part, from the small number (20) examined and the high rate of digestion. Each of the 18 stomachs analyzed in the spring from Station III contained food. This may be correlated with the high frequency of dipterans (88.9%) and ephemeropterans (55.6%) in stomachs of dace at that season.

DIEL FEEDING The daily feeding activities of dace were studied by comparing the numbers of empty stomachs taken at night with those taken during daylight hours (Table 3) and by noting the stage of digestion of foods in those stomachs. Those data show that the western blacknose dace feeds primarily in the morning and that such activities are very limited at night. Although about a fifth of the stomachs collected early in the morning (0600-0700 hours) were empty, most of the items present in those containing food had been freshly ingested. The relatively high

TABLE 2.—Percentages of empty stomachs collected from Stations I-III. Numbers of empty stomachs and total numbers of stomachs examined in each category in parentheses STATION I STATION II STATION III Autumn 25.2 18.0 23.1 (26-103) (34-188) (15-65) Winter 28.8 38.5 10.8 (23- 80) (35- 91) ( 8-65) Spring 7.9 21.0 0.0 ( 3- 38) ( 8- 38) ( 0-18) Summer 20.8 17.6 55.0 (11- 53) (26-153) (11-20) TOTAL 23.0 21.9 20.2 (63-274) (103-470) (34-168) 1970 TARTER: FEEDING HABITS OF DACE 157

percentage of empty stomachs probably indicates that those individuals had not yet started feeding that day. By noon, nearly all stomachs contained food in various stages of digestion. Again, by late afternoon (1800-1900 hours) most stomachs contained food but in most instances that food was pretty well digested. At midnight, 60% of the stomachs examined were empty and foods present were in advanced stages of digestion. Also, by 0300-0400 hours, more than three-fourths of the stomachs examined were empty and whatever food was present was unidentifiable.

GENERAL CONCLUSIONS AND DISCUSSION References to stomach contents of members of the genus Rhinich- thys usually are for a limited number of individuals collected over a short time. Kuehn (1949) and Reed (1959) reported that adult or immature stages of ephemerids, simuliids, and chironomids made up about 90% of the stomach contents of the longnose dace R. cataractae (Valenciennes) . Gerald (1966) found that baetids constituted the highest percentage volume in each size class in the longnose dace, and noted that algae occurred in the highest frequency in the 0-49 mm group, chironomids in the 50-69 mm group, and baetids and chironomids about equally high in the 70-100 mm group. Gee and Northcote (1963) presented data on the food habits of the leopard dace R. falcatus (Eigenmann and Eigenmann) in the lower Fraser River of British Columbia. They reported that yearlings, during the time of high water level, fed primarily (by volume) on ephemeropteran and dipteran larvae, while adults fed on Lumbricus and aquatic insect larvae. Later in the autumn, yearlings and adults fed primarily on terrestrial insects (winged ants). Breder and Crawford (1922) reported that vegetable (24%) and insect remains (61%) made up the greatest percentages of food in the eastern blacknose dace R. a. atratulus ( Hermann) . Traver (1929) found that immature aquatic insects made up about 67% and plant material made up 23% of the diet of 191 young eastern blacknose dace from Cascadilla Creek, New York. Stomach analyses of 57 older fish indicated that insect food comprised 47% of the diet and plant materials (mostly diatoms) 36%. Crustaceans rarely were found in the stomach contents of any fish. Moore et al. (1934) summarized the

TABLE 3.—Numbers of dace stomachs examined and percentages found empty at different times during 24-hour periods in the summer at Station II TIME COLLECTED 0300-0400 0600-0700 1200-1300 1800-1900 2300-2400 Collec- Hours Hours Hours Hours Hours tion % % % No No Empty No. Empty No. Empty No. Empty No. Empty 46 15.2 33 0.0 28 0.0 .... 19 36.8 16 0.0 30 3.3 - 3 37 78.5 7 28.6 16 6.2 32 6.2 YO 65.0 1-3 37 78.5 72 22.2 65 1.5 90 3.3 20 60.0 158 THE AMERICAN MIDLAND NATURALIST 83(1) kinds of food eaten by 121 blacknose dace collected at one time from a trout stream in New York. About 75% of the diet consisted of immature aquatic insects, and amphipods of the genus Gammarus made up less than 1% of the total volume of food. Dipterans and trichopterans made up an average of 75.0% and 15.5%, respectively, of total food of 90 eastern blacknose dace from Cascadilla Creek, New York (Hess and Swartz, 1941) . Dipteran larvae, copepods, and algae made up the largest percentages in the diet, depending upon the season, of western blacknose dace from Boone Co., Iowa (Noble, 1964). Minshall (1967) reported that the western blacknose dace in Morgan's Creek, Meade Co., Kentucky, fed mainly on Gammarus (maximum 14 in one specimen) and chironomids (maximum 61 in one specimen) and apparently, on whatever was most available. Amphipods, primarily Gammarus bousfieldi, and immature stages of aquatic insects, mainly chironomids, the ephemeropteran Baetis vagans, and the trichopterans Agraylea multiplicata, Hydro psyche sp., and Cheumato psyche sp., were the most important food items in the diet, depending upon the age group and season, of the western blacknose dace in Doe Run. It was difficult to compare this diet specifically with the diets mentioned in other studies since the food habits in most of those were not separated into age classes, or seasonal differences. Amphipods are more important in the diet of dace in Doe Run than in most studies cited. Generally speaking, however, immature stages of aquatic insects were more important in the diet of the eastern blacknose dace than in the western subspecies in Doe Run. Plant materials, uncommon most of the time in the diet of Doe Run dace, were important in most studies on the eastern form mentioned. The seasonal feeding on terrestrial insects and Lumbricus by the leopard dace resembled that of the dace in Doe Run occasionally. The western blacknose dace in Doe Run was almost entirely carnivorous. Stomach analyses of the western blacknose dace indicated that its role in the trophic structure of Doe Run was that of secondary con- sumer, feeding upon benthic invertebrates. It formed a food relation- ship with the banded sculpin, probably the "top" carnivore in Doe Run (Craddock, 1965) . The sculpin fed on decapods and other fishes, in addition to most of the organisms utilized by the dace.

REFERENCES BREDER, C. M., JR., AND D. R. CRAWFORD. 1922. The food of certain minnows. Zoologica, 2:287-327. CRADDOCK, J. E. 1965. Some aspects of the life history of the banded sculpin Cottus carolinae carolinae in Doe Run, Meade County, Kentucky. Un- published doctoral dissertation, University of Louisville, Louisville, Ken- tucky. 157 p. GEE, J. H. AND T. G. NORTHCOTE. 1963. Comparative ecology of two sympatric species of dace (Rhinichthys) in the Fraser River system, British Colum- bia. J. Fish. Res. Bd. Can., 20(1) :105-118.

1970 TARTER: FEEDING HABITS OF DACE 159

GERALD, J. W. 1966. Food habits of the longnose dace, Rhinichthys cataractae. Copeia, 3:478-485. HESS, A. D. AND A. SWARTZ. 1941. The forage ratio and its use in determining the food grade of streams. Trans. Fifth N. Amer. Wildl. Con f.: 162-164. KRUMHOLZ, L. A. 1967. Accumulation of radioactive fallout materials in the biota of Doe Run, Meade County, Kentucky, 1959-63, P. 791-818. In B. Aberg and F. P. Hungate (Eds.). Radioecological concentration processes. Pergamon Press, New York. KUEHN, J. H. 1949. A study of a population of longnose dace (Rhinichthys c. cataractae). Proc. Minn. Acad. Sci.,17:81-87. LARIMORE, R. W. 1957. Ecological life history of the warmouth (Centrar- chidae). Bull. Ill. Natur. Hist. Sure., 27(1) :1-83. LYMAN, F. E. 1943. A pre-impoundment bottom fauna study of Watta Bar Reservoir area (Tennessee). Trans. Amer. Fish. Soc., 72:52-62. MINCKLEY, W. L. 1963. The ecology of a spring stream: Doe Run, Meade County, Kentucky. Wildl. Monogr.,11:1-24. MINSHALL, G. W. 1967. Role of allochthonous detritus in the trophic structure of a woodland springbrook community. Ecology, 48:139-149. MOORE, E., J. R. GREELEY, C. W. GREENE, H. M. FAIGENBAUM, F. R. NEVIN AND H. K. TOWNES. 1934. A problem in trout stream management. Trans. Amer. Fish. Soc., 64:68-8. NOBLE, R. L. 1964. Life history and ecology of western blacknose dace, Rhinichthys atratulus meleagris Agassiz, Boone County, Iowa. Unpub- lished master's thesis. Iowa State University, Ames, Iowa. 76 p. REED, R. J. 1959. Age, growth and food of the longnose dace, Rhinichthys cataractae in northwestern Pennsylvania. Copeia, 2:160-162. TRAVER, J. R. 1929. The habits of the black-nosed dace, Rhinichthys astronasus (Mitchill). J. Elisha Mitchell Sci. Soc., 45:101-125.

SUBMITTED 3 DECEMBER 1968 ACCEPTED 4 JUNE 1969