IN 1964, the Massachusetts Cooperative FisheryUnit initiated a long-term study of certain ecologicalparameters in a 57 .3 km section of the ConnecticutRiver between the Holyoke and Turners Falls dams.Several researchers have contributed informationon bottom types, benthos, fish composition anddistribution, food of selected, fish and life historyof the American shad (Alosa sapidissima) (reviewedby Levesque MS 1970). Watson's (MS 1968) pre-liminary food analysis highlighted the need for adetailed investigation.

lContribution No.24 of the Massachusetts CooperativeFishery Unit jointly supported by the U.S. Bureau ofSport Fisheries and Wildlife, the Massachusetts Divisionof Fisheries and Game, the Massachusetts Division ofMarine Fisheries, and the University of Massachusetts.

2Based on a thesis submitted in partial fulfillment ofthe requirements for the degree of Master of Sciencefrom the University of Massachusetts.

3Present address: Biology Department, HolyokeCommunity Col1ege, Holyoke, Mass. 01040, USA.

Printed in Canada (J2346)

NorEs 1495

Food Availability and Consumption by Young ConnecticutRiver Sharl A/osa saX,idissimaL

R-lvNaoNID C. LnvnsQup2'3 lwp Rocrn J. Rpeo

Massachusetts Cooperative Fishery Unit(Jniversity of Massachusetts, Amherst, Mass. 01002, USA

Lnvnsqur, R. C., AND R. J. Rlro. 1972. Food availability and consumption by young

connecticut River shad Alosa sapidissima. J. Fish. Res. Bd. canada 29:1495-1499'

Food habits of young American shad. (Alosa sapidissima) were studied in the Connecticut

River above Holyok-e, Missachusetts, 1969. Diurnal feeding data revealed a peak in stomachcontent volume at 8:00 pu during midsgmmer. Larval shad fed mainly on aquatic crustaceansand tendipedid larvae and pupae. Juveniles ingested the most abundant organisms: crustaceans'tendipedib larvae and popi., hydropsychid lirvae and adult insects. Electivity data indicatedpositive selection for te"Oip.dia p"pie and crustaceans and negative selection for hydropsychidiarvae and tendipedid larvae. Selection of Trichoptera larvae by young shad in significantamounts was documented for the initial time.

Lrvnsque, R. C., .lr.,o R. J. Rnnp. 19'72. Food availability and consumption by young- bonnecticut River shad Alosa sapidissima, J. Fish. Res. Bd. canada 29:1495-1499.

Les auteurs ont 6tudi6 le r6gime alimentaire de jeunes aloses savoureuses (l/o sa sapidissima)de la riviEre Connecticut en amont d'Holyoke, Massachusetts, en 1969, Les donnees recueilliesdurant le jour d 1a mi-€t6 r6vdlent un maximum de volume du contenu stomacal d 2000 h. Les

aloses larvaires se nourrissent surtout de crustac6s aquatiques et de larves et pupes de tendip6-

dides. Les jeunes se nourrissent des organismes les plus abondants: crustac6s, larves et pupes de

tendip6dides, larves et adultes d'hydropsychides. Les donn6es sur le choix de la nourriture d6-

montient une s6lectivit6 positive d l'endroit des pupes de tendip6dides et des crustac6s, et uno

s6lectivit6 n{gative vis-d-vis des larves d'hydropsychides et de tendip6dides. Le choix de larves

de tricoptdres par les jeunes aloses est d6montr6 pour 1a premidre fois.

Received November 17, l97l

Our research provides specific data on (1) stomach

content of young-of-the-year shad and (2) rela-

tionships between stomach content and relative

abundance of planktonic and benthic organisms.

Although other studies have analyzed food ofyoung

shad, only Lei:m (1924), Mitchell et al. (1925), and

Maxfield (1953) related stomach content to food

availability. Of these only Mitchell et al. worked

on the Connecticut River and his work was below

the Holyoke Dam.

Materials and methods - Young-of-the-year shad,plankton, and benthos were collected from June toOctober. 1969 at three stations on the Connecticut Riverlocated at 1,1 .3,30.7, and 53.3 km above the HolyokeDam, Beach seines proved best for shad collection.Six fish per sample (two large, two small' and two ofmeciium size) were measured for total length (:t 0. I mmrl-) and weighed (+ 1.0 mg). Stomach contents wereenumerated in a Sedgewick-Rafter counting chamber.Like items were grouped and the percentage of thetotal volume visually estimated. Dry weight and waterdisplacement techniques were tried but rejected becauseof the extremely small volumes involved' During Julyand again in August, 1969, young shad were collected

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at z-}:Lr irtervals to determine feeding chronology. Fivestomachs per interval were examined for percentage offullness. These data were tested in a Kruskal-Wallisone-way analysis of variance by ranks for a differenceamong the amounts of food present in stomachs.

Plankton was collected at each station with a Clarke-Bumpus plankton sampler (00 size mesh) at a depth of1-2 m (due to variable water depth) on a back andforth course that extended to mid-stream. The meanvolume of water sampled per tow was 5433.7 liters.Analysis of plankton followed a method outlined byKutkuhn (1958), modified by Miller (1961) and slightlyaltered for our study. Items were visually assignedvolume percentage values. Benthic samples (0.3m2) wereobtained with a Peterson dredse.

The presence of a very similar larval type, Alosaaestivalis, made larval (less than 28 mm rr) identificationdifficult. Myomere counts from operculum to anus(Leim 1924), the ratio of body depth to length anddorsolateral pigmentation were used as distinguishingcharacters.

Ivlev's (1961) "Electivity Index" was employed toassess shad feeding selectivity. E values obtained mayrange between -1 and * I ; the former indicates completeselection against an item (avoidance) and the latterindicates total selection for an item, Indices in this studywere restricted to major food items: hydropsychid larvae,tendipedid larvae, tendipedid pupae, and crustaceans.

Results and discussion - (Feeding chronology)The 24-hr feeding intensity of larval shad 25.5mm mean rr (Fig. l) shows stomach contentvolume increasing during the July samples up to7:00 prr,r. However, no specimens were obtainedeven with hourly sampling, from 8:00 pM until the6:00 nu collection. A highly significant differenceamong the amounts of food present in stomachsduring August (mean rL 55.9 mm) was determinedby using the ratio of dry stomach with contentweight to the fish's wet weight in a Kruskal-Wallisone-way analysis of variance by ranks. Our cal-culated H value and the tabled value are:

calculated H : 28.57 (10 df)tabled H : 23.21 (.01 confdence level).

This difference may be the result of increasedfeeding at 8:00 pM. Our observations agree withMassmann (1963), Walburg and Nichols (1967),and Marcy (1969).

Larval food - Of 147 larvae examined, 94 con-tained food (Table 1). In fish, 14-21 mm rL, themost abundant (volume) items were cyclopoidcopepods (27.8%), tendipedid larvae (24.3/"),tendipedid pupae (12.5/), and Daphnia pulex(12.3%). Combined crustaceans totaled 57 .2% ofthe stomach content by volume and diptera Iarvae

JOURNAL FISHERIES RESEARCH BOARD OF CANADA, VOL. 29, NO. 10, 1972

and pupae accounted for another 36.7%. Nolarval shad were eaten by this size range of fish.'fhe 2l-28 mm fi sh ingested less cyclopoida (10 . 0 %),more tendipedid larvae (30.7%) and the volumeof D. pulex eaten remained similar (12.O%). Largerfish ate their own lawae (14.4/o by volume), whichrepresents the only major difference between thetwo size ranges. Shad feeding on their own kindhas been described by Mitchell et al. (1925) andI*im (1924). A specimen 14.5 mm rL was thesmallest fish with food. Other researchers citedinitial feeding at 10.0-15.0 mm (Leim 1924;McDonald 1884).

Juvenile stomach content - Stomach content of189 juvenile shad was compared with the abundanceof organisms in the environment (Table 2). Althoughphytoplankton appeared in all plankton hauls(86/o by volume) and stomachs, its appearance inthe stomachs was only in trace amounts and didnot constitute a major food sowce. Tubifex wormsocculred in 70.5% of all benthic samples but werenot ingested by shad.

We found that five food items dominated (80% bVvolume) the juvenile stomach content (crustacea,3470; tendipedid larvae, 15/o; Iendipedid pupae,7/6; hydropsychid larvae, l3/o; and adult insects,ll%). Chi-square tests using the numbers of ten-dipedid lawae, tendipedid pupae, and hydropsychidlarvae between stations indicated that there wereno significant differences in the distribution oftendipedid larvae or pupae between stations 30.7and 53.3 and also the distribution of tendipedid

a o

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t ? ? 4 6 A t O t 2 2 4 6 8 t O t 2N o o N

s a M p L E T I M E - z H R T N T E R V A L

Frc. l. Diurnal feeding pattern of young shad collectedfrom the Connecticut River, Massachusetts: on JulyI and 2,1969 at stat ions 11.3 and 16.1 (mean 25.5mm rr) and on August I and 2,1969 at station 16.1(mean 55.9 mm rr)

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pupae between the stations at 30.7 and 53.3 kmabove Holyoke Dam was nonsignificant. All otherchi-square data indicated significance between allstations for the three items tested. Because chi-square data indicated that stations were generallydissimilar in their distributions of three of the mainfood items, we did not combine station data foruse as an overall sample.

Our electivity data (Fig. 2) suggest that shadwere positively selecting tendipedid pupae andcrustaceans at all stations and negatively selectinghydropsychid larvae and tendipedid larvae at allstations except for hydropsychid larrrae at station53.3. A complex bottom type and a daily dischargeof impounded water just above station 53 . 3 may havereduced the accuracy of our hydropsychid larvaedataal station 53.3 and affected the electivity index.

Although the data show negative selection forhydropsychid larvae they are still an importantfood (13% by volume). Ours is the first study toidentify these larvae as substantial shad food.Massmann (1963) and Marcy (1969) mention

1497

trichopterans as shad food but only as occasionaland insignificant.

H. LARVAE T. PUPAE CRUSTACEA

I T E M S

Frc. 2. Electivity indices of four shad food items bystations, 79 69, Connecticut River, Massachusetts.

=FotrJJul

Tagr,B l Larval shad food by size range in mean number of organisms per

stomach (X) and, mean percentage of total stomach content vol:ume (7d.

Size range

l4J1 mm (n:47) 2l-28 mm (n:47)

Items 7oX%X

Cladocera unidentifiedAlona affinisBosmina longirostrisChydorus sp,Daphnia pulexDiaphanosoma b rachy ur umHolopedium gibberumLeptodora kindtiL ey dig ia quadr ang ular i sMoina macrocopaSida crystallina

Total cTadoceraCopepoda unidentifled

immaturesCyclopoidaCalanoida

Total copepodaDiptera

Tendipedidae larvaeTendipedidae pupae

TrichopteraHydropsychidae larvae

EphemeropteraHeptageniidae nymph

Larval shadInvertebrate eggsGrand total

0 . 1 1 3 . 4 00 . 2 6 1 4 . 3 62 . 4 9 1 . 4 98 .92 100.00

o.0z

0 .280 .060.02

o.o2o .o20.090 . 5 1

0.040 . 5 70 .090 .70

0 . 380._t7

0 .06

0 .962 .78

:2 . 1 3

12 .341 . 7 00 . 2 1

1 . 0 61 . 0 6+ . z o

22.'76

27 .774 . 3 6

34.47

24.2612.45

z . t l

3 . 9 4100.0

0.600 .020.04o.o20 .890 .020.020.020 . 1 1o .2 l0 . 382 . 3 30.94

o .720 .261 . 9 20.02l .5 l0 .26

0 .02

4.06o .2 l0 .340 .32

12.040 .210 .210 .660 .551 . 1 72 .67

L L . J J

6 . 1 7

10.002 . 1 3

18 .300 . 86

30.74I . 7 +

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1498 JOURNAL FISIIERIES RESEARCH BOARD OF CANADA, VOL, 29, NO. 10, 1972

Tasrr 2. Percentage occurrence of food items in juvenile shad stomachscompared with their occurrence in the plankton and the benthos

ltems Stomachs Plankton Benthos

PhytoplanktonEctoprocta statoblastsTubifex sp.ArachnidaLebertiidaeAmphipodaCladocera

Bosmina IongirostrisLeydigia quadrang ulo r isDaphnia pulexHolopedium gibberumLeptodora kindtiSida crystallinaDiaphano soma brachy ur um

Total CladoceraCalanoidaCyclopoidaTotal CopepodaIsopodaOstracodaInsectaLarvae

pupaeColeoptera

Haliplidae larvaeElmidae larvae

DipteralarvaepupaeHeleidae larvaeTendipedidae larvae

pupaeEphemeroptera

larvaenymphBaetidae nymphEphemeridae nymph

Ephoron sp.IarvaeHexagenia sp.

Heptageniidae nymphHemipteraHomoptera

CicadidaeHymenoptera

FormicidaeLepidopteraHydropsychidae larYae

pupaeGastropodaPelecypodaSample size

100.01 5 . 8

2 . 5

z - o1 0 . 59 . 0

44.416.9

6 . 939.r0

65.63 2 . 82 1 . 837 .O

l . o

1 0 . 61 )

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0 . 5tr_t

79.9s9 .8

3 . 2

'-'

1 . 0

J . L

5 . 89 . 55 . 3

1 . 01 A

50 .3'-o

189

100.0,_,

a t

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d . J

+ / . 62 . 1d . J

3 1 . 97 . 0

100.042 .s34.0

100.0

40.44 . 3

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47

+.e70.5

4 . 5

L . )

L . 3

4-.59 . 0

L . )

6 . 82 . 5

3 1 . 88 8 . 640.9

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s .oL . )

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9 . 0

L . J

61.4

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Adult insects, an important food in our study,have been reported as shad food by others (Mass-mann 1963; Davis and Cheek 1966).

We suggest that juvenile shad are essentiallyopportunistic in their feeding; however, they doappear to select food more from the water columnthan from the bottom or surface,

Acknowledgments - We are grateful to Dr J. F.Watson, G. Kuzmeskus, R. Waltermire, and M. Schererfor their field assistance. Special thanks is extended toMrs A. J. Mansueti of the Chesapeake Biological Lab-oratory, Solomons, Maryland, for examining a sampleof our larval clupeids and aiding in their separation,We are also grateful to Drs J. A. McCann, C. F. Cole,and J. E. Johnson for their manuscript review.

Drvrs, J. R., lNo R. P. Csnrr. 1966. Distribution,food habits, and growth of young Clupeids, CapeFear River System, North Carolina. Proc. 20thAnnu. Conf. S.E. Assoc. Game Fish Comm. 250-260.

Ivnv, V. S. 1961. Experimental ecology of the feedingof fishes. (Transl. from Russian by D. Scott, YaleUniversity Press, New Haven, Connecticut. 302 p.)

KurrunN, J. H. 1958. Utilization of plankton byjuvenile gizzard shad in a shallow prairie lake. Trans,Amer. Fish. Soc. 87: 80-103.

Lrrrrr, A. H. 1924. The life history of the shad Alosasapidissima (Wilson) with special reference to thefactors limiting its abundance. Contrib. Can. Bio1.2(ll'l: 161284.

Levesqr,re, R. C. MS 1970. The relationship of avail-able fauna to the food intake of young-of-the-year

r499

American shad Alosa sapidissima (Wilson), in theConnecticut River above Holyoke, Massachusetts.M.S. Thesis. Univ. of Massachusetts, Amherst, Mass.32 p.

Mnncv, B. C., JR. 1969. Shad early life historystudies and resident fishes, Conn. River Invest.Semi-annu. Progr. Rep. Conn. Water Res. Comrl.8: 19-50.

MlssnalNN, W. H, 1963. Summer food of juvenileAmerican shad in Virginia waters. Chesapeake Sci.4: 167-1,71.

Mlxrrnro, G. H. 1953. The food habits of hatcheryproduced pond-cultured shad (Alosa sap idis sima) rearedto a length of two inches. Md. Dep. Res. Educ.Publ. 98: 1-38.

McDoNar,o, M. 1884, The shad-C/a2ea sapidissima,p. 594-607. In G. B. Goode [ed.] The fisheries andfishery industries of the United States. Sect. I. U.S,Government Printing Office, Washington, D.C.

Mnr-rn, R. V. MS 1961. The food habits and someaspects of the biology of the threadfin shad (Dorosomapentenense, Gunther). M.S. Thesis. Univ. of Ar-kansas, Fayetteville, Arkansas, 44 p.

Mrrcurlr,, P. H., rr .a.r. 1925. A report of investi-gations concerning shad in the rivers of Connecticut.Conn. State Bd. Fish Game Rep. (Part I): 1-44.

WArnunG, C. H., nNo P. R. NIcnors, 1967. Biologyand management of the American shad and statusof the fisheries, Atlantic coast of the United States,1960. U.S. Fish Wildl. Serv. Spec. Sci. Rep. Fish.550: 105 p .

WarsoN, J. F. MS 1968. The early life history of theAmerican shad, Alosa sapidissima (Wilson), in theConnecticut River above Holyoke, Massachusetts,M,S. Thesis, Univ. of Massachusetts, Amherst, Mass.49 p.

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