FOOD OF BROOK, BROWN, AND RAINBOW TROUT FROM STREAMS IN WESTERN NORTH CAROliNA

Transcription

1 44 THE JoURN AL O>' 1'HE MITCH>OI,J, Soc 11:TY [May (1937) recognized four varieties and a form Oe11othem [ruticos11 and made research facilwithin the species. This variability, coupled ities available to her during with the known ex istence of tetraploid, hexaploid, and octoploid populations, suggests that further investigation of this species throughout its range would be worth while and might well throw light on the origin of the polyploids. Summary Plants from six populations of Oenothera f ruticosa L. from Durham County, l\orth Ctii'O!ina, were hexaploid, 2n = 42, while those from a population, in Jackson County, Korth Carolina, were tetraploid, 2n = 2. Associations of six and foul' clu omosomes nnd bivnlents were present at n1eiosis in the hcxnploid s, uud associations of fou1 ch1 omosomes nnd bivalcnts were observed in the tetraploid. It was show n that these multivalent chromo ome configurations were composed of bomologues and that tmnslocation hctcrozygo ity could not be involved. Ten plnnts rrom a hexnploid population were round to be self-incompatible but each plnnt was co 111patibl c with all tho others; )), eeding bchavi o1 wns concluded to be p1 obnbly controlled by " "'ultiplp-nllelic co"'jl'ltibility series. ACKNOWLF.DGMENTS The author wishe: to ( x p1 ess her thanks to Dr. Lew is K Anderson of Duke niversity, who made the field collection of tetraploid Ll'ri!:RAT R.E CITED Ct.f:I.AND, R. E Chromosome structure in Oe11ofhert' a n<l its effect on the evolution of t ho genus. Cy tologia ( upplement), Proe. Interna t ioual Ge netics Symosium, 1956 : GAJUnm, E. D Cytotnxonom ie studies in the genus Sorghnm. III. The polyploid species of the ~ ubg c n e rn l'ara-sorgllmn and Stiposorghru11. Bot. Gnz. 115 : GJtt:oOitv, lj. P., AN D \V. M. KLEIN luvcstigntious of meiotic chrom osomes of six gcncrn iu the Onng r <~ CCH C. Aliso 4 : H Ao.,~. W A contribution to the eytogenel ics of the genus Ocnot1tc ra, with special refer cuec to certain forms from South Ameriea. ludinnn Uui'' Publ. Sei. Series 16 : Hto:CII 'I', A Colehici11 C iuduccd tctrnploidy in Oenoflt era. Tndin.na Aend. Sci. 51 : LEWIS, n Com petition and dominaucc of in eom)ln fi h ili t~ nllclcs iu diploid poljcu. Heredity 1: Lr.w1 s, H., P. n. HAv :N, c. s. Vr.Nc.vt f:su,.\xo I-1. L. \\'imhero Observations of meiotic chromosomes in the Onagraecnc. AJjso 4 : J,JNJH: R, B. l954. J!;tud(' gcn6tique des m ~ea ni M mes qui limitcnt Ia fcrt ilitl> dans Oenotlterll mi.t~.vourie1lsi.y ct Oe11othem [I'Utico.rw. AunCe Bio i. 30 : ~ I UNZ, P. A Studies in Onngraec::te X. 'l'h subgcuus l(nci..ffia (genus Oenothera ) nnd mi :serlla ucous new species of Oenothera. Bull. Tor re.v Bot. Club 64 : ~87-:106. FOOD OF BROOK, BROWN, AND RAINBOW TROUT FROM STREAMS IN WESTERN NORTH CAROliNA L. B. TEBO, Jn.," AN u \V. W. H A:. J. >:n" 11 1Votcr QuolitJJ Section, U. S. P ~t bli c llealfh Service, Oincin nat i, Ohio bjjepartmcn f of Zoology, Norrh Caroli'llo Store Collegt>, Ralei(Jh,.\". ('. ltltroductiot~ In 1952 the North Carolina \Yildlife Hesource Com u1 ission began a Dingell-.Johnson rederal aid to fish restoration project to deterllline the effects of vnriou land-use munngcment pmctices on trout streams of western Xorth Curolina. Treated und untreated stre111ns were eompared p1imhrily 011 the tandino- crops of bottom f>1una. Such comparison would he meaningless unless the bottom organisms were nn import.ont component of the diet of trout i11 the streu111. Thc, cro re, " study of the importnnec of stren n1-hottom organisws in the di<'t of trout wn.- included in the project. Although numerous workers have studied the rood or trout, most of thrsr St11dies a i'(' seusonnl in na tu, c since they fw ve been conduet,,d in streums which are ice hound in wintet. outhcrn A ppnlachinn trout ::;treh ms 11 r r usual!.' ice free t.l11 oughout the year and present an excr llent opportunity to s tud~ the yearround foods and reeding of trout.. During th e 1953 trout season, creel chn kers on the trout mr1nagcmrut nrcas of westm n Xorth C'a, olinu collected the stomachs of trout Cllllghl on tlwse fl reas. Tlw. tomachs were 1)re-srrved in fonnnlin, und the date, total length. 11 1HI species were reeoi'dcd. In addi tion, tmut stomachs were collected from the strenm of Cowr1ltn l~ xpe r imcntal Forest in l\iacon Couu-

2 1963] ty, North Cnrolinn, during all months of the yea r. Stomachs from 241 rainbow trout, 84 brown trout, and 33 brook trout were collected and analyzed. "tomachs, nrc the most abundant insects taken in the bottom samples und occupy a pnrtieularly exposed position in the habitat. 1l nyflies we t e the srcond most abulldant Mdrr of iuun11tu e lujuntie insects foulld in the stomachs. Again the exposed!llld active memh 'rs of the family Bnetidae and Ephemerelli<lae (including B11etis SlJjJ.. l'seucu!cloeon sp1j., and Bphemerel/a spp.) show higher total muube and fre<jueucy values than the burrowiug und flattened fo rms of Epheme1idae :1nd Reptugr-niiduc. Diptc rh were the thit d most abundant ordrt of itlltunturt) nquuti, with the larvae of 'fendi Rai11bow Tro11t tomach Contents-The 241 t ainhow trout stomnchs exa mined contained 3,87 recognizable food items. The most important foods in descending order wcr c vnrions terre trinl insects, caddis fly larvae, mayily nymphs, and two-winged fly lnrn1c. These fom N1tegorics com t>rised 84.4 percent of t-he total (Table I). The adults of aquatic insects and stonc!ly nymphs, compt ising 7.7 pet ccnt and -!.5 pcrtf'nt r e!:> p ectir e l~r, were next in order of inq>or pc didnt "' Hliug the list (Table I). Unle we assu""' lhnt t out selectively feed on them, tance. the nhundance of midges in the stomachs i lmmature aqu:1tic in eels, emyfish and mollusk:; fo med 58.9 percent of the total number ~o newhat puzzling considering thei relntivc of food items, indieating that the e minbow i naccessihility and the rapid rate at whi ch these "< ft-bodied larvae are digested. However, most trout were primat ily subsurface feeders. of I :xcludiug rettehrates, 41.0 percent of the these larvae were t"ken durin <>-.Jnnuary and food items were taken from the surface. Ant February, when midge larn1.c nre fur more and various other Hymenoptera were the most nbundant than the other insects in the sh eam importnut surfnee foods, nnd Diptera, Coleop mul low water temperature would inhibit the r:t!t tern, Hcmiplcl'a, 1111d.Homoptera ranked next or digestion. in order of intpo..tanee ('L'nble I). Twt nty-( ight of the ruinbow trout had Cftten The ll<lults of aquatic in rots <loulprisecl only f t nyfish, although these crustn ceans a e not 7.7 percent of the total food items. nbund:lllt in Southern.A.ppnlachinn streams. Cad clc~ llics, mayfl ies, and stoncflies were the most 'l' h 241 trout examined contained only u f't w Vl'rtcbrntcs. C'nidentified fish remains were nhundant of the U<tuutic adu lt. Although cnddi s fly lurvac were less abnndnnt thnn muyfl y n) ntphs in bottom samples found in one rninbow trout. Also, one 7.1-inch trout contained two snakes whose combined from western Xo rth Carolina trout trrams total lengths were over three times that of the trout which had eaten them. ('febo uud ll.usslc, 196 1), the adult cadd is ntsotutl Clumges-rro fly wn.s more f equcntly found in the trout mea ure scasonnl diffpn\nct!ol in feeding. the dnta from t.he 241 stomachs ( Tnble f ), indicating that the adult cuddis flips m a~ r he 1nore vulnerable to surfncefccding trout.,l,he indiscriminate nature of rninhow trout ~toma t' h s were combined hy twomonth period' ('ruble II). the surface frt'ding of the rainbow trout is There is no appa eu t correlation between shown by the high incidence of plant foods in thl numbet of 1H1uatic oro'nui ms in trout s tom ~ the stomachs exmnincd. The stomachs of twent) -two rainbow trout contained hemlock needles ac hs ;lt diite cut seasons and the nhundnn cc of invet tehrutes in ritlle samples from streams of and small bits of wood presumably token at \\'t'slem Ko rth Cnrolinn. Tbe immatut'(' stnges of aquatic ill~cct.s constituted the major portio11 of the stomach eon the surface. The Trichoptera, com pri sing 24.7 percent of the total, were most important numerically tents during the late winter and spring, while among the immature aquati c: iuseet$. Exeludiug the genus 1/ e litop.~yche, which leads the through December. terrestrinl iusrtls p edominuted from July list as It result of the selective feed ing of u The fnll doiltimhh\e of leitcstriul insects fpw trout, thet e is companttively Little difference in the total numbers of cu<ldi fl ies, mny flies, nnd two-winged flies. It i worth noting that the lan ue of the fl t'>1. nine eat.egori<'s of c-addis flies in Table J arc c-a ~e nnd net-huild ing forms which oc eupy nn exposed position in the habitat 11nd nrc pltrtieularly vulnerable to "grubbing" hy trout. Larvae of the genus might be considered somewhnt m1u nal, since the prak of ttlnmdance of a<junti inull!lture occ-urs dtn ing < ptembcr (Tebo and Hasler. _1961.). Appnrcntly ten-estrin! insects fulling 1nto the wnter lll'c pill'ticulnrh vulnerable to fcc-din!t trout, find the trout concentrate on then during the period of the year when such insects nre available. Also, normully low water llrt~ chy cr nt u.,. oecuning in 40 of the trout levels during the fn ll months force the trout in- 45

3 46 TaE J ournal, OI' THE MITCHELL SOCIETY [ Mi!y '!'able I Tota l 11U illbet and f requency of occurrence of organisms in sto1hach contents of 2U raiubow trout collected f rom streams of westel'll North Carolina during 1952 and Total %of Frt:(]ueney Number Total TttiCHOPTERA flelicop&ychtsji Bnu;hyctlllrtlllSJl /eophy/azsji... 13fl Gftmo&oma sp.. H Hydrop8ychespJ) Diplonectraspp Jr. Parap~~ych e spp J,imncphilidae Gocridae.. I~ 8 Rhyacophila spp,, 13 II l..tpidostom(lsp Trt'!loniutsp.. II HhyacOJihilaf!A8Cula 10 Pvlyw!lropu&sp... 1/ydropli/asp Le,toufw sp CheumaloJMychr sp P8ilotreta sp Undetermined TotaL i f:pi!f.lo!eroptei\a Haetidae lleptageniidae., Ephemerellidae Ephellleridae.. 2Q Baetiscidae Undetermined Total Dn''tERA Tendipedidae Blepharocerasp Simuliumsp Tip!da spp Aldochasp., Helcidae A.therhtarieoaJa Tipulidae Eriocerasp.. o. Protoplasafitchii Undetermined Total rehte8ra'te8 Natrh&eptemriUata Diadoph!A3 pundat!as.. o.o Salamander Fish... o.o Total Total o/cof Frequenry Toral ~ u rnbl> r Pl.t:COPTt: IIA Ltuclra sp Pteronarrys 3rolti Acroneuriaspp.. 28 O.i 19 Pl'lloper/a maria J)ipioptrlat~pp Tacnio-,Jeryzstt Ntmourasp Perlodidae 0.1 Undeterrnin<'d.. Total... Ji3 4.5 Ooo~HTA L«nthussp.. 26 O.i 18 D ~XAPODA Cambarussp S MOLL\'SCA Lymnaea sp lfndetermiued 0.1 Total Orum; " Elmidae 0.1 Jlelich~A8sp. 0.1 Sia/Usp Corydaliscorn~J ta Hirudinea Undetermined Total AQt;ATIC ADULTS Trichoptera i 56 Ephe-meroptera PJecoptera Diptera Total 293 i.i T tltltesthiau! Hymenopw.ra. 307 i.s 83 Forrnicidae Diptera Coleoptera Homoptera &. Hemiptera Aphids Arachnida Ge rridae Orthopt-cra Lepidoptera.. II 10 fkrma1jtera. 8 3 Undetermined.. 2Q Total , Su TOTAL to large pools, and lhey are not able to utilize the very abundant insect faumt of the riffl es. The abundance of adult aquatic insects in rainbow trout stomachs during January and February appears to he somewhat unusual. These fish were all collected from streams of Coweeta Experimental ForestJ and many of them contained large numbers of the stone6y Leuctnt sane Thi s species emarges in large numbers during these months. All of the trout collected during the closed trout season ( Septemher 1 through April 1) were taken on hook and lin e by project personn el. Most of these fish were caught on dry flies and wide differences in temperature seemed to have no effect on their readiness to strike at surface lures. Caddis fl ies were the most abundant aquatic adult in the stomachs during all periods, except the ~ ov em ber-d ecemb e r and.janna.ry F ebruary periods when adult Coleoptera were most abundant. Adult mayflie were most frequently eaten by trout during the eptember October period but were never a major ite111 in the diet.

4 1963j TROPT FOOD IN ".ESTERN ;\OHTH CAROLINA STR~A.MS 47 Table II Percentage composition, by two-month periods, of the stomach contents of rainbow trout collected from streams of western.xorth Carolina. Jan.-Feb. ~1ar.-April ~lay-jun e July-Aug. Sept.-Oct. Nov.-Dec. Number stomachs AQUATIC Fooos Trichoptera. Ephemeroptern. Diptera. Plccoptma... Odonatn.... Mollusca. Crayfish. Neuroptera. Coleoptera l Total G AQUATIC ADULTS Caddis flies. Mayflies.. Stoneflies.. Diptera. Coleoptera ! Tot.al ~ TERUESTRIALS Hymenopt-era. Ants.. Diptera.. Coleoptera. Homoptera and Hemiptera.. Aphids.... Arachnida. Gerridae. Grasshopper. Lepidoptera. Other Total VERTEBRATES..'-'-'--'-'-'-'-'-'-'-'------'----0_.4, ;0_.1. 0_._3,, The larvae of Trichoptcra were an important component of the diet in every two-month period nnd were the dominnnt aquatic during the )Iay-J nnr, September-October, and November December periods. The May-J nne period coincides with the time of maximum abundance of the caddis fly larvae llra c h.ll cen t.ru.~ sp.j and large numbers of these very accessible larvae were eaten by the trout. Mayfly nymphs were most important during the March-April period, which coincides with the ti111e of thci1 maxunum abundance in the fauna {Tebo and Hassler, 1961). Aquatic Diptera were the most abundant item of food in the stomachs during January-February, which also coincided with thell period of maxi~t~ um abundnnce in the stream. Aquatic Diptera were also the most important aquatic food item during the July-August and Septe111ber-October periods, when terre trials dominated the over all stomach contents. The variation in food and feeding habits of

5 48 'r"" Joua NAJ, Oi' rhe MITCHELL Sooa :TY lmay dijicrcnt-sizcd trout is best illustrated by a co111parison of the food of a series of fingerling and adult rainbow tt out collected with cresol fro111 Coweeta streums on August 20, 1953 (Tahir III). The range in total length for the fingerlings was inches 1md for the udults :~ inches. Table III Compurison between percentages of surface and undcr-wu tcr foods eaten by fingerling and adult rainbow trout from Ball and Shope creeks, Coweeta l xperimental Forest, August 20, Fingerlinp,s Adult Total Num ber ot Fish Total Number of Organisms Aquatic imrnaturcs Aquatic Adults Terrestrial ntlults... 21\.1 5 n. 76 These datn indi cate thn.t fingerling trout nre more dependent on strcnm foods t.hun arc tlw adults. The fi ngerling obtained 70 percent of thrir food underwater while the udult rainbow were securing slightly over 24 percent underwntcj' und app1 ox imntely 76 percent from th e sul'fnce. In Table IV, th l rninhow trout were grouped ncco t ding to si"', and the stomn eb contents were examined iu relation to this cutcgo r ~' 1,ht' stmnuch routcnts of the l'llinbow trout in the snwllcst group nvcragcd 0.56 r<. iu volume. Table IV Mc nn ntunbct and volume of orgnni ms in stomachs of ruinbow trout. A vera.ge volume or stomach contents in cc.. Standard Error. Ave utge number of organisms pc'r stomnch. Standard Error i inches inches (67 fish) (H).q fish) 0.5(i tt;. o 2. (!4 o.. n inrhes (6 fish) 1.1>~ The inch rainbow had stonwch rontents averaging 1.15 cc., while the spec imen large r than 12.1 inches had stoma ch contents avernging 1.68 cc. Obviously, the stomnch eontents of these fish incrt,1ascd iu, ohmic iu rt' lntion to size of the individuul. There is a different picture in respect to the number of orga nisms contained in these rainbow trout ' tojjjachs. The inch group averaged.16.5 organisms per stomach, the group averaged 16.0 organisms per stomach, and the inch and larger group averaged organisms per stomach. Although the volume of the stomach contents incrca ed with the sir.c of rninbow trout, the ntuubcr of organisms per stomach va ried only slightly. Thus it appears that. with increased size in the rainbow trout, bu gcr food iterus 1 n selected. Although small food itcn1 s lllll.y he ;1 hund~:~ nt in the stream; these orga nisms 1nay be pnssed over in order to s( eurc lctrgc 1' organisms. Fo. age llatio-with the pos ible ext;eption of sir.e selection by hu ger fish, it is appnrcnt l'rom lhc preceding dnta that the rainbow trout is an opportunist, feeding on those o1 gani 111 which are most nbundnnt nndfor occupy a vuluc rnbl<' position in the habitut. Xot all organisms collected in a,c, ies of bottom sumples arc <'(Jnall) ava ilable as foo d for trout because of dift, rr n~:es in their hitbits and li fe hi.stor). A number ol' workers (All en, 1942 ; Hess and Hai1nratcr, 1939; nnd lless and, wnrtz, 1941) hnyc di scussed the cnlculation of a "forage mlio" to determine the rchttive extent to whi ch th e various constituents of the bottom fa una a1 e utilized by the trout. The forage ratio of a food orgunism is obtained by dividing its relntivc ll bundnnce, in percentnge, in the stomach t ont.cnts of a scril's of fish by the percentage ahundant'e of the orgauisn1 in the totnl fauna. Thr stomach samples nnd hottom s11 mples should be collected at about the same time nnd place. Further, it is important to include nll!) pes of habitat in the fu unistic sampling and to tollcct the sujuplcs in a representative manner. This method of calculation mnkes the fo rage rutio an cxcclleut measure of the avnilability of the vari ous bottom organi ms found in the slt cum. Barring select.ivity by the tt out, those ol'gnnisms luwing a rntio gn atcr tbun ouc nrc readily avhilable to th e trout, while organisms lwying :1 ratio less than one are not nvuilable in proportion to their nbundnnce in the faun a. Preceding sections point out that the invertehratl' bottom organisms arc the most im portant t OJIIl)Onent of food of thr rninbow ti'out. To detprmijje the relativr importance of the varlom; species, the fol'ngc rntios of. the organisms in a scrie of samples from the Xnntahala Hivcr and Ba ll Creek, Coweeta Rxpcrimental Forest.. II'CJ'e compared (Tables V and VI). On.June 13, 1953, eighteen bottom Slllllples

6 196$] TROUT Fooo IN WESTERN NORTH CAROLINA STnt;AMS 49 Table V Forngc ratios for the most important food orgnnisms in the stomach contents of 18 rainbow trout collected from the Nantahala River, June 13, Percent Percent in in Forage Stomach Fauna Ratio TRICIIOPTEHA Brachycentrus sp " Agap<tus sp Hydrop<yche sp.. O.M PLECOPTERA Pteronarcys sp :-1:-1 RPH MEROPTERA Heptageniidac (Iron and Ste11o11ema). L Baeti8 sp Ephemerclla sp DIPTERA Blepharocera sp MOLLUSCA Lymnaea sp Table VI l!'orage ratios for the most important food organisms in the stomach contents of 14 rainbow trout collected from Ball Creek, Coweeta Experimental Forest, August 20, Percent Percent in in Forage St.omach Fnunn. RatiO TJUCHOP'J'ERA Brachycentrus sp.. 4.: PLECC'PTF.RA Leuclra sp.. PteronarC1J8 scotti... Pelloperla maria. Acroneuria sp.. EPlfEM"&ROPTERA Baetis sp.. Stenonema sp... DIPTJ-:RA Simtdium sp.. Atherix sp.. Tendipedidae. 0DONA1'A Lanthus Ap CotEOPTEilA Elmidae adults. 2(\ : ;.! :UI {) 1.32 were collected fro m the Nantahala River in Macon County, North Carolina. By visual estimate two-thirds of the area of the river channel was in riffle and one-third in pools. Accordingly, twelve samples were collected from riffles and six from pools and a weighte1l mean computed f i'oiii thrse eighteen snmples. Eighteen rainhow h'ont, ranging in total length from 6.1 to 9.6 inches, were taken on book nnd line on the same day and thci r stomach contents preserved for future identifi cntion. The forage ratios of the organisms identified from these eighteen stomachs were computed and are pres ntcd in Tnble V. The forage ratios of the organisms found in the stomachs of fourteen trout collected with cresol from Ball Creek in Coweeta Ex llci'imrntal Forest on August 30, 1953, were also determined (Table VI). The twelve bottom samples used to compute the forage ratios in Table VI were all collected from riffles and are therefore not rep1 esentative. This would tend to lower the ratio of fast-water forms found in the stomachs and increase the rntio for quiet water form s. All the organisms havi11g forage mtios greater than one in the smnples from both Bnll Creek and tlw Kantahala River are d is tin ~ uis h able by chari!c:trri:ties which would make them particularly vulnemhle to trout: l. 'pecies whieh ~lrr :wtive crawler. and swimmers-baeti.1 sp., TJeuctra sp., Hnd l<jl?nidae adu lts. 2. Rp< f:in.; whieh ilre hu gc in size-ptct onltrt ys ~cotti nn<l T.Jtmthus sp. :l. Species inhabiting an exposed position ou the rocks-br"ch ycent.m s sp., Sim.ulitMn sp., Ble]Jiwmcera sp., and t.ymnaea sp. Again, avnilability is apparently the most importnnt factor in determining the strram food s cnten b)' minbo\r trout. Brook Tro11t The thirty-three trout stomach examined rontained 535 recognizable food items. The majority of these 'lomach: were collected dul' ing the open trout season hom April through August. The total diet was very similar in composition to that of rainbow trout. Various terrestrial insects, ca ddis fly lnl'vae, mayfly nymphs, and two-winged fl y larvae were most abundant. These four categories comprised 85.9 percent of the total food items (Table VII). The adults of aquatic insects, snails, and stoncay nymph, comprising 4.3, 4.3 and 4.0 percent respectively, were next in order of importance. Terrestrial insects and aquatic adults forme<l 51.6 percent of the total uumber of organisms, which indicated that the feeding of the brook trout was about. equally divided between sm--

7 50 TROGT l~ood IN WESTERN KORTH CAROLINA STREAl!S [May Table VII Total umnber nnd 1 cquency of occunence of organisms in 33 brook trout stomachs.' Fre<tuency Fr('{juen~.y Organism No. in %or or Organism No. in o/,. ur or Stomach Total Occurrence Stomach Total Occurrence 'J'KICUOPTE.R.\ Diplopn/11spp Al hrip~~'ldtssp Undetermined Hrachycenlrusspp Nemourrzsp.... Psilotrtta sp l..eudrasp. l..epidoatoma 11p.. 9 l.i Total Lim.oephilidae Ooo:uTA Neophukusp... O.i 0ASTROP0llA Hhyacophi/4spp LumnatRsp Trt,doniussp. 0.4 O tcapolla.... o.; Paraptychespp,,, AQUATIC Auut.T8 l>ipiontdraspp Trichoptcra GfouO!Oma sp..... EphemerotJlera /ydroJUrchespp, Pleeoptera Pycn01MJIChtstJ... Total. 23 l.3 A gaptlu3si),,,.. T mtrt:stjuauj Undetermined Aphids Total Diptera,, II i!.'j>b )1 ROPTERA Anti i Baetidae Caleoptl'ra 33 IL2 II Epheme.reUidae Hymenoptera Heptagt:lliidae Homoptera & Hemiptera \ Undetermined 1.3 Undetermined.. l.i Total Spiders OII'TERA Gerridae Simuliumsp ThtiJl8... Tendipedidae Total Bleplwrocna sp Orn&r.s Tipulidae Leerh.. llc1eidac 0.4 \\-atcrnnte.. Undetermined.., 0.4 Total Total \'V.KTEBRATES Pu:cOPTtRA. Salamander~ tcronturiaap Fish. I PltronarciJ~ acolli Total Ptlloperlamaria Total Averago!engtb o 7.0 inches: range inche.'i. Taken durinlt months of February, April. May, J110e, July, August, and Dettmbet, faee and subsurface foods. This is a much highe1 percentage of surface foods than reported by other workers (Needham [1938] repo rted that aquatic organisms constituted twothirds of the diet of brook trout and terrestrial order of immature nninuils 11bout one-thil'd. ) The large rep resentation of terrestri nls in om report, is attributed to seven brook trout collected iu J une whose stomachs contained 262 land organisms. The totnl number of terrestrials consumed by nil thirty-three trout was ouly 276, thus in our study only 20 percent of the specimens sampled contau1ed 95 percent of the land organisms. Aphids were the most importa nt surface foods, with various two-w inged flies, Hnt, and beetles next Ul order. Th e adults of aquntic insects fo rmed only 4.R percent of the total with caddis fli es, mayflips, and stoneft ics most abundant (Table VII). Of the immature aquntic insects, the Trichoptera, comp rising 26.7 percent of the total, were most important. Again, the exposed, casebuilding fo rms predominate, with the very abundant llrachycentn is ncar the top of the list. :\lay ft ics were the second most abundant fo un d in the trout stomachs. The, exposed and active members of the fam ilies Bnetidae and ~;p h emcre llida e were more abundantly taken than the fl attened forms of Heptageniidae. 'l'here is comparatively little diffe rence in the relative abundance ol' Diptera, P lecoptera, and Gastropodn. The relnti vely large nulllber of snail s eaten is the resul t of selective feeding by only three trout (Tnble VII). The mean, olumc of the stomach contents of thirty-three brook trout was 0.94 cc., and the mea n number of organisllls found per stomach was I n Tnblc VIII, the data fo r brook trout wer(' separated into two groups according to trout size, and the men n number of organisms and mean volume of organisms were determined for each group. The trout less than

8 1963] TROUT FOOD I!< W ESTl~RN XORTH CAROLJNA S'fRE>IM S 51 Table VIII )[enn number and volume of organisms in stomachs of 33 brook trout. Less t.hnn Greater thnn Size 7.n in. 7.0 in. :-lo. of fish \[ean no. of organisms lli.9 Stet. t rror ~ l ean vol. of 01ganism~. O. lq l.f(j Std. error ~ 7.0 irwlws in total length consmued au average of 18.7 organisms, while larger ones consumed an nvernge of 15.9 organisms. This difference i11 number was not signifi ca nt when it was tested by Student's "t" test. However, a siguifi en nt difference was fo und between the mean volu me of 0.49 cc. in the stomachs of the " lesstluuhwven-ineh" brook trout when compared with the.1.56 cc. average for the "greater-thanseven-i nch'' fish. This would indicate that larg( l' food organi sms a re selected by the larger t rout. TRICBOPTER.\ The greatest volume an1ong all thirty-three speciiuens was 5.5 ee., contained in the stomach of an.0-inch fish. Of the nineteen brook trout less than 7.0 inches in total length, onl y one fish had stomach contents greater than 1.0 cc., while in the group of brook trout greater than 7.0 inches, eight individuals had stomach contents g reater than 1.0 cc. Crayfish, fish, salu mumlers nnd m oll u ~ca were seldom taken by trout less than 6.0 inches in total length. The only exception was a solitary mollusk recovered f rom the stomach of a 5.9-inch individual. Brown Trour Thl' stomach contents of eighty-foul' brown trout colkctcd from April through August, 1953, a nd ranging fro m 7.1 to 22.7 inches in total length were examined. These stomachs contained a total of 652 recognizable food items. Various terrestrial insects, snails, caddis fli es, and nwyfli es, respectively, were most important numerically. These four categories fo nned 82.0 percent of the total number of organisms found in the stomachs (Table IX). Table IX.rota! number a nd f requency of occurrence of organisms in 84 brown trout stomachs. Organism Htlicopcych ~sp.., P ilotrttasp Limnephilidae Brat:hflttr!tru8sp. 7 I. I Rhuarop}Jila/uuuln Athrip&Odt sp Undetermined.,., G/o«(W)ma sp lllldtopayclttsp. I Total EPfLUU:ROPTERA Baetitlae Heptageniidae Undetermined... Total DIPTI:I'tA Simu!iumsp,,, Tendir.le<Jidae B/epllarowa sp... I Total Pu:coPTERA Di'J)IoJ)tT/aspp,, Acr011turiasp Undetermined.. I Total CDONATA LonJ/t!&~ap..... AQUATI<' AruLTB Trichopttra Ephen,eroptera J>lecopk>ra Total Frequency No. in Stomach % of Total 1--- of Otcurrence Organism ~o.in %of Frequency of Occurrence ---!! _sto_m _<_b _T_o_"' 'J.:RRESTRIAL5 Coleoptera... llymenoptcra.,.. Ants. Aphids. Spiders... Undetermined.. Grasshopper.,.... HomopU>ra &. Hemipttra... Diptera.. Gerridae Total rHtfl8 6 Elmidae.. Corydali!sp. Leeeh... Total..... Yt:RTElUL\Tf!S Uudetermined fish., Sculrlin.. Salatnallder... Rodent Total.. Tot:ll.. <1ABTH0P0DA Lwr.naoosp... Dt:CAPOOA.' Summary. Surface Invertebrates.. Aquatic lnvertebtatet1 Vertebra tes. 104 i!l i IIi % 434% 2.5% 100.0%

9 52 ~ m~ J ouh,;a~ O>' TH~ MITCllBLt. SOCIETY [Moy The importance of surface foods to the brown trout is shown by the large numbers of terrestrial insects and adults of uquatic insects, f'om prising 54 percent of the total, which were con urned. Adult beetles were the most important surface food s, with vnriou Hymenoptera, ants, and aphids next in order (Table IX). The adults of aquatic insects were inf', equently taken by brown trout and in limited numbers. This is similar to the findings for both b ook and rainbow t. out. Caddi s flies, mayflies and stonefli es, in that order, were the adult aquatics consumed. Immature aquatic insects only formed percent of the totnl nmnbei' of o ganism eonsumed by brown ti out. This is in sharp eontrust to the importance of immatme aquatic insects in the diets of both minbow and brook trout. Caddis flies, nnyflie and stonefliescomprising 11.7 percent, 8.3 percent, and 3.2 percent respectively-were the most abundant immature found in the stomachs. The most exposed and /or most active members C\f raeh order were most frequently c11ten. Cray fish were fr('qu(\ntly eaten, mo s U~r by large individuals, find occurred in twcnty ~ four of tlw :tomnchs examined. Appnrcntly the rrn) fish is n staple item in the diet of large brown trout in Southern Appalachian streams. Snails were of considrnthlr importance in the diet of the brown trout studied. Twentytwo fish contained eighty snail amon" them ot 12.3 percent of the total number of organisms found. Table X Menn numbet and volume of organisms in stomachs of brown trout. number of organisms were determined for each size group. Two individuals less than 7.0 inches in length were also included to give additional information. Thr eighty-four brown trout used in t.he detailed food analysis wcrr divided equa lly between two size groups. The two fish under 7.0 inches had an avcmge stomach content of 0.5 ec. of food organisms. The ineb brown trout had an average content of 1.92 ec., while the specimens larger than 12.1 inches contained 3.30 cc. of organisms. The volume of the stomach contents of brown trout increased as the size of the flsh increased. The greatest. volume in any of the stomachs was a 17.2-cc. content 1rhich occulted in a 20.9-inch fi h. This brown trout contained only four organisms-two ma~~ fli es, which OC cupird an insignificant volume, and two cra)' fish, whi ch fo mposed the bulk of the 17.2 cc. Discttssion The food of brook, brown, and ruinbow trout collected from streams of western North C'm olina varied considerably, especially in the propo t.ion of surface and subsurfuce food s cnlen. }'or the summer period, when all three S]Jccics were collected, rainbow trout took the major part of theit food under water, while the brook und brown trout consumed slightly smaller amount. Subsurfucc orgnn isms eaten by rnin bow, brook, und brown trout con1prised ~ , nnd 45.8 percent I'<'Spectively of tlw totnl number ingested (Table XI). Table XI Percentage composition of numbers of organisms eaten by brook, brown, and rainbow trout.. L tlngth Qlo' FISH Under inches inches inches No. of fish A vemge v()l. of stomach t ontenta in cc.'s. tl.50 I 92 :u Average no. of organisn1s per st.omaeh Vertebrates were found in sixteen of the stomachs. 'rwo of the trout had eaten rodents, two had eaten salamanders, and twelve (or about one in every seven) had taken fish (Table IX). In Table X, the brown trout were grouped according to length, and the mea n volume and Sur ace invertebrates. Bottom inverwbrates.. Vertebrs.tes. Brook Pl'own Rai nbow 54. t o.:l The brown trout. was the most frequent surface feeder, taking 54.1 percent of tbeil' food from the surface, while b ook and rainho11 took ~l.6 and 41.0 perc1mt of thei1 food from tlw surface. The brown trout fed to a greater extent on vertebrate, crayfish, and snails than thp other two species. Vertebmtcs comprised 2.fi percent of the diet of brown trout, an d constituted only 0.6 percent and percent. respectively of the diets of brook and rainbow trout. Crayfish were nn important item of food for brown trout, pnrtieularly la rger trout, and were found

10 1963 ] in twenty-four oc the eighty-four brown trout stou1aehs exan1incd. All th ee species of t out took larger nun he s of caddis flies than any other o der or immnturr aquutic' insects. Tmnu.tture mayflies a11<l two-winged fly lnrn1e mnkcd next in order of im portance. lu addition, the trout eonsun ed in lnrgcst numbt rs those :lpccit s of aquati c jn..,(1-t b whi( h adi\'< ly movtl nhout and jo1 oe upy nn l'xpos<'d position in the habitat. The data indit lllt 1hnt trout,,,.,, oppoi"tnnisb iu their ferdiu;:, and avnilnhi lity is definitely the most in1portant f'netor r!( lt'l'lll ining whnt foods nre eatc u. Tlu only f'x( t plio n to uvailnbility as tbc most impmt nnt dc trr111iniug faetor b; the tpii(it nty for ltn ger t out to :elect the ltn ger organisms available in the habitat. LITERATu RE CITED AJ,J,Jo:K, 1\. RADWAY Comp:nison of bottom fu unag a sources of <l \'ailable fis h food. Trans. Am..r-,i~b Soe. 11 : lh~ss, A. D., ANU J. H. H. \ I NWA'I't-~n A mctl1od for mea uring the food preference of trout. <'opein 1939 (3 ) : H "ss, A. D., AN\1 A. Sw.IRTZ The forage ratio nud its use iu dctcrmin.iug the food grade of :ilrcnms. rrnms. 5th N. A. Wildlife Con.f. 1941: rr~: u o, 1. B., JR.., AND w. w. llasslf.k. l96j. Sen son:.tl abundance oe aquatje insectli iu western No rth C~1roJiu a. trout streams. J ou r. Elisha Mitchell Sci. Soe. 11 : :! ~ SOME NEW GENERA AND SPECIES OF THE ACTINOPLANACEAE 1 J. N. Coucu /h Jmrlm t' ll( of Hotmry, University of Xorth Ca roli11a,. Chapel H ill, X. C. Tlw genus. I ctinopllul e.~, de:-wrihc d in 1950, i ohametel"izecl by the hneterin-like, fhl g011nte<l, ')winnning spore5 for med in sporangia. 1\ n hers or this falllily, and at the present (Jan Hill")', 1 91i~) we hnvr nhout J~OO isoh1 tes in pure ellltnrl'. The g re:tt~r nu11>her of those hnve nut ;l dditiomll gt Hns, 8 tr t pt 0,<~~1JOra ngiu:m. charnel< rizrd yet bern ndcquntely stud inl by nonmotile, bacteria-like spores ln distinguishing tlw genera uud species of' fonnt d in ~porang i n, was described in 1955, this new fttntily we IHwe ns(l-d both rnorphologienl und physiolot;i<:al c!hu'a<:ters. Pn1.eticnlly a"'l IIller the same vcar the fmnily Actinoplmmecae was 11ddl'd. to the,\ ctin~ m ycetn l es nil of the species grow well on Liqu idamlwr (Cnnth, 1955n, 19.'\5b). ~r cmbc t-s of tbe family pullt u in soil wntrr, and the extent nnd structure of thr nt)'celium nnd tbe sbnpcs a11d sizt s '"'~"~' lwen isolated nnd studied by T\11rl in~ ( 19.'\~) nnd Hoth wrll (1957) in the l"niled of titl' spornngin on polll'll arc vcr~ uspful St.. t ' hy Gar~tner (1955) in Germa ny, h)' blx itujj~. rnn Brunnnelcn nucl Went (1957) in Hollnnd C:mwth chnrad(l rs on ('l'rluin agnrs Hl't' 11lso """ llt nnwrk, b)' \"onomur11 nn d Obn rn (1960) Wi<'f' nl ns!-iupplemcntary aids in dl tcrnlining in.j,p;ln, by '\l!itloc k ( 1960) in \"orth (',rolin n. and h) Tnig, Budu~ n, nnd Solovievn hll'g'f' nunll>< r of different ngnrs!selc<:tl d f ro1h gcn(lrn, species, and v;~rietil's. ' \ie havfl u ~Nl H ( J 91i2) ill Russia.!host used by 1\"nksnllln (J.9:30) "'"1 his g roup, Since the discovc y of Actinoy1/ct11es, the nnthor hns been gc nd ously SUflpli('(] with so il.jc nst n ( ), and others. ]<' rom these Wt hnn! Sl lccted!'our: Czitpf:lk H l'nr ('Vuk~miln, sumph 8 fr0111 mt~ny p;l rts of tlw world nnd Hl~O), Peptone Czll pt k (snhstitlll l'.'j grn ms ln1s nhldt extensi1 e soil collection himself. Usin;: the pollen technic (Conch, 1939, 1949, peptone for tlw 2 grhnt :-; of sodiun1 nitnttf), Cnscin agnr (Gordon nnd, mith, 1955), and ) we have found thnt about 66 percent of th e soil snmples examined yield mem- Tyrosint ug11r (Cordon and Bruith, 19:3!5 ). The ino!'uluru i:-; snwnrcd on one bnlf of th(' agn r 1 rtlili work has been m:.hie possible b,v grauts surf'ht t in stu udnrd-siz;e P etri dish('s, nnd on from the National Scicncr Foundntiou (grn nl tlw otht'j' lnd f two point inoculations are mude, numijrr G-872), the 'onu11itlee ou the Ta xo nomy using nbout one cuhic mill imeter of inoculum ut of the Aetinotllytcte:i of the Society of American each point. The culture nrc stored in ca binc t" Bncteriologists, and the "Eli Lilly Com pnny. Tt is with elenr glass doors at a temperature of io - n pleasure to nckuowleclgc the valuable nssistnnec of Drs. E. R. Goldie Smith, W. J. Koch, C. J. 78 F., and after about six wel'ks to two Umph lett, nnd C. E. Mi ller nud of Mrs. C. E. months the growth characters nrc J eco rderl..\ Liller a ud.m rs. Auuc Nielsen. Tha nks a1so to The growth ehnracte s of significance nrc th t' ) lisg M{lr iou Sei ler fo r inkiug iu t.he flgures. mnount and rate of growth; color of the my -