(1968–1969) Job Progress Report: Life History Study of the Flathead Catfish (Pylodictus olivaris), Federal Aid Project No. F-9-R-17, Fisheries Investigations - Region 5-A

--- Page 1 --- JOB PROGRESS REPORT } fr. } As required by FEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Federal Aid Project No. F-9-R-17 FISHERIES INVESTIGATIONS - REGION 5-A Job No. IV Life History Study of the Flathead Catfish (Pylodictus olivaris) © Project Leader: K. W. Gholson J. R. Singleton Executive Director Parks and Wildlife Department Austin, Texas Marion Toole Eugene A. Walker D-J Coordinator ; Director, Wildlife Services March 19, 1970 --- Page 2 --- SUMMARY Field work was continued on the Medina and Rio Grande watersheds. The most efficient collection tools were found to be the telephone generator and large mesh gill nets. After a period of three months, one of every three fish caught in a four-inch bar mesh gill net was a tagged fish, thereby illustrating how effective gill nets would be in drastically reducing the flathead population. Stomach analyses were completed on over 800 young-of~the-year flatheads, and 600 adult fish were tagged and released in the two The growth rate of young fish is approximately 9 mm per month 12-month period. There has not been sufficient data gathered to make any valid pertaining to movement patterns of reproduction, The distribution of Pylodictus olivaris on the North American is included in the text and shown by map. and juvenile watersheds. over a assumptions continent A bibliography of published and unpublished reports is also included herewith. --- Page 3 --- JOB PROGRESS REPORT State Texas Project No.; _F-9-R-17 Project Title: Fisheries Investigations - . Region 5-A Job No.: IV Job Title: Life History Study of the Flathead Gatfish (Pylodictus olivaris) _ Period Covered: December 1, 1968 to November 30, 1969 _ Background: The need for an efficient predator to control forage and overproductive game fishes in streams and lakes has long been recognized as one of the most pressing problems in fisheries management. Numerous fisheries investigators have conducted limited research with the flathead catfish, stocked alone and in combination with other fish species. However, this research has been restricted by the fact that adequate numbers of stocking-sized catfish of known age have not been available. Because fisheries personnel have recognized this need for large numbers of various sized flathead catfish of known ages, many attempts have been made to propagate this species. Disease, cannibalism, failure of fry to accept food, and other yet un- known factors have greatly hindered the success of these endeavors. Because of its possible value as a tool in fisheries management, and its value as a food and sports fish, and the difficulties encountered in the propagation of this species, it seemed necessary to conduct a life history study of the flathead catfish. This study was designed to investigate and research this fish in its native habitat. Two radically different watersheds were chosen as sites for the initial phases of this study, the Rio Grande River with its highly turbid waters, and the much smaller Medina River with its clear spring-fed waters. Both rivers are known to support substantial flathead populations, This contrast will provide an excellent opportunity to observe any differences in feeding habits, spawning, growth rates, and other pertinent data. Objectives: During this segment, research objectives included the following: --- Page 4 --- l. To research literature on the use of sonic and radio tracking equipment. 2. To compile a bibliography on flathead catfish in general. 3. To determine size range and growth rates of 0-1 age class in both river and lake habitats. 4, To determine food and habitat requirements for pre»adult flat- heads. 5. To determine whether flatheads in connecting rivers and lakes maintain separate and distinct populations. 6. To determine spawning locations and seasons. 7. To determine individual movement and migration patterns. 8. To determine methods of spawning and rearing flatheads in hatchery ponds. Procedures: Correspondence was continued with various agencies and individuals connected with research on the flathead catfish. A bibliography is included in this report with the annotated bibliography to be included in the final report. During this segment, 803 young flatheads were collected for stomach analyses, and 709 larger fish (200 mm+) were tagged with plastic spaghetti tags and monel strap tags to determine movement and rate of growth (see Table 4). The telephone generator was used for collecting young-of-the-year and juvenile flatheads in both the Medina and Rio Grande watersheds. Can traps were again used in varied arrangements with negative results. A fine mesh nylon bag (1/8" mesh) was sewn into a thirty-foot bag seine and used in conjunction with a telephone generator on the Medina and Rio Grande Rivers to collect post-larval flathead fry, This method also proved inefficient. The seine was used in small, isolated areas of the Rio Grande during rotenone collections. Again, juvenile fish were collected, but no fry appeared. For larger fish, the telephone generator was utilized during the warmer months and gill nets during winter months. --- Page 5 --- Snosuey Leos TH, ansstq Teurue sTqetyrqueptug suteuiad usta aeploieg sokyAyuote sg S}].8sUT snosUuPT[S9S TW SUT eUlat JOeSUT BTQeTFTRUepTug erajdooald l -ds snjepAzo5 | ° aeprteps109 | piaqdoiney Sepriptnwts aeprwMouorTyy eraqdig sept Terdg eraiadoptday eraqdoayto9 aeptyossdoapAy eroqdoyotay, aeptuotsiseus0) SepTINTLTeqty sepruyosey eB ]eUuCpgO seprqerg ezajdoroweydy 3B] 90SUT BOSNT LOW epodroag Booeysnig [erTz9qeR_ Wwe Ta Zl el 0 ce "7 =O 0 0 tL OO pooy/m pauTuexe syovulois ee 89-11 89-01 89-6 =| 89-B OE ): W oa W ou W ou w oa W ou peysiojeM pure out], SdUaTINIVQ [PIO], JO Jue Jeg 6961-8961 “I *g wm 6/-6 YSTFIeD peoyjeTA Jo spoog uT uot eTAeA ATYIUOW T 219PL --- Page 6 --- TOATY SUTPOW - W poutuexe yoeuojs suo ATUQ xy J9ATY epueszy OTY ~ OY eleqdoajto) ydacKe ernjeMWT Ss}O9SUT [TITY x SHOVUPT LEIS TH ¥¥001 onssTa [euyue eTqeTyTqueptTup gt ! suyeuler YsTa veptoreg i sekuqyoteisg I’ | SJO8SUT snosueT[oosTW suTeUIeI JovsuT eTqeTyTqueptug eaaqjdosatg | | “ds SHTBPAIOH | aeptTepAroy eraqdoiney SEPTETNUTS dep TWOUOATY) Z°9 earaqdtq eeprpTearsg eraqdoptday eiajdoa[top oeptyoksdosapsy earajdoystay, aeptuotaseus0) SepTT AT lTeqri septuyosey eB ]eUOpPYO i eepTjeeg S ote. | visqdosoweydy OT | 0° O00T yeqoesuy i] 0 . eat Net ei coon a a a i Oo Lo | ee tr gm ll oOmMmnm ms re ml uy wo oO cA 2 ™~ ME NN NE A 2 ae | o Ns co =t ~ e “ ei ba i>) co wy i=) <t isa) NI a ~ N wwrd AAA AtoHAM s a oO un ™ NN SOM HH — mS MON NAN AHN NN ~m moan NN ttn anaannno er OOOoONnNom m™ oO oO NOOO mM Oo N AOI NTO NDA HN woOM a a ~ co N °o rei i=) ~t wore on xt MS =f nw Tee TT TT TE TT TR ME Ot oO an {=} cO: x oe nan Wn nn BOISNT [OW epodesag BpaoRjsnig [etreqe_ que TT rr eit ea | ANN HAD AMHANKEDOONDOMANAAA 4 ey co 06 é ae NOON AHO sts NN pooy/M pauTuexa syoPruiojs peysiejemM pue swTy, 6961-8961" “T°s ww 6/-6 YSTFIeD peeyIe,|A Jo spoog ut uoTIeTae, ATYQUOW (°uod) T eTqeL --- Page 7 --- anssty TewTUe eTqeTFTIueprug C°lZ GZ suTeueYy YsTy aeproreg ‘ds stuodey eeplyoresrqusg STIBATTO SAIDTPOTAA Z CZ snqjejound snan{,eqoy ZG aeptanyeqoy cz ‘ds stdoxjoy c ZL in un nos om unum um eeptutidésy f 0s seAy JuITeqs9 suTeUaYy JOVsuy | c aeptTeikg | G* ZT eraqdoptdey extojdosetTg | ‘ds snypepAao9 aeptpTepssaoy) eroqdorinoy SeprrpnwtTs aeptTwoucIty) eraqdtq paaqjdoapo) aeptyodsdoirpséy eiaqdoyotay, eeptuotaseuacg PEPTETAT Ted? T seprluotasy aepruyossy Gz eBIeUOpYO aepTyzeeg ey : eraqdorowsydy 6°2Z yeIDesUuy SNOsURT [AIST POSNT LOW Ppoderovaq PpeoRysnig [erszeqeW JueTd pooy/M peutTwexe syoeuojs um uy im re peysie1em pue ouTy, | BIUsTANIOQ TRIO] Jo Jueg A9ag 6961-8961 "T'S WW 661-08 USTZIeD peoy eT | Jo spoog ut uotzerszea ATYIUOW ei ea be ie a --- Page 8 --- tia sia o*T monde wo wouostor NM At ett ann et OttgeNnadn noma * I Ce ee) E ry . ONAN NN NS mam me 1 -inen oY ral: are an Wn JOATY PUTPER - W 61 o uy om 8 o . STN OST N ONAN — TON Sa e —t =f = PO Te Te eT, eT Se ee ott tTN OOM cy o Nowaonmn an aet Tum oo Se TT m4 reo ~o AN owned a+: = i ™~ eat NN ret ori AN spe ce +°Oo° - i | NOAA NN TOMO wo wo ~AN Ho ain Noi A Onm wv ! i rnp ananassae re EAM nla ary area a nt 7 8°9 € AoOomnm +tormn co "tC él TeIOL TeIOL 69-8 | I1etes9 | W ou W ou "I ‘S WW 661-08 YSTFIVD peoeyIeTY JO spoog uy uoTIeTaea ATYQUOW Ly ™ 6°47 cot AOATY epuerzy oTY - O94 a 7 oO. .o NN 10 10 NNN wy val 6°ST B° LE 8° LE ET vans +m nO i ayn FoMned am l ré L 8 ¢ ww ae moo L’T él c° 66 a a BoveTINDIQ TeIOT, JO jus) Jog 6961-8961 (°u0D) Z PTqRL Dan + wowowo m4 6°9 © Orc c° wn *eraqydoajtog Jdeoxe aANjeUNMIT sqJOeSUT [IV - x A MN Wy Oo cc m~ ™ Nemnte) ci aon N td aN : ansstz Tewpue eTqets r4ivepruy suTPWOYy UST] eeptoieg ‘ds Stiodaq aeptyoieszquag STABATTO SNqDTPOTAd snqjejound sninyejoy SePTANTeIIT ‘ds stdoajoN aeptutadsg seAYYOTIa4soO SUTRUdYy JOVsUT aeptyieakg eraqjdoptdeay eaaqdosatg -ds EnpepsI05 aeptTepsaoyg pris zdoansy SepTTTNWTs depTmouorTY) paiaqdtq eaojdoayo) aeptyohsdospAy eraqdoyotay, aepTuoTiseus0) PRPELELIPIE YD eeprluotasy SepTuyossy eB jeUuopO septyerg ezojydorzsueydy ye ]O8sUT Snosuey, [Post BISNT LOW epodesaq BpooRISsNIyV [etszsieEW Juel” pooy/M peutTuexe syoruojs peysisjeM pue swt], --- Page 9 --- L°9T 09 09 0¢ O¢ 08 0c 0¢ 0¢ €°€8 02 4 — 69-% ou 69-€ W Ww “I ot oe | 0g enssty [ewTue aT qeTyTqueptuy suTeuDYy YSTA aeptoteg £°8 00T @PPTUBseTIS -ds pulosol10g eeptedn{t9 ‘ds stxoulog | | ‘ds stuoday i eeptyozezqus| SUT PUY ‘ds snanyeqoy SEPTANT eT ‘ds stTdoijoN aeptutadsy sefkyqyoteqsg ‘ds snyepAazo5 aeprlepAro0g easqdosnoey aeptyosAsdospAy ero doystay, eraqdorswaydy yb] DesSuy pooy/M peutwexe syoruojg 0g 0¢ Ov 02 0¢ 0¢€ OOT aovovonmanown 6 are eK4 OM] H BO=TT W AM OOM MAM OMY faa] ise] 89-01 W od WwW oF] NW An39Q [BIO] Jo 4useg aag peysie eM pue salty, ape aoued 6961-8961 "S + uw QOOZ YSTy2eD preyIe[ yA Jo spoog ut uorjzerszea ATYIUOW € ?19deL --- Page 10 --- ASATY pue eye T Pulpa_ - W AaaTy apuesig oTy = 94 -swioy eInjeWwwT atom s}2eSUT TTY - » T x | “|| TI | | | | | | = ansst2 | 1 [eurue a[qetytj}ueptuy | | 1°6 / 7°6 | suteweay UsTg | O’€ OOoT/ aeptoteg | | of (ve | | ‘ds SnjouTpoTay | i Ove / TE aeptuertos | | ove /1'€ 001 ‘ds BilosoT0g dae 3 /6°T2 OOT aeptednt9 | ore {te | ds STxotI0g T°6 /76 | | ‘ds Stmodsy i T*é1 OE 4 | aepryoreirjque) Lg / 9 SULPWOY Z°C1 Jost | -ds Sanyeq>T | Z* te | / 6°L2 1 aeplan[e}2] | o°€ / Ve | ds Stdox70N O'€ | ye | i aeptutaddg ' L-éL OOT/ 6°TL | OOT ool sadyqyotaiso 16 / 9°6 | “a9 BAPSpRIOD 1°6 /4°6 aeptleps109 16 / 4°6 piojdoiney T°9 / 29 aeptysdsdosapséy | T’9 / 29 eraqdoyotay, T’9 / 29 prsjdoremseydy | | aes f 6°T¢ 4P}I9SUT 02@ T/ 61 z Zz pooy/M peutwexea syoeruojgs es en ee vd a a CCE CoS Trezea9 | OW ou W oa W ou W ou W ou 6961-8961 : “Ty *§ + UW QOZ USTsIeO peoyReLA JO spoog UT uoTIeTae, ATYQUOW ("uoD) € FTGeL --- Page 11 --- a i I | 8 4 | Zz pereaosey s3ey, z9 LE 94 pessel usta 69-6 | 69-8 | 69-2. i - SCOR | Y10M On 6) | 0 pelarosay s3ey, yIoM ON ST 0) pessey usta ~ 89-1T | g9-0T | © Sqau0oM acne: me en “Sye] BUTpEW = xy | A9ATY BUTPOW - x Pperoaod9y sBey z pessey, usta 69-L 699 TON 0 | 1-0 persaozv0y ssey, a-9 0 | exe Tm € | 3¢a= tL pessel usta . a aT SUS ejeq AraAooey pue Burssey y eTqey --- Page 12 --- ~ 10 Findings: Previous collection methods were improved, and flatheads of all sizes (except post-larval) were collected efficiently. The telephone generator is ineffective in waters below 60° F. The majority of the gill nets were 4-inch bar mesh and were extremely successful in winter months (Table 5), As noted, this bar mesh proved highly selective for flathead catfish from 10-70 pounds and larger cyprinids. This size mesh will be employed extensively in the next segment along with 5-inch mesh nets. In an effort to collect more young adult fish (1-8 pounds), 1,000 feet of 3-inch bar mesh gill netting was employed with limited success, Many other species of fish, including many game fish, were collected in the 3-inch nets along with a few flatheads in the desired size range. There- fore, for time expended and specimens acquired, 3-inch nets were not suitable, Two flatheads were taken from an illegal hoop net on the Rio Grande River that had been placed in a narrow channel of swift-flowing water. These fish were tagged and released at a point some distance downstream. One of the two fish had been tagged before. Habitat: Adult lake fish were collected in water from 10-90 feet in depth by gill nets, but with limited success in depths over 45 feet, Most fish were taken near the old river channel in 15-35 feet of water The only areas in this depth range that did not yield fish consistently were heavily silted or were old submersed fields. Adult lake and river fish were collected with the telephone generator in water depths of from 4-25 feet around obstructions such as boulders, large trees, and rock ledges. As determined in the previous segment, adult fish were always found where some current existed, regardless of water depth. Also, as in segment 16, young-of-the-year and 1-2 year class fish were collected in shallow, fast-moving water over a hard rock or brush littered bottom, In the summer the old river channel in the upper part of Medina Lake was approximately 18 feet deep in the center with the banks of the channel being 7-10 feet under water. Late in the summer, heavy rains on the water- shed raised the lake level by 12-14 feet and telephone generator collections a few days afterward produced numerous young: of-the-year fish along the oid river channel in 18-20 feet of water where only one such fish had been observed during all previous collections. --- Page 13 --- 00L‘z 69-9 007°Z 69-S 69-7 a S][Nsey BUTIION aye] euTpey G eTqPL 3eN JO Jeeq jo “ON o3eutxorddy peyzom s7ystN suinjoy Bry ustleysTy jaods sainqdesey pessey usta nay] “JON JO Jooy Fo “ON oJeUTxOAddy pex10M siyustIN suinjey sey uselliaysty 3aods sainjdesey pessey usta --- Page 14 --- «19+ Reproduction: Information on flathead reproduction is still vague and inconsistent. It is apparent, in both the Rio Grande and Medina watersheds, that all females do not develop at the same time of the year. Insufficient numbers of spawning sized adults have been sacrificed to show any definite spawning activity patterns. Specimens will be sacrificed in greater numbers from the Rio Grande River during the next segment in order to gain more knowledge of sexual development patterns. The Medina River will be ex~ cluded from this phase of data collection because of its relatively small size. Its recruitment potential is far below that of the Rio Grande and continued harvest of adult fish would probably produce a noticeable change in the overall population. In the few fish sacrificed previously, there were few mature females in any specific size group. In the course of stomach analyses, 9 fish in the 79-235 mm (1.125% of the total) range contained ovaries with developed eggs. Of these nine fish, taken from the Rio Grande River, eight were be- tween 79 and 168 mm. Work was initiated on the Medina Hatchery in an effort to spawn flat- heads artificially. Three pairs of fish were used, and females were injected with chorionic gonadotropin at the rate of 500 I. U. per pound of body weight. One spawn was obtained and moved to the San Marcos Hatchery catfish incubator. The resulting fry appeared to be deformed, did not absorb the yolk sac, and eventually died. Water temperature at the Medina Hatchery was 83° F. preceding and during the spawn and was probably the key factor involved in the failure of the fry to survive. A total of eight feral fish were transferred from Medina Lake to the Medina Hatchery to be used in the 1970 spawning season. A number of fish in the .5 to 2.0 pound size range from the Rio Grande were stocked in ponds on the hatchery in 1968 for use as broodfish in the future. Valuable information during this segment, relative to reproduction and culture of flatheads, was obtained at the U. S. Department of Interior Fish Farming Experimental Station, Stuttgart, Arkansas, from Kermit Sneed and John Guidice. Their findings indicate that the combination of healthy, hatchery-reared broodstock and the use of chorionic gonadotropin injections is the most consistent method of inducing flatheads to spawn under hatchery conditions, Growth Rate: To date, data does not show a definite growth rate of adult fish by weight during a specified period of time. However, tagged adult fish do exhibit an average length increase of 7.5 mm per month. --- Page 15 --- =] 3. Growth of young-of-the-year during the past two years averages 10.0 mm per month for fish in the Medina River and 8.3 mm per month for Rio Grande flatheads (Table 6a and 6b). Although Medina River fish overtook the Rio Grande fish by November in 1968, the reverse occurred by November 1969, The only explanation of this reversal, that can be offered at this time, is that there is nearly six weeks difference in the fall collection times in 1969 and the Rio Grande fish had a lead of 4 mm more in July 1969. By adding an extra six weeks growth to the Medina fish (15 mm) and subtracting the 4 mm gained by July from the average length of the Rio Grande fish, the growth trend of 1969 is the same as in 1968. Considering these inconsis- tencies, data will be collected in 1970 as it was in 1968 to substantiate the trend. The smallest fingerlings collected in June average 110 mm standard length and are believed to be one year old. Assuming the spawn occurred in June of the preceding year, they would, therefore, exhibit a growth rate of approximately 9 mm per month over a 12-month period. This rate appears consistent in both watersheds. Movement Patterns: Movement of all recaptured fish appears to be quite random both in frequency and distance (Table 7). Of the 709 fish captured and tagged, only 22 fish were recaptured. Two of these were recaptured two times and two, three times. The average number of days of freedom between recapture is 28.1 days. There is no correlation between period of freedom and distance of movement, Movement of fish in both the Medina and Rio Grande Rivers is basically the same as that for Medina Lake. Some were recaptured two and three times exhibiting erratic movement with no relation to period of freedom. Twenty additional tags have been returned by fishermen and game manage~ ment officers. The weight of these fish varied from 1 to 45 pounds and showed movements of from .25 to 4.0 miles in Medina Lake. One fish tag returned from the Rio Grande River showed the fish moved approximately 10 miles upstream. Although biased by a number of factors, tag returns from anglers indicate that 65 per cent of these fish were caught within 60 days after release (Table 8). It is hoped that a larger number of fish can be tagged in early 1970 and sonic instruments will be used to obtain more conclusive data on movement patterns. Food Studies: A total of 823 flathead catfish stomachs were examined during this segment. These specimens were divided into three size groups: --- Page 16 --- e*9 . ZIGVL WU SS WSUS, *Bay (sUTT usforg) 606T ATnp ‘zeaty epresy oTY umg*ol 44.3ueT ay (PUTT PFIOS) 6961 Arne Saxeaty euTpey *Wu UF YYZUeT pPrepTEys OzT ; fy) ) ott OOT g L og os oO} o€ oz ot ‘ pitty? A PEE TN TTT TTY TT T pti ttt tT | SPE TN ET ee tTTT TT TTT RTT TTT TTT TTT Ty TEP PrP ; q Pt tt TT TT tT TE ET TT cs ptt ttt tT Ty TEE eR Te TT 7 ose : : : 9 pti tt TT tT TT eNO TE TP TT L COPE erect: sg SEERA eee COPE Ere COPE EEE eras EEEEE EEE EE EEE tL COPE cee COPE Ere CEE EEE EEE EE EEE ETH it CEP are --- Page 17 --- CECE CECE eer 7?,2mm FREER EEE / \ \ al ver, lenetn ne AG f \ Vt Ee Kanada lane) ris / / \ f ) 5 , Oatohner LOS va ‘ ‘ ra O60 eAlinng Sava TV TA an of A A a Y +t M4 N a er ct 18 17 16 3 Number of Specimens 87 Ome \ave, J man Vine j 5 apn TQLO ( “yende River, Nov. 0 24 6-b kr --- Page 18 --- -16- Oc Tu Z/T T 07 - “Tm y/T = “TW 4/T Z | €€ "Ta Z/T 1 if | HE “ta 2/1 T [ 3 ‘ 0 T | 89 Fu y/T T z 0 I ! 0 1 z 0 if tz 0 I 6€ “Fu T T 61 "Tw ¥/€ 1 T | 92 Fm 2/1 i 92 “Ta Z/T T I = 02 “Tul /T = “FW 7/E T z 61 “Tu y/T if tz yw T 1 + tv€ = T= 12 “Tu y/E = “TW y/T - “TW H/€ T € | 9€ 0 I 14 “Tu T is i 26 yu T T f f= -% <= Qt 0-0 = *TaT € Wopeeitg jo sAeq | SguauBAOW~~—~CSYSSC‘“‘z IOS JOOTOIg &q soaanqdesey sein3tq JUeWoACW eye eUTpEH L eTqez, --- Page 19 --- a Table 8 Elapsed Time Between Tagging and Recovery - Sportfishing November 13, 1969 July 3, 1969 June 24, 1969 March 21, 1969 October 3, 1969 April 15, 1969 June 12, 1969 June 12, 1969 May 14, 1969 May 2, 1969 March 19, 1969 May 14, 1969 March 20, 1969 | June 24, 1969 March 13, 1969 | May 9, 1969 July 30, 1969 March 12, 1969 April 1, 1969 | March 14, 1969 July 14, 1969 July 4, 1969 April 7, 1969 October 23, 1969 May 12, 1969 July 10, 1969 July 19, 1969 June 26, 1969 June 18, 1969 May 9, 1969 July 7, 1969 May 17, 1969 September 6, 1969 June 6, 1969 August 8, 1969 November 22, 1969 August 9, 1969 September 16, 1969 September 13, 1969 Tag Recovered _ November 18, 1969 Days Elapsed = oi 5 TL 11 17 20 27 28 37 42 47 51 54 58 74 85 91 115 150 168 187 --- Page 20 --- -18- A. 9-79 mm standard length - Table 1 B. 80-199 mm standard length - Table 2 C. 200 mm standard length - Table 3 These tables substantiate the assumption drawn in the previous segment that Medina River flatheads change to a fish diet at an earlier age than do the Rio Grande fish. -From Table 3 it should be noted that 71.9 per cent of the stomachs from the Rio Grande fish contained fish or fish remains while 100 per cent of the stomachs from the Medina River contained fish remains, Tablesl and 2 show the same trends but with some Variation in percentages relative to Table 3. Analysis of these tables yields the fol- lowing stomach content percentages: Fish or Fish Remains Insects or Insect. Remains ED ea LTS Table j Medina 0.8 92.1 Rio Grande 0.0 99.0 Table 2 Medina £,6 84.1 Rio Grande L2 97.1 Table 3 Medina 100.0 0.0 Rio Grande 71.9 21.9 Although many insect orders were present in these analyses, Ephemeroptera was the preferred food, The stomachs of the larger flathead catfish (10 pounds or greater) in- dicate these fish feed on gizzard shad, Crappie, carp, and various sunfish as large as is Possible to swallow, Shad removed from Stomachs range up to 200 mm, Partially digested carp that had an approximate total length of 200 mm have been found in Sill nets alongside large flatheads. Stomach analyses will be conducted on those fish from the Rio Grande that are to be Sacrificed for sexual development data in the next segment, These analyses should provide more basis for conclusive feeding habits of large adult flatheads. Discussion of Tables: Tables 1-3 were compiled from examinations of 823 flathead stomachs Figures given are for percentage of occurrence, Table 4 is a record of tagging activities for each watershed, Fish listed were taken by either a telephone generator or gill net, --- Page 21 --- -19- Table 5 illustrates the effectiveness of large-mesh gill nets in col- lecting flatheads, Nets used were primarily 4-inch bar mesh with 3-inch bar mesh being employed 25 per cent of the time. Table 6a compares standard lengths of young-of-the-year collected in July in the Medina and Rio Grande Rivers. This chart is used to determine the average length in July for comparison with average length in November to yield a growth rate during the prime growing period, Table 6b is the average lengths in the fall used in conjunction with Table 6a. Table 7 lists information gained from fish recovery by project personnel in an effort to determine movement trends and periods of freedom. MInsuf- ficient fish recoveries were made to draw sound conclusion. Table 8 is a record of tagged fish captured by fishermen and the “tag recovered" data is occasionally an estimated time accurate to +5 days. As noted earlier in this report 65 per cent of these returns occurred within 60 days after release. Most tag returns were from Medina Lake. The tagging operation was concentrated in a part of the lake where the most trotline fishing is encountered. Also, most fish tagged in Medina Lake were at a time just prior to the peak trotline fishing period. Therefore, the only valid conclusion to be drawn is that handling the fish did not have an adverse effect on feeding habits or movement. Distribution on the North American Continent; Although it was not included in the original job description, corre- spondence with virtually every state agency yielded complete distribution information on Pylodictus olivaris, and is included herewith. The flathead catfish is found (and native to) the Gulf Coast from Texas, across to the western two-thirds of Alabama, then northeastward through the northwest corner of Georgia, western fringes of North Carolina and Virginia, through most of West Virginia to the southwest corner of Pennsylvania. Its northemrange extends westward through Ohio, southern Michigan, Indiana, Illinois, southern part of Wisconsin, southeast corner of Minnesota, Lowa, up through central South Dakota to its northernmost range in the Bismark area of North Dakota, It extends southward through Nebraska, Kansas, Oklahoma, and westward through most of New Mexico. It then ranges south into Mexico (but east of the Continental Divide down to the 18th Parallel). Its southernmost range is believed to be the Rio Balsas, (Personal correspondence, May 1969, Amin Zarur Menez, Biologist, El Director Del Instituto Nacional De Investigeciones Biologico Pesqueras.) In addition to its native range, the flathead has been introduced in other areas. Those introductions are as follows: --- Page 22 --- ~20- Florida: 1965 Lake Beulah (in south Florida) - 1 specimen captured 1969. South Carolina: 1965 Santee-Cooper Reservoirs and Hartwell Lake - results unknown. Colorado: 1958 Adobe Creek and Bonny Dam Reservoirs - believed un- successful (personal correspondence 1969, R. A. Jones, Director of Game, Fish, and Parks, State of Colorado). Idaho: Early 1940's Snake River - apparently producing. Oregon: Snake River - apparently reproducing. Washington: Not recorded but may have moved downstream in Snake River. Arizona: 1962 Colorado River, also San Carlos Reservoir on Gila River. Responding well. Reproducing populations established. California: Imperial County, All American Canal system. Recruited from Arizona introductions in Colorado River. Established population. \ fr | Prepared by K. W. Gholson Approved by WZ ep viz A Ot ( a Project Leader - Coordinator Date March 19, 1970 Elgin M. C. Dietz Inland Supervisor --- Page 23 --- (ih CIONGOYINI c . =~ Wehkeg > c 7 nvVany vA the ge Ne ee eo hee ty HA A BAG Vet, 4,7 LA 4b t4 > ‘ at + LWA - a » at +, Th >Asyt*a eho chatAve ad at pete re yy 7 a? ry? . eakA Pht > ARFT Ate aw é NOTLNGTYLSTO WYnlyN'? «Bf HSISLVD GVSHIVIS 40 NOILAGIYISIG --- Page 24 --- 2276 Pylodictus olivaris Bibliography Barnikol, Paul G. and William C. Starrett. 1951. Commercial and Sport Fishes of the Mississippi River Between Caruthersville, Missouri, and Dubuque, Iowa. Bulletin of the Illinois Natural History Survey. Beckman, William C. 1952. Guide to the Fishes of Colorado. Boulder, Colorado, Bottroff, Lawrence, James A. St. Amant, and Wayne Parker. 1969. Addition of Pylodictus olivaris to the California Fauna. California Department of Fish and Game. Breukelman, John. 1947. What Have I Caught? Forestry, Fish and Game Commission, Pratt, Kansas. Brown, Bradford and J. S. Dendy. Observations on the Food Habit of the Flat- head and Blue Catfish in Alabama. Brown, William H. 1960. The Fresh-Water Catfishes of Texas and How to Know Them. Texas Game and Fish Commission, Austin, Texas. Brynildson, Clifford, Arthur Ensigh, and John Truog. 1959. A Progress Report on the Wisconsin River Catfish Survey. Wisconsin Conservation Department, Fish Management Division. Calovich, F. E. and B. A. Branson. 1964. The Supraethmoid-Ethmoid Complex in the American Catfishes, Ictalurus and Pylodictis. Published in the American Midland Naturalist. Carroll, Billy B. and Gordon E. Hall. 1964. Growth of Catfishes in Norris Reservoir, Tennessee, TVA, Norris, Tennessee. Journal of the Tennessee Academy of Science, Vol. 39, No. 3. Carroll, Billy B., Gordon E. Hall, and Robert D. Bishop. 1963. Three Seasons of Rough Fish Removal at Norris Reservoir, Tennessee. Reprint from Transactions of the American Fisheries Society, Vol. 92, No. 4. Clemens, Howard P. and Kermit E. Sneed. 1962. Bioassay and Use of Pituitary Materials to Spawn Warm-Water Fishes. Research Report 61, U. S. Fish and Wildlife Service, Washington D. C. Clemens, Howard P. 1954. Pre-Impoundment Studies of the Summer Food of Three Species of Proceedings of the Oklahoma Academy of Science. Cooper, Gerald P. and Karl F. Laglher. Appraisal of Methods of Fish Popu- lation Study - Part III. The Measurement of Fish Population Size. Twenty-first North American Wildlife Conference. --- Page 25 --- “9a Cross, Frank B. and Claude E. Hastings. 1956. Ages and Sizes of 29 Flat- head Catfish from the Kansas River, Douglas County, Kansas. Transactions of the Kansas Academy of Science, Vol. 59, No. lL. Davidson, Gladney. Drum Fishing for Blue Catfish and Flathead Catfish. Louisiana Wild Life and Fisheries Commission, DeLury, D. 8. 1953, The Estimation of Population Size by a Marking and Recapture Procedure. Department of Mathematical Statistics. Ontario Research Foundation, Toronto, Ontario. Dietz, Elgin M. C. 1962. Experimental Control of Fish Populations with Flathead Catfish. Texas Game and Fish Commission. Douglas, Neil H. and James F. Davis. 1963. Checklist of the Freshwater Fishes of Louisiana. Louisiana Wild'Life and Fisheries Commission. Dupree, Harry K. and 0. L. Green. Comparison of Feed Conversion and Growth Rate of Six Catfish Species and Their Hybrids. Southeastern Fish Cultural Research Laboratory, Marion, Alabama. Fajen, Otto F. 1960. A Study of the Standing Crop of Fish in Two Small Ozark Streams. Missouri Conservation Commission, Jefferson City, Missouri. Fish and Wildlife Service, U. S. Department of the Interior Catfish Feeding and Growth. Bureau of Sport Fisheries and Wildlife. Fish Farming Experimental Station. Stuttgart, Arkansas. Fontaine, Pierre A. 1944. Notes on the Spawning of the Shovelhead Cat- fish, Pylodictus olivaris (Rafinesque) Funk, John L. 1957. Relative Efficiency and Selectivity of Gear Used in the Study of Fish Populations in Missouri Streams. Special Technical Report No. 2. Missouri Department of Conservation, Jefferson Gity. Funk, John L. 1954. A Study of the Migration of Stream Fishes. Missouri Conservation Commission, Jefferson City, Missouri, Guidice, John J. 1966. Growth of a Blue X Channel Catfish Hybrid as Compared to its Parent Species. Reprint from the Progressive Fish- Culturist, Vol. 28, No. 2. Guidice, John J. Investigations on the Propagation and Survival of Flat- head Catfish in Troughs. Fish Farming Experimental‘Station. Stuttgart, Arkansas. Hackney, Peter A. 1965. Predator-Prey Relationships of the Flathead Cat- fish in Ponds Under Selected Forage Fish Conditions. Auburn University Agricultural Experiment Station, Auburn, Alabama, --- Page 26 --- “Dk - Hambric, Robert N. 1967. Growth Rate of Channel Catfish Fingerlings Fed Low Protein Food Versus Growth Rate of Fingerlings Fed High Protein Foods and Significance of Stocking Fin Clipped Catfish in a Large Park Lake. ~ Hanson, Willis D. 1960. A Fish Tagging Program for the Large Impoundments of Missouri. Missouri Conservation Commission, Jefferson City, Missouri. Haskell, David C. and Robert G. Zilliox. Further Developments of the Electrical Method of Collecting Fish. N. Y. State Conservation Depart-~ ment Gansevoort, N. Y. Hasler, Arthur D. and H. Francis Henderson. 1963, Instrumentation Problems in the Study of Homing in Fish. Reprinted from ''Bio-Telemetry". Henderson, H. Francis, Arthur D. Hasler, and Gerald G. Chipman 1966. An Ultrasonic Transmitter for Use in Studies of Movements of Fishes. Transactions of the American Fisheries Society, Vol. 95, No. 4. Henderson, Harmon. 1968. Observations on the Propagation of Flathead Cat- fish in the San Marcos State Fish Hatchery, Texas. Reprinted from Proceedings on the 17th Annual Conference, Southeastern Association of Game and Fish Commissioners, 1963 held in Biloxi, Mississippi. Horrall, RossM., Gerald G. Chipman, and James D. Bruins, 1967. Development and Improvement of Instrumental and Data Processing Methods in Limnology and Fishery Biology. State of Wisconsin. Horrall, Ross M., M. F. Henderson,and A. D. Hasler. 1965. Uitrasonic Tracking of Migratory Fishes With an Internal Tag. American Fisheries Society Meeting. Houser, Alfred and Michael G. Bross. 1963. Average Growth Rates and Length-Weight Relationships of Fifteen Species of Fish in Oklahoma Waters, Norman, Oklahoma. Jenkins, Robert M. 1952. Growth of the Flathead Catfish, Pylodictus olivaris, in Grand Lake (Lake 0' the Cherokees). Oklahoma Research Laboratory, Norman, Academy of Science. Johnson, James H. 1968. Ultrasonic Fish Tags: A Behavior Research Tool. Bureau of Commercial Fisheries Acoustical Workshop, Seattle, Washington. Jones, David J. 1963. A History of Nebraska's Fisheries Resources. Nebraska Game, Forestation and Parks Commission. Kansas Forestry, Fish and Game Commission, 1965. Flathead Catfish, Information Bulletin No. 103 . --- Page 27 --- Koster, William J. Guide to New Mexico Fishes. University of New Mexico Press. Albuquerque, New Mexico. Langemeier, Ralph N. 1965. Effects of Channelization on the Limnology of the Missouri River, Nebraska, with Emphasis on Food Habits and Growth of the Flathead Catfish. University of Missouri Little, Ralph G. 1964. State Wide Fisheries Investigation-Periodic Check of Lower Black River. New Mexico Department of Game and Fish. Martin, Mayo. 1967. Techniques of Catfish Fingerling Production, Reproduced from the Proceedings, Commercial Fish Farming Conference, Memorial Student Center, Texas A & M University. Meyer, Fred P. Dylox as a Control for Ectroparasites of Fish. Fish Farming Experimental Station. Stuttgart, Arkansas. Minckley, W. L. and James E. Deacon. Biology of the Flathead Catfish in Kansas. Ming, Arvil. Boom-Type Electro-Fishing Device for Sampling Fish Populations in Oklahoma Fishery Research Laboratory. McCoy, H. A. 1953. The Rate of Growth of Flathead Catfish in Twenty-One Oklahoma Lakes. Oklahoma Academy of Science. Moen, Tom. 1964. Feeding Young Flathead Catfish. Progressive Fish- Culturist 26: (1) 26 Iowa Conservation Commission, Spirit Lake, Iowa. Morris, Larry. 1966. Flathead Catfish Investigations in the Missouri River, Nebraska. Project No. F-4-R-11. Morris, Larry. 1967. Flathead Catfish Investigations in the Missouri River, Nebraska. Project No. F-4-R-12. Morris, Larry A. and Paul F. Novak. The Teiephone Generator as an Electro- fishing Tool. Project F~4-R. Nebraska. Morrissette, Douglas. 1966. Grandad of Catfish. Oshkosh, Wisconsin Conservation Bulletin. Muncy, R. Jess. 1967. Towa Conservationist. Vol. 16, No. 5. Posey, Lloyd and Harry Schafer. 1964. Evaluation of Slat Traps as Com- mercial Fishing Gear in Louisiana. Pritchard, David L. Experimental Cold-Branding and Anchor-Tagging Chainel Catfish, Texas, Region IV, Inland Fisheries Project F-12-6a. Purkett, Charles A., Jr. 1958. Growth of the Fishes in the Salt Water, Missouri. Columbia, Missouri. --- Page 28 --- -26- Purkett, Charles A., Jr. A Study of the Growth Rates of the Important Stream Fishes of the Salt River Watershed. Missouri Department of Conservation. Jefferson City, Missouri. Riggs, Carl D. 1958. Selected References on the Channel Catfish, Ictalurus punctatus. Scientific Report - Fisheries No. 240, Washington, D. C. Rosa, H., Jr. 1965. Preparation of Synopses on the Biology of Species of Living Aquatic Organisms. Food and Agriculture Organization of the United Nations. Rome. Schafer, Harry, Lloyd Posey, and Gladney Davidson. The Use of Cans in Harvesting Catfish. Louisiana Wild Lifeand Fisheries Commission. Schoonover, Roy and William H. Thompson. 1954. A Post-Impoundment Study of the Fisheries Resources of Fall River Reservoir, Kansas. Trans- actions of the Kansas Academy of Science, Vol. 57. Schomacher, Roger. 1968. Some observations on Flathead Catfish in the Mississippi River Bordering Iowa. Transactions of the American Fisheries Society, Vol. 97, No. l. Scott, Donald C. Sampling Fish Populations in the Coosa River, Alabama. University of Georgia, Athens, Georgia. Sneed, Kermit E. and Howard P, Clemens. 1959, The Use of Human Chorionic Gonadotropin to Spawn Warm-Water Fishes. The Progressive Fish-Culturist. Sneed, Kermit E., Harry K. Dupree, and 0, L. Green. Observations on the Culture of Flathead Catfish Fry and Fingerlings in Troughs, South- eastern Fish Cultural Laboratory, Marion, Alabama. Snow, J. R. 1959. Notes on the Propagation of the Flathead Catfish, Pylodictus olivaris (Rafinesque). The Progressive Fish-Culturist. Stubbs, John M. 1963. Warmwater Stream Management. Tennessee F-17-R-6: Stubbs, John M. 1965. Warmwater Stream Management. Tennessee, Swingle, H. S. 1963, Experiments with the Flathead Catfish in Ponds. Auburn University Agricultural Experiment Station. Auburn, Alabama, D. J, Project F-10-R, Swingle, H. S. 1969. Production of Threadfin Shad, Dorosoma petenense (Gunther). S$. E. Association of Game and Fish Commissioners, October 1969, Trandahl, Arden J, 1966. Intensive Rearing of Flathead Catfish at the Senecaville National Fish Hatchery, Ohio. --- Page 29 --- ~27- Truog, John. Fishing for Flatheads. Boscobel, Wisconsin. Wyoming Game and Fish Commission. 1967. Federal Aid in Fish and Wildlife Restoration - Miniature Radio Transmitters for Tracking Freshwater Fish.