TPWD 1956 F-6-R-3 #241: Inventory of Fish Species Present in Some of the Small Lakes in the Rio Grande Valley

PROJECT .010. ,5, _ _ _ _ , .. Jbb Cempletion Report Le Va Guerra Assistant Projeet Leader TITLE .Inventery of Fish Species Present in Some of the Small Lakes in the Rio Graade Valleyo ' OBJECTIVES To determine the.speeies present and their relative numbers in Lake Bentsen, Delta Orchards Lake, sad Olmite Lakea PROCEDURE The investigatien ef the small lakes in the Rio Graade Valley was divided iste tee jabs: Jhb AME, Basie Survey of Small Lakes ih-theRie Grande Valley, to gather ,uhdasehtal data on the shamisal and physical sharasteristiss of the lakes, and the present jeho Refer ts Jab Csmpletieh Report an the Basis Survey fer applieatiens ts this jeho The present job sensisted ofzmaking monthly experineatal net sets at two desighe ated statiens in sash ef the lakes as sheen is Maps 1, 2, and 3c Seining eollestiens were made when receding water levels esposed beaehes that could be seinedo The infermam ties collected included kind and relative numbers sf fish from the various lake, size, eeeffeeient of sonditiem,-sex and sexual ssnditien, parasites and diseases, and the seam sehal changes and flusuations in the whole pepulatieno NETTING COLLECTIONS la Six netting statiehs were selected in the three as: l lakes in the His Grands Valleyo These are sheen in Maps 1, 2, and 3a The tee netting statishs is sash lake were seleeted for their ecological signifisanee and.expesure to prevailing windso The two statiehs seleeted as Lake Bentsen represent two eeelogieal “niches"a Statieh N00 1, was located at the southmest end sf the lake in relatively silt free water sf very little current velesity'When the lake is impeunding watero This sestieh of the lake is perpendicular to the prevailing seutheast windso The yearly average depth in this leeatien was 1h feeto Station He. 2, was lesated in the middle of the lake share same of the deeper'sater Occurred, the bettem for the mast part was sandy silt as this area is in the outer edge of the densiltation sens when water is being impeundedo The edges of the lakes at this leeatieh are abundant in growth sf trees and some willsss at she waters edge, and consequently'wihd astieh in this section is very mildo The yearly average depth for this leeatish was seventeen feeto The twe,netting stations selected on Delta Orchards Lake were also of different analogical signifieaneeo Statien N00 1, was located in spen'water near an island of willows, (Salin nigra), and bulrush beds, (Snag-pus “20)., Station as, 2, was lnsated in spen.water with he nearby severo For the most part the stations were expesed to strong ssutheast winds that prevail almost the year reund on this lakeo Station Hon 1, had an average depth of 8 feet and Station 2,10 feeto The lake batten is entirely Eilto Netting statiens on 01mite Lake were seleeted to shew the twp eselegisal senditm inns present in the lakeo Station Neo 1, was lesated in the upper part ef the lake, near the bridge ever the lakeo This leeatien has a fine sawd,bottam'with same sandy lsem.spets, whieh preduee abundant grawths of masses and same swaLh willewso The yearm ly average depth for this leeation.was ten feeto Statisn N00 2, was lssated in the bend ef the lake near abundant willows gaw2i1r in water abeut six feet deepo The years ly average depth fer the leeatien was eight feeto 20 Experimental gill nets semposed sf five sestisns of varying mesh (1”, la“ ,2“, %" and 3“) sash twenty five feet long, and eight feet deep were set at sash station menthly, except in Insemher'195h on Felts Grahards Lake when only one net'was seto Several times during the prsjeet nets were not set in Delta Orshards Lake besause sf high winds and very reugh waterso .A tetal sf ll2 experimental gill nets were set in ¢;L three lakes in the period severed by this prejeeto All nets were “fleaters” resting en the surfaee and reaehing the batten enly'where the water was less than nine feet deepo -Galvseised steel rings en the batten line served to weigh the net dawn, while plastie er eerk fleets helped ts keep the net tight vertieallyo Generate weial- apprenimately ens quart sf senerete were_used ts ansher the nets sets at sash and, and ten quart plastie fleets were used ts keep the ends higho Nernally the nets were set areund less P¢M¢ and picked up the fellswing earning between the heurs sf 5300 and 8300 Acidic Twe 100 by 8 feet gill nets with twewineh square mesh and three 100 by 8 feet gill nets with threeeinsh mesh were set ease in Lake Bentsen after swawning buffalo had been lesated by mean ef experinental netso A tetal sf 2&1 fish sf nine speeies were taken, and bananas ef the nets8 selestivity for the larger fish, the results are net ineluded in this rewerto 30 the fish taken in all experimental gill nets were preeessed en the share as seen as the nets were breuget inc All fish were laid en a measuring beard, and the 'standard and tetal less he in millimeters were retarded, eneept in sertain instamees when large numbers sf buffale or fresh water drum were taken they were enly shunted sxd.weighed after a represtentive sellestien had been workedo Eanhg fish up ts 500 »~ , read an a Hansen platferm seals, larger*ftsh were weighed en a Perfeete hanging sealso Peunds and sunses were eenverted inte grass and reesrdsdo When feed was feund in the stenash sf a game er predatory fish, the stanaeh was renewed, tagged and preserved in ten pereent fernalin fer later laberatery studya Spaniel notes sens derhinfl the fish sueh as waxes, parasites, stunted grewth, entilatien, and ether features were neted and are diseussed under the individual spesieso Seals samples were net taken beeause sf their spearent leek sf distinst sireullio All fish handling was dene'by the twe field assistants, while the Assistant Prejest Leader*made all the antes, reserds, and ebservatienso SEINING CQLLESTTQNS 10 Two seining stations were selested in sash of the three lakeso The banshee were not opposed eroept during low water stages and seining oollestions were made irregularlyo Seining Station not 1, in Lake Bentsen was looated at the southeast and of the lakeo the batten had a gradual slope of fine sandy silt and loan devoid of vegetation with the enseption of a few stands of Coastal Bermuda grass along the south shoreo Baiting Station N90 2, was losated about 200 h adred yards east of Station 10 The bottom was fine sandy silt and loana Vegetation in the form of insert Willows (Baosharis pp?) was wary ab“odajto Both stations had good pretestion from the mild southeast winds 'by virtue of the high_sliffwlike banks of the lakeo Banshee of different analogy were not usable beoanse of the steep banks and deepwatero Seining Station Not 1 in Delta Grahards Lake was losated on the northwest shore of the lake olose to State Highway 880 The bottom was fine sandy silt with a gradual slope for about twentyefive feet and than a sudden drop offo Vegetation was present in small neonate along shore, mostly; willows and dryiwillowso Station Hon 2, losated on the northeast shore of the lake had a bottom of fine needy silt with a gradual slopeo Vegetation present was the same as in Station N00 1, but here we found some old.willow stumpso {nth seining stations were looated in the northern sestion of the lake bananas of their shallownsss during low water periods and para;lel losation to strong southeast winds the water was as: Zly roiled and:nnrkyo Two seining beashes of ©1mito Lake were selested and sampled twine when the low water ends seining possibleo Station who 1 was losated on the west side of the lake ed had a sandy silt and loan bottom with a gradual slope towards the osnter of the lakeo some submerged vegetation was present and there were a few stands of emerged hesert Wile a.» tie! .-_' lowso Station Nos 2 was losated on the opposite side of the lake in.front of the Sto tiair honeo Golleotions were made by swimming the seine out or dropping off the piero The bottom of sandy silt had a rather steep slope and was oowered.by submerged equation and a few stands of drywillowso Seining was done whenever possible'with a thirty by sin foot bag seine with open fourth insh nesho When brash prevented the use of a bag seine, a sirteen'by four foot seine with oneuqnarter’insh mesh was usedo A representiwe oollestion of fish seined was preserwsd in two quart fruit jars sontaining ten persent formalin and sorted, ideas tified and sedated later in the laboratoryo Enssssiwe numbers of a single spanies or fish too large for the jars were soonted, retarded on fish sards, and dissarded at time of tallestiono 20 Data oonserning weather, water sonditions, and other observations were kept on.Fish Cards and Fish tollsstion Sheetso A desoription of the lakes and their shoes 0 ioal and physisal oharasteristiss is giwen in the Job Completion Report for Job Amps 30 Although adult largenowth base were resowered from all three Valley Lakes, Seining sollestions failed to show any signs of spawning bass, as no bass fry or fingers lingo were reooweredo This may be detonated for by assessive rough fish populations, flnsuating water levels, murky water, and leak of adequate spawning bedso Rough fish and muddy waters were probably the most important fosters sontrolling bass spawningo INDENGS The seasonal variation of fish nativity, as reflested by ooaparison of monthly 50' netting catches, may be_seen in Tables 3, h, snd.5 for Lake Bentsen, in Tables ll, 12, and l3 for Delta Orchards Lake, and in Tables 19, 20, 21, and 22 for Olmito Lakeo LAKE BENTSEN On the basis of increased not catch as a criterion of fish activity, it can be seen from Tables h and 5 that there was a very slight peak of fish activity in may 1952+, June, August, and September 1955, when the water level wee somewhat constanto I Thelargest percent (lOeh6) of fish for the project period was caught in August 1955, shile the least amount (2°92) percent'was caught in July 1954. On the basis of meecs_u and.min1e-e catches for the project period no definite strong peak of fish activity can be noted; The relative absence of fish activity is in all probability due to a receding water level of the lake in the spring months of the year when an activity peak could be expected, but this is the time when water_is drawn from.Lake Bentsen for crop irrigation purposes» Table 6 shows the snnllmouth buffalo to be well established in Lake Bentsen as it leads by number and'weighto Tables 7 and 8 show the sexual condition of the fish in Lake Bentsenn Condition 1 indicates that eggs or milt were flowing; 2, gonads were sell developed; 3, sexes are discernable; h, sexes are not discernable; 5, indicates that the fish had just spawneda Seasonal trends of sexual condition are not distinct or clear cuto Receding water levels during spring probably accounts for this, as many specimens shoved signs of or: remabsorptiono The coining collections made on Lake Bentoen show the absence of bass spawn, even though the water level waszmaintained rather constant for two months during late February to the middle of mayo DELTA ORCHARDS LAKE Table ll, for Delta Orchards Lake shows two peaks of fish activity, a strong peak during.April, May, and June receding and then rising in September with a slightly , higher peak in Qctnbere Table ls shows the rank by weight and numbero~ It is interm eating to note that blue catfish leads by number and was second'by'weighto The sexual condition of the six:most common fish species can be seen in Tables 15 and 16a Largee mouth bass (Micropterus salnoides) have never been too successful in this lake as the numbers that showed uprin netting results are not proportional to the stocking records over the yearsa The sport fishing catch of bass is small compared to that of fresh water drum, catfish and.white crappieo QEEETQ LAKE Tables 19 ted-20 for leito Lake show the numbers of fish taken in experimental nets during the period of studye High fish activity occurrred in June 195%, and a slightly higher one in April l955e Periods of least activity were January and February 19550 Table 20 shows that five species of re'an fish make up 77 percent of the fish population of the lakeo This is correlated'with the interconnection of this lake with the recess system in the Lower Rio Grande Valley which is predominately rough fish in contento The reunds of each fish species taken in exterimental nets are shown in Tables 21 and 220 Stockings of Goggleye (Chaenobryttus coronarius) largenouth bass and blue catfish (Iotalurus furcatus) prior to project study have shown up in netting resultso Game fish populations in this lake are hampered by excessive rough fish populations, receding water levels, sudden inflows of rain runeoff ester, and the absence of spa m .3; bedso Ranks, lengths, weights, and.“K“ factors of the fish caught are shown on Table 236 Sexual condition of sin common fish species is shown on Tables 2% and 25a BIQCUSSION 0F INDIVIDUAL SEEQIES Th1 di££11111 fish 1p11111 of all th111 Vall1y lak11 111 discusa1fi 11111 1a1h 1p11i11, tcg1th1r with 10111 01 parasites, 10111, and.mutilatiano Tabl1 26 ahows 11111 11h 11aly111 £11 fiah caught 11 the thr11 valll1y 1111110 A total of 48 1t®maeh1 1111 ;.-;r-;_.«._11.111d,o L11 111b11 1f atamacha 1111111111 £10d.may b1 1111unt1d for by tha 1111 111111 11 the V1ll1y lak11 11d 1££11t 1f Wind and'w1v1 111111 01 tha capturaa £i1h 1111111 1h11 t1 regurgitat1 111111h 111111110 * __Mu _ sgatfl a an alligat11 garo Alligat1r 111 111 rath11 111111 11 all 11111 Vall1y'lak11 and by far th1 larg1at in 1111 of tha fish 11ttada Th1 aflul+1 1111 1£t11 in£11t1d‘11th 1111 11111 in th1 1t1ma1h and 1111111110 E1tampara1it11 i1 th1 form 1f £11h L 11 (A1s -_ ‘;Ea) 11d,111ll 1111h11 1111 fauna 11.111y 1p1111111 £111 B1111 11h1111 1111, 1 £11 £111.Lak1 B111111 111 111111111lly 11 th111 £111 0111*11 Lak1o Fi1h 1111 11111d 11 pr1£11 11111 ar1und th1 gill 11v111 £11 111111111111110 8111111 11111 1111 111111 1111'11ighihg 1v1r 11111y ymund1 1111 11111 £111 D1111 11111111 Lak1o » - Lu . 11 1111t1d gara Th1y'w1r1 th1 1111 111111 gar in L111 B11= 1111 an& 011111 Lak1, 1311111S m11y'w111 fauna £1 h111 r1p1 gonadal d111l®pm1nt 111111 th1 111111 111th10 N011‘1111 £1111 11 1111111 11ll11t1011o faay W111 £1111 £1 1111 1111 £11h 1111 111.11111 l111h11 111111 th1 111110 This 1p11i11, b11aua1 1f 11111 1111 b111 1111111 11 011111 Lak13 11 1 1111111 thr1at £11 th1 £11d supply avail1bl1 £1 th1 1111 11h 1f tha 111:1a L1 11111111 111111 11 11111111 garo L1111111 gar 1111 p111111 11.Lak1 3111111 and D11? 1 11111111 Lak1 but 1111 11t 11111d1d £111.0l1111 L1k13 althaugh th1y 111 1111111 11.111 111111 1y1t11”0 U1ually, thay 111 £1111 in tha 1p11'111111 1f th1 1111 11d 11111d bru1h 111111 11 both lak11 g111d11 11111011111 111 11111 during th1 111115 1111.1o P11111111 11 th1 £111 1f fish 1111 111 11111 brawn 1111h11 1111 £1111 1111111 111111 1h1 gill1o - D1111111 1911111111 mm thr1afi£11 1hado 111 £11131 1111111‘111 found in all thr11 Vall1y 11111 but not in 11111 numb111 £111 D1111 Or1harda 111:1o S1111l d1v1lwpm 1111 111h pla11 111111 th1 Spring 111 1arly fall and apparantly Spawning 11111111 11111 during th1 y1aro This £11131 fish 111 £111d 11 11111 numb1r1 11 1111 1f th1 11111 1f th1 “111111 ay1t1mw 1f th1 L111r R11 Granda Vall1yo “611111.11 1112111 shado Th1y 111 1 20111111 1:1 s in all 11 111 11111;; 11111 11 11111 111b1110 311111 11111111111 111 11111 111111 tha 111115 1111h1 111 1a1ly £allo Th11 £11111 £111 11111111111 11.111111111 1111 Of d11t £11 th1 1111 £i1h 11 1h1 1111111o Th1 1111111 11111111111 1f thi1 1111111 1111 11tt1d 11 ®l1111 Lah1‘1h111 111111 11tly th1 1ngh £11h 111 111 11111111 th11, 11 it 11 111 111 1f th1 p11£1111d 11111 1f th111 11110 3111K I 1111 gr111h1 111umfl £11 1111111l £111 1111 11111 11 1111 111111111a ' 3,11%" 11cm ””Tfl -1‘“"tuf mm R11 G111d1 111111 Qf 111111 1111111111 11 all 1f h1 53111119 it 11 1111 pr1ll£i1 11 D111: Qr1harfl1 Laka Thi1 1111111'111 u1ually £1111 11 rath11 1hall11 gradual 111p111 ”b111h11o l1ti1bus hubalu§ a: 1mallm1uth buffal1o 811llm1uth hu££111 111 1111 111111 11 all th111 lak11 11 11111 111b111 thIngh111 th1 y111o Thay 111 u1ually £1111 11 11111 1p11 11111 flaring th1 111111 and araunfl 1h1 1hor1 11111 during 1h1 1111110 Th11 1111111 11111111111 1 1111111 £11h1.1111 111bl11 in all 1f th1 lak113 1111h 11 £111111 ggr11111d by th1 1111 11111111111 wha 11£111 t1 allww 11mn111ial :f11h11111 to 111 111110 -111 1111111119 11131111 up 11 twaniy pea1d1, 1111 11111do E1111111111 1f 1111 1111111 1111 1131111b113 11 th1 vall1y*lak1a 1111 in 11111 £111 tha Rio G11nd1 1h11 availahl1 11d pump 11 1111 th1 lak11 Witheut b111£11 1f 111111111 11 £11111t1110 G11adal 11111111 1111 111 11111111 111111 th1 1pring;111th1o £121; 1f 1h11 1111111 1111 111111 £111 Delta Orchards Lake. Several specimens caught in nets showed signs of’mutilation apparently due to gar bites while netted. Garpiodes carpio an river oarpsuckera They were uncommon, only ten specimens having been taken, and all of these from Delta Orchards Lakeo It is possible that because of their similarity to smallmouth buffalo some of them could have been missed. This species is present in the Rio Grande and could be expected to occur in the other lakeso Cyprinus carpio we carpa Carp were found in all of the lakes but they are least common in Lake Bentseno This is probably due.to the lack of sufficient underwater plants and overpopulations of smallmouth buffalo, directly competing with them for the availm able food and covero Carp were found at all netting stations but seemed to have a prom forence for the shallower parts of the lake, Gonadal development was noted to occur in the spring monthso No parasites were noted-although mutilation was common, especially in the tail regiono None were found in the coining collectionso Notropis braytoni aw Tamaulipas shinera This shiner was very Common in all three lakes, especially on shallow beaches and around the shorelineo Spawning apparently took place in May as gonadal development began in March and Aprilo This species is an important forage fish to the game fish of the valley lakeso Notrs is lutrensis mm redhorse shinern This species was taken only in Lake Bentsen during coining collectionso Gonadal development apparently took place in March and Aprilo No endomparasites were noted but a few specimens showed signs of "fin rot”a Mugil cephalus mm striped mulleto This apparently brackish and salt water species has become established in Delta Orchards Lake and Olmito Lakea A.sirppound and twelvemounce specimen was taken in a not at Delta Orchards Lakeo No young were taken and the adults were netted in the middle of the lakeso No parasites were observed and no young species were taken by seineso Cyprinodon varigatus an sea pupfish. This species was found in small numbers. in Lake Bentsen and Delta Orchards Lakeo This little forage fish was usually found around the.shore lines in the quiet watero lctalurus pm metatus an southern channel catfisho This catfish occurs in Delta orchards Lake and Dlmito Lake, thong; more common in the formero Their occurrence was occasional in both lakes and they were netted in open water on cool days and especially on cool nightsa Gonadal development occurred in say, Round worse in the stomach and stomach mesentcries were noted on the specimens from Delta orchards Lakeo lctalurus furcarus as blue catfisho The most impo rtant gene fish in all of the three Valley lakes and was found in all parts of the lakes at all times of the, yearo This species is well established in Lake Bentsen and Delta Orchards Lake, but predation has apparently kept the populations down in DImito Lakeo Ecological conditions apparm ently are wary adequate for this species in both Lake Bentsen and Delta Drchards Lake as a'sixteen pound specimen was caught in Lake Bentsen and a sportfisherman caught a thirtywthree pound specimen in Delta Orchards Lakeo Parasites were observed on spec» imens from all three lakes in the form of small brown leeches, attached around the gills and fins and round worms in the visceral and mescntery regionso Ameiurus melas mm black bullheado This species was found in Lake Bentscn and Olmito Lakeo Their occurrence is not very common, but neither is it rareo One specs imen.was recorded from Lake Bentsen and twentyathree from Olmito Lakeo This species did not begin to appear in leito Lake until after rain runmoff water came into the lake, apparently washed down from some other part of the “resaca system}?o Shore fish= ermen usually caught them in wood beds and shollOw areaso 8'. Strongylura marinus an needlefish. Two specimens were netted in Delta Orchards Lake. This species and the striped mullet are the only two salt water fish recorded from these lakes. They apparently ascend the Rio Grande and are taken into the pumps. Gambusia affinisha_-~ gambusia. Very common in all three Valley lakes. Gonadal development occurred in the early Spring and continued throughout the summer. They are very numerous in seining collections and are usually found in shoreline areas and around.mats of grass. Manidia beryllina aw tidewaters silversides. These species are very common in all three lakes, apparently one of the forage fish for some of the game fish, but definitely not one of the preferred items of diet. This species was usually found around very shallow water and under docks and piers. Micropterus salmoides -1 largemouth base. This species occurred in all three Valley lakes but is more prevalent in Lake Bentsen. This can probably be attributed to the clearer water and more available food supply. Gonadal development occurred in the spring months. No fry or fingerlings were recovered, as spawning grounds are few and receding water levels may have stranded them in very low and warm.water, or on land. Predation is apparently also very high. One specimen weighing four pounds was caught in Lake Bentsen. Rod and reel catches were made on all three lakes. Visceral worms were found in fish netted in Delta Orchards Lake. Ghaenob tus coronarius um warmouth bass. warmouth bass occurred in both stem tions of all of the lakes. They were very common in Olmito Lake probably due to big stocking during the early part of the project period. Gonadal development occurred in April and May. Lepomis cyanellus as green sunfish. Green sunfish were found in small numbers in all three Valley lakes. Gonadal develOpment was not apparent at time of capture and parasites were not noted. Lepomicxnacrochirus m— bluegill. Bluegill sunfish occurred in all of the three valley lakes. Some were caught by shore fishermen. Seined specimens were small and usually caught around underwater shelves near the shoreline. Greatest numbers of bluew gills were found in Olmito Lake, although their size and weight were not enough to attract the "perch fishermen”. qummfis auliiu&_me yell.owbelly sunfish. Few specimens were caught in halts Ore shards Lake and Olmito Lake. None were caught in Lake Bentsen. They were usually found on all netting stations. Lepomis megalotis mm longear sunfish. This species occurred only in Olmito Lake where only three specimens were taken. Pomomis annularis mm white crappie. White crappieynnxgabsent in Lake Bentsen but present in fair numbers in Olmito Lake and in large numbers in Delta Orchards Lake. This species has shown a great comeback in Delta Orchards Lake. Some specs imens weighed up to two and a half pounds. They usually netted in Open water but occasm ionally were found around vegetation patches. Parasites in the from of visceral and mesentery round worms were found on almost all specimens. Gonadal development bee gan in February and march. Aplodinotus grunniens as fresh water drums Fresh water drum wenecommon in all three Valley lakes but more numerous in Lake Bentsen. This species was found in all stations but no definite habitat preference could be determined. In this region this 9w fish could be considered a game fish as it is preferred next to catfisho Gonadal development occurred in the spring months of the yearand sometimes lasting until Julya many were infected with visceral and.mesentery'worms. Many showed up in periodic seinw ing collectionso Cichalsoma cyanoguttata we Rio Grande Perch. This species was of common occurs reuse in the coining collections from the three Valley lakesa In netting collections they were nest prominent from Olmito Lake, Gonadal development was noted in the early spring months of the yearo Parasites were relatively few, except on one specimen that has caudal mutilation and white fungus growthso Stomachs failed to reveal any signs of predation on game fish spawn, fry, or younga AQUATIC VERTEBHATES OTHERTHAN FISH Large flocks oftmmma and wild geese and ducks winter on Lake Bentsen and Delta Orchards Lakeo Other common'water birds that were more prominent in the winter were the Mexican cormorant, coots, anhingas, sea gulls, and ternso Turtles were common and occasionally caught in netso Both the soft shell turtle (Amide spa! and the slider (Pseudemys s a) were foundo Few frogs were found on the lake; most common being the leopard froEETRana pipiensz and the cricket frog (Acris crepitans)o RECOMMENDATIONS Lake Bentsen, near Mission, and Delta Orchards Lake, near Raymondville, are both major irrigation reservoirs, while there is a limited amount of irrigation from.Olmito Lakea As all of these lakes are filled from the Rio Grande as water is available, the rough fish populations predominaten So far, no traps, weirs, screens or filters prom venting the entry of rough fish fry and fingerlings has been successful, and until such time that means are taken to control the entry of rough fish from the Rio Grande no fisheries improvement program can be very successfulo There has been an earnest effort on the part of some of the lake managers and owners to have something done about this condition of rough fish entry into the lakes, but when it comes to the actual.erpense, interest fades as some of them.expect the state to do the work, maintenance, and pay all the expensesa m-u» It is recommended that the annual or bimannual stocking with game fish fry for these lakes be discontinued for the following reasons: Lake Bentsen has a sufficient game fish population, but flucuating water levels prevent the spanning from being _ successful and the water that is brought into the lake is high in rough fish fry cone tent. In Delta Orchards Lake, because of its heavy populations of smallmouth buffalo, ' shallow and murky water, and constant wind action causing siltation of any bass nets, 'further stocking of largemouth bass'would not be advisable until drastic changes take 'place_in-the lake ecologyo Under present conditions, crappie and catfish populations have been very successfulo Dimito Lake, because of its interconnection with the ”reason system", is also heavily populated with rough fish and until some time when measures are taken to ins sure the exclusion of rough fish from the lake, stockings of the lake are of doubtful valueo summer The fish populations of Lake Bentsen, Delta Orchards Lake, and.fllmito Lake were investigated by monthly netting and irregular coining collections for the period from Joly l, 1954 to March l956° A description of the netting stations is given and the kind and numbers of fish taken are discussedo The seasonal and.monthly changes in numbers and percentages of the various fish are given and the other common vertebrates and screw sites are consideredo Stomach analysis, coefficient of condition, sizes and numbers are shown in table forma Twentymsix tables, six photographs, and three maps are included in this report. _ 10. Table lo A List of Fish Species Recorded from Lake Bentsenn Ssieutifie flame Common Name Symbols Used in Le isosteus sEatula alligator gar o sEatula * '- spotted gar o Eroduetus gm_ _ ‘_ longnose gar . osseus Dorosoma Egteuensis threadfin shad a Egtenensis Dtresoma eegngahuh. gizzard shed a eegedianum “ ax faseiatus mm Rio Grande Tetra ¢ fasciatus Ea. Hybogs1s aestival is , . speckled daee , aestivalis Ie1obus bubalus smallmouth buffalo a bubalus Gal iodes saggie river oarpsueker @gmhus eagle _ easz ' a sag. io Estes-1s braytoni Tamaulipas Shiner a brazgoni Notrogls lutrensis redhorse shines . lutrensis mimic shiner plains shiner Metro-is volueellus Bfiflgflnfibfla sh? s * smaflahn *ssunnnndnjnsnsua .Efimeghales v1g1laxvu ' parrot minnow Egpsinodon varigatus v sea pupfish a varigatus If MbIl1ensia latiginna sailfin molly Iotalurus fureatus blue catfish o fureatus Ameiurus melee black bullhead a melee bambusia aff1nis an Gambusia a affinis E Mbmidia be:1Ilinam tidewaters silversides a berxllina _fiero terus salmoides largemouth black bass . salmoides Ghaeuob'.ttus eoronarius goggleye 2f eoronarius Legemio eyanellus green sunfish Iéwngnellus 7g omis maeroeh1rus bluegill Lo maeroehirus mgwodiuotus grunniens fresh water drum £9 grunniens Wehlasomga exanoguttata Rio Grande Perch gr Q;339§;FF§39HM Gobionellus boleosema darting goby * *Rotehone Colleetion July 22, 19520 ll. Table 2a Seining Collections Lake Bentsen July 1, 195h to June 30, 1955. Species Total number Percent of Total pesosona_s+tenensis 66 3.33 Dorosoma ceggdianum. 1011 - 51.08 Astxanax fasciatus m:__ 97 h.90 Hgbogsis aestivalis 9 .h6 Notrogis braitoni 62 3.13 Netrogis lutrensis 262 13.23 Czarinodon_varigatus Ex 83 h.l9 Gambusia affinis L 279 11+ .10 Henidia-be5111ina 85 h.29 -Chaenob£zttus eoronarius l ..05 Leggmis maeroehirus 2 .10 Leggmis ozggellus 3 .15 Aglodinotus grunniens l .05 Ciohlasoma czanoguttata 18 .91 1979 99-97