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

--- Page 1 --- STATE Texas PROJECT FOR} = Job Be5 PERIOD July 1, 1954 = March 30, 1956 Job Completion Report L. V. Guerra Assistant Project Leader TITLE Inventory of Fish Species Present in Some of the Small Lakes in the Rio Grande Valley. OBJECTIVES To determine the species present and their relative numbers in Lake Bentsen, Delta Orchards Lake, and Olmito Lake. PROCEDURE The investigation of the small lakes in the Rio Grande Valley was divided into two jobs: Job A-5, Basic Survey of Small Lakes in the Rio Grande Valley, to gather -undamental data on the chemical and physical characteristics of the Lakes, and the present job. Refer to Job Completion Report on the Basic Survey for applications to this job. The present job consisted of making monthly experimental net sets at two designe ated stations in each of the lakes as shown in Maps 1, 2, and 3. Seining collections were made when receding water levels exposed beaches that could be seined. The informa- tion collected included kind and relative numbers of fish from the various lake, size, coeffecient of condition, sex and sexual condition, parasites and diseases, and the sea- sonal changes and flucuations in the whole population. NETTING COLLECTIONS lL. Six netting stations were selected in the three small lakes in the Rio Grande Valley. These are shown in Maps 1, 2, and 3. The two netting stations in each lake were selected for their ecological significance and exposure to prevailing winds. The two stations selected on Lake Bentsen represent two ecological “niches”. Station No. 1, was located at the southmost end of the lake in relatively silt free water of very little current velocity when the lake is impounding water. This section of the lake is perpendicular to the prevailing southeast winds. The yearly average depth in this location was 14 feet. Station No. 2, was located in the middle of the lake where some of the deeper water occurred, the bottom for the most part was sandy silt as this area is in the outer edge of the de-siltation zone when water is being impounded. The sdges of the lakes at this location are abundant in growth of trees and some willows at she waters edge, and consequently wind action in this section is very mild. The yearly average depth for this location was seventeen feet. --- Page 2 --- The two, netting stations selected on Delta Orchards Lake were also of different ecological significance. Station No. 1, was located in open water near an island of willows, (Salix nigra), and bulrush beds, (Scirpus sp.). Station No. 2, was located in open water with no nearby cover. For the most part the stations were exposed to strong southeast winds that prevail almost the year round on this lake. Station No. 1, had an average depth of 8 feet and Station 2, 10 feet. The lake bottom is entirely silt. Netting stations on Olmito Lake were selected to show the two ecological condite ions present in the lake. Station No. 1, was located in the upper part of the lake, near the bridge over the lake. This location has a fine sand bottom with some sandy loam spots, which produce abundant growths of mosses and some small willows. The yeare ly average depth for this location was ten feet. Station No. 2, was located in the bend of the lake near abundant willows growing in water about six feet deep. The year- ly average depth for the location was eight feet. 2. Experimental gill nets composed of five sections of varying mesh (1",14",2", 4" and 3") each twenty five feet long, and eight feet deep were set at each station monthly, except in December 1954 on Delta Orchards Lake when only one net was set. Several times during the project nets were not set in Delta Orchards Lake because of high winds and very rough waters. A total of 112 experimental gill nets were set in all three lakes in the period covered by this project. All nets were "floaters" resting on the surface and reaching the bottom only where the water was less than nine feet deep. Galvanized steel rings on the bottom line served to weigh the net down, while plastic or cork floats helped to keep the net tight vertically. Concrete weights of approximately one quart of concrete were used to anchor the nets eown at each end, and two quart plastic floats were used to keep the ends high. Normally the nets were set around 1:00 P.M. and picked up the following morning between the hours of 5:00 and 8:00 A.M. Two 100 by 8 foot gill nets with two-inch square mesh and three 100 by 8 foot gill nets with three-inch mesh were set once in Lake Bentsen after spawning buffalo had been located by mean of experimental nets. A total of 241 fish of nine species were taken, and because of the nets' selectivity for the larger fish, the results are not included in this report. 3. The fish taken in all experimental gill nets were processed on the shore as goon as the nets were brought in. All fish were laid on a measuring board, and the standard and total lengths in millimeters were recorded, except in certain instances when large numbers of buffalo or fresh water drum were taken they were only counted and weighed after a represtentive collection had been worked. Each fish up to 500 grams was weighed on a Hanson platform scale, larger fish were weighed on a Perfecto hanging scale. Pounds and ounces were converted into grams and recorded. When food was found in the stomach of a game or predatory fish, the stomach was removed, tagged and preserved in ten percent formalin for later laboratory study. Special notes con« cerning the fish such as worms, parasites, stunted growth, mutilation, and other features were noted and are discussed under the individual species. Seale samples were not taken because of their apparent lack of distinct cireulli. All fish handling was done by the two field assistants, while the Assistant Project Leader made all the notes, records, and observations. --- Page 3 --- SEINING COLLECTIONS 1. Two seining stations were selected in each of the three lakes. The beaches were not exposed except during low water stages and seining collections were made irregularly. Seining Station No. 1, in Lake Bentsen was located at the southmost end of the lake. The bottom had a gradual slope of fine sandy silt and loam devoid of vegetation with the exception of a few stands of Coastal Bermuda grass along the south shore. Seining Station No. 2, was located about 200 hundred yards east of Station 1. The bottom was fine sandy silt and loam. Vegetation in the form of Desert Willows (Baccharis spo) was very abundant. Both stations had good protection from the mild southeast winds by virtue of the high cliff-like banks of the lake. Beaches of different ecology were not usable because of the steep banks and deep water. Seining Station No. 1 in Delta Orchards Lake was located on the northwest shore of the lake close to State Highway 88. The bottom was fine sandy silt with a gradual slope for about twenty-five feet and then a sudden drop off. Vegetation was present in small amounts along shore, mostly, willows and dry willows. Station No. 2, located on the northeast shore of the lake had a bottom of fine sandy silt with a gradual slope. Vegetation present was the same as in Station No. 1, but here we found some old willow stumps. Both seinming stations were located in the northern section of the lake because of their shallowness during low water periods and parallel location to strong southeast winds the water was usually roiled and murky. Two seining beaches of Olmito Lake were selected and sampled twice when the low water made seining possible. Station No. 1 was located on the west side of the lake od had a sandy silt and loam bottom with a gradual slope towards the center of the lake. some submerged vegetation was present and there were a few stands of emerged Desert Wile lows. Station No. 2 was located on the opposite side of the lake in front of the St. Clair home. Collections were made by swimming the seine out or dropping off the pier. The bottom of sandy silt had a rather steep slope and was covered by submerged aquatics and a few stands of dry willows. Seining was done whenever possible with a thirty by six foot bag seine with one- fourth inch mesh. When brush prevented the use of a bag seine, a sixteen by four foot seine with one-quarter inch mesh was used. A representive collection of fish seined was preserved in two quart fruit jars containing ten percent formalin and s ted, idene tified and counted later in the laboratory. Excessive numbers of a single spacies or fish too large for the jars were counted, recorded on fish ecards, and discarded at time of collection. 2. Data concerning weather, water eonditions, and other observations were kept on Fish Cards and Fish Collection Sheets. A description of the lakes ang their cheme ical and physical characteristics is given in the Job Completion Report for Job Aes. 3. Aithough adult largemouth bass were recovered from all three Valley Lakes, Seining collections failed to show any signs of spawning bass, as no bass fry or finger- lings were recovered. This may be accounted for by excessive rough fish populations, flucuating water levels, murky water, and lack of adequate spawning beds. Rough fish and muddy waters were probably the most important factors controlling bass spawning. TNDINGS The seasonal variation of fish activity, as reflected by comparison of monthly --- Page 4 --- 5. netting catches, may be seen in Tables 3, hk, and 5 for Lake Bentsen, in Tables 11, le, and 13 for Delta Orchards Lake, and in Tables 19, 20, 21, and 22 for Olmito Lake. LAKE BENTSEN On the basis of increased net catch as a criterion of fish activity, it can be seen from Tables 4 and 5 that there was a very slight peak of fish activity in May 1954, June, August, and September 1955, when the water level was somewhat constant. ‘Thelargest percent (10.46) of fish for the project period was caught in August 1955, while the least amount (2.92) percent was caught in July 1954. On the basis of maximum and minimum catches for the project period no definite strong peak of fish activity ean 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 smallmouth buffalo to be well established in Lake Bentsen as it leads by number and weight. Tables 7 and 8 show the sexual condition of the fish in Lake Bentsen. Condition 1 indicates that eggs or milt were flowing; 2, gonads were well developed; 3, sexes are discernable; h, sexes are not discernable; 5, indicates that the fish had just spawned. Seasonal trends of sexual condition are not distinct or clear cut. Receding water levels during spring probably accounts for this, as many specimens showed signs of egg re-absorption. The seining collections made on Lake Bentsen show the absence of bass spawn, even though the water level was maintained rather constant for two months during late February to the middle of May. DELTA ORCHARDS LAKE Table 11, 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 October. Table 14 shows the rank by weight and number.~ It is intere esting to note that blue catfish leads by number and was second by weight. The sexual condition of the six most common fish species can be seen in Tables 15 and 16. Large- mouth bass (Micropterus salmoides) have never been too successful in this lake as the numbers that showed up in netting results are not proportional to the stocking records over the years. The sport fishing catch of bass is small compared to that of fresh water drum, catfish and white crappie. OLMITO LAKE Tables 19 and 20 for Olmito Lake show the numbers of fish taken in experimental nets during the period of study. High fish activity occurrred in June 1954, aad a slightly higher one in April 1955. Periods of least activity were January and February 1955 - . Table 20 shows that five species of rough fish make up 77 percent of the fish population of the lake. Thie is correlated with the interconnection of this lake with the resaca system in the Lower Rio Grande Valley which is predominately rough fish in content. The pounds of each fish species taken in experimental nets are shown in Tables 21 and 22. Stockings of Goggleye (Chaenobryttus coronarius) largemouth bass and blue catfish (Ictalurus furcatus) prior to project study have shown up in netting results. Game fish populations in this lake are hampered by excessive rough fish populations , receding water levels, sudden inflows of rain run-off water, and the absence of spawn- ing beds. Ranks, lengths, weights, and "K" factors of the fish caught are shown on Table 23. Sexual condition of six common fish species is shown on Tables 24 and 25. --- Page 5 --- DISCUSSION OF INDIVIDUAL SPECIES The different fish species of all three Valley lakes are discussed under each species, together with notes on parasites, worms, and mutilation. Table 26 shows stom- ach analyses for fish caught in the three vallley lakes. A total of 48 stomachs were analysed. Low number of stomachs containing food may be accounted for by the warm waters in the Valley lakes and effect of wind and wave action on the captured fish causing them to regurgitate stomach contents. Lepisosteus spatula _-- alligator gar. Alligator gar are rather common in all three Valley lakes and by far the largest in size of the fish netted. The adults were often infected with tape worms in the stomach and intestine. Ecto-parasites in the form of fish lice (Argulus sp.) and small leeches were found on many specimens from Delta Orchards Lake, a few from Lake Bentsen and occasionally on those from Olmito Lake. Fish lice seemed to prefer areas around the gill covers for attachment. Several large alle igator gars weighing over twenty pounds were taken from Delta Orchards Lake. Lepisosteus productus -- spotted gar. They were the most common gar in Lake Ben- tsen and Olmito Lake, where many were found to have ripe gonadal development during the spring months. None were found in seining collections. Many were found to cone- tain fish lice and small leeches around the gilis. This species, because of large nume= bers present in Olmito Lake, is a serious threat for the food supply available to the game fish of the lake. Lepisosteus osseus -- longnose gar. lLongnose gar were present in Lake Bentsen and Delta Orchards Lake, but were not recorded from Olmito Lake, although they are present in the "resaca system". Usually, they are found in the open waters of the lake and around brush piles. In both lakes gonadal development was noted during the spring months. Parasites in the form of fish lice and small brown leeches were found present around the gills. Dorosoma petenensis -- threadfin shad. is forage species was found in all three Valley lakes but not in great numbers from Delta Orchards Lake. Sexual develop- ment took place during the spring and early fall and apparently spawning occurred twice during the year. This forage fish was found in great numbers in some of the lakes of the "resaca system” of the Lower Rio Grande Valley. Dorosoma cepedianum -- gizzard shad. They are common in all of the Valley lakes im great numbers. Sexual development was noted during the spring months and early fall. This forage fish constitutes an important item of diet for the game fish in the lakes. The heavier populations of this species were netted in Olmito Lake where appare- ently the rough fish are not cropping them, or it is not one of the preferred items of their diet. Black fungus growths around the pectoral fins were noted on some specimens. Astyanays fasciatus mexicanus -- Rio Grande tetra. Of common occurrence in all of the lakes, it is more prolific in Delta Orchards Lake. This species was usually found on rather shallow gradual sloping beaches. ictLobus bubalus -- smallmouth buffalo. Smallmouth buffalo are very common in all three lakes in large numbers throughout the year. They are usually found in deep open water during the summer and around the shore lines during the winter. This species constitutes a serious fisheries problem in all of the lakes, which is further aggravated by the lake supervisors who refuse to allow commercial fishermen to net them. ome specimens, weighing up to twenty pounds, were netted. Eradication of this species seem impossible, as the valley lakes take in water from the Rio Grande when available and pump it into the lakes without benefit of screening or filtration. Gonadal develope ment was apparent during the spring months. Young of this species were seined from --- Page 6 --- Delta Orchards Lake. Several specimens caught in nets showed signs of mutilation apparently due to gar bites while netted. Carplodes carpio -- river carpsucker. They were uncommon, only ten specimens having been taken, and all of these from Delta Orchards Lake. 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 lakes. Cyprinus carpio -=- carp. Carp were found in all of the lakes but they are least common in Lake Bentsen. This is probably due to the lack of sufficient underwater plants and overpopulations of smallmouth buffalo, directly competing with them for the availe able food and cover. Carp were found at all netting stations but seemed to have a pre- ference for the shallower parts of the lake. Gonadal development was noted to occur in the spring months. No parasites were noted although mutilation was common, especially in the tail region. None were found in the seining collections. Notropis braytoni -- Tamaulipas shiner. This shiner was very common in all three lakes, especially on shallow beaches and around the shoreline. Spawning apparently took place in May as gonadal development began in March and April. This species is an important forage fish to the game fish of the Valley lakes. Notropis lutrensis -- redhorse shiner. This species was taken only in Lake Bentsen during seining collections. Gonadal development apparently took place in March and April. No endo-parasites were noted but a few specimens showed signs of "fin rot”. Mugil cephalus -- striped mullet. This apparently brackish and salt water species has become established in Delta Orchards Lake and Olmito Lake. A six-pound and twelve-ounce specimen was taken in a net at Delta Orchards Lake. No young were taken and the adults were netted in the middle of the lakes. No parasites were observed and no young species were taken by seines. Cyprinodon varigatus -= sea pupfish. This species was found in small numbers in Lake Bentsen and Delta Orchards Lake. This little forage fish was usually found around the shore lines in the quiet water. ictalurus punctatus -- southern channel catfish. This catfish occurs in Delta Orchards Lake and Olmito Lake, though more common in the former. Their occurrence was occasional in both lakes and they were netted in open water on cool days and especially on cool nights. Gonadal development occurred in May. Round worms in the stomach and stomach mesenteries were noted on the specimens from Delta Orchards Lake. Ictalurus furecarus -=- blue catfish. The most important game fish in all of the three Valley lakes and was found in all parts of the lakes at all times of the year. This species is well established in Lake Bentsen and Delta Orchards Lake, but predation has apparently kept the populations down in Olmito Lake. Ecological conditions appare- ently are very adequate for this species in both Lake Bentsen and Delta Orchards Lake as a sixteen pound specimen was caught in Lake Bentsen and a sportfisherman caught a thirty-three pound specimen in Delta Orchards Lake. Parasites were observed on spece 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 mesentery regions. Ameiurus melas -- black bullhead. This species was found in Lake Bentsen and Olmito Lake. Their occurrence is not very common, but neither is it rare. One spece imen was recorded from Lake Bentsen and twenty-three from Olmito Lake. This species did not begin to appear in Olmito Lake until after rain run-off water came into the lake, apparently washed down from some other part of the “resaca system". Shore fishe ermen usually caught them in weed beds and shollow areas. --- Page 7 --- « 8B. Strongylura marinus -- 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 affinis a -- 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. Menidia beryllina -- 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 -- largemouth bass. 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. Chacnobryttus coronarius -- warmouth bass. warmouth bass occurred in both sta- 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 -=- 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. Lepomi:; macrochirus -- 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 blue- gills were found in Olmito Lake, although their size and weight were not enough to attract the "perch fishermen". Lepomis i 22 yellowbelly sunfish. Few specimens were caught in Delta Ore chards Lake and Olmito Lake. None were caught in Lake Bentsen. They were usually found on all netting stations. Lepomis megalotis -- longear sunfish. This species occurred only in Olmito Lake where only three specimens were taken. Pomoxis annularis -- white crappie. White crappie were absent 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 spec- imens weighed up to two and a half pounds. They usually netted in open water but occas- ionally were found around vegetation patches. Parasites in the from of visceral and mesentery round worms were found on almost all specimens. Gonadal development be- gan in February and March. oo Aplodinotus grunniens -- fresh water drum. Fresh water drum were common 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 --- Page 8 --- 9. fish could be considered a game fish as it is preferred next to catfish. Gonadal development occurred in the spring months of the yearand sometimes lasting until July. Many were infected with visceral and mesentery worms. Many showed up in periodic sein- ing collections. Cichalsoma cyanoguttata «- Rio Grande Perch. This species was of common occur- rence in the seining collections from the three Valley lakes. In netting collections they were most prominent from Olmito Lake. Gonadal development was noted in the early spring months of the year. Parasites were relatively few, except on one specimen that has caudal mutilation and white fungus growths. Stomachs failed to reveal any signs of predation on game fish spawn, fry, or young. AQUATIC VERTEBRATES OTHER THAN FISH Large flocks of tame and wild geese and ducks winter on Lake Bentsen and Delta Orchards Lake. Other common water birds that were more prominent in the winter were the Mexican cormorant, coots, anhingas, sea gulls, and terns. Turtles were common and occasionally caught in nets. Both the soft shell turtle (Amyda sp.) and the slider (Pseudemys sp.) were found. Few frogs were found on the lake; most common being the leopard frog Rana pipiens ) and the cricket frog (Acris erepitans). 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 Lake. As all of these lakes are filled from the Rio Grande as water is available, the rough fish populations predominate. So far, no traps, weirs, screens or filters pre- 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 successful. 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 expense, interest fades as some of them expect the state to do the work, maintenance, and pay all the expenses. acer It is recommended that the annual or bi-annual stocking with game fish fry for thege lakes be discontinued for the following reasons: Lake Bentsen has a sufficient game fish population, but flucuating water levels prevent the spawning from being successful and the water that is brought into the lake is high in rough fish fry con- 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 ecology. Under present conditions, crappie and catfish populations have been very successful. : Olmito Lake, because of its interconnection with the "resaca system", is also heavily populated with rough fish and until some time when measures are taken to ine sure the exclusion of rough fish from the lake, stockings of the lake are of doubtful value . SUMMARY The fish populations of Lake Bentsen, Delta Orchards Lake, and Olmito Lake were investigated by monthly netting and irregular seining collections for the period from July 1, 1954 to March 1956. A description of the netting stations is given and the kind and numbers of fish taken are discussed. The seasonal and monthly changes in numbers and percentages of the various fish. are given and the other common vertebrates and para- sites are considered. Stomach analysis, coefficient of condition, sizes and numbers are shown in table form. Twenty-six tables, six photographs, and three maps are included in this report. --- Page 9 --- Table 1. A List of Fish Species Recorded from Lake Bentsen. LO. Seientific Name Lepisosteus spatula Lepisosteus productus Lepisosteus osseus Dorosoma petenensis Dorosoma cepedianun Astyanax fasciatus m. Hybopsis aestivalis ietiobus bubalus Carplodes carpio Cyprinus carpio Notropis braytoni Notropis jutrensis Notropis volucellus Hybognathus placitus_ Pimephales_v: vi igilax v._ Ve Cyprinodon varigatus V Vo Molliensia latipinna Tetalurus furcatus Ameiurus melas Gambusia affinis a. Menidia. | peryllin: ryllina Heropterus salmoides Chaenobryttus coronarius Lepomis cyanellus Lepomis macrochirus Aplodinotus grunniens Cichiasoma cyanoguttata Gobionellus boleosoma *Rotenone Collection July 22, 1952. Common Name alligator gar spotted gar longnose gar threadfin shad gizzard shad Rio Grande Tetra speckled dace smallmouth buffalo river carpsucker carp Tamaulipas shiner redhorse shiner mimic shiner plains shiner parrot minnow sea pupfish sailfin molly blue catfish black bullhead Gambusia tidewaters silversides largemouth black bass goggleye green sunfish bluegill fresh water drum Rio Grande Perch darting goby Symbols Used in Following ° ° e oe ° ° ° ° HIOMZIRIQIPIH slo * * AITO IM PI OIDIF ICI ° L. A. CG. ¥ Tables ._ spatula productus osseus petenensis_ cepedianum fasciatus m. aestivalis bubalus carpio braytoni lutrensis varigatus v. furcatus melas_ affinis a. beryllina salmoides » coronarius cyanellus macrochirus grunniens cyanoguttata --- Page 10 --- ll. Table 2. Seining Collections Lake Bentsen July 1, 1954 to June 30, 1955. Species Total Number Percent of Total Dorosoma petenensis 66 3.33 Dorosoma cepedianum 1011 51.08 Astyanax fasciatus m. _ 97 4.90 Hybopsis aestivalis 9 46 Notropis braytoni 62 3.13 Notropis lutrensis 262 13.23 Cyprinodon varigatus v. 83 419 Gambusia_ affinis a. _ 279 14.10 Menidia beryllina 85 4.29 Chaenobryttus coronarius 1 O05 Lepomis macrochirus _ 2 «LO Leponie Cyanellus 3 eL5 Aplodinotus grunniens 1 05 Cichlasoma cyanoguttata 18 91 1979 99.97 --- Page 11 --- 12. Table 3. Numbers of Fish Taken in Experimental Nets from Lake Bentsen, March 1954 through October 1955. Species Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Total Percent L. spatula 0 ) 1 3 7 2 1 3 0 1 ) ) 18 1.39 L. productus fo) 5 2 us 12 6 fe) ) fo) fo) 4 1 34 «2.62 L. osseus 1 fe) 7 6) ) ) 1 3 3 1 ) 6) 16 1.23 D. cepedianum 4 9 ak 9 2 fe) 4 0) ©) 1 yok val 5.48 I. bubalus 39 23 87 hg 85 30 35 85 82 58 20 ha 635 49.03 C. carpio ) 3 2 1 2 2 5 2 5 1 0 2 25 1.93 I. furcatus 2 7 17 23 18 23 13 21 10 17 Hh 9 164 12.66 A. melas fe) ) fe) ) 1 ) @) ) @) fe) fe) ) 1 0.07 M. salmoides re) 2 2 1 ) 2 2 3 fe) 1 1 2 16 1.23 L. macrochirus 0 ) 2 Ty 2 6) 1 ) 0) 1 ©) ) 10 O.TT L. eyanellus ) @) 0) O 1 O 1 ) re) ) 0) 0 2 0.15 A. grunniens 1 WL 29 95 59 21 26 8 y 6) 13 3 300 23.16 C. cyonguttata_ 0 2 fe) ) ) @) re) ) 1 ) 0 0 3 0.23 Total 7 92 173 189 188 86 89 125 105 81 46 73 1295 99.87 Percent 3.62 7.10 13.36 14.60 14.50 6.64 6.87 9.65 8.10 6.25 3.55 5.63 99.87 No of Nets Set 2 2 k 4 h y 4 k h 4 2 2 ho Avg. No. Fish Per Net 23. h6. ho, oT, 47. «621. 22 31 26 20 23 34 te tenes pte --- Page 12 --- 6) GH" qUSsoTEg og'e =o Q*E «=CLT'S oh OLE B'S = HOTE-sCTS* Sy'te LOTOE zZo°gh OH'OH OL*HE syle HO"gzZ 96°6L = O OB'TS TeLOL ) fo) ©) OT°0 O fo) fe) fe) oe eyeqqnsomeko °D f°) So°Hh OS*T 1e°e O (Oe) €9°s O 98h sueyaunis *V ) fe) fo) o 0 fe) 0) fo) o Oo sntpeueko °7T fo) fo) fe) oO §S°O #T°O fo) fo) o Oo snizyooroeu °T 0 L6°0 LS*T Oo Tet 32°00 06°0 42°0 o Oo sepTowres *W fo) fo) fo) o Oo fe) fe) fo) o Oo seTeu *y G6°ST eE°9 66°6 HIST EIT ES°TT Eases 6y°TE O 8 SH°ST sngeoiny °T ge°T =O TS°E TS°E€ €L° 0 ) fe) o 0 oydres °9 0) 99°6T 92°SZ = OG QT GETHT EET GLE EO°9E Oo TE°22 snTeqnq °T 65° 69°0 O - o oO 96°00 S2°0 Oo 0 unueTpedes *q 90°T O fe) Lo“E €9°T 0 0 fo) O HTS snesso °] ) eL°e 4Q°O Oo 0 fe) f°) 0 Oo ge°2 snjonpord *J ) ) G6°S 3) Z6°y = Lee T eL°T TS°S fe) 69°0 etayeds *] ° 29g “AON =—-°- 490 *qdeg *Sny 0 ATne) = oune) = ke Of ady Sey sotoadg °HG6T teqmecsq Ysnoryy Yyoreyl ‘uesjusg oye] WOls sey Tejusewtszedxg uy useyel, usta fo spunog “+ eTqBI, eT --- Page 13 --- 14. Table 5. Pounds of Fish Taken in Experimental Nets from Lake Bentsen, January through Octeber 1955. O 121.04. 5.52 O ¢) L. spatula 0 0 fo) 0 fo) 3.89 L. productus 0 - 6.86 0.75 3.51 11.28 7.72 fo) 0 © O 37-63 4.00 L. osseus 0.97 fo) 0.63 fe) Oo oO 1.31 fo) fo) O 13.81 1.48 D. cepedianum 0.63 . 1.13 5.04 1.75 0.13 O fo) fo) 0.09 O 12.86 1.37 I. bubalus 26.22 13.30 20.60 14.82 6.73 16.79 13.46 69.60 45.15 50.96 432.43 6.05 C. carpio O 4.84. 4.89 2.00 2,005.51 9.21 1.75 8.21 O 48.0h 5.11 I. fureatus 3-07 12.82 10.22 0.79 8.67 23.10 11.60 2.77 8.03 3.44 245.91 26.19 A. melas fe) 0 an?) 0 0.36 O 0 ) ) O 0.36 0.04 M. salmoides O 2.44 2.06 0.88 (0 0O fe) fe) O 1.75 12.55 1.33 L. macrochirus 0 0 0.33 0.08 o oO fo) fo) O 0.0L 21-11 0.11 L. cyanellus fo) 0 0 f°) 0 O- 0.12 ) 0 O 0.12 0.01 A. grunniens 1.75 7.83 8.92 22.5815.65 8.07 8.90 2.12 2.32 QO 97-26 10.35 C. cyanoguttata oO 0.24 fo) fo) Oo 0 fe) fe) fo) fo) 224 = 0.03 Total 32.64 49.46 53.44 57-45 50.34 61.19 44.61 98.24 63.80 56.16 938.94 99.96 Percent 3.48 5.27 5.69 6.12 5.37651 4.75 10.46 6-79 5.98 99.96 --- Page 14 --- 09° 00°S Oe o0°9L OTT Qt 0S °9TT O€tT €0T eT Tt e767] 4nsoueko ve) LUZ one 60° GL°€64 €oSt Ze 00°9L2 06£ SOT € Z suojTuunis “V 09°€ oL°€ OSE O06°SS LS 4S 00° OTT GTT GOT €T al suqjeuehko J Lae € GQ°t = E6°T =O’ TS SQ S 09° HOT O€T QS OT OT SNITYOOLOeW *'T 00°2 6S°e LO°T OO°€se +61, €TT 19°62 O9€ got 6 g SsepToures “W 94° T o9°T §=86ST°T) = 6—SL°QHT elt 92T 00° 20g OZ SOT aa €T seToul °V HE°T €9°T €T°T 00°6T6 +141 OST Z9° ale GOH Gez is € snyeoing °L OT’2 OS°S =ST°T STITT cete 002 try’ SEE 09h 092 + 9 oTdres °D 16°2 GQ°E = OH SCE* EGGS OggOT 2S 09° THE on9 GET T T suteqnq °T tQ°T ee €9°TeT L3e ot 00°gTT 0€Z O£T g t mustpedes °q Z° T° 0S° ZT CE een Z9z of LTH SE9 Oc€ ds 6 snesso °7T 19° eL° €S° 09°0LS ggsTt ong 0S °61h +01 oLe S S sngonpord_**T €L° 0O°T €S° O€°O9TT 6922 6€S OT°9SS 099 ONE 9 ds etnjyeds *] asersay “XB «°C UTW «| SBerTSAy °XBY “UTA 20s OBRTOAY ° Xen “UTW oom °ON I0OVDBT My swery UT VyusTOM uysueT prepueys fq yoy ; setoadg °GG6T 18qg0700 Yeno1y4 HG6T WIM ‘Uasqueg Sy] UT S48" TTT) UT yuBNeD ysT|a Jo ssoqoeg ,y, Pue ‘sqUuBtem ‘syasueT ‘syuey °9 eTABL °6T --- Page 15 --- 16. Table 7. Sexual Condition of Seven Common Species of Fish Taken in Experimental Nets from Lake Bentsen, March through December 1954. teen npn Species March April May June July 1234 5 1234 5 1234 5 1234 5 1234 5 . M 1 1 2 1 L. spatula F 1, M ou 1 L. productus F 1 M 3 D. cepedianum F 1 M 2 37 1 2 231 3 4 2h 8 I. bubalus r i 21 6 L 3 3 M 1 C. carpio F 1 M h 6 1 3 14 13 4 11 2 i. furcatus F 2 dl. 1 2 2i Mil 1 1 2 1 A. grunniens F 1 August September October November December 1234 5 123 4 5 123 4h 5 123% 5 1234 5 M 11 L. spatula F 1 1 M 1 1 L. productus F 2 M 1 217 D. cepedianunm F h M 6 26 2 6 19 17 5 3 3 9 5 3 ah I. bubalus F 1 4 nok 1 4 2 7 M hy 1a 1 1 C. carpio F 1 1 1 L M 13 °5 3 2 3 6 2 1 @i 3 i. furcatus F 2 L 3 21 3 3 M 1 1 2 4 3 1 A. grunniens F 11 y 2 --- Page 16 --- t 6 g Qg a suetuunid -y 9 T TT § 6 € T 6 € T Ww rf € T Z tT a snyeoing “TL ro T T 4 T 2 TE € € Ww T T Tt. T i oTdres *5 T TT T Ww HT €T T OT T 9 G¢ T a snqteqnq *y L 9T T 2 qw OL € ¢ T qT 2 oT W a Unaetpeddss -¢ Ww € a snjonpoaid “Ty € Ww a einjzeds “"] W G4 € @T G4 € @T G4 € 2@T Gre 2@t G4 € @tT 13890390 requez,deg qensny Atop eune t € 2 ¢ T 4 iT T J SsusTuinie “Vy 0S 2 26 62 oe 2 Z@ €2 ¢ W = £ T rf € T € A snpeoimy “T Z 2 2 T € W T TT T a OTarTes J T Ww € T G$ 4 ot T HT T el “enteqnq “tT € T 6 Q 92 £& 2 9 € T og L 2 Ww T T t + TT i wtefpsdss “7 L ETT T € TT z W Ze T € rf i snjornpord “| Lt ot W T a epnyeds TY T Z W Fo Ter! °6G6T 2eqo0799 Wanoryy Arenuer uesiueg SyeyT Wooly sien Tequewtzedxg ut uexey, ystz so seToedg uommog ueAeg JO UOTATpuoD Tenxeg °¢g asTqBlL ° LT --- Page 17 --- pe Ro BENTSEN TATE PARK BAL DRIDGE Map. 1 LAKE PENTSEN WY, = Submerged Willows [] -Seining Stations O Netting Stations 4 mi. Filling Canal SS —-Dirt Dam ith Gates ey mp RIO GRANDE --- Page 18 --- 19. Fig. 1. Netting Station No. 1. Lake Bentsen Fig. 2. Netting Station No. 2. Lake Bentsen --- Page 19 --- le 9. A List of Fish Species Recorded from Delta Orchards Lake Seientific Name Lepisosteus spatula Lepisosteus productus Lepisosteus osseus Dorosoma petenensis Dorosoma cepedianum Astyanax fasciatus M. Ictiobus bubalus Carpiodes carpio Cyprinus carpio Notropis braytoni Ictalurus punctatus Ictalurus furcatus Ameiurus melas Strongylura marinus Cyprinodon varigatus v. Gambusia affinis Bo Mugil cephalus Menidia beryllina Micropterus salmoides ™ aenobryttus coronarius _ 2,omis cyanellus Lepomis macrochirus Lepomis auritus Pomoxis annularis Aplodinotus grunniens Cichlasoma cyanoguttata Common Name alligator gar spotted gar longnose gar threadfin shad gizzard shad Rio Grande Tetra smallmouth buffalo river carpsucker earp Tamaulipas shiner southern channel catfish blue catfish black bullhead needlefish sea pupfish Gambusia striped mullet tidewater silversides largemouth black bass goggleye green sunfish bluegill yellowbelly sunfish white crappie fresh water drum Rio Grande Perch Symbols Used in Following Tables spatula productus osseus petenensis cepedianum fasciatus m. bubalus -_carpio carpio braytoni punctatus furcatus melas » marinus varigatus v. affinins a. cephalus beryllina salmoides coronarius cyanellus macrochirus auritus annularis grunniens cyanoguttata o ° ° ° PINIVIFIEt ? Ee ° AL PIHIHiZ1a eo e¢ © © © ° ° ° ° IAP MIMO HON ZIZIaIa ° --- Page 20 --- el. Table 10. Seining Collections Delta Orchards Lake July 1, 1954 to March 30, 1956. gee rn nen Species Total Number Percent of Total nnn nnn nnn nn ea UEttt Ean SSSR Dorosoma petenensis 2 09 Dorosoma_cepedianum 1419 62.92 Astyanax fasciatus m. 16 18.44 Tetiobus bubalus 33 1.46 Notropis braytoni 74 3.28 Cyprinodon varigatus v._ 9 40 Gambusia affinis a. 52 2.30 Menidia beryllina 232 10.29 Lepomis macrochirus 3 213 Aplodinotus grunniens 12 053 Cichlasoma cyanoguttata 8 o13 2255 . 99.97 --- Page 21 --- 22. Table 11. Numbers of Fish Taken from Experimental Nets from Delta Orchards Lake, March 1954 through October 1955. Species Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Jan. Feb. Total Percent L. spatula ) 17 =7 6 4 5 5 5 y 1 3 5 61 3.05 L. productus 1 1 5 3 1 1 ) 2 1 ) 6) ) 15 0.75 L. osseus 1 1 8 1 0) 1 1 fo) 4 0) fo) fe) iy 0.85 D. Cepedianum 5 19 7 2 8 21 2 4 5 2 6 9 70 3.50 D. petenensis 2 9 2 6) 1 6) 6) 1 6) ¢) 6) 3 18 0.93 I. bubalus UT@) 46 67 90 39 +52 63 97 #16 13 13 «20 556 27.80 Carp. carpio fe) 2 6 1 Qa Oo @) i fe) fe) fe) ) 10 0.50 C. carpio 11 47 = 26 4 10 6 @) 3 2 6) 4 10 123 6.15 I. furcatus 28 30.—s:* 73 110 2h. 16 90 127 14 4 4 21 605 30.25 I. punctatus ) ) 9 fe) 3 ) 2 @) fo) @) fe) fe) 14 0.70 M. cephalus 10 1 18 16 ) 9 0) 2 fe) 6) fe) 3 59 2.95 St. marinus 6) fe) fo) 0) 6) 1 0) 1 fe) ) fe) fe) 2 0.10 M. salmoides-- 0 1 6) fe) 1 1 @) fe) ) fe) 6) 2 s 0.25 C. coronarius 0 HE A. 0) 0 1) 6) fe) fe) fe) re) 0) 2 0.10 L. macrochirus 0 0 3 fo) 1 Oo fe) oO oO fo) o oO 4 0.20 L. ¢cyanellus @) ts) 9) a) a) fs) @) 6) 3) a) a) 2 2 0.10 L. auritus fe) 1 6) fe) fe) fo) fe) @) ) 6) fe) 1 2 0.10 P. annularis 36 16 9 a. 23 12 17 28 13 12 1k 31 222 11.10 A. grunniens 9 4) 29 16 39 14 4 7 3 ) 16 9628 207 10.35 C. cyanoguttata O fe) 6) fe) fe) 0) 1 1 fe) fo) fe) 6) 2 0.10 Total 1k4h = 230 270 260 154 119 186 278 62 32 77 182 2006 99.80 Percent 7-20 11.60 13.50 13.00 7.70 5.95 9.30 13.95 3.10 1.60 3.85 9.10 99.85 --- Page 22 --- cn rEnEnnnnnnnnerninnnnnrnnnnen ememeenenneseeneansnnaneneasmnenemeneteeneeenneeeeenenneenenenennanemennene eee e *oTqTssodwy 78S JON xx pee erence NC NL re) 6T°S 9T°S fe) QT°99T 4S°S9T ) ) fe) ) Tg°OT tr’ S ) ST°OT 6E°OT ) ) fe) (0) ) ) fe) ) fe) re) fe) fe) fe) fe) ) @) 3) ez°0 ) OT'S ) ) fe) ) fe) TT°S2 T6°0€ ) AS 96° ) 9) @) 0) LG° qT 66° 42 ) Oo. - g0°O ) 68°0 0£°0 ) €a°LT fe) 0 69°S @) @) 16°69 LT° 06 x* Lequeseg aSsqUsAON 2aqo7sQ arsqueqdag 00° 9 69° Tat XO LN “NCO aooooocoo4 Oo ° oma! N \oO En" ge 6) 99° LT 6£°0 ETE 92° 4 19° LE oy’ 14°69 Ao do ~ oO CObOHROOCOOHAO No ow \O \o e MN oO a 4s 99° SS Qe°TT 60°O ° e e 6 Se Mgods ees aes OnANOrF ON MAOWN to OV ° ) 6°), ) T8°O9T @) ) @) 60°6 ) fe) fe) re) ) ) ) Ge°O fe) fe) ) re) ) ) ) LT°et (e) TL°09 ) 0) ) 19°ST ) 99°, fe) 6L°0€ ) GE°0 ) Hye € fe) OL? h fe) GH’S 0) TH’ OT 9L°L 9S°T eyLSt 6L°TE a ° aan fomsg) ina) CODCOD COMDNO e oO at es) fa! ae) o 60° TE €o°Tt 12°6 LET 88° h eT’? oy LN ° ° ANON oy ON (jo) ON eooegeace eqooocoooone 98°95 Trady yor ey qusoleg ‘J ° i e487 neoueko ‘Suetuunis S$p2re nue Sn} Tine ~snTteueko sna FYoOLO eu SNTIBUuOLOD Sop Toues snu Trew snteydeo snyeyound snyeoiny OTa189 e o ¢ e© oe 8 @ OIHIGESInOSlomalalaiciol ° ° OTdreo °dat snTeqnaq, ST susuojed mnie Tpeaeo snesso snj}onpo1rd. BO ° o 8 «6 HIAIAIAIATEAI “HG6T 2equeseg YBnoryy YOM ‘SxeT spreyoro eITeC Wor sje Teyueupredxy UT ueyeL, YsTA JO spunog *ZT TAL i te --- Page 23 --- 2h. . Table 13. Pounds of Fish Taken in Experimental Nets from Delta Orchards Lake January through October 1955. Species January February March April May June duly August September October Total Percent HR : L. spatula 0 105 46 14.57 66.42 13.75 78.81 20.07 0 fo) ) 626.44 30.88 L. productus ) 5.01 2.57 3.70 5.89 7025 2.25 0 ) 2.69 47.09 2.32 L. osseus @) @) ) 0 17.68 3.51 @) ) ¢) @) 54.59 2.69 D. cepedianum @) 2.30 1.06 0.46 O.LT 0.54 0.13 ) 0) ) 18.53 0.91 D. petenensis fo) 0.41 fo) ) fe) fo) oO 0 fo) fo) 2.48 0.01 i. bubalus 0 17.30 29.48 33.35 23.07 38.82 13.58 20.63 15.84 26.50 332.26 16.32 Carp. carpio 0 0) 0 ) 0 862.04 0 0 0 0.37 11.11 0.60 C. carpio 0 15.65 2.00 2.98 7.52 4.21 o oO 0 O42 103.68 5.11 I. furcatus O 59.56 28.93 51.66 28.98 62.54 13.95 8.11 49.37 20.88 khgo,74 22.17 I. punctatus f°) fe) fe) fe) fe) fo) Oo Oo fe) fe) 70.43 3.47 M. cephalus fe) 0.84 6.98 0.35 1.15 4.37) 0 243 447 0.69 5.01 59.89 2.95 St. marinus 0 fo) 0 ) 0) fe) 0 0.26 0 0 0.54 0.00 * M. salmoides 0 2.24 ) 1.50 0 O 1.25 0 ©) ©) 5.38 0.26 CG. coronarius f°) fe) fe) O48 O.17 fo) o 0 fe) fe) 0.65 0.00 * L. macrochirus ©) ) 0 0.07 0.26 ©) 6) 0 fe) 0 0.67 0.00 * L. cyanellus ) 0.19 @) 0 0 ) ) 0 0) @) 0.19 0.00 * L. auritus 0 0.08 0) 0 @) ) 0 ) 6) 0 0.20 0.00 * P. annularis fo) 23.05 16.16 8.21 3.57 4.46 1.11 0.69 3.36 2.14 91.18 4.49 - A. grunniens 9) 18.48 5.94 16.39 14.14 9.07 4.10 0.30 2.47 0.24 153.19 ‘7.55 C. cyanoguttata fo) fo) 0) fe) fe) e) o Oo 0.07 0.08 0.16 0.00 * Total 0 250.57 107.58 185.57 116.35 215.62 58.87 34.36 71.80 57.96 2028.39 99.87 Percent ©) 12.35 5.30 9.14 5.73 10.63 2.90 1.69 3.53 2.85 99.87 * Decimal. in thousanths. ** Net set impossible. --- Page 24 --- 25 o Table i. Ranks, Lengths, Weights, and "K" Factors of Fis.. caught in Gili Nets in Delta Orchards Lake, Marc. 1954 through October 1955. Species Rank By Standard Length Weight in Grams "K" Factor No. Wt. Min. Max. Average Min. Max Average Min. Max. Average L. spatula 8 1 422 980 730.66 652 15890 3286.00 89 1.68 1.00 L. productus 11 10 420 670 551.00 567 2268 1463.00 57 “72 65 L. osseus 10 9 510 610 588.33 680 1558 1072.33 40 62 52 D. cepedianum 6 11 115 340 = 208.33 32 397 123.80 65 2.12 1.25 D. petenensis 9 14 140 160 148.30 50 57 52.33 TL 085 »76 I. bubalus 2 3 120 400 342.75 56 3288 1908.25 3.20 3.50 3.47 Carp. carpio 13 12 205 290 256.66 2he 507 438.66 1.07 1.30 1.23 C. varpio 5 5 144 288 21p.75 85 4.82 283.00 2.90 a ag 3.13 I. furcatus 1 2 175 580 42 .60 80 3969 1010.25 80 1.7% 1.33 I. punctatus 12 7 282 500 406.40 369 2495 1304.20 1.28 2.57 1.79 M. cephalus 7 8 190 360 306.66 130 2155 801.33 1.07 2.40 2.02 St. marinus 19 17 380 =. 4436 407.00 120 130 125.00 1.05 1.07 1.06 M. salmoides... 14 13 185 310 258.75 178 680 468.00 145 1.80 1.61 ¢. coronarius 16 16 130 175 151.60 80 220 152.50 2.10 2.56 2.32 L. macrochirus 15 15 95 110 102.00 32 57 4.7.80 57 2.20 1.71 L. caynellus Lag 19 100 105 103.50 FX) 51 45.70 2.25 2.35 2.29 L. auritus 18 18 95 100 97-50 53 57 55.00 5.50 5.70 5.60 P. annularis 3 6 55 230 141.80 5 410 =: 147.30 1.38 3.97 2.58 A. grunniens 4 4 120 350 22h.00 57 1162 504.80 1.40 3.25 2.73 C. cyanoguttata 20 20 80 100 91.66 33 ho 36.33 62 2.10 1.60 --- Page 25 --- 26. Table 15. Sexual Condition of Six Common Species of Fish Taken in Experimental Nets from Delta Orchards Lake 2 March through December 1954, . . Species March April May June July M 12 7 111 2 Bb. spatula F 2 121 1 ~ M 2 2 1 8 3 4 30 hh 7 I. bubalus F 1 2 3 3 M 3 2 yh 3h 2 123 1 3 3 C. carpio F 1 1 2 11 1 2 M 11 11 2 1 I. furcatus F 1 1 dk M 11 2 5 P. annularis F 1 - M 1 iL 1 5 14 I3 9 ‘2 2 19 A. grunniens F 1 2 2 1 i August September October November December 123 4h 5 1234 5 123h 5 1234 5 1234 5 M 1 2 1 L. spatula F 1 3 1 2 11 1 2 M 3 7 2 hk 20 hk 5 37 2 3 8 I. bubalus F y 3 7 3 M 1 1 3 1 C. carpio F 2 2 2 M 11 3 3 2 25 22 5 I. furcatus F 2 3 14 1 4 M 3 3 11 5 21 14 P. annularis F 2 3 1 3 h 4 M 12 5 11 121i 22 5 A. grunniens F 1 3 1 2 24 --- Page 26 --- 21. Table 16. Sexual Condition of Six Common Species of Fish Taken in Experimental Nets from Delta Orchards Lake January through October 1955. eee Et es ee nt sei esp eS A RES RE So P= en Sete =e nee SN ae sues Seance See January February March April May Species 1234 5 i. 8-2-5 1234 5 1234 5 1234 5 “eeepc nannies igh ng ii me ig L. spatula M 1 2 2 3 2 1 F 2 2 1 I. bubalus M 16 @ 1 6 23 1 9 16 1 6 15 ~ F 1 5 1 6 9 6 C. carpio M 1 3 3 2 2 L ‘é 2 3 F 3 1 1 3 I. furcatus M 1 2 1 6 12 6 8 4 2 1241 ~ F 1 6 3 4 18 P. annularis M 2 3 2 8 18 25 1 3 2 ~ F 1 3 2 6 3 3 4 A. grunniens M 1 7 10 3 2 3 2 1 3 8 ~ F 2 8 2 h 3 7 June July August September October Species 1234 5 123 4 5 123 4 5 1234 5 123 4% 5 L. spatula M 3 F 1 2 1 I. bubalus M 2 14 64 1 2 8 3 31 1 3 25 6 31 F 10 1 6 1 3 5 1 6 C. carpio M 1 2 F 1 I. furcatus M 1 15 80 14 9 2h 6 2 6 65 1 16 59 F 1 13 1 7 1 4 7 2 14 P. annularis M 14 3 9 L- i 2 2 F 5 3 1 2 1 A. grunniens M 1h 5 La 7 1 1 1 F 6 2 1 1 --- Page 27 --- 28. Fig.5. Netting Station No.1,Delta Orchards Lake. Fig..6. Netting Station No. 2. Delta Orchards Lake. --- Page 28 --- 29. RAYMONDVILLE OUTLET EAST OUTLET INLET CANAL WITH GRAVITY FILLING GATES DIRT ROAD CIRCLING LAKE TEXAS H’WAY NO. 88 MAP 2. DELTA ORCHARDS LAKE [I=seining STATION O= NETTING STATION A =SUBMERGED WILLOWS ie) 440 880 1320 YARDS CANAL TO PUMP STATION --- Page 29 --- 30. Table 17. A List of Fish Species from Olmito Lake. Seientific Name Lepisosteus spatula Tepisosteus productus Dorosoma petenensis Dorosoma cepedianum Astyanax fasciatus m. Ietiobus bubalus Cyprinus carpio Notropis braytoni Ictalurus punctatus ictalurus furcatus Ameiurus melas Gambusia affinis a. Mugil cephalus - Menidia beryllina Micropterus salmoides Chaenobryttus coronarius Lepomis cyanellus Lepomis macrochirus Lepomis auritus Lepomis megalotis Pomoxis annularis Aplodinotus grunniens Cichlasoma cyanoguttata Common Name alligator gar spotted gar threadfin shad gizzard shad Rio Grande Tetra smallmouth buffalo earp Tamaulipas shiner southern channel catfish blue catfish black bullhead Gambusia striped mullet tidewater silversides largemouth black bass goggleye green sunfish bluegill yellowbelly sunfish longear sunfish white crappie fresh water drum Rio Grande Perch Symbols Used in Following Tables ° ° ° o 8 6 ° o © © ¢ © 6 @ HHOlSiSISI>1>IHI Hl ald >t loli ° ab ° 2 ° IQS Wi ripe spatula productus petenensis cepedianum fasciatus bubalus carpio braytoni punctatus furcatus melas affinis a. cephalus beryllina salmoides coronarius cyanellus macrochirus auritus megalotis » annularis grunniens cyanoguttata --- Page 30 --- 31. Table 18. Seining Collections Olmito Lake July 1, 1954 to June 30, 1955. Species Total Number Percent of Total Dorosoma cepedianum 38 8.87 Dorosoma petenensis 125 29.20 Astyanax fasciatus m. 34. 7.94 Notropis braytoni 6 1.40 Gambusia affinis a. 104 2h .29 Menidia beryllina van 16.59 Lepomis macrochirus macrochirus 8 1.87 Lepomis cyanellus _ 22 5.14 Aplodinotus grunniens 8 1.86 Cichlasoma cyanoguttata 12 2.80 Total 4.28 99.96 --- Page 31 --- 79N Jeg UsTd * N ‘Say qusoreg 22g SYON JO ‘on o°ee €6°H 99 og €o"n 4G S*He To*s 49 0°6S 28°8 QTT G° eh 0S°9 1g 0°02 66°2 O° 12 65°E et G°SE TE*S +06 GS°) TOT gg o£°g TIL lAlPlIFIA MIO SI> IH Hlobelolee g @ qQ. QlAIO Q Q bs] Q ele Be IS ISIRISIRIE [21g Ie [3 £ MEISTER IEIISI | 8 SERIE SRC REI EIEEIE @ 1) SEITE" (Eee! lle! le ey et Alan Alei* n g/m bs) a ct n i) ¥ 5 FHWAIOCOOOCDCOOCOOOHFONaO a > > fo e ig WOKTOONnNDVDCOCOOWMFORW He i 5 4 ! : ine) SOCCORPNDODDCDOOO FROG F PO PO ww SCONTOHH OOOO C OOO Au B i) 3?) FE po VEFNDDOOWOODODODODOCOWW Ow E fd NOTOCOWDFODOOCOONjUWAIWwO zsnsny ep Pep g FWOrFCOWDDDDOCOO FOUR ¢ = ® R bP HN SCFONOOUNEFONRON ERE NW VI fo SOFRPOOONNNOWONF-]FWO ed CHCOCOPOPEPHOOFS BO Laquelaq sZeqMaAoN 198q0700 *7S6T eqms.eq YBnosry. YoreW ‘eye] OLTWTO WarZ sqoy Tevusuyiedxy Uy ueyeL Ysty Jo szequmy °6T eTaey "Ze --- Page 32 --- 336 Table 20. wumbers of Fish Taken in Experimental Nets from Olmivo Lake January through October 1955. Species January February March April May June July August September October Total Percent L. spatula fe) fo) fe) oe) fe) 0 0 fo) fo) ) 30 2.2h L. productus 8 0 7 27 26 14 h 2 16 Xt 269 20.11 3D. cepedianum 8 10 UT 9 8 9 2 fe) 6 fe) 158 11 82 1. bubalus 16 20 13 @) 37 23 9 13 2 fe) ae 33.13 C. carpio o) fe) i 2 h 3 fe) 6 2 0 14k 8.52 I. furcatus fe) ) fe) 0) f°) ik 1 1 fe) 8 15 1.12 I. punctatus 0 fe) ) 0) ) ©) ©) 1 2 0) 3 22 Z. melas 0) ) 1 \ 4 2 ) ) 2 0 23 1.72 WM. cephalus ) 1 ) 0) ) 4 ©) 13 3 0) 22 1.64 M. salmoides 0 0 0 0 1 0 0 0 0 0 5 37 C. eoronarius ) ) 1 16 8 7 5 @) ) ¢) 6 3.34 I. macrochirus 9) ) ) 5 4 6 i 2 0 ©) 39 2.91 L. auritus @) f°) f°) ) 0) 0) @) 6) ) 6) 12 89 LL. megalotis ) fe) 6) @) 6) fe) 0) f°) 1 1 3 22 L. eyanellus f°) ©) 9) fe) fe) 1 fo) ) 1 6) 5 37 'P. annularis ) i 3 12 1 2 11 4 6 aL 8 6. ee ‘A. grunniens fe) S 2 3 5 5 ) 1 1 3. C. cyanog…