Dwight A. Webster

Comparative First Year Survival and Production in Wild and Domestic Strains of Brook Trout, Salvelinus fontinalis

Abstract Brook trout (Salvelinus fontinalis) from three wild populations were compared with domesticated hatchery strains with respect to growth, survival, and production in semi-natural environments (drainable ponds). Eggs from all strains were hatched and reared in the hatchery and planted as spring or fall fingerlings. Over-summer survival consistently favored wild strains (65 to 76 percent compared with 43 to 53 percent survival for domestic strains). Over-winter survivals were not different, although the effect may have been masked by other overriding factors in the test waters. Domestic strains maintained the initial size advantages held at planting. Larger size at planting was due to faster growth rate during hatchery existence. Net production, based on recovery weight less stocking weight, was similar for wild and domestic groups during the over-summer period (higher survivals in wild strains balanced by size advantage of domestic), but domestic groups generally showed lower production or net loss...

Upwelling Water as a Factor Influencing Choice of Spawning Sites by Brook Trout (Salvelinus fontinalis)

Abstract Brook trout (Salvelinus fontinalis) generally select areas of upwelling spring water for spawning under natural conditions. When presented with suitable gravel containing an artificially controlled aquifer of about 0.1% the area of a circular tank, female trout selected spawning sites that were either in close proximity to the upwelling water or adjacent to it in 21 of 22 trials. Average time lapse for completion of spawning was about 30 hours. Use of a tank several times larger than 1.9 m2 would probably improve conditions for making more precise observations on discrimination of aquifers under laboratory conditions.

The Spring Migration of the Common White Sucker, Catostomus c. commersonnii (Lacepede), in Skaneateles Lake Inlet, New York

OBSERVATIONS over several years have shown that most streams which enter the Finger Lakes in central New York are visited annually by a run of large common suckers, Catostomus c. commersonnii (Lacepede). At this time suckers are taken by angling and by spearing. This is especially true of the lake suckers which reach a large size (see Table III). They are an important local food fish and might be utilized to a greater extent during the next few years. Much of the information to be presented below may be useful in connection with the pond culture of the muskalonge, Esox masquinongy. Here the problem involves supplying an abundance of living forage fishes of varying sizes for the young muskalonge after they have eaten the available stock of Daphnia and similar small animals. Suckers may be stripped, the eggs incubated in jars, and the young raised in small ponds until they are of the desired length. If eggs are obtained several times during the sucker run, a plentiful supply of all sizes of suckers would result. A number of incidental notes on these migrations in New York State waters have appeared in the literature. Surface (1899: 241) observed the run to last from the last of March to the middle of May in Cayuga .Lake Inlet. In Beebe Lake, at Ithaca, Stewart (1927: 150) found that the spawning season lasted approximately one month, and ended on May 25. Greeley and Bishop (1932: 81) report a spawning run as early as April 13 to 15 in Fish Creek at Popes Mills. Greeley (1930: 77) also found them breeding as late as June 17 in Stacy Brook, a tributary of Lake Champlain. The most complete studies on migrating suckers are those by Dence (1937 and 1940) on the dwarf white sucker, Catostomus commersonnii utawana Mather. Mather (1886), Kendall and Dence (1929: 287), Greeley and Greene (1931: 84), Greeley and Bishop (1932: 81), and Greeley (1934: 101) have noted that the dwarf subspecies, utawana, spawns later than the common white sucker where they occur at the same locality in the Adirondack Mountains. Migrations of utawana usually occur in June. In Michigan some interesting data on sucker migration were obtained by Shetter (1938: 335). A two-way fish trap was operated continuously over one calendar year (1937) in Canada Creek, Presque Isle County. He found that the greatest number of suckers taken in April and May were moving downstream, possibly out of small lakes to spawning grounds. He also found a considerable number of suckers moving both upstream and downstream during September and October. During the spring of 1939 an attempt was made to obtain a picture of the sucker migration in Skaneateles Lake Inlet. This was possible since a weir had been installed in connection with research on the rainbow trout, Salmo gairdnerii, by Dr. H. John Rayner, of the Laboratory of Limnology and Fisheries, Cornell University. The sucker studies covered a general description of the main characteristics of the run, and included the length

Standing Crops of Brook Trout in Adirondack Waters before and after Removal of Non-trout Species

Abstract Ponds and lakes in the Adirondack Mountain region of New York State that contain brook trout Salvelinus fontinalis are generally infertile and trout production is low when brook trout have to compete with non-trout species. Standing crop estimates for seven waters with mixed-species associations ranged from 50 to 100 lb/acre; suckers Catostomus spp. were a major component of each assemblage, Brook trout standing crops were under 1 lb/acre in all but one water and were particularly low where yellow perch Perca flavescens were present. Following reclamation, during which major competing species were removed, brook trout were restocked. Subsequent estimates of brook trout standing crops ranged from 5 to 16 lb/acre, and good trout fishing prevailed where previously there had been little or none.

Problems in Sampling Wild and Domestic Stocks of Brook Trout (Salvelinus fontinalis)

Abstract In the spring of 1959 two wild stocks and a domesticated stock of brook trout were planted as fingerlings in Bear Pond in the northern Adirondack Mountains of New York. A resident population of brook trout of domesticated parentage was also present. Differences in behavior between the four groups affected the catch by angling and trap-netting. During the summer of 1960, when all four groups were approximately the same length, over 30 percent of the domesticated stocks were taken by fly fishing, while during the same period only 12 percent of the two wild stocks were recovered. The stocked domestic group was found to be much more vulnerable to trap-netting than the other groups. During the first 24 hours of netting, 46 percent of the trout estimated at large from this stock were recovered. At the end of three weeks of trap-netting, 84 percent of the stocked domestic, 64 percent of the resident domestic, 66 percent of the Long Pond Stream wild, and 44 percent of the Honnedaga Lake wild brook trout ...

Relation of Temperature to Survival and Incubation of the Eggs of Smallmouth Bass (Micropterus Dolomieu)

Abstract Field observations indicated considerable loss of eggs of smallmouth bass and a high incidence of fungus infection in the nests in Cayuga Lake, New York, and tributaries. To investigate the possible effect of temperature changes on embryo survival, several tests were run using constant-temperature facilities at the Cornell University Insectary. In 1945, two trials were run raising the temperature of developing ova from 53° to 77° F., and no eggs were killed. During 1946, eggs developing at 65° F. were transferred at 0, 1, 2, 3 and 4 days following fertilization to 50° and 75° F. None of the eggs was adversely affected. The temperature changes took place within one-half hour. The mean incubation period was determined to vary from about 2 1/4 days at a constant temperature of 75° F. to nearly 10 days at 55° F. The observations presented lead to the conclusion that temperature changes in the ranges indicated are not directly responsible for the death of smallmouth bass embryos.

Artificial spawning facilities for brook trout, Salvelinus fontinalis

Abstract Lack of suitable conditions for natural spawning is a limiting factor in brook trout production in waters in the Adirondack Mountains, New York. Presence of ground water or springs is considered a major requirement for successful spawning in this species. Two kinds of improved spawning areas have been offered: (1) replacement of unsuitable bottom material with gravel on or near known natural spawning areas; (2) piping and dispersing water through a gravel-filled box. Both types of improvements have been used by brook trout under some conditions. Further studies are required to determine factors responsible for acceptance or rejection of improved areas and to evaluate efficiency in the production of fry.

Food Progression in Young White Perch Morone Americana (Gmelin) from Bantam Lake, Connecticut

Abstract On August 26 and 27, 1941, collections of young white perch, Morone americana (Gmelin), were made at 8:30 and 11:30 p.m. and at 2:30 and 4:30 a.m. when the fish had moved over shoals. The stomach and intestinal contents of 50 specimens in each collection were examined; estimates were made of the fullness of the stomachs and of the volume of the various food organisms. The position of the food was diagramatically noted. The stomachs examined from the 8:30 p.m. collection held considerable food, but those from subsequent ones held increasingly less, until the 4:30 a.m. collection, when about 95 per cent of the fish examined had empty stomachs. The most important food organisms in the 8:30 p.m. collection were Cladocera, chironomid larvae, and a certain adult of the Hymenoptera. In the following collections, the volume of Cladocera gradually decreased in the digestive tract and such forms as Hyalella, ant adults, midge pupae, and mayfly nymphs increased greatly. In the several collections there was ...

The Food and Growth of the Young of the Common Bullhead, Ameiurus Nebulosus Nebulosus (LeSueur), in Cayuga Lake, New York

Abstract An analysis is presented of the food of 170 specimens of the young of the common bullhead, Ameiurus nebulosus nebulosus (LeSueur), taken at intervals from June 21 to October 10, 1938, in quiet coves of Cayuga Lake, Ithaca, New York. A large variety of organisms were utilized for food. The main staples were Crustacea (approximately 60 per cent) and Diptera (approximately 25 per cent). Almost all of the Diptera were chironomid larvae, while 80 per cent of the Crustacea were ostracods and cladocerans. Considerable variation in the length attained by the common bullheads was noted in the collections taken after the middle of July. By October 10 the largest specimen was more than twice the length of the smallest. While the mean total length does not exceed 3 inches at the end of the first growing season, some individuals may reach a total length of nearly 4 inches.

Population Depletion in Brook, Brown, and Rainbow Trout Stocked in the Blackledge River, Connecticut in 1942

Abstract A section of the Blackledge River, 1.7 miles long, was blocked off by weirs and fish traps and a total of 4,757 marked brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Salmo gairdnerii) were stocked in the experimental area in three plantings. Only a small number of the marked trout attempted to leave the area as indicated by the 46 fish taken in the traps. Subsequent recapture of these trout, which were tagged, indicated no inclination to move any great distance. The mortality of the marked trout after planting was slight during the period of observation, except in one planting where the brook and brown trout stocked showed advanced symptoms of furunculosis. The total catch of marked trout during the season of April 17 to August 31 was 3,446 trout taken by 3,152 anglers spending 9,746 hours on the stream. There was about an 80 per cent return of the available population from each planting and from each of the three species of trout planted. Of the 97 unmarked t...