Search USGS⌕ Search

SEARCH · Search USGS

Results for “Progressive Fish-Culturist”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
USGS1991

System for maintaining sediment suspensions during larval fish studies

A new system was developed for maintaining suspensions of inorganic solids during laboratory studies on early life stages of fish. Microfine bentonite was successfully held in suspension in specially constructed units during a 21-d fishless test, a 28-d experiment with juvenile green sunfish (lepomis cyanellus), and four shorter experiments (5-9 d) with four species of larval fishes, white sucker (catostomus commersoni), northern pike (esox lucius), channel catfish (ictalurus punctatus), and walleye (stizostedion vitreum). Each experiment on larval fish was conducted until the yolk-sac had been absorbed. Concentrations of bentonite ranged from 0 to 728 mg/l. Each unit consisted of a holding chamber set in a stainless steel bowl and two submersible pumps that recirculated the suspension. Turbidity readings remained nearly constant throughout each experiment. Because the turbidity of suspensions was well correlated with bentonite concentration ( r 2 = 0.989) And easy to measure, turbidity was used as an indicator of concentration. The system is inexpensive, easy to assemble, and does not require a diluter system to maintain constant concentrations of suspended material.

Progressive Fish-Culturist↗
USGS1992

Effects of day length and cleaning regimen on the growth of yearling parr Atlantic salmon

Yearling Atlantic salmon ( Salmo salar ) were reared with 8 or 16 h of light each day in laboratory tanks that were cleaned daily or weekly, and growth was measured weekly for 10 weeks. Growth was greatest for fish on the 16‐h light and weekly cleaning routine. Reduced frequency of tank cleaning (weekly) significantly enhanced growth but accounted for only 8.5% of the partitioned variance, compared with 78.9% for increases in day length alone. Results of this study suggest that the increased growth observed at longer day lengths was primarily due to the stimulatory effects of increased amounts of light.

Progressive Fish-Culturist↗
USGS1992

Tricaine used to separate phase‐I striped bass with uninflated gas bladders from normal fish

Tricaine (MS‐222) was used to separate striped bass ( Morone saxatilis ) with uninflated gas bladders from normal fish. Pond‐reared, phase‐1 striped bass (19–71 mm total length) were anaesthetized in a 12.5‰ saltwater solution containing 110–123 mg MS‐222/L. Fish with inflated gas bladders were neutrally buoyant or floated, whereas fish with uninflated gas bladders remained on the bottom. Dissection of buoyant and nonbuoyant fish indicated the procedure was 90–100% accurate. Eliminating fish with uninflated gas bladders will improve efficiency and quality of phase‐11 production.

Progressive Fish-Culturist↗
USGS1993

Growth, survival and food conversion of Atlantic salmon reared at four different densities with common water quality

Our objective was to determine the maximum effective rearing density for Atlantic salmon ( Salmo salar ) at 17.5°C, a temperature typically used in hatcheries to accelerate growth. We reared 5.8‐g (mean weight) parr for 80 d to final rearing densities of 14–55 kg/m 2 (rearing unit bottom area) or 80–310 kg/m 3 (rearing unit volume). Weight gain was slightly depressed in fish at a final rearing density of 26 kg/m 2 (146 kg/m 3 ), but mortality, food conversion, and gain in length were not affected. At densities greater than 26 kg/m 2 , fish growth was slower and food conversion was higher, but mortality was unaffected. Atlantic salmon may be reared at 17.5°C to densities of at least 14 kg/m 2 (80 kg/m 3 ) without adverse effects on growth and health, but final rearing densities should not exceed 26 kg/m 2 .

Progressive Fish-Culturist↗
USGS1993

Single-feeding response of chinook salmon fry to potential feed intake modifiers

A study was conducted to determine the effects of various potential feed intake modifiers on initial feed consumption by spring chinook salmon ( Oncorhynchus tshawytscha ). Feed intake was immediately and significantly influenced when glycine, trimethylamine, or betaine was added to experimental diets. Results support the notion that glycine enhances feed intake, whereas trimethylamine and betaine decrease it. The reduced consumption of diets containing betaine, which has often been described as a feeding attractant, may have been a response to the chemical form of this compound used in this study (betaine hydrochloride) and may not occur if the free form of betaine is used.

Progressive Fish-Culturist↗
USGS1994

History of early diet development in fish culture, 1000 B.C. to A.D. 1955

This paper traces the observations and speculations of early fish culturists as they sought to define the feeds necessary to keep hatchery fish alive. Although prescientific ideas about feeding fish existed in Egypt and China over three millennia ago, it was not until the 1700s that scientific studies of feeding and digestion by fish were documented. Aside from several books that provided early anecdotal accounts of feeds and feeding, much of the technical literature up to the 1930s is found in a few journals and relatively obscure bulletins. Such was the state of knowledge regarding the feeding of fish until about 1927 when Clive McCay, a professor at Yale University, and Abram Tunison, a hatchery worker, began some part‐time research on the nutritional requirements of trout at Connecticut's Burlington Fish Hatchery. In June 1932, these men founded an experimental hatchery, designed to study the nutrition, feeds, and feeding of fish, at Cortland, New York; this hatchery was operated under the auspices of the federal Bureau of Fisheries, the Conservation Department of New York State, and Cornell University. Over the next 25 years, it was research from this hatchery as well as from other federal, state, and university facilities that led to the development of purified test diets and the identification of the (unknown) growth factors in fresh meat, both essential criteria for scientific diet formulation, The first nutritionally complete diets appeared about 1955.

Progressive Fish-Culturist↗
USGS1994

Hatchery performance of six Atlantic salmon stocks from fry to smolt

Atlantic salmon ( Salmo salar ) from four Penobscot River, Maine, brood stocks (two wild and two captive) and two landlocked brood stocks (Grand Lake, Maine, and Lake George, New York) were evaluated in hatchery tests to measure differential performance characteristics. Each stock was received as eyed eggs and cultured under standardized rearing conditions through 16 months. Penobscot stocks did not differ in growth rate or time of smoltification but did differ in frequency of six of seven body abnormality traits. Domestication effects on postyearling weights and smolt ATPase levels were detected in Penobscot stocks. The Grand Lake landlocked stock had a higher growth rate after 245 d and was heavier than Penobscot stocks after 280 d (36%) and 480 d (58%). Although differences among the Penobscot stocks were small and generally nonsignificant, the presence of domestication effects on 17‐month weight and Na + K + ‐ATPase indicates that progeny from fish held in the hatchery for four generations exhibited different hatchery performance characteristics than progeny from sea‐run parents.

Progressive Fish-Culturist↗
USGS1994

Short-term cold storage of Atlantic sturgeon sperm

Short‐term cold storage of fish sperm with oxygen, an established fisheries technique, was successfully used to preserve milt from Atlantic sturgeon ( Acipenser oxyrhynchus oxyrhynchus ). All milt samples stored for 5 d on ice and replenished daily with oxygen retained at least 80% motility and at least 99% viability. One sample exhibited 40% motility after 17 d. For management personnel involved in restoration of this rare fish, this technique offers an alternative to dependence on the simultaneous capture of ripe males and females from severely depleted stocks. It may also be used during transport prior to fertilization or cryopreservation.

Progressive Fish-Culturist↗
USGS1994

Evaluation of the effects of an oxygen injection system on the growth, hematology, and immunity of lake trout

Fingerling lake trout ( Salvelinus namaycush ) were reared for 64 d at three pressures of dissolved gases, expressed in relation to saturation values (▵P)–untreated (control) water, ▵P = 10 mm Hg; water treated by column degassing with air, ▵P = 9 mm Hg; and water treated with an oxygen injection system, ▵P = −20 mm Hg. Dissolved oxygen concentration for experimental groups was increased with column degassing by 7.8% and with oxygen injection by 8.7%. Nitrogen level was reduced 2.2% with columns receiving air and 7.4% with the oxygen injection system. There were no differences in production, mean lengths, or mean weights among fish reared in the three treatments. Hematocrit, plasma protein levels, and mean antibody microtiters to injected Salmonella H antigen were not different among fish from the three water treatments.

Progressive Fish-Culturist↗
USGS1994

Use of electronarcosis to immobilize juvenile and adult northern pike

Electronarcosis, the immobilization of a fish after an electric current has been applied and discontinued, is a potential alternative to chemical anesthetics. Successful narcosis was defined as the immobilization of a fish for 1–15 min without causing physical damage. In the laboratory, AC successfully narcotized juvenile (13–19‐cm standard length, SL) northern pike ( Esox lucius ) at selected voltages; however, AC voltages that produced narcosis or resulted in physical damage were variable and unpredictable. In contrast, 60–90‐V pulsed DC (PDC) for 10–60 s successfully narcotized juvenile pike without inducing physical damage. Duration of narcosis was directly related to voltage and inversely related to fish length. In the hatchery, sexually mature northern pike (45–97 cm SL), collected from the Mississippi River, were successfully narcotized by 60‐V PDC for 10 s. Duration of narcosis was unrelated to fish length or sex, and averaged 58 ± 7 s (mean ± SE). This allowed sufficient time to collect eggs or milt. All fish were swimming upright within 3 min after treatment, and no mortalities were observed over the next 24 h. Survival of eggs from fertilization to eye‐up did not significantly differ between eggs collected from electronarcotized adults and adults anesthetized with MS‐222 (tricaine methanesulfonate). Electronarcosis represents a possible alternative to chemical anesthetics for immobilizing northern pike broodstock without an apparent impact on egg survival.

Progressive Fish-Culturist↗
USGS1994

Duration of protection against Aeromonas salmonicida brook trout immunostimulated with glucan or chitosan by injection or immersion

Brook trout ( Salvelinus fontinalis ) were given the immunostimulants glucan or chitosan by single injections or by a 30‐min immersion to induce protection against the fish disease furunculosis. At 1, 2, 3, 7, 14, 21, and 28 d after immunostimulation, sublots from these groups were challenged by a 1‐min bath exposure to a 48‐h culture of Aeromonas salmonicida . All four groups showed high levels of protection against challenges given 1, 2, and 3 d after immunostimulants were administered. The groups injected with the immunostimulants showed a higher degree of protection than the immersed fish. They also retained a higher degree of protection against the pathogen challenge. However, by 14 d after immunostimulation, protection in both groups was greatly reduced. No significant differences in protection levels were noted between the glucan and chitosan immunostimulants. The effective short‐term protection induced by these immunostimulants demonstrates the importance of nonspecific defenses in fish and how, under certain conditions, these immunostimulants could be used for the prevention of diseases in fish culture.

Progressive Fish-Culturist↗
USGS1995

Flowing recirculated-water system for inducing laboratory spawning of sea lampreys

We describe a water‐recirculating system for inducing spawning of sea lampreys ( Petromyzon marinus ) held under laboratory conditions. Water temperature in the system was gradually increased to and maintained at 18 ± 2°C, the optimal temperature for spawning. About 10% freshwater was added daily to prevent buildup of waste products. Sea lampreys were provided substrate (approximately 3–6 cm in diameter) to build nests, and a water velocity of 0.2–0.3 m!s was maintained with an electric trolling motor. Sea lampreys held in this system exhibited characteristic spawning behavior. Prolarvae produced from artificial fertilization of gametes developed according to the standard timeline.

Progressive Fish-Culturist↗
USGS1995

Flowing-recirculated water system for inducing spawning phase sea lampreys to spawn in the laboratory

We describe a water-recirculating system for inducing spawning of sea lampreys ( Petromyzon marinus ) held under laboratory conditions. Water temperature in the system was gradually increased to and maintained at 18 ± 2°C, the optimal temperature for spawning. About 10% freshwater was added daily to prevent buildup of waste products. Sea lampreys were provided substrate (approximately 3–6 cm in diameter) to build nests, and a water velocity of 0.2–0.3 m!s was maintained with an electric trolling motor. Sea lampreys held in this system exhibited characteristic spawning behavior. Prolarvae produced from artificial fertilization of gametes developed according to the standard timeline.

Progressive Fish-Culturist↗
USGS1996

Prevention of zebra mussel infestation and dispersal during aquaculture operations

The zebra mussel Dreissena polymorpha , an exotic invasive species, poses a major threat to North American fish management programs and the aquaculture industry. Fish hatcheries may become infected with zebra mussels from a variety of sources, including the water supply, fish shipments, boats, and equipment. The hatcheries could then serve as agents for the overland dispersal of zebra mussels into stocked waters and to other fish hatcheries. We evaluated the effectiveness and safety of aquaculture chemicals for use in controlling zebra mussels in fish hatcheries and preventing dispersal of veligers during fish transport. Chemicals were evaluated for use in fish transport and as disinfectants for ponds and equipment. Standardized static toxicity tests were conducted with representative species of warmwater, coolwater, and coldwater fishes and with larval (3‐d‐old veligers), early juvenile (settling larvae), and adult zebra mussels. Chemical concentrations and exposure durations were based on recommended treatment levels for fish, eggs, and ponds. Recommended treatment levels were also exceeded, if necessary, to establish lethal levels for zebra mussels of different developmental stages. Our results indicate that some chemicals currently in use in hatcheries may be effective for controlling zebra mussels in various operations. Chloride salts were the safest and most effective therapeutants tested for use in fish transport. The toxicity of chloride salts to fish varied among species and with temperature: only one treatment regime (sodium chloride at 10,000 mg/L) was safe to all fish species that we tested, but it was only effective on veliger and settler stages of the zebra mussel. Effective disinfectants were benzalkonium chloride for use on equipment and rotenone for use in ponds after fish are harvested. The regulatory status of the identified chemicals is discussed as well as several nonchemical control alternatives.

Progressive Fish-Culturist↗
USGS1996

Feeding trials with juvenile Atlantic sturgeons propagated from wild broodstock

Juvenile Atlantic sturgeons Acipenser oxyrinchus produced by hormone‐induced spawning of wild broodstock from the Hudson River, New York, were used in a diet study. Fish fed live Artemia sp. as first‐feeding fry for 35 d were observed to convert readily to formulated diets. At 79 d posthatch, four formulated feeds were offered: sturgeon starter 9304, Biokyowa, Zeigler esocid diet, and Tunison sturgeon starter. At the end of 60 d, fish fed Biokyowa had the greatest growth and best feed conversion ( P ≤ 0.05). Feed conversions were significantly different between all treatments, indicating wide variability in growth response to the diets tested. Proximate analyses of diets showed Biokyowa highest in protein (59.43%) and dry matter (97.28%).

Progressive Fish-Culturist↗
USGS1996

An evaluation of fluorescent elastomer for marking bluegills in experimental studies

We evaluated subdermal injection of a fluorescent elastomer for marking bluegills Lepomis macrochirus in laboratory and pond studies. Marking did not affect the growth or survival of adult or juvenile bluegills. Marks were visible for at least 6 months. This technique is a reliable, relatively inexpensive marking method for the identification of individual fish in experimental studies. Costs of application range from US$0.01 to $0.03 per mark.

Progressive Fish-Culturist↗
USGS1997

Manipulations of the reproductive system of fishes by means of exogenous chemicals

Environmental control of reproductive activity of captive fish is feasible (or potentially feasible) but, with few exceptions, is currently impractical for most species. Therefore, chemical methods of manipulating reproductive activity continue to be widely used in fish production operations worldwide. However, the control of fish reproduction in captivity cannot be exercised without regard to adequate environmental conditions, which can differ markedly for different species. This review provides a synopsis of relevant aspects of fish reproductive physiology and addresses current and promising future chemical methods of sex control, gonadal recrudescence, and spawning. Most research on the control of reproduction in fishes has focused on female physiology because ovarian development and maturation are easily disturbed by environmental stressors. Control of sex ratios by steroid treatment has become a well‐established technique for several fish species, but the technique continues to be problematic in some cases. Final gonadal growth and spawning usually can be achieved by implant treatment with gonadotropin‐releasing hormone analogs (GnRHa), which in some species have to be applied in combination with dopamine antagonists to enhance responsiveness to GnRHa. However, efforts to accelerate gonadal recrudescence and maturational competence by chemical means have yielded mixed results, reflecting a relative lack of understanding of the basic physiological and biochemical mechanisms controlling these processes. The potential benefits of using reproductive pheromones to manipulate gonadal development and spawning has been demonstrated in a few species, but further research is needed to determine whether this technique is applicable to fish culture. Because a reliable supply of young fish is critical for the expansion and diversification of fish culture operations, the use of chemicals in combination with adequate environmental conditions to control gametogenesis and spawning in fishes will continue to be an important tool for the fish culturist.

Progressive Fish-Culturist↗