Showing papers in "North American Journal of Aquaculture in 2013"
TL;DR: Seven experimental diets that varied in the concentration of inactivated cells of Enterococcus faecalis and mannan oligosaccharides were examined on Rainbow Trout Oncorhynchus mykiss to find out the effects of these diets on weight gain.
Abstract: We examined the effects of the following seven experimental diets that varied in the concentration of inactivated cells of Enterococcus faecalis (Ef) and mannan oligosaccharides (MOS), on Rainbow Trout Oncorhynchus mykiss: control (C) diet (no Ef and no MOS), diet E0.25% (2.5 g/kg Ef), diet E0.5% (5 g/kg Ef), diet M0.25% (2.5 g/kg MOS), diet M0.5% (5 g/kg MOS), diet EM0.25% (2.5 g/kg Ef + 2.5 g/kg MOS) and diet EM0.5% (5 g/kg Ef + 5 g/kg MOS). Rainbow Trout, initially weighing 36.27 ± 0.42 g (mean ± SD) were distributed into fourteen 60-L glass tanks at a stocking density of 35 fish per tank. Each diet was hand-fed to duplicate groups of fish twice daily for a 12-week period. After the feeding test, an intraperitoneal injection challenge test of Aeromonas salmonicida was conducted over 14 d. Resulting data were submitted to a multivariate analysis of variance. Weight gain increased significantly (P < 0.05) in E0.25%, M0.25%, and EM0.5% experimental groups compared with the control. Specific growt...
99 citations
TL;DR: Multifamily rearing provides an efficient way of achieving a breeding population of 500 in a smaller facility, and juvenile survival increased from 18% in 2009 to 39% in 2010, as facilities and methodologies improved.
Abstract: In response to Federal listing of the Delta Smelt Hypomesus transpacificus as a threatened species in 1993, intensive fish culture techniques were developed to provide a supply of fish for research activities. The Delta Smelt was listed as endangered by the state of California in 2009, and several agencies worked quickly to develop a captive refuge population under genetic management. Captive 2-year-old wild-origin Delta Smelt served as the founding population in 2008. Each year, 250 genetically selected, single pair crosses are made in vitro, and the resultant full-sibling families are combined to rear in multifamily groups. Typically, eight families are reared together from egg to adult stage, with 80% or more of the initial families represented at the adult stage. Multifamily rearing provides an efficient way of achieving a breeding population of 500 in a smaller facility. Juvenile survival increased from 18% in 2009 to 39% in 2010, as facilities and methodologies improved. Growth rate also in...
66 citations
TL;DR: Replacing fish oil with beef tallow altered tissues in favor of tallow-associated monounsaturated fatty acids at harvest results in the loss of long-chain polyuns saturated fatty acids from farmed fish tissues.
Abstract: Sparing fish oil with alternative lipids in aquafeeds generally results in the loss of long-chain polyunsaturated fatty acids (LC-PUFAs) from farmed fish tissues; however, finishing feeds can be used to augment LC-PUFA levels prior to harvest. We reared Rainbow Trout Oncorhynchus mykiss (initial weight, 47.0 ± 0.2 g [mean ± SE]) in a recirculation aquaculture system (190-L tanks; 16.1 ± 0.0°C water temperature) on grow-out diets containing fish oil (FO; 100% FO), beef tallow (BT; 100% BT), or blends of these lipids (50% BT, 75% BT) in combination with 4, 8, or 12 weeks of finishing with the 100% FO feed (three replicate tanks per feeding regimen; N = 3). After 31 weeks, production performance was unaffected by feeding regimen: weight gain = 1,151 ± 30%, feed conversion ratio = 1.50 ± 0.03, specific growth rate = 1.15 ± 0.01% body weight/d, and feed intake = 2.19 ± 0.02% body weight/d. Replacing fish oil with beef tallow altered tissues in favor of tallow-associated monounsaturated fatty acids at ...
41 citations
TL;DR: Feed conversion ratio, weight gain, and specific growth rate were not impaired by partial or complete replacement of dietary fish oil, and the use of saturated fatty acid (SFA)–rich lipids instead of C18 polyunsaturated fatty acid–rich (C18 PUFA) lipids may be advantageous in maintaining tissue levels of LC-PUFAs.
Abstract: Fish oil sparing has proven difficult for some fish species, especially marine carnivores like White Seabass Atractoscion nobilis that require one or more long-chain polyunsaturated fatty acids (LC-PUFAs). Recent studies have suggested that the use of saturated fatty acid (SFA)–rich lipids instead of C18 polyunsaturated fatty acid–rich (C18 PUFA) lipids may be advantageous in maintaining tissue levels of LC-PUFAs; SFA-rich lipids may also offer a strategic advantage in terms of meeting the LC-PUFA requirements of marine carnivores while minimizing dietary fish oil inclusion. Accordingly, we assessed the performance and tissue fatty acid composition of White Seabass (3.8 ± 0.2 g [mean ± SE]) fed diets containing fish oil or graded levels of C18 PUFA–rich standard soy oil or SFA-rich hydrogenated soy oil (replacing 25, 50, 75, or 100% of dietary fish oil) for 8 weeks. Feed conversion ratio, weight gain, and specific growth rate were not impaired by partial or complete replacement of dietary fish oi...
38 citations
TL;DR: Using 0.5% chromic oxide as an external indicator, apparent digestibility coefficients (ADCs) were determined for 12 protein feed ingredients fed to Pacific white shrimp Litopenaeus vannamei to assess their digestibility.
Abstract: Using 0.5% chromic oxide as an external indicator, apparent digestibility coefficients (ADCs) were determined for 12 protein feed ingredients (fish meal [FM], blood meal [BM], meat-and-bone meal [MBM], poultry byproduct meal [PBM], shrimp head meal [SHM], squid visceral meal [SVM], soybean meal [SBM], rapeseed meal [RM], cottonseed meal [CM], peanut meal [PM], corn gluten meal [CGM], and brewer's yeast [BY]) fed to Pacific white shrimp Litopenaeus vannamei (mean initial weight ± SD = 4.45 ± 0.21 g). The shrimp were randomly allocated to thirty-nine 150-L tanks (20 shrimp/tank) and were hand-fed a reference diet or test diet (70% reference diet and 30% test feed by weight) twice daily to satiation. Feces were collected by siphoning. The observed range of ADCs of the 12 ingredients was 48.6–87.0% for dry matter, 55.7–92.3% for crude protein, 2.1–92.5% for crude lipid, 52.1–79.9% for phosphorus, and 51.1–97.2% for gross energy. Relatively high ADCs were observed for dry matter in FM (87.0%) and MBM ...
38 citations
TL;DR: Fatty acid metabolism, specifically the efficiency of LC-PUFA utilization, may be influenced by the dietary saturated fatty acid (SFA) content versus that of C18 polyunsaturated fatty acids (PUFAs) in fish oil deficiencies.
Abstract: The high cost and limited availability of fish oil makes plant-derived lipids attractive for aquafeed manufacturing, but replacing fish oil with these lipids can result in long-chain polyunsaturated fatty acid (LC-PUFA) deficiencies. Fatty acid metabolism, specifically the efficiency of LC-PUFA utilization, may be influenced by the dietary saturated fatty acid (SFA) content versus that of C18 polyunsaturated fatty acids (PUFAs). We assessed the growth and tissue composition of Cobia Rachycentron canadum (55.3 ± 0.2 g initial weight [mean ± SE]; 10 fish/tank, 3 tanks/diet) fed diets (∼49% protein, ∼10% lipid) containing fish oil; 22:6(n-3)–amended standard, partially hydrogenated, or fully hydrogenated soybean oil; and these same soybean oils supplemented with soybean lecithin for 8 weeks. Although survival (range = 97–100%), final weight (160–189 g), and feed conversion ratio (1.40–1.52) were unaffected by diet, differences were observed in weight gain (185–241%), specific growth rate (1.87–2.19%...
33 citations
TL;DR: Production performance of juvenile hybrid Striped Bass fed diets containing 30% menhaden fish meal, or reduced or fish-meal-free feeds (0, 5, or 10% fish meal) containing traditional soybean meal or PepSoyGen fermented soybean Meal as the principal sources of dietary protein are assessed.
Abstract: Soybean meal is one of the most common fish meal alternatives used in aquafeeds because of its high protein density, favorable amino acid profile, comparatively low price, and widespread availability. However, palatability issues and antinutritional factors limit soybean meal inclusion, particularly in feeds for carnivorous fishes. Various processing strategies, including fermentation, may offer some advantage in terms of reducing or eliminating antinutritional factors while enhancing protein content, improving protein absorption rate, and feed intake. Accordingly, we assessed production performance of juvenile hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis) fed diets containing 30% menhaden fish meal, or reduced or fish-meal-free feeds (0, 5, or 10% fish meal) containing traditional soybean meal (47.5% crude protein) or PepSoyGen fermented soybean meal (52.0% crude protein) as the principal sources of dietary protein. Each dietary treatment was fed to quadruplicate t...
32 citations
TL;DR: Although some differences were observed for feed conversion ratio, none of the soy-fed groups were significantly different from the FO-fed group, and coefficient of distance values indicated the SFA SO and HYD SO feeds yielded fillet fatty acid profiles that were more similar to the FO control.
Abstract: In order to assess the relative merits of different soy oils as alternatives to fish oil, we evaluated the production performance and fillet fatty acid profiles of hybrid Striped Bass fed feeds containing fish oil (FO) or 50:50 blends of fish oil and standard (STD SO), saturated fatty acid-enriched (SFA SO), low alpha-linolenic acid (LOW ALA SO), or hydrogenated (HYD SO) soy oil for 12 weeks (4 tanks/diet, 8 fish/tank; initial weight = 67.8 ± 0.2 g, grand mean ± SE). Weight gain (214 ± 5%) and specific growth rate (1.4 ± 0.0% body weight/d) were unaffected by diet. Although some differences were observed for feed conversion ratio, none of the soy-fed groups were significantly different from the FO-fed group (1.2 ± 0.0). Feeding the soy diets altered fillet fatty acid composition, but coefficient of distance values indicated the SFA SO (Djh = 3.9) and HYD SO (Djh = 9.1) feeds yielded fillet fatty acid profiles that were more similar to the FO control than the STD SO (Djh = 17.3) and LOW ALA SO (Dj...
27 citations
TL;DR: This work assessed the production performance and consumer acceptance of hybrid Striped Bass, and compared the value of alternative proteins in side-by-side comparisons.
Abstract: Numerous alternative proteins have been assessed and reported as adequate for fish meal (FM) sparing; however, few studies have directly compared the value of alternative proteins in side-by-side comparisons. Previous research also suggests that changes in dietary protein source may affect fillet quality, but comprehensive data on this subject are lacking. We assessed the production performance and consumer acceptance of hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis; mean weight ± SE = 43.4 ± 0.2 g) reared on a control diet containing menhaden FM (30% FM) as the primary protein source or on experimental feeds containing approximately 10% menhaden FM and one of the following protein sources: soybean meal (10% FM–46% SBM), poultry byproduct meal (10% FM–21% PBM), grain distillers’ dried yeast (10% FM–36% GDDY), corn gluten meal (10% FM–21% CGM), or distillers’ dried grains with solubles (10% FM–33% DDGS). Weight gain (1,055–1,323%), specific growth rate (SGR; 1.29–1.40...
23 citations
TL;DR: A factorial experiment was conducted to compare the responses of heat shock protein 70 (Hsp70) in seven different tissues of White Sturgeon Acipenser transmontanus and Green Sturgeon A. medirostris after they were exposed to four different stressors, and found that Hsp70 responses were significantly affected by stress.
Abstract: A factorial experiment was conducted to compare the responses of heat shock protein 70 (Hsp70) in seven different tissues of White Sturgeon Acipenser transmontanus and Green Sturgeon A. medirostris after they were exposed to four different stressors. Three White Sturgeon (2.3 ± 0.1 kg [mean ± SE]) and three Green Sturgeon (2.3 ± 0.1 kg [mean ± SE]) were each subjected to one of four different stressors, after which the Hsp70 levels in seven different tissues were measured using Western blot. The four stressors were heat shock, cold shock, air exposure, and food deprivation; and the seven tissues sampled were mucus, heart, liver, gastrointestinal tract, gill, spleen, and white muscle. We also sampled tissues of three White Sturgeon and three Green Sturgeon without any stressor, and measured their Hsp70 levels as a control. We compared Hsp70 responses of the stressed sturgeon with those of the control, which was set at 100%, and found that Hsp70 responses were significantly (P < 0.05) affected by t...
23 citations
TL;DR: Among the extracts tested, the PE extracts of the three plants exhibited the highest efficacy, and the PE extract of A. lappa exhibited the best anti-Saprolegnia and anti-Achlya activities.
Abstract: Saprolegniasis is a common fungal disease in aquaculture, causing severe damage to cultured fishes. To find natural agents for controlling and treating saprolegniasis, we investigated methanol extracts of 40 traditional Chinese medicinal plants. Saprolegnia sp. strain JL and Achlya klebsiana were used to evaluate the antifungal activity of the plants. Cnidium monnieri, Magnolia officinalis, and Aucklandia lappa at a concentration of 62.5 mg/mL exhibited antifungal activity on Saprolegnia and Achlya klebsiana mycelium and were selected for further evaluation. The three plant species were extracted with four solvents (petroleum ether [PE], ethyl acetate, methanol, and water), and the extracts were evaluated with an in vitro bioassay using a rapeseed (Brassica napus) microplate method. Among the extracts tested, the PE extracts of the three plants exhibited the highest efficacy. The PE extract of A. lappa exhibited the best anti-Saprolegnia and anti-Achlya activities (50% effective concentrations = ...
TL;DR: Three extenders, Alsever's solution, egg-yolk citrate, and urea egg- yolk, as well as three cryoprotectants, DMSO, methanol, and ethanol, were used for the preservation of sperm.
Abstract: This study focused on the development of a protocol for cryopreservation of sperm of the endangered fish species, Pabda Catfish Ompok pabda. The activation of sperm motility was tested at various osmolalities of NaCl. The motility of sperm decreased with the increase of osmolality; it was completely inhibited at 319 mOsmol/kg. Toxicity of cryoprotectants to sperm was evaluated using dimethyl sulfoxide (DMSO), methanol, and ethanol at 5, 10, and 15% concentrations at an incubation time of 0–35 min. Five percent and 10% cryoprotectants produced 45–75% and 40–75% motility for the 5- and 10-min incubation times, respectively. Sperm incubated with 15% cryoprotectant had less motility from the beginning of incubation. The cryoprotectant was toxic to sperm. Three extenders, Alsever's solution, egg-yolk citrate, and urea egg-yolk, as well as three cryoprotectants, DMSO, methanol, and ethanol, were used for the preservation of sperm. Alsever's solution with DMSO showed best performance producing highest e...
TL;DR: A trial to evaluate the safety of SLICE for freshwater-reared Rainbow Trout when administered in feed at a dose of 0 (0×), 50 (1 × the maximum proposed therapeutic dose [1×]), 100 (2×), or 150 (3×) μg of EB for 14 d.
Abstract: SLICE (0.2% emamectin benzoate [EB]) is an in-feed treatment that has been shown to be effective and safe for controlling infestations of several ectoparasitic crustacean copepods and branchiurans in a variety of seawater- and freshwater-reared fishes. Although the safety of EB (in a pre-SLICE formulation) for use with seawater-reared Rainbow Trout Oncorhynchus mykiss has been demonstrated, the safety of SLICE for freshwater-reared Rainbow Trout has not. Consequently, we conducted a trial to evaluate the safety of SLICE for freshwater-reared Rainbow Trout when administered in feed at a dose of 0 (0×), 50 (1 × the maximum proposed therapeutic dose [1×]), 100 (2×), or 150 (3×) μg of EB·kg of fish body weight (BW)−1·d−1 for 14 d (2 × the proposed 7-d treatment duration). Medicated feed was prepared by top-coating commercially available feed with SLICE. Rainbow Trout fingerlings (mean TL ± SD = 7.4 ± 0.7 cm; mean weight ± SD = 4.4 ± 1.2 g) were stocked into 57-L flow-through tanks at 20 fish/tank. Di...
TL;DR: Generally, temperature was positively correlated with growth of juveniles, and final mean maximum growth occurred at 26°C for juvenile mussels, which is significantly higher than the global average.
Abstract: The effects of temperature on growth and survival of laboratory-propagated juvenile freshwater mussels of two federally endangered species, the Cumberlandian combshell Epioblasma brevidens and oyster mussel E. capsaeformis, and one nonlisted species, the wavy-rayed lampmussel Lampsilis fasciola, were investigated to determine optimum rearing temperatures for these species in small water-recirculating aquaculture systems. Juveniles 4–5 months old were held in downweller buckets at five temperatures. Growth and survival of juveniles were evaluated at 2-week intervals for 10 sampling events. At the end of the 20-week experiment, mean growth at 20, 22, 24, 26, and 28°C was, respectively, 0.75, 2.22, 3.27, 4.23, and 4.08 mm for Cumberlandian combshell; 1.35, 3.73, 3.81, 4.90, and 4.70 mm for oyster mussel; and 2.09, 3.96, 4.99, 5.13, and 4.87 mm for wavy-rayed lampmussel juveniles. Generally, temperature was positively correlated with growth of juveniles. Final mean maximum growth occurred at 26°C for...
TL;DR: This study evaluated performance characteristics for a slow-rotating paddlewheel pump that looked at the relationships among power input, rotational speed (circular tip velocity), water velocity, and water flow rate.
Abstract: Commercial catfish farmers are intensifying production by retrofitting ponds with variations of the partitioned aquaculture system. The split-pond system is the most common variation used commercially. The split-pond consists of a small fish-holding basin connected to a waste treatment lagoon by two conduits. Water is circulated between the two basins to remove fish waste and provide oxygenated water to the fish-holding basin. Although much research has been devoted to algal and fish production dynamics in variations of the partitioned aquaculture system, little information is available on basic engineering considerations for devices to circulate water in these systems. This study evaluated performance characteristics for a slow-rotating paddlewheel pump that looked at the relationships among power input, rotational speed (circular tip velocity), water velocity, and water flow rate. Rotational speeds of 1.0, 2.0, 3.0, and 4.0 rpm were evaluated in open channels and in channels with fish barriers....
TL;DR: Investigation of variation in sperm quality metrics of hatchery-reared Lake Trout Salvelinus namaycush throughout the spawning season showed that seasonality can have a significant impact on the quality of sperm.
Abstract: The objective of this study was to investigate variation in sperm quality metrics (motility, velocity, linearity, longevity, and density) of hatchery-reared Lake Trout Salvelinus namaycush throughout the spawning season. Seasonal variation in sperm quality was investigated using both a regression and repeated-measures approach. Sperm was collected from the same 16 individuals over four sampling periods, separated by 3-week intervals. Regression analyses showed that 7–27% of the variation in sperm traits could be explained by seasonal variation, indicating that seasonality can have a significant impact on the quality of sperm. Significant positive linear relationships were found for percent motility and linearity at 5 s postactivation. Significant negative quadratic relationships were found for velocity at 5 s postactivation, longevity, and density, whereas a positive quadratic relationship was found for linearity at 10 s postactivation. Repeated measures ANOVAs showed a significant effect of seas...
TL;DR: Survival significantly decreased for catfish in the warmest treatment compared with cat fish in the coolest treat, whereas activity levels were highest in the 31–35°C treatment.
Abstract: Effects of high summer temperatures on Channel Catfish Ictalurus punctatus are poorly understood, particularly for thermal regimes that mimic pond aquaculture conditions. Therefore, this study examined the effects of three cycling upper-range temperature regimes (23–27°C, 27–31°C, and 31–35°C) characteristic of aquaculture environments in the Mississippi Delta. Feed conversion ratio, feed consumption, specific growth rate, activity levels, survival, and overall growth in terms of wet weight and TL were measured in fingerling channel catfish over an 8-week period in a flow-through, multiple-tank system. Specific growth rate, feed consumption, TL, and wet weight of fish increased significantly in the 27–31°C treatment in contrast to the 23–27°C and 31–35°C treatments. Feed conversion ratio was lowest in the 27–31°C treatment, whereas activity levels were highest in the 31–35°C treatment. Survival significantly decreased for catfish in the warmest treatment compared with catfish in the coolest treat...
TL;DR: The optimum water temperature for handling Yellow Perch that results in minimal stress may be 20°C, and research is needed to identify the optimal salinity level for this temperature.
Abstract: Yellow Perch Perca flavescens were subjected to handling stress and salt treatments at different temperatures to determine their physiological changes. Yellow Perch, held at 8–10°C, were divided into three groups with four replicates and subjected to water temperatures of 14, 20, and 26°C to acclimate. Then they were subjected to acute handling twice within separate intervals, in addition to a salt treatment at a salinity of 5‰ for each of the fish groups. Plasma cortisol was used as a stress indicator, and blood samples were taken periodically for plasma cortisol concentration analysis. An increase in plasma cortisol after handling occurred in all groups, but the lowest level of plasma cortisol was in fish subjected to 20°C. We concluded that the optimum water temperature for handling Yellow Perch that results in minimal stress may be 20°C. Salt treatment after handling further stimulated the stress response and increased plasma cortisol levels. Research is needed to identify the optimal salinit...
TL;DR: Children's Red Drum Sciaenops ocellatus exposed to sublethal concentrations of waterborne copper for 242 d using an ethanolamine chelated Cu compound as a prophylactic treatment to control ectoparasites in recirculating aquaculture systems accumulated Cu at a rate that was strongly influenced by the environmental Cu load.
Abstract: Juvenile Red Drum Sciaenops ocellatus were exposed to sublethal concentrations of waterborne copper (Cu; 0.25–0.35 mg/L) for 242 d using an ethanolamine chelated Cu compound as a prophylactic treatment to control ectoparasites in recirculating aquaculture systems. Skin, muscle, gill, liver, and intestine tissues were collected on days 1, 3, 5, 15, and 21 during the 21-d depuration. Liver and intestine tissues accumulated Cu at a rate that was strongly influenced by the environmental Cu load. Skin, gills, and muscle tissues did not accumulate substantial amounts of Cu despite its presence at therapeutic levels. The rank order of the Cu concentrations in the different tissues was as follows: intestine > liver > gills > skin > muscle. Predictive equations for tissue Cu concentrations (μg/g) relative to time of withdrawal (d) and waterborne Cu concentration (mg/L) were generated using trend analysis. The relationships between tissue Cu concentrations and time of withdrawal were significant, with all ...
TL;DR: In this article, coded-wire-tagged and reared juvenile landlocked fall Chinook Salmon Oncorhynchus tshawytscha in 1.8m-diameter circular tanks at a low or high density for up to 52 d prior to stocking in Lake Oahe, South Dakota, during late May of 1999, 2003, and 2004.
Abstract: Juvenile landlocked fall Chinook Salmon Oncorhynchus tshawytscha were coded-wire-tagged and reared in 1.8-m-diameter circular tanks at a low or high density for up to 52 d prior to stocking in Lake Oahe, South Dakota, during late May of 1999, 2003, and 2004. Final hatchery rearing densities ranged from 7.29 to 11.72 kg/m3 for the low-density tanks and from 15.02 to 25.22 kg/m3 for the high-density tanks, with the higher densities being at least double the lower densities in each year. Flows were adjusted to maintain similar loadings (kg·L−1·min−1) between the treatments each year. The fish used in this study came from spawns collected during the October prior to stocking; TL at the end of hatchery rearing ranged from 103 mm in 1999 to 124 mm in 2004. In each year-class, the percentage of fish that were harvested by anglers or that returned to spawn was significantly greater for the lower-density treatment than for the higher-density treatment. Angler harvest primarily consisted of age-3 fish, wit...
TL;DR: The Guinean Fingerfish Monodactylus sebae is a popular euryhaline ornamental fish species with limited aquaculture production but lack of knowledge of the nutritional requirements for broodstock is a bottlenecks to commercial production.
Abstract: The Guinean Fingerfish Monodactylus sebae is a popular euryhaline ornamental fish species with limited aquaculture production. One of the bottlenecks to commercial production is lack of knowledge of the nutritional requirements for broodstock. Therefore, three broodfish diets were formulated and fed to Guinean Fingerfish broodstock to determine their quantitative and qualitative effects on egg production and egg and larval morphology. The dietary treatments consisted of a control, a diet with increased docosahexaenoic acid (DHA), and a diet with increased DHA and arachidonic acid (DHA + ARA). Broodfish fed the DHA + ARA diet spawned more frequently than broodfish fed the DHA diet and those fed the control diet. The greatest egg production was also observed from broodfish fed the DHA + ARA diet. The mean hatching success of floating eggs was not significantly different among diets. The mean egg and oil globule diameters for both floating and sinking eggs were significantly smaller for broodfish fe...
TL;DR: Evaluating the effectiveness of CLT or HP to control mortality associated with external columnaris in Florida Largemouth Bass Micropterus salmoides floridanus and Blu...
Abstract: Columnaris (causative agent, Flavobacterium columnare) is a widespread fish disease of concern among fish culturists in the USA. If left untreated, an entire population of fish may become infected, and morbidity and mortality may reach high levels. In virtually all instances, columnaris outbreaks require intervention to prevent significant losses. A number of sanitizing agents, most notably chloramine-T (CLT) and hydrogen peroxide (HP), have been used to control mortality associated with a variety of bacterial pathogens causing external infections. However, the majority of trials conducted to demonstrate the effectiveness of these chemicals, thereby gaining U.S. Food and Drug Administration approval for their use in treating fish infected with columnaris, have been conducted on salmonids. Accordingly, we conducted seven experiments to evaluate the effectiveness of CLT or HP to control mortality associated with external columnaris in Florida Largemouth Bass Micropterus salmoides floridanus and Blu...
TL;DR: A production-scale “out-of-season” spawning protocol yielding Florida Largemouth Bass Micropterus salmoides floridanus swim-up fry in a 3- to 4-week period in the fall to naturally induce gonad development without the use of hormones is established.
Abstract: The objective of this research was to establish a production-scale “out-of-season” (OS) spawning protocol yielding Florida Largemouth Bass Micropterus salmoides floridanus swim-up fry in a 3- to 4-week period in the fall. The OS photothermal manipulation began each year on approximately June 18 and was completed by September 20. The intent was to simulate winter to spring temperatures and day length over a 90-d period to naturally induce gonad development without the use of hormones. Adult bass were stocked at a 1:1 or 2:3 male-to-female sex ratio and spawned in late September through mid-October. Total numbers of spawns collected for 2009, 2010, and 2011 were 193, 205, and 199, representing an average 1.4, 2.0, and 1.0 spawns per female, respectively. Spawning duration required to achieve production numbers were 26, 31, and 23 d, respectively. Off-season spawning was accomplished without photothermal manipulation in December 2008–January 2009, but cold pond temperatures resulted in 10% survival....
TL;DR: To determine seasonal, geographical, and species variation in body composition, fatty acids, and oxidative stability, Asian carp were collected from five reaches of the Illinois River during the fall, spring, and summer and analyzed.
Abstract: Incentivizing overfishing through the creation of high-value markets for Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis has been proposed as a management strategy for controlling Asian carp in the Illinois River. Asian carp may be rendered into a protein-dense fish meal, and one of the most attractive, high-value end uses for such a product is aquafeed manufacturing. However, the nutritional content and shelf stability of Asian carp as a raw material must be determined to assess its suitability for rendering and subsequent use as a protein source in aquafeeds, which was the focus of this study. To determine seasonal, geographical, and species variation in body composition, fatty acids, and oxidative stability, Asian carp were collected from five reaches of the Illinois River during the fall, spring, and summer (up to 12 individuals of each species per reach per season) and analyzed. Slight geographical, seasonal, and species variation exists in the body composition and fatty ...
TL;DR: A recirculating aquaculture system supporting rapid growth of juvenile freshwater mussels and an algal turf scrubber was evaluated for its potential to maintain and improve water quality within the system.
Abstract: To develop a system supporting rapid growth of juvenile freshwater mussels, a recirculating aquaculture system was designed and built at the Laboratory for Conservation Aquaculture and Aquatic Ecology, Virginia Polytechnic Institute and State University. The system included a rectangular trough tank, a sump (biofilter), a pump, a microalgae drip feeder, and an air delivery system. An algal turf scrubber (ATS) was evaluated for its potential to maintain and improve water quality within the system. Growth and survival rates of juvenile rainbow mussels Villosa iris after 90 d were compared between system units with and without ATSs. Flow rate through the culture units was approximately 23.3 L/min. Results showed no statistically significant differences between the growth and survival rates of juvenile mussels reared in systems with ATSs and those reared in systems without ATSs. Ammonia and nitrite levels were low and did not differ among treatments. However, systems with ATSs exhibited significantly...
TL;DR: Investigation of the susceptibility of Channel Catfish fingerlings to columnaris disease when they were preexposed to copper sulfate (CuSO4) revealed significantly lower survival than did fish not exposed and then challenged.
Abstract: Columnaris disease is one of the most important bacterial diseases affecting Channel Catfish Ictalurus punctatus commercially grown in the USA. This disease can greatly diminish the profitability of aquaculture operations by large-scale mortality events, particularly in the fingerling production phase. Three experiments were conducted to evaluate the susceptibility of Channel Catfish fingerlings to columnaris disease when they were preexposed to copper sulfate (CuSO4). In experiment 1, fish were exposed for 24 h to 0, 1, 2, or 4 mg/L CuSO4 and were challenged immediately with Flavobacterium columnare, the etiological agent of columnaris disease. The resulting survival data indicated that fish preexposed to CuSO4 and then challenged exhibited significantly lower survival than did fish not exposed and then challenged. Experiment 2 was designed as above, except after the 24-h static exposure to CuSO4, fish were subjected to an additional 24 h in flow-through water prior to the challenge with F. colu...
TL;DR: The temperature and photoperiod requirements of spawning in ovary-mature red swamp crayfish Procambarus clarkii were evaluated and the feasibility of inducing spawning in them by inexpensive and practical, nonhormonal treatments was examined.
Abstract: This study evaluated the temperature and photoperiod requirements of spawning in ovary-mature red swamp crayfish Procambarus clarkii and examined the feasibility of inducing spawning in them by inexpensive and practical, nonhormonal treatments. In a spawning induction experiment lasting 20 d, four water temperature gradients (12–14°C, 16–18°C, 20–22°C, 24–26°C) and four photoperiods (completely light [CL], 16 h light: 8 h dark [16L:8D], 12 h light: 12 h dark [12L:12D], and completely dark [CD]) were evaluated. Spawning in ovary-mature red swamp crayfish could be observed in a relatively broad temperature range, from 16°C to 22°C. A period (5–14 d) of low temperature (16–18°C) significantly induced spawning in ovary-mature females (p < 0.01), but hibernation began to occur and spawning could not be observed when the temperature was below 14°C. Spawning occurred in both CD and CL circumstances, but long-period light-groups showed a higher spawning rate—68.9 ± 10.2% (mean ± SD) for CL and 69.6 ± 6.4...
TL;DR: Four different lipid sources in Channel Catfish Ictalurus punctatus diets are investigated for their ability to enhance fatty acid profiles of fillets to benefit human health while maintaining or improving fish performance.
Abstract: Fish consumption is a common method of obtaining beneficial n-3 highly unsaturated fatty acids (LC-PUFAs), but increased use of vegetable oils in fish diets to reduce dependence on fish oil dilutes the amounts of LC-PUFAs. Conjugated linoleic acids (CLAs) are also considered beneficial for human health. Therefore, we investigated four different lipid sources in Channel Catfish Ictalurus punctatus diets for their ability to enhance fatty acid profiles of fillets to benefit human health while maintaining or improving fish performance. In a 175-d grow-out trial, Channel Catfish (71.4 ± 0.1 g [mean ± SE]) were fed a commercial 32% protein diet supplemented with 2% lipid from soybean oil (SO), soybean oil enhanced with conjugated linoleic acids, menhaden fish oil (FO), or an algal supplement of Schizochytrium sp. high in 22:6(n-3) (docosahexaenoic acid, DHA). Diet effects were assessed by measuring fish growth performance, muscle proximate and fatty acid composition, sensory characteristics of fillets...
TL;DR: To determine dietary protein and lipid levels for juvenile June Suckers, practical-type diets were formulated with 35, 40, or 45% protein and 8, 12, or 16% lipid and tested in a 3 × 3 factorial design.
Abstract: Reports from hatcheries have demonstrated that commercially available diets are inadequate for June Suckers Chasmistes liorus and suggest that fish quality can be improved through species-specific diet optimization. To determine dietary protein and lipid levels for juvenile June Suckers, practical-type diets were formulated with 35, 40, or 45% protein and 8, 12, or 16% lipid and tested in a 3 × 3 factorial design. Two additional diets (45% protein and 16% lipid [45:16] without dicalcium phosphate supplementation and 45:16 with 2× dicalcium phosphate) were formulated to test the necessity of dicalcium phosphate supplementation. Each diet was fed to three replicate tanks (average initial fish weight ± SD = 4.48 ± 0.24 g) of fish per treatment (85 fish/tank); only duplicate tanks were used for the nondicalcium phosphate-supplemented treatment. Fish were reared in 80-L tanks supplied with 4 L/min of 22°C spring water and fed 6–4% body weight (BW)/d by automated belt feeders, 6 d/week. At the end of 1...
TL;DR: Aquinaflor (florfenicol, 50% with/without) is a potent, broad-spectrum, antibacterial agent with bacteriostatic properties that are active against a variety of Gram-positive and Gram-negative bacteria.
Abstract: Aquaflor (florfenicol, 50% with/without) is a potent, broad-spectrum, antibacterial agent with bacteriostatic properties that are active against a variety of Gram-positive and Gram-negative bacteria. This product is approved by the U. S. Food and Drug Administration for use on several fish species to control mortality associated with a variety of diseases, including columnaris (causative agent, Flavobacterium columnare). Two independent experimental trials were separately conducted to evaluate the effectiveness of Aquaflor to control mortality associated with columnaris disease. Aquaflor was administered in feed at a targeted daily florfenicol dosage of 10 mg/kg of body weight for 10 consecutive days. Test species were fingerling Florida Largemouth Bass Micropterus salmoides floridanus and Bluegill Lepomis macrochirus. In each trial, 8 or 10 test tanks (4 or 5 treated, 4 or 5 control) were stocked with either approximately 473 bass (mean length = 6.4 mm; mean weight = 3.3 g) or 100 Bluegills (len...