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1.
This study documents early out-of-season induced spawning of channel catfish Ictalurus punctatus. During the early spring (February–April) of 1999, 2000 and 2001, ponds containing (1) male and female channel catfish (mixed-sex ponds) or (2) male channel and blue catfish I. furcatus only, or female channel catfish only (single-sex ponds) were heated to 24–30°C to encourage gonadal maturation and spawning. Unheated ponds were stocked with males and females and were monitored during the duration of heating. When natural spawning occurred in the heated ponds, the fish were captured by seining and unspawned females were injected with 100 μg kg−1 of synthetic leutenizing hormone-releasing hormone. Injected females were either paired with males or held in communal all-female groups, and monitored for ovulation. Eggs were collected and fertilized with sperm of channel catfish or blue catfish. Females paired with males were induced to spawn 44 days (mixed-sex ponds) and 50 days (single-sex ponds) before natural spawning occurred in unheated ponds. Spawning latency (the time between injection and ovulation) and the percentage of neurulated embryos from eggs fertilized using channel catfish sperm was not different between spawning before the natural season (P=0.68) and during the natural season in fish from mixed-sex ponds (P=0.57). Females held in all-female groups produced eggs 34 days before the onset of spawning in unheated ponds. Spawning latency was not different between spawns before and during the natural season (P=0.16), and the percentages of neurulated embryos from eggs fertilized with channel catfish sperm (P=0.76) or blue catfish sperm (P=0.77) before or during the natural season were not different. This study demonstrates the feasibility of conditioning of channel catfish females for early out-of-season induced spawning in the laboratory.  相似文献   

2.
This study was designed to determine the effect of ovarian fluid pH of stripped unfertilized channel catfish, Ictalurus punctatus, eggs on fertilization and hatch rate of channel catfish ♀ x blue catfish, Ictalurus furcatus♂, hybrid catfish eggs. A significant correlation was established between ovarian fluid pH of stripped channel catfish eggs and hybrid embryo hatch rate (R2 = 0.75, P = 0.01), suggesting ovarian fluid pH of stripped catfish eggs prior to fertilization can be predictive of the hatching success of hybrid catfish embryos. These data were used to categorize pH of stripped eggs: pH <7.0 as “low pH eggs,” pH 7.0–7.4 as “medium pH eggs,” or pH >7.4 as “high pH eggs” quality eggs. The range in percent hatch rate for these pH categories was <15%, 15–30%, and >30%, respectively. Higher calcium concentrations during incubation do not appear to improve hatching success of “low pH eggs.” The predictive model presented herein describes a quick method for evaluating stripped catfish eggs for hybrid fry production in catfish hatcheries.  相似文献   

3.
This study addresses rapid methods to identify mature channel catfish, Ictalurus punctatus, females for induced spawning with luteinizing hormone releasing hormone analog (LHRHa) and common carp pituitary extract (CPE) and the effects of stage of maturity, hormone dose, season, and cannulation before hormone injection. Hormonal intervention is the most effective method for inducing maturation and spawning in channel catfish × blue catfish, Ictalurus furcatus, hybrids. A total of 80 mature channel catfish were staged for maturity based on secondary sexual characteristics and 20–30 oocytes cannulated to ascertain their maturation stage based on the position of gonadal vesicle. Twenty females were randomly assigned to one of the four hormone regimes (priming + resolving dose): CPE 2 + 8 mg/kg (CPEC); LHRHa 20 + 40 µg/kg (LHRHaL); LHRHa 20 + 60 µg/kg (LHRHaM); and LHRHa 20 + 80 µg/kg (LHRHaH) and a fifth treatment consisted of 20 females selected based on apparent maturity as evidenced by external appearance were injected with CPE, 2 + 8 mg/kg without cannulation (CPEO). Two trials were conducted in early part of the spawning season and two trials in peak season. External methods to identify maturity correlated (r = 0.63) with that of “germinal vesicle position” method to identify the stage of maturity in females. Mean percent of females that ovulated, hatched, and fry produced per kg body weight did not differ (P > 0.05) among the five hormone treatments. The mean percent females that ovulated was higher (P < 0.05) for CPE‐induced females that were identified as “excellent” females based on external examination. The performance of cannulated females did not differ (P > 0.05) with that of non‐cannulated catfish. The mean egg quality of hormone‐induced females and percent of females ovulated in response to hormone treatment established a weak but significant linear relationship (Y = 3.85 + 0.008 × ovulation, r2 = 0.39, P < 0.05).  相似文献   

4.
This study monitors the progression of oocyte size and plasma hormone profiles of female channel catfish, Ictalurus punctatus, at monthly intervals to stage expectant ovulating, females for strip spawning. The “critical minimum” diameter of an oocyte to reach threshold maturity for channel catfish was 2.5 ± 0.21 mm. Monthly increases of oocyte diameters and plasma vitellogenin concentrations were linear until spawning. The reproductive performance of cannulated and noncannulated catfish did not differ, negating adverse effects of routine cannulation. This study suggests oocyte diameter in channel catfish can be used as a predictive factor to determine and stage potential broodfish suitable for hormone‐induced spawning.  相似文献   

5.
Channel catfish, Ictalurus punctatus, pituitary powder (CP) was prepared and administered to determine the effect of pituitary preparation, head selection criteria, and season of collection on the biological potency of this gonadotropic preparation. Pituitaries were harvested from three catfish processing plants throughout the months of December, February, March, and April to investigate the effect of season on CP potency. Gravid female channel catfish were injected intraperitoneally (IP) with priming (2 mg/kg) and resolving doses (8 mg/kg) of CP treatments, luteinizing hormone‐releasing hormone analog (LHRHa), or saline. Pharmaceutical grade Carbopol 971P resin (CAR) was tested as a 1% aqueous dispersion in physiological saline and administered with CP (10 mg/kg) as a IP single injection at a final volume of 2 mL per kg as a slow‐release vehicle. Individual females were hand‐stripped, and eggs were fertilized with freshly harvested blue catfish, Ictalurus furcatus, spermatozoa. Pituitaries processed with either acetone or ethanol/acetone resulted in significantly different ovulation rates of 35 and 73%, respectively (P≤ 0.01). Ovulation success was not significantly different among CP and LHRHa treatment groups. Ovulation rates were not significantly different among treatment groups of CP collected in April (74%) or December (67%), or collected from male (69%), or small individuals (55%). The shortest latency period among CP treatment was from CP collected in December and from males at 39.1 ± 0.7 and 38.5 ± 0.4 h, respectively. The CAR vehicle treatment performed poorly resulting in an average ovulation rate of 19.0%, with 3.3% viable embryos at 36 h post‐fertilization. Pituitaries collected from channel catfish potentially represent a viable spawning aid for the production of hybrid channel × blue catfish.  相似文献   

6.
The interspecific hybridization of channel catfish, Ictalurus punctatus, females with blue catfish, I. furcatus, males has been identified as a method to further improve production; however, lack of spawning success has affected its commercial application. To facilitate our understanding of the interaction of brood stock nutrition and reproductive performance, we evaluated the interaction of feed quality and feeding frequency. Channel catfish females were classified into two genetic groups, namely, high and low spawning. The treatments were offered during the spring season 70–90 d prior to the start of the spawning season. Induced reproduction was performed using luteinizing hormone releasing hormone analog. Condition of the fish as well as reproductive performance using spawning success, egg production, egg size, and fertilization at 48 h were determined. Changing protein level of the diet from 32 to 42% did not influence spawning, fecundity, or fertilization, but affected egg size and biochemical composition of the eggs. Increasing the feeding frequency from three to six times per week negatively affected spawning in one of the two genetics groups, did not affect egg production and egg fertilization, but had a significant effect on egg size. Older fish performed better than younger fish in terms of spawning success and egg production.  相似文献   

7.
A length–weight relationship was developed for pond‐raised hybrid catfish fingerlings, Ictalurus punctatus × Ictalurus furcatus. A total of 4663 fish were sampled ranging from 20 to 240 mm total length. Predicted weight (g) from length (mm) is based on the equation: Y = 0.000017311X2.868474309 (r2 = 0.996) where Y is the estimated individual fish weight and X is measured total length. The predicted values generated by this model differ from, but follow the same general trends seen with channel catfish, I. punctatus, fingerlings and can be used as a baseline for the development of a length–weight table for hybrid catfish fingerling production.  相似文献   

8.
Fingerling HS‐5 channel catfish, Ictalurus punctatus, NWAC 103 channel catfish, D&B blue catfish, Ictalurus furcatus, HS‐5 female channel × D&B male blue catfish F1 hybrids, and NWAC 103 female channel × D&B male blue catfish F1 hybrids were stocked into twenty‐five 0.04‐ha earthen ponds at 12,500 fish/ha and grown for 277 d. Fish were fed daily at rates from 1.0 to 3.0% biomass based on feeding activity and temperature and adjusted weekly assuming a feed conversion ratio (FCR) of 1.8 and 100% survival. At harvest, 40 fish from each pond were sampled, and all other counted and weighed. Mean survival, growth rate indexes (a), FCR, and skin‐on fillet percentages were not significantly different. Mean harvest weights and net production were higher for HS‐5 channel and its hybrid than for the NWAC 103 channel, NWAC 103 hybrid, and D&B blue catfish, partially because of their larger mean stocking weights. D&B blue catfish was more uniform in size than NWAC 103 channel and NWAC 103 hybrid. D&B blue catfish was the easiest to seine. HS‐5 hybrids and NWAC 103 hybrids had lower mean head percentage and a better processing yield than their parent channel catfish.  相似文献   

9.
The prophylactic use of potassium permanganate (KMnO4) and oxytetracycline and its effects on catfish growth were assessed. For eleven weeks, healthy channel catfish, Ictalurus punctatus, juveniles were exposed to KMnO4 and oxytetracycline. KMnO4‐treated fish were exposed to 1 ppm twice a week for 1 h, while oxytetracycline‐treated fish received a 50 mg/kg dose in the feed (35 fish per tank, two tanks per treatment). Assessed parameters included body weight and length, specific growth rate (SGR), feed intake (FI), condition, and feed conversion index (FCI). Potassium permanganate did not have a suppressive effect on growth, while oxytetracycline significantly enhanced growth on channel catfish (weight and length), as they were heavier (12.5%) than KMnO4‐treated fish and controls at the end of the trial. SGR (%/d), FI, and FCI were not significantly different (P > 0.05) among the three groups of fish. Condition index (K) was significantly higher (ANOVA, P < 0.05) in the oxytetracycline‐treated fish. The present study suggests that, at concentrations commonly used in aquaculture, exposure of healthy channel catfish to oxytetracycline enhanced growth, while KMnO4 does not induce growth suppression.  相似文献   

10.
Fillets of channel catfish, Ictalurus punctatus, from three geographic areas, fillets of hybrid catfish (♀ I. punctatus × ♂ blue catfish, Ictalurus furcatus) from one of the areas, water samples from the culture ponds, and feed samples were subjected to elemental analysis by inductive‐coupled plasma atomic emission spectrometry (ICP‐AES). The fillets were low in concentrations of several elements, and ICP‐AES could consistently detect only 11 elements. In addition, the composition of the fillets was not greatly influenced by water chemistry or feed composition. Nevertheless, both canonical discriminant analysis and K‐nearest‐neighbor analysis were reliable in separating the fillets to geographic area of origin and separating hybrid from channel catfish fillets based on elemental composition. Although this study suggests that multielement analysis and pattern recognition techniques have potential for validating the geographic origin of catfish fillets, much more work is needed to perfect the technique .  相似文献   

11.
Hormone‐induced spawning of channel catfish held communally in tanks is a reliable method to produce channel catfish, Ictalurus punctatus ♀ × blue catfish, Ictalurus furcatus ♂, F1 hybrid catfish fry. However, mature catfish are crowded, and repeatedly handled during the process of induced ovulation. Repeated handling of gravid females is stressful and may impair ovulation, egg quality, and reproductive performance. Three trials were conducted to evaluate the effects of two methods of confining post‐hormone‐injected female channel catfish on stress response (cortisol concentrations) and reproductive performance: fish were either held individually while suspended in soft, nylon‐mesh bags or communally in a concrete tank. Percent of females ovulated to hormone treatment, relative fecundity, percent egg viability, and latency of channel catfish did not differ for fish in the two treatments. However, percent hatch and fry/kg of females was higher (P < 0.05) for fish held in bags that for fish held communally in tanks. Mean plasma cortisol response immediately prior to the first hormone injection (0 h) did not differ among fish groups in the two treatments. However, mean plasma cortisol concentrations were significantly lower (P < 0.05) for fish in the bag treatment at 16 and 36 h compared to fish held communally in tanks. Plasma estradiol levels (measure of oocyte maturation) were assessed at 0, 16, and 36 h after hormone injection; concentrations were (P < 0.05) higher at 16 h compared to 0 and 36 h; however, estradiol concentrations did not differ for fish held in the two treatments (P > 0.05). Suspending hormone‐injected broodfish individually in soft bags reduced stress response, improved egg hatching rate, and increased hybrid fry produced per kg weight of female broodfish. Using this simple technology, farmers can improve the efficiency of hatcheries producing hybrid catfish fry.  相似文献   

12.
Previous research has shown that winter feeding is beneficial in preventing weight loss and maintaining catfish health. Although several studies suggest the importance of winter feeding of channel catfish, Ictalurus punctatus, less is known about optimal winter feeding strategies for channel‐blue hybrid catfish (♀ Ictalurus punctatus × ♂ Ictalurus furcatus). Three winter feeding treatments (unfed, fed daily, and fed based on temperature‐threshold feeding) were each assigned randomly to four replicate 0.10‐ha earthen ponds. All ponds were stocked with large channel‐blue hybrid catfish (0.96 ± 0.40 kg) at the rate of 3409 kg/ha and fed using a slow‐sink 28% protein pelleted feed. The two feeding treatments showed significantly greater mean weight at harvest, gross yield, and growth rates than the unfed fish after the 113‐d winter trial. Partial budget analysis indicated that additional costs incurred from the additional feed, fuel, and labor costs over the winter in fed treatments offset the additional revenue from daily winter feeding. However, in the temperature‐threshold feeding treatment, additional costs were similar to additional revenues when 10‐yr average prices were used. Results were sensitive to feed prices and spring catfish prices with positive net benefits from winter feeding at fish prices above $1.58/kg and feed prices below $0.286/kg.  相似文献   

13.
The channel catfish (Ictalurus punctatus, Rafinesque) ovary (CCO) cell line is the standard cell line used for channel catfish diagnostics. Next‐gen sequencing studies of a virus cultured in the CCO cells revealed mitochondrial sequences matching those of brown bullhead (Ameiurus nebulosus, Lesueur). Therefore, we systematically performed partial cytochrome oxidase 1 gene sequencing of several sources of the CCO cell line and all matched the brown bullhead and not the channel catfish.  相似文献   

14.
The severity of gill damage (percentage of gill lamellae with lytic lesions) was determined in juveniles from 10 USDA 103 line channel catfish Ictalurus punctatus full‐sib families, 10 channel catfish×blue catfish I. furcatus backcross hybrid (7/8 channel catfish, 1/8 blue catfish) full‐sib families and a mixed‐family group of blue catfish placed in a commercial catfish pond experiencing proliferative gill disease (PGD)‐related fish mortalities. An initial challenge was conducted with all families, and a second challenge was conducted using the two most susceptible (most gill damage) channel catfish and backcross hybrid families and the two most resistant (least gill damage) channel catfish and backcross hybrid families. In the initial challenge, percentage gill damage was not different between channel catfish (12.3%) and backcross hybrids (11.6%), but was lower in blue catfish (0.2%). Mean percentage gill damage in the second challenge was not different among resistant backcross hybrid families (6.9%), resistant channel catfish families (7.6%) and blue catfish (4.8%), but was higher in susceptible backcross hybrid and channel catfish families (19.0% and 11.9% respectively). The correlation among family means for gill damage from challenge 1 and challenge 2 was r=0.87. Consistent differences between channel catfish and blue catfish and between resistant and susceptible families within genetic groups for gill damage after PGD challenge suggest that there is a genetic component for resistance to PGD and that improving PGD resistance through selection may be possible.  相似文献   

15.
Abstract. Three feeding trials, involving pre-pupal larvae of soldier fly, Hermetia illucens L., grown on poultry manure, were conducted to assess: (1) channel catfish, Ictalurus punctatus (Rafinesque), response to substitution of dried meal larvae for the fish meal component of the catfish diet and (2) if feeding 100% whole or chopped larvae to channel catfish or blue tilapia, Oreochromis aureus (Steindachner), will support normal growth comparable to those fed a commercial diet. Effects on fish quality were also evaluated. Replacement of 10% fish meal with 10% soldier fly larvae resulted in slower growth over a 15-week period for subadult channel catfish grown in cages (trial 1). However, the replacement did not reduce growth rate significantly when channel catfish were grown in culture tanks at a slower growth rate (trial 2). Feeding 100% larvae did not provide sufficient dry matter or protein intake for good growth for either species grown in tanks (trials 2 and 3). Chopping of the larvae improved weight gain and efficiency of the utilization.  相似文献   

16.
2-Methylisoborneol (MIB) and structurally related terpenoid compounds are responsible for millions of dollars of lost revenue to catfish farmers. In an attempt to determine enzymatic pathways of biotransformation and elimination of MIB, the in vitro metabolism of MIB was examined in the Ulvade strain of channel catfish (Ictalurus punctatus). Although cytochrome P450 (CYP) activities were observed and correlated with expression of specific isoforms (i.e. steroid hydroxylation and CYP3A expression), no metabolites of MIB were observed. To determine whether extrahepatic biotransformation may be occurring the in vivo metabolism and disposition of 14C-MIB was examined in Uvalde, USDA-103 channel catfish, and a channel catfish X blue catfish (Ictalurus furcatus) hybrid species. Confirming in vitro hepatic studies, no metabolites were observed in plasma from animals treated with an intra-arterial dose of 14C-MIB. 14C-MIB elimination was predicted using a two compartment model in each strain of fish. There was no significant difference in terminal half-lives between strains but possible differences in total body clearance and apparent volumes of distribution which may be related to higher lipid content in the hybrids. Results of these studies indicate biotransformation has no involvement in MIB elimination and that other physiological processes may play a more significant role in MIB disposition within Ictalurid fish species.  相似文献   

17.
Production of channel catfish, Ictalurus punctatus, female × blue catfish, Ictalurus furcatus, male hybrids has increased dramatically in the USA. Hybrid production requires surgical removal and maceration of blue catfish testes. Farmers report individual and seasonal variation in blue catfish testes development, and understanding the factors influencing testes development could improve hybrid catfish production. Effects of season (mid‐May vs. mid‐June), strain (D&B, Missouri, and Texas), and body weight on testes development in 5‐yr‐old blue catfish were determined. Males were measured in mid‐May and mid‐June for length, body weight, testes weight, and gonadosomatic index (GSI). Total sperm/g of testes, percent motility, and motile sperm/g of testes were determined. D&B strain males weighed more and had larger testes with more sperm than Missouri or Texas strain males in both months. Mature Texas strain males were larger than immature Texas strain males in both months. Testes were larger and had more sperm in May than in June for all strains; however, there were males from each strain with good quality testes in June. GSI, sperm/g of testes, percent motility, and motile sperm/g of testes were positively correlated. Information from this study provides a better understanding of factors influencing testes development in blue catfish.  相似文献   

18.
The deceptive marketing of imported basa, Pangasius bocourti (Sauvage), fillets as catfish has resulted in serious economic losses to the channel catfish, Ictalurus punctatus (Rafinesque), industry in the US. The similar appearance of channel catfish and basa fillets created a need for a rapid method to differentiate uncooked, cooked and/or marinated channel catfish fillets from basa fillets and other fish products. A monoclonal antibody (MAb) specific for a 36.8 kDa channel catfish fillet protein was produced and characterized by an indirect enzyme‐linked immunoabsorbent assay (ELISA) and Western blotting. This MAb was used to develop an indirect ELISA specific for a fillet protein unique to fish of the genus Ictalurus. Using this ELISA, 100% of raw and cooked channel catfish fillets were correctly identified and differentiated from other fish in a single‐blind study. These results show that the indirect ELISA using MAbs specific for unique Ictalurus sp. fillet proteins is a rapid and sensitive method for the identification of raw and cooked catfish fillets.  相似文献   

19.
Two concurrent pond studies were initiated in April 2011 to evaluate feeds containing solvent‐extracted distillers dried grains with solubles (SE‐DDGS) in both 28 and 32% protein catfish feeds. Channel catfish, Ictalurus punctatus, were stocked in multiple‐batch production ponds at the University of Arkansas at Pine Bluff (UAPB) and hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus, in single‐batch production ponds at the National Warmwater Aquaculture Center (NWAC), Mississippi State University, Stoneville, Mississippi, USA. The experimental design was a 2 × 2 factorial with two protein levels (32 and 28% protein), with and without 20% SE‐DDGS. Fish were fed once daily to apparent satiation, and managed similarly to a commercial farm for 186 d at UAPB and 172 d at NWAC. For channel catfish, two‐way ANOVA showed significant effects of both protein level (28% being better than 32%) and protein source (20% SE‐DDGS diets being better than traditional diets) on yield, survival, total diet fed, and feed conversion ratio (FCR), due primarily to effects on the understocked fingerlings. Partial budget analysis suggested that the 28% protein diet with the 20% SE‐DDGS was preferred economically for the prevailing feed costs. For hybrid catfish, two‐way ANOVA did not show significant differences in total diet fed, yield, survival, and processing yields, but use of SE‐DDGS resulted in a lower FCR. Results showed that both channel and hybrid catfish can utilize 20% SE‐DDGS in the diet without adversely affecting production or processing characteristics.  相似文献   

20.
A comparative study was conducted on growth and protein requirements of channel catfish, Ictalurus punctatus, and blue catfish, Ictalurus furcatus. Four diets containing 24, 28, 32, or 36% protein were fed to both channel (initial weight 6.9 g/fish) and blue (6.6 g/fish) catfish for two growing seasons. There were significant interactions between dietary protein and fish species for weight gain and feed conversion ratio (FCR). No significant differences were observed in weight gain of channel catfish fed various protein diets, whereas higher protein diets (32 and 36%) resulted in better weight gain in blue catfish than lower protein diets (24 and 28%). No consistent differences were observed in the FCR of channel catfish fed various levels of dietary protein, whereas significantly higher FCRs were noted in blue catfish fed the 24 and 28% protein diets compared with fish fed 32 and 36% protein diets. Regardless of dietary protein levels, blue catfish had higher carcass, nugget, and total meat yield, and higher fillet moisture and protein, but lower fillet yield and fillet fat. Regardless of fish species, fish fed the 36% protein diet had higher carcass, fillet, and total meat yield than fish fed the 28 and 32% protein diets, which in turn had higher yields than fish fed the 24% protein diet. It appears that blue catfish can be successfully cultured by feeding a 32% protein diet.  相似文献   

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