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1.
The objective of this study was to analyze channel catfish feeds for folic acid and pteroic acid concentrations and correlate these substances with anemia in channel catfish, Ictalurus puncratus. From 1983 to 1987, feed-related anemia was diagnosed 298 times in cultured channel catfish in Alabama. Analysis of eight brands of anemia-associated feeds (AAF) and nonanemia-associated feeds (NAAF) suggested that AAF were either lower in folic acid or were higher in pteroic acid concentrations than the NAAF. AAF contained a folic acid: pteroic acid ratio of less than 1.8:1, compared to a folic acid:pteroic acid ratio of greater than 10:1 in NAAF. Low folic acid concentrations were due either to insufficient addition at the feed mill or due to degradation during storage.  相似文献   

2.
Putative nonautonomous transposable elements from channel catfish (Ictalurus punctatus) were identified. They were named Tipnon elements for Tc1-like transposable elements from channel catfish that are nonautonomous. These elements were defined by their terminal repeats that share identity to members of the known Tc1/mariner transposon superfamily. They show structural similarities to Tc1-like elements, but share little sequence identity beyond the terminal inverted repeats. They do not harbor any amino acid blocks that show similarities to the Tc1-like or other transposases and thus may represent truly nonautonomous transposons in channel catfish. They are abundant in the channel catfish genome with a copy number of 32000, having 500 base pair per copy, this family of nonautonomous transposon-like elements account for 1.6% of the channel catfish genomic DNA. Their high abundance and transposon-like terminal repeats indicate that they may play important roles in gene evolution and in genomic architecture of catfish. Similarity search for potential coding capacity of the Tipnon elements revealed that they contain sequence blocks that can potentially encode amino acid blocks similar to the para-type sodium channel proteins in cockroaches or house flies, proteins that function in the central nervous system as voltage-gated sodium transporters. Sequences surrounding the terminal inverted repeats are divergent from those used by the reconstructed Sleeping Beauty fish transposase.  相似文献   

3.
Half-sib ictalurid families were produced when eggs from three channel catfish, "Ictalurus punctatus," females were fertilized with a mixture of sperm from channel catfish, blue catfish, "I. furcatus," black bullhead, "Ameiurus melas," and flathead catfish, "Plyodictis olivaris." Sperm from all four species successfully fertilized channel catfish eggs, although individual families contained different percentages of the various crosses. The enzyme glucose phosphate isomerase distinguished the different hybrids and parental groups, and confirmed sorting of offspring based on morphology. At 1 month of age, channel catfish ♀ X flathead catfish ♂ hybrids (0.36 ± 0.07 g, mean ± SD) were heavier (P ≤ 0.05) than channel catfish ♀ X black bullhead ♂ (0.12 ± 0.03 g), channel catfish ♀ X blue catfish ♂ hybrids (0.11 ± 0.03 g ), and channel catfish (0.10 ± 0.4 g). By 8 months of age, channel catfish ♀ X black bullhead ♂ hybrids (36.4 ± 21.9 g) and channel catfish ♀ X blue catfish ♂ hybrids (34.5 ± 24.2 g) were similar in weight, and each was significantly heavier than channel catfish ♀ X channel catfish ♂ (26.9 ± 16.1 g), while channel catfish ♀ X flathead catfish ♂ (17.0 ? 6.8 g) weighed the least. Morphometric ratios of channel catfish ♀ X blue catfish ♂ were intermediate between channel catfish ♀ X channel catfish ♂ and blue catfish for four of 16 features and were similar to either or both of the parental species for 10 others. Ratios for channel catfish ♀ X black bullhead ♂ hybrids were intermediate between channel catfish ♀ X channel catfish ♂ and black bullhead for seven of 16 features. Ratios for channel catfish ♀ X flathead catfish ♂ hybrids were larger than channel catfish ♀ X channel catfish ♀ for eight of 16 features and smaller than channel catfish ♀ X channel catfish ♂ for five of 16 features. All channel catfish ♀ X flathead catfish ♂ hybrid offspring were female, based on examination of the urogenital region or gross appearance of the gonands, while other groups had normal sex ratios. Production of half-sib interspecific hybrid families provides a unique opportunity to evaluate genetic influences on commercially important traits and to evaluate the potential of these ictalurid hybrids in aquaculture.  相似文献   

4.
Culture of channel catfish, "Ictalurus punctatus," accounts for virtually all catfish production. Recently, however, an increasing number of catfish farmers are growing or are considering the culture of blue catfish, "I. furcatus." Current and past research the compared the culture traits of channel and blue catfish are reviewed. Blue catfish could be potentially advantageous for certain farm environments. Strain effects in both species are important. In general, channel catfish grow faster to market size than do blue catfish. However, some strains of blue catfish grow faster than many strains of channel catfish. Blue catfish are more vulnerable to parasites such as "Icthyophthirius" and to bacterial infections such as those from "Flexibacter columnaris when compared to channel catfish. Blue catfish do not tolerate handling as well as channel catfish, and handling stress often leads to infections in blue catfish. However, blue catfish have high resistance to enteric septicemia of catfish caused by "Edwardsiella ictaluri" and to channel catfish virus when compared to channel catfish. Blue catfish are twice as vulnerable to harvest by seining than channel catfish, and have a higher dress-out percentage than most strains of channel carfish. Channel catfish tolerate lower dissolved oxygen levels than do blue catfish. Blue catfish require one more year to reach sexual maturity than do channel catfish.  相似文献   

5.
A Preliminary Bacteriological Study of Refrigerated Channel Catfish Sperm   总被引：1，自引：0，他引：1  
Abstract.— This study was designed to simulate conditions encountered routinely during refrigerated storage of channel catfish sperm. Sperm samples were stored at 4 C in non-sterile and sterile Hanks' balanced salt solution (HBSS). Non-sterile HBSS was prepared with distilled water stored for 2 wk in a plastic carboy prior to use. Observations were made on the frequency and abundance of bacteria in samples, and on changes in sperm motility and quality. Sperm samples stored in non-sterile HBSS had a complete loss of motility within 72 h. Samples maintained in sterile HBSS showed an initial decrease in motility between 48 and 72 h, and a complete loss of motility within 10 d. Quality of the sperm in each buffer decreased as motility decreased; morphologic changes and reduced motility of sperm were coincident with increased bacterial numbers. Bacteria were cultured on tryptic soy agar and Pseudomonas F agar (PFA) by spread-plating 10–μL aliquots from each sample onto bacteriologic media and incubating for 5 d. The dominant bacteria observed were members of the genus Pseudomonas , representing 67% of the total bacteria identified. The dominant pseudomonad ( Pseudomonas sp.) cultured from sperm samples stored in sterile buffer produced caseinase, lecithinase, and was β-hemolytic, whereas the dominant bacteria ( P. putida ) cultured from samples stored in the non-sterile buffers did not. Highly motile pseudomonads, present in two samples stored in sterile buffer, colonized below the surface of the PFA media at 4 C. The attributes of the bacterial contaminants that likely contributed to the decrease in sperm quality were production of extracellular enzymes, consumption of oxygen, and a high level of motility. Potential sources of degradative bacteria were commensal flora of channel catfish and the water used in preparing the storage buffer.  相似文献   

6.
采用实时定量RT-PCR方法研究斑点叉尾在不同病原(链球菌、嗜水气单胞菌、迟钝爱德华菌、斑点叉尾病毒)感染后TICAM基因在mRNA水平的组织和时空表达特征。感染嗜水气单胞菌可引起TICAM基因在肝脏和脾脏中的上调表达,在注射后24h和12h后上调最大分别为2.3倍和1.9倍;而在头肾和后肠中的表达则下调到感染后48h的0.15倍和24h的0.53倍;感染链球菌后则导致在肝脏、脾脏、后肠和头肾中TICAM基因表达的强烈上调,最大上调幅度为感染后7d肝脏中表达提高了23倍,其次,在脾脏和头肾中基因表达最大可上调到感染前的10倍左右;在感染迟钝爱德华菌后,TICAM基因在肝脏、脾脏、后肠和头肾中表达上调。其中,感染后7d脾脏中的表达提高到感染前的23.1倍。而感染叉尾病毒后,TICAM基因在肝脏、头肾和后肠的表达上调但幅度不大,基因表达在4种组织内表达变化量在1.5～3.7倍范围内波动,而在脾脏中TICAM表达下调,在感染24h后达到最低为感染前的0.13倍。以上实验结果显示,斑点叉尾TICAM基因表达变化与病原感染密切相关,暗示TICAM基因在斑点叉尾天然免疫中起重要作用。  相似文献   

7.
Most microalgae evaluated in aquaculture diets have been produced autotrophically. In order to produce a cost‐efficient biomass at greater magnitudes for biofuel feedstock, heterotrophic production may be warranted. However, the chemical/nutritional attributes of these microalgae could differ from those grown autotrophically. An 8‐wk feeding trial was conducted to evaluate Chlorella spp. algae meal (AM) that had been cultured heterotrophically. The oil (lipid) was extracted to simulate biofuel production. Juvenile channel catfish, Ictalurus punctatus (5.7 ± 1.4 g; 8.9 ± 0.8 cm), were stocked at 10 fish/tank into fifteen 37.7‐L aquaria in a closed recirculating system and fed one of the five experimental diets to apparent satiation twice daily. Diets contained either 0 (control, CTL), 10, 20, or 40% AM and an additional diet containing 40% AM was supplemented with 2% lysine (40% AM+LYS). After 8 wk, there were no statistically significant differences in terms of survival, dressout percentages, whole‐body proximate composition, or fatty acid composition of the fillets among fish fed the diets containing varying levels of AM without added lysine. Feed consumption and weight gain for fish fed the 10, 40, and 40% AM+LYS diets were significantly greater than those fed the CTL diet. Feed conversion ratio was significantly lower for fish fed the 40% AM+LYS diet compared to those fed all other diets, which did not differ significantly from each other. These data indicate that channel catfish readily accept and can efficiently utilize heterotrophically produced AM at levels up to at least 40% of the total diet and that AM may enhance diet palatability.  相似文献   

8.
Channel catfish (Ictalurus punctatus) have been previously shown to express two major cytochrome P450 (CYP) protein bands that are cross-reactive with anti-CYP2K1 (rainbow trout, Oncorhynchus mykiss) antibodies on Western blots. These proteins appear to be the major constitutive CYPs in channel catfish and show distinct sex- and age-specific variations in expression. Because I. punctatus is an important agricultural and ecological commodity, and because it displays a high degree of resistance to the toxic effects of many pesticides, the molecular and catalytic characteristics of its biotransformation systems are of interest to those in areas of environmental science and aquaculture research. Using a chromatographic method similar to that employed in the purification of other fish CYP2 enzymes, a single CYP2-related protein (CM-HA3) was isolated from channel catfish hepatic microsomes. The isolated protein displays a relative molecular mass of approximately 47 kDa, and a CO-reduced difference spectrum max of 449.6 nm. The sequence of 15 residues at the amino-terminal of CM-HA3 is 27% identical to both CYP2K1 and CYP2M1 isoforms of rainbow trout. Correlational analysis was employed to characterize potential substrates for this isoform, but no significant relationship was observed with E2 hydroxylation, testosterone hydroxylation, or 7-ethoxycoumarin O-deethylase activities. These data indicate that CM-HA3 is a CYP2 family protein, with as yet uncharacterized substrate specificities.  相似文献   

9.
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10.
Abstract  Channel catfish, Ictalurus punctatus (Rafinesque), are commonly stocked into small impoundments that contain bluegill, Lepomis macrochirus Rafinesque, and these species may compete for food resources because both prey on macroinvertebrates. Prey selectivity and diet overlap of sympatric bluegill and channel catfish were evaluated in two small impoundments. Both fish species fed primarily on macroinvertebrates; but diet overlap between the species generally was not extensive because channel catfish consumed a more diverse array of foods, including more crayfish, fish and plant material. The use of foods other than macroinvertebrates increased as channel catfish grew larger. Bluegill also ingested large quantities of plant material at times, and ingestion of plants increased with fish size. Results of this study suggest that food competition between bluegill and channel catfish may occur when small channel catfish are abundant because, like bluegill, they feed almost entirely on macroinvertebrates and may reduce macroinvertebrate abundance. Thus, overstocking channel catfish in small impoundments managed for bluegill should be avoided.  相似文献   

11.
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12.
Understanding the effects of specific management strategies on yields and economic outcomes on commercial catfish farms could provide useful guidance to catfish farmers on the most profitable sets of production practices. Data from the U.S. Department of Agriculture–National Animal Health Monitoring System (USDA–NAHMS) 2009 survey of production practices on catfish farms in Alabama, Arkansas, Louisiana, and Mississippi were used to identify five clusters of catfish farms that use various stocking densities, channel versus hybrid catfish, different aeration levels, and utilize automated oxygen sensors. The lowest production costs ($1.96/kg) were found in cluster 1 and were followed in order of increasing costs per kilogram of clusters 2 and 4 ($2.16/kg) and cluster 5 ($2.73/kg); the highest cost corresponded to cluster 3 ($2.84/kg). The lowest risk levels corresponded to the clusters with the lowest production costs per kilogram of fish and the highest risk levels to the highest production costs. This analysis demonstrated that different types of management models can achieve similar levels of production costs ($/kg), and it appears that there is not one single economically optimum way to raise catfish. The key to least‐cost production is to balance the use of inputs, their associated costs, and the yield produced to achieve economic efficiency within the farm's overall business and management model.  相似文献   

13.
Four cases (representing outbreaks in four different ponds on three farms) of branchial mycosis caused by Branchiomyces spp. were identified in channel catfish fry during the summer of 1996. Mortalities ranged from a few hundred to several thousand fish per pond. Significant gross and histopathological findings from these four cases were limited to the gills. All fry examined had fungal mycelia that were mainly but not entirely confined to the base of the primary lamellae and the gill arches. These fungal hyphae were intravascular and occluded vessels in the gill tissues. The present paper describes the fungal characteristics and pathology of branchial mycosis caused by Branchiomyces spp. in channel catfish.  相似文献   

14.
The National Agricultural Statistics Service surveyed by telephone and mail in January and February 1997 all known producers of channel catfish letalurus punctatus to acquire current information about wildlife-caused losses in calendar year 1996. Many producers tried to prevent wildlife-caused losses of their catfish by shooting (57%), vehicle patrol (55%), or frightening (36%), at an estimated cost of >$5 million. Yet, 69% of catfish producers cited some wildlife-caused losses. Birds were most frequently cited as a cause of losses, and double-crested cormorants Phalacrocorax auritus was the species cited most frequently (53%). The next most frequently cited birds were herons Ardea spp. (48%), egrets Egretta spp . (16%), and pelicans Pelecanus spp. (8%). Muskrats Ondatra zibethicus were cited by 10% of producers, primarily for damaging dikes and roads. The main problems caused by wildlife were feeding on catfish (67%), injuring catfish (40%) or disturbing feeding patterns of the catfish (23%). The total estimated cost of losses was $12 million. Overall, wildlife damage and damage prevention may have cost catfish producers > $17 million, about 4% of the total $425 million of catfish sales in 1996. Of the 44% of all catfish producers who were familiar with Wildlife Services (WS), 51% had ever contacted WS for assistance, 55% used methods suggested by WS to reduce their losses, and 40% received direct assistance from WS in 1996. Mississippi producers, who most frequently received direct assistance from WS, had proportionately lower wildlife-caused losses.  相似文献   

15.
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   

16.
Abstract. The plasmid content of 18 isolates of Edwardsiella ictaluri found in channel catfish was analysed by agarose gel electrophoresis. Each isolate contained an identical set of plasmids. This set consisted of two prominent plasmids of 5.2 and 4.4 kilobase pairs, and three smaller and less apparent plasmids. One plasmid (the 5.2 kilobase plasmid) was radiolabelled and used to probe a blot of DNA from all isolates. All plasmids were hybridized but no chromosomal DNA was labelled. These plasmids must share some homologous regions. DNAs from other bacteria, including the related Edwardsiella tarda, were also probed and no hybridization was seen. It is suggested that a plasmid probe may be a sensitive, specific probe for detection of E. ictaluri in channel catfish  相似文献   

17.
Channel catfish, Ictalurus punctatus (Rafinesque), populations in six lakes in northern Idaho, USA, were sampled to describe their population characteristics. During the summers of 2011 and 2012, 4864 channel catfish were sampled. Channel catfish populations had low to moderate catch rates, and length structure was dominated by fish <400 mm. Channel catfish were in good body condition. All populations were maintained by stocking age‐1 or age‐2 fish. Growth of fish reared in thermally enriched environments prior to stocking was fast compared to other North American channel catfish populations. After stocking, growth of channel catfish declined rapidly. Once stocked, cold water temperatures, prey resources and (or) genetic capabilities limited growth. Total annual mortality of age 2 and older channel catfish was generally <40%. Tag returns indicated that angler exploitation was low, varying from 0 to 43% among lakes. This research provides insight on factors regulating channel catfish population dynamics and highlights important considerations associated with their ecology and management.  相似文献   

18.
Estimates of dynamic rate functions for riverine channel catfish, Ictalurus punctatus (Rafinesque), populations are limited. The open nature and inherent difficulty in sampling riverine environments and the propensity for dispersal of channel catfish impede estimation of population variables. However, contemporary population models (i.e. robust design models) can incorporate the open nature of these systems. The purpose of this study was to determine channel catfish population abundance, survival and size structure and to characterise growth in the lower Platte River, Nebraska, USA. Annual survival estimates of adult channel catfish were 13%–49%, and channel catfish abundance estimates ranged from 8,281 to 24,261 fish within a 10‐km sampling reach. Channel catfish were predominantly (90%) <age 5 and <400 mm total length, and adult growth was similar to other populations across the species’ range. The channel catfish population characteristics in the lower Platte River are likely a result of a combination of factors including recreational harvest and potential shifts in habitat during different life stages. A multifaceted sampling and analytical approach provided additional information such as movement and abundance estimates and may also help to decipher abiotic and biotic factors that interact when managing fish populations in riverine environments.  相似文献   

19.
Channel catfish, Ictalurus punctatus, in a quadruplicate flowthrough aquaria for 15 weeks, were fed a semipurified basal diet containing no folic acid or with folic acid levels ranging from 0.2 to 10.0 mg/kg with or without antibiotic. A second study was conducted for 25 weeks under similar conditions but with semipurified diets containing either 20 or 200 mg/kg ascorbic acid and either 0, 0.4, or 4.O.mg/kg folic acid in a factorial design. Mortalities throughout both experiments were monitored and the etiological causes noted. Fish remaining from the second study were overwintered in circular tanks, kept on the same experimental diets, and challenged with Edwardsiella ictaluri after having been on experimental diets for 50 weeks. In both studies, the addition of folk acid to the basal experimental diet resulted in a decreased incidence of columnaris, Flexibacter columnaris. Folic acid concentration in the diet significantly affected mortalities in fish exmrimentallv challenged with E. ictaluri; however, there was significant interaction between the folic acid concentration and the concentration of ascorbic acid. At the lower concentration of ascorbic acid, 4 mg/kg of folic acid was required to reduce mortalities, but at the higher concentration of ascorbic acid, only 0.4 mg/kg folic acid was needed to reduce mortalities below that of the diet without folk acid. Antibody tilers were not affected by folic acid concentration at the lower concentration of ascorbic acid; however at the higher concentration of ascorbic acid, the diets containing 0.4 or 4 mg/kg of folic acid resulted in increased antibody production.  相似文献   

20.
Channel catfish virus (CCV) disease is an acute haemorrhagic disease in juvenile channel catfish ( Ictalurus punctatus ). To date channel catfish is the only species affected by natural outbreaks of the CCV but juvenile large mouth bass ( Micropterus salmoides ) and silurus ( Silurus meriaionalis ) have suffered high mortalities in recent years in China. Histopathological phenomenon of sick fish is similar to CCV disease, and the identified virus was CCV. In this report, the pathogenicity of infectious CCV was examined by infection trials on the first known host species, the channel catfish and other teleosts. Our results indicated that there were higher detection rates of CCV from large mouth bass and silurus fish. Channel catfish virus did not induce mortality in other cypriniformes, but histopathological studies revealed that carp might be infected by both bathing and intraperitoneal infection. No deaths, clinical or histopathological signs, were found in the six other species exposed by immersion or injection. Experimental infection studies confirm that CCV infect not only channel catfish but also other species (large mouth bass, silutus and carp). The outbreaks of CCV disease only occurred when the cultured temperature was above 25 °C.  相似文献   

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