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1.
Abstract The antiparasitic effects of piscidin 2, an antimicrobial polypeptide (AMPP) first isolated from mast cells of hybrid striped bass, were tested against three protistan ectoparasites of marine fish (the ciliates Cryptocaryon irritans and Trichodina sp., and the dinoflagellate Amyloodinium ocellatum) and one ciliate ectoparasite of freshwater fish (Ichthyophthirius multifiliis). I. multifiliis was the most susceptible parasite, with all theronts killed at 6.3 microg mL(-1) piscidin 2. The most resistant parasite was Trichodina, where a few cells were killed at 12.5 microg mL(-1), but several were still alive even at 100 microg mL(-1). C. irritans was of intermediate sensitivity, with some theronts killed at 12.5 microg mL(-1) and all killed at 25 microg mL(-1). High parasite density apparently exhausted the piscidin 2 before it could attain its maximal effect, but surviving parasites were often visibly damaged. The lower efficacy of piscidin 2 against marine parasites compared with the freshwater ciliate might be related to the inhibitory effects of high sea water cation levels. The tissue concentration of piscidins estimated in healthy hybrid striped bass gill (40 microg mL(-1)) suggests that piscidin 2 is lethal to the parasites tested at physiological concentrations and is thus an important component of innate defence in fish expressing this type of AMPP.  相似文献   

2.
Piscidins are potent, broad‐spectrum, host‐produced antimicrobial peptides (AMPs) that appear to constitute the most common AMP family in teleost fish. Here, we show that piscidin 2 has potent activity against the water mould Saprolegnia, one of the most important pathogens of freshwater fish. The minimum oomyceticidal concentration (MOC100) of piscidin 2 against zoospores of three pathogenic isolates of Saprolegnia ranged from 12.5 to 25.0 μg mL?1. This piscidin concentration is well within levels that have been estimated to be present in at least some fish (1–32.5 μg mL?1). In the presence of either copper or malachite green, two drugs commonly used to treat water moulds, there was evidence for partial synergism (PSYN) with piscidin 2. There was also evidence for PSYN after exposure of the ciliate parasite Tetrahymena pyriformis to piscidin 2 plus copper. Our data provide further evidence that piscidins may be an important host defence against skin and gill pathogens and that the piscidin levels in host tissue might influence the success of drug treatments.  相似文献   

3.
Trophic dynamics and conceptual niche spaces of top piscivores were assessed using stable isotope analysis following the introduction of hybrid striped bass Morone saxatilis (Walbaum) × Morone chrysops (Rafinesque) into an established reservoir fishery devoid of gizzard shad, Dorosoma cepedianum (Lasueur). Hybrid striped bass were initially stocked into Three Mile Lake, Iowa as an attempt to biologically control pervasive yellow bass, Morone mississippiensis Jordan & Eigenmann, populations. From the analyses, it concluded that hybrid striped bass predominately targeted prey fish located in the littoral habitats of the reservoir and did not selectively consume yellow bass as intended. Bayesian isotope mixing models described the diets of hybrid striped bass to include a variety of prey fish, predominantly consisting of young bluegill Lepomis macrochirus and yellow bass. Food resource overlap among hybrid striped bass, largemouth bass, Micropterus salmoides Lacépède, and walleye, Sander vitreus (Mitchill), appeared substantial based on the isotopic niche overlap model. Results from this case study, in conjunction with the hindsight that yellow bass populations became prolific even with stockings of hybrid striped bass, suggest that their use to control yellow bass populations may not be a viable management strategy in southern Iowa.  相似文献   

4.
Palmetto bass are produced by crossing the female striped bass, Morone saxatilis, with the male white bass, Morone chrysops; whereas, the sunshine bass is the reciprocal cross. The hybrid striped bass industry typically rears sunshine bass in earthen ponds, because of the ease of handling, availability, and early maturation of the white bass female broodstock. Growth performance has been assumed similar between the crosses. Under commercial pond conditions, sunshine bass (19.8 ± 0.4 g (mean ± SEM)) and palmetto bass (23.2 ± 0.3 g) were grown to market size (617.0 ± 17.2 g sunshine and 620 ± 3.6 g palmetto) within 15 mo, yielding 4532.6 kg/ha. The net production between the crosses was not significantly different and averaged 4373.4 kg/ha. Feed conversion ratio (FCR) of sunshine bass (FCR 1.70) was better (P = 0.0158) than palmetto bass (FCR 1.76). Commercial processing metrics of each cross demonstrated significant differences, with sunshine bass exhibiting lower frame waste (P = 0.0457) than palmetto bass, probably due to fish body shape or conformational differences at this size. Without growth performance differences between the hybrids, there might be an advantage to rearing sunshine bass due to the slightly better FCR and increased skinless boneless fillet yield.  相似文献   

5.
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6.
Abstract.— Meiotic gynogens were produced using hybrid striped bass (♀ white bass, Morone chrysops , ×♂ striped bass, M. saxatilis ) eggs and white perch M. americana UV-irradiated sperm. Diploidy of the fertilized eggs was restored by application of hydrostatic pressure, which induced retention of the second polar body. Use of white perch sperm provided an unmistakable marker for detection of a paternal genetic contribution. Two assays were developed using the polymerase chain reaction (PCR) to amplify specific regions of the Morone genome . Primers for gene amplification were developed based on the DNA sequence of the striped bass growth hormone gene (SB-GH) or an anonymous striped bass locus (SBI-10). Control experiments using DNA from the three Morone species demonstrated that gene amplification yielded species-specific patterns of DNA fragments for both of these loci. Therefore, any progeny with a paternal contribution of a set of white perch chromosomes could be identified. Using these assays, we demonstrated that greater than 75% of the progeny obtained from successful experiments were true gynogens. These striped bass hybrid gynogens will provide the basis for future efforts to calculate gene-centromere distances and to identify markers linked to specific traits of interest to aquaculture.  相似文献   

7.
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8.

Two commercial trout diets (Oncorhynchus mykiss) and one commercial pike perch diet (Sander lucioperca) were fed to hybrid striped bass (Morone chrysops × M. saxatilis) (mean initial weight ± SD of 60.7 g ± 12.1; mean initial length SD of 17.2 cm ± 1.1) for 69 days at rations of approximately 1% average body weight. While final body weight (FBW), final length (FBL) and condition factor (Cf) were not significantly influenced by diets, specific growth rate (SGR) in hybrid striped bass fed with the pike perch diet (1.15) was significantly higher than those fed with either of the two trout diets (1.04 and 1.07). The feed conversion ratio (FCR) in hybrid striped bass fed with the pike perch diet (1.0) was significantly lower than the FCR in hybrid striped bass fed with either of the two trout diets (1.1 and 1.2). When hybrid striped bass (mean initial body weight: 65.7 ± 4.5 and 127.7 ± 2.9 g) were fed with the pike perch diet twice per day until satiation for 52 days, the SGR was 1.7 and 1.15% d?1 in fishes with an average body weight of 116 and 183 g, respectively. Present results demonstrate that growth performance in hybrid striped bass can be improved when fishes are fed with commercial pike perch diets rather than using commercial trout diets as is the current practice.

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9.
《Fisheries Research》2007,87(2-3):99-104
A bow-mounted surface pushnet and an obliquely towed plankton net were compared to evaluate gear efficiency and effectiveness in collecting larval fishes under daytime and nighttime conditions. The diadromous species targeted were striped bass Morone saxatilis, white perch, Morone americana, and river herring Alosa sp. We sampled the lower Roanoke River, North Carolina, from March through June of 2002 and 2003. Striped bass, white perch and river herring represented over 90% of the larvae collected during the study period. Mean larval densities (number/100 m3) were 63.4 for striped bass, 26.4 for river herring, and 17.7 for white perch. Striped bass larval densities were significantly higher in the surface pushnet for both years (P ≤ 0.05). In 2002, white perch mean larval density was significantly higher at night in the surface pushnet samples, but in 2003 there were no differences between day and night samples. River herring mean densities were significantly higher in the surface pushnets for both years, but showed no clear patterns between day and night samples. Larger larvae were consistently collected in the surface pushnets for all species. Overall, the surface pushnet was easier to operate. The pushnet was mounted on the bow of a small jon boat and required less specialized gear and fewer personnel than oblique sampling. The method also allows for sampling in shallow water or vegetated habitats. Because larvae were significantly larger in the surface samples, using surface pushnets may not allow for detection of the smaller-sized larvae therefore underestimating the abundance of smaller fish. Depending on the question being asked, we recommend that sampling programs should use both gear types to reduce any gear biases.  相似文献   

10.
New and viable species for aquaponics and integrated multi‐trophic aquaculture (IMTA) in freshwater systems can improve yields and sustainability of aquaculture. Freshwater crayfish species such as Astacus astacus and Pontastacus leptodactylus are omnivorous feeders and considered candidates for feeding on faecal matters in existing aquaculture systems. Feeding trials were conducted to determine growth response and RNA/DNA ratio in freshwater crayfish fed fish waste. Carapace length and wet weight were measured to determine the growth response. Juvenile A. astacus was fed faeces of hybrid striped bass (Morone chrysops × Morone saxatilis) and rainbow trout (Oncorhynchus mykiss), while adult P. leptodactylus was fed with two commercial pellet diets and pikeperch (Sander lucioperca) faeces. The nutritional composition of hybrid striped bass faeces was close to optimal diet composition of A. astacus, and crayfish showed significantly higher carapace growth, weight gain and weight gain per moult as the group fed rainbow trout faeces. The growth of P. leptodactylus was significantly lower in terms of weight gain and weight gain percentage per moult for crayfish fed on pikeperch faeces. Thus, this study can recommend a co‐cultivation of hybrid striped bass and A. astacus within one system, but cannot recommend co‐cultivation of P. leptodactylus with pikeperch. Additionally, this study showed controversial results of RNA/DNA ratio and weight gain of both crayfish species. Thus, RNA/DNA ratio cannot be approved for investigations on crayfish physiological status in controlled feeding experiments if animals are fed with an inadequate diet.  相似文献   

11.
The recent increase in the Atlantic coast population of striped bass, Morone saxatilis (Walbaum), prompted managers to re‐evaluate their predatory impact. Published and unpublished diet data for striped bass on the Atlantic Coast of North America were examined for geographical, ontogenetic and seasonal patterns in the diet and to assess diet for this species. Diets of young‐of‐the‐year (YOY) striped bass were similar across the Upper Atlantic (UPATL), Chesapeake and Delaware Bays (CBDEL) and North Carolina (NCARO) areas of the Atlantic coast where either fish or mysid shrimp dominate the diet. For age one and older striped bass, cluster analysis partitioned diets based on predominance of either Atlantic menhaden, Brevoortia tyrannus (Latrobe), characteristic of striped bass from the CBDEL and NCARO regions, or non‐menhaden fishes or invertebrates, characteristic of fish from the UPATL, in the diet. The predominance of invertebrates in the diets of striped bass in the UPATL region can be attributed to the absence of several important species groups in Northern waters, particularly sciaenid fishes, and to the sporadic occurrences of Atlantic menhaden to UPATL waters. In all regions, across most seasons and in most size classes of striped bass, the clupeiod fishes; menhaden, anchovies (Anchoa spp.) and river herrings (Alosa spp,) and Atlantic herring, Clupea harengus L., dominated the diets of striped bass above the first year of life.  相似文献   

12.
The diet of Chesapeake Bay striped bass in the late 1950s   总被引：1，自引：0，他引：1  
The diet of Chesapeake Bay striped bass, (Morone saxatilis) Walbaum, based on unpublished stomach content data from 916 fish collected between 1955 and 1959 was described. The diet in the late 1950s, quantified using an index of relative importance (IRI), was dominated by Atlantic menhaden, Brevoortia tyrannus Latrobe. Atlantic menhaden (66%) and bay anchovy, Anchoa mitchilli Valenciennes, (19%) had the highest IRI value overall. Small striped bass (<600 mm total length) ate predominantly bay anchovy (IRI = 67%). Large striped bass (≥ 600 mm total length) ate predominantly Atlantic menhaden (IRI = 93%). Since 1990 small striped bass rely more on invertebrate prey and larger fish now rely more on small pelagic prey, such as bay anchovy and 0‐age clupeids. Analysis of historical data using current techniques provided a valuable tool for comparison to help in understanding the current striped bass predator–prey relationship in Chesapeake Bay.  相似文献   

13.
Columnaris disease is responsible for substantial losses throughout the production of many freshwater fish species. One of the ways in which the bacterium Flavobacterium columnare is so effective in initiating disease is through the formation of biofilms on fish skin and gills. To further explore the interaction between host factors and bacterial cells, we assayed the ability of vertebrate mucus to enhance F. columnare biofilm development. Different concentrations of catfish, tilapia and pig mucus (5–60 µg/ml) increased biofilm growth at varying degrees among F. columnare isolates. Our data suggest that vertebrate mucus acts as a signalling molecule for the development of F. columnare biofilms; however, there are clear disparities in how individual isolates respond to different mucus fractions to stimulate biofilms. The expression of iron acquisition genes among two genomovar II isolates showed that ferroxidase, TonB receptor and the siderophore synthetase gene were all significantly upregulated among F. columnare biofilms. Interestingly, the siderophore acetyltransferase gene was only shown to be significantly upregulated in one of the genomovar II isolates. This work provides insight into our understanding of the interaction between F. columnare and vertebrate mucus, which likely contributes to the growth of planktonic cells and the transition into biofilms.  相似文献   

14.
It has been reported that metabolic rates of striped bass Morone saxatilis and hybrid striped bass M. chrysops♀ x M. saxatilis♂ are different. A series of experiments were conducted to further characterize oxygen consumption and metabolism of striped bass and its hybrid, the sunshine bass. Oxygen consumption was measured to determine standard and routine metabolic rates of striped bass and hybrid striped bass in a freshwater, flow‐through tank system. Additionally, blood chemistry stress indicators of the two bass groups were compared in both fresh and brackish water. Hematocrit (% PCV) and hemoglobin were measured in order to compare oxidative efficiencies of the bass. Plasma glucose, chlorides, and cortisol levels were measured to compare the relative stress status of the two bass types reared under experimental conditions. No significant differences were found in average daily oxygen consumption between striped bass and sunshine bass for either standard metabolism (P= 0.92), or routine metabolism (P = 0.86). Standard metabolic rates of oxygen consumption were 69 ± 4.1 and 68 ± 3.5 mg 02/kg3/4 bw/h for sunshine bass and striped bass respectively. Routine metabolic rates were 132 ± 30 and 125 ± 30 mg O2/kg3/4 bw/h for sunshine bass and striped bass respectively. While there were no significant differences in oxygen consumption between species, normal feeding activity generally resulted in increased oxygen consumption by the fish. Striped bass had significantly lower hematocrit values (P= 0.0001), but significantly higher hemoglobin concentrations than sunshine bass maintained in freshwater (P= 0.0001). Striped bass had significantly higher (P= 0.0001) levels of plasma glucose compared to sunshine bass (176 ± 8.6 vs. 103 ± 5.6 mg/dL respectively). Plasma chloride levels for striped bass (123 ± 1.9 mEq/L) were significantly higher (P= 0.041) than plasma chloride levels of sunshine bass (117 ± 1.7 mEq/L). Plasma cortisol levels were significantly higher (P= 0.0081) for striped bass (147 ± 8.4 ng/mL) compared to sunshine bass (119 ± 5.6 ng/ mL) when reared in freshwater. When maintained in brackish water, sunshine bass had significantly higher hematocrit values (P= 0.0001), and hemoglobin concentrations (P= 0.0012) when compared to striped bass. However, sunshine bass had significantly higher hemoglobin concentrations (P= 0.0012) when compared to striped bass. In addition, plasma glucose levels were significantly lower (P = 0.0079) for sunshine bass (79 ± 4.1 g/dL) when compared to striped bass (115 ± 11 g/dL). There were no significant differences between the bass in levels of chlorides or cortisol. No differences were detected in oxygen consumption. However, hybrid striped bass may have more efficient oxidative metabolism due to elevated hemoglobin concentrations. While striped bass hemoglobin values tended to be higher in brackish water than in freshwater, sunshine bass hematocrit or hemoglobin values generally were significantly higher than striped bass in both fresh and brackish water. Based on these results, hybrid striped bass may be capable of directing more energy towards growth than striped bass due to more efficient oxidative metabolism and lower losses of energy related to increased stress.  相似文献   

15.
Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops × M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0% and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole body protein content, whole body compositional indices and nutrient retention efficiencies were linearly related to dissolved oxygen concentration. Results demonstrate that as hypoxia becomes more severe, juvenile hybrid striped bass feed intake is reduced, which affects growth and nutrient retention.  相似文献   

16.
Within the framework of a larger project aimed to assess the potential of second generation hybrid striped bass for German aquaculture the genotypic segregation of five microsatellite loci was analysed in two progeny lots (n = 74 and 76, respectively). There was no consistent correlation between microsatellite genotypes and phenotypic category (white bass, hybrid, or striped bass). None of the individuals expressed neither only white bass nor only striped bass genotypes at all five loci. On the other hand, only hybrid genotypes at all five loci were detected in three individuals of lot 1 and four individuals of lot 2. Single loci tests for conformity of microsatellite genotypic segregation with Mendelian rules revealed significant deviations (P < 0.05) in four cases for lot 1 and in three cases for lot 2. If pooled over all five loci, both lots displayed highly significant deviations (P < 0.01) with an excess of hybrid genotypes and a deficiency of white bass genotypes. It is concluded that stabilizing selection performed on hybrid genotypes might be a suitable approach for practical aquaculture in Europe if the goal is to become independent of first generation hybrid fry supply and/or if establishing domesticated brood stocks of both parental species is impossible. However, more detailed studies on the characteristics and performance of multiple hybrid generations are needed.  相似文献   

17.
It has been recently demonstrated that hybrid striped bass Morone chrysops × M. saxatilis exhibit intestinal phytase activity, an enzyme capable of liberating inorganic orthophosphate from the phytate molecule, thereby making phytate phosphorus (PP) available for absorption and utilization by the fish. However, it was also determined that hybrid bass were able to digest only 1–2% of dietary PP. Therefore, an experiment was conducted to determine if exogenously administered recombinant bovine somatotropin (rbST) would increase intestinal phytase activity in hybrid striped bass to a level that would improve PP availability. The results indicate that exogenous rbST treatment, administered either through intraperitoneal injection or orally, does increase intestinal brush border membrane protein concentration. While injection with rbST led to significant increases in both specific brush border membrane and total intestinal phytase activity, oral rbST administration did not cause similar increases. Total P and PP digestibility were not influenced by rbST administration. While treatment with rbST does have the potential to enhance intestinal phytase activity in hybrid striped bass, it does not appear to increase PP digestibility. This observation limits the hormone's utility as an effective technique for improving PP bioavailability to this species.  相似文献   

18.
Aeromonas hydrophila and Flavobacterium columnare, the aetiological agents of motile aeromonas septicaemia (MAS) and columnaris disease respectively, have been recently causing crippling mortalities to the sunshine bass, Morone chrysops female ×Morone saxatilis male (Percichthyidae), industry in the United States. Isolates of A. hydrophila and F. columnare obtained from fish that died during farm outbreaks were subjected to in vitro evaluation of florfenicol (FFC), copper sulphate (CuSO4) and potassium permanganate (KMnO4). Florfenicol inhibited the growth of A. hydrophila and F. columnare more than CuSO4 and KMnO4. The minimum inhibition concentration (MIC) of FFC was 0.04 ± 0 and 0.2 ± 0.1 mg L?1 for A. hydrophila and F. columnare respectively, while the 50% inhibition concentration (IC50) for A. hydrophila and F. columnare was 0.23 ± 0.01 and 0.4 ± 0.2 mg L?1 respectively. Copper sulphate was more effective against A. hydrophila than KMnO4; CuSO4 had a MIC of 83.2 ± 0 mg L?1 compared to 158.0 ± 0 mg L?1 for KMnO4. Copper sulphate was also more effective against F. columnare than KMnO4. The IC50 values of CuSO4 and KMnO4 towards F. columnare were 4.8 ± 0.3 and 8.7 ± 1.6 mg L?1 respectively, and the minimum bactericidal concentration values of CuSO4 and KMnO4 towards F. columnare were 25.0 ± 0 and > 158.0 mg L?1 respectively. In addition, F. columnare was more sensitive to CuSO4 and KMnO4 than A. hydrophila.  相似文献   

19.
Columnaris disease can be problematic in tilapia (Oreochromis spp.) production. An understanding of the pathogenesis and virulence of Flavobacterium columnare is needed to develop prevention strategies. The objective of this study was to determine the virulence of genetically defined isolates of F. columnare in sex‐reversed hybrid tilapia, Oreochromis niloticus (L.) × O. aureus (Steindachner). A series of immersion challenge trials were performed using isolates of the five established genomovars of F. columnare: I, II, II‐B, III and I/II. The mean per cent mortality of fish challenged with genomovar I, II and III isolates ranged from 0 to 100, 3.3–78 and 3.3–75%, respectively. The mean per cent mortality of fish challenged with genomovar II‐B ranged from 35 to 96.7%, and the only genomovar I/II isolate tested caused no mortality. Contrary to previous work in other fish species, there did not appear to be an association between F. columnare genomovar and virulence in tilapia. The challenge model used resulted in acute mortality. An alternative challenge model was tested by cohabitating healthy fish with dead fish infected with F. columnare. This method resulted in rapid appearance of clinical signs and mortality, suggesting the potential for F. columnare to increase in virulence upon growth on/in a fish host.  相似文献   

20.
Stable carbon isotope ratios were measured in archived striped bass, Morone saxatilis (Walbaum), scales to identify changes in the feeding behaviour of this species over time. Striped bass tissue and scale samples were collected from Rhode Island coastal waters during 1996 and archived scale samples (1982–1997) were obtained from Chesapeake Bay. Known striped bass prey items were also collected from Chesapeake Bay and analysed for δ13C. A significant correlation was observed between carbon isotope ratios in striped bass scales and muscle tissue (r2 = 0.52; P < 0.05). Carbon isotope ratios were enriched (less negative) in scales relative to muscle tissue by about 3‰. Carbon isotope ratios in archived striped bass scales from Chesapeake Bay increased significantly from ?16.7 ± 0.2‰ in 1982 to ?15.1 ± 0.3‰ in 1997. Benthic species, especially invertebrates, were isotopically enriched relative to pelagic fish species collected from the main‐stem of Chesapeake Bay. Prey samples collected from riverine locations within Chesapeake Bay were isotopically depleted relative to those collected in the open portion of the Bay. The changes in the carbon isotope ratios of the striped bass scales could be related to changes in the relative proportions of pelagic and benthic food items in the diet of striped bass or to changes in the feeding locations of this species. In either case, there have been changes in the feeding behaviour and/or relationships of the striped bass between 1982 and 1997. Such changes may be related to changing ecological conditions within the estuary, which could influence the health of Chesapeake Bay striped bass.  相似文献   

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