Volume 68, 2016
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ItemAeromonas veronii, Associated with Skin Ulcerative Syndrome, Isolated from the Goldfish (Carassius auratus) in China( 2016)Aeromonas infections are the most common bacterial disease in cultured fish. In April 2013, an epizootic ulcerative syndrome occurred on a goldfish farm in Xuzhou, central China. A gram-negative bacterium was isolated from the ulcerative lesions and internal organs of infected dragon-eye goldfish (Carassius auratus), tentatively named strain CAV-134. The results showed that the isolate was identified as Aeromonas veronii by physiological and biochemical characteristics, furthermore it was confirmed by 16S rRNA, gyrB, mu, asl and aha1 genes sequencing analysis. The pathogenicity of the isolate was confirmed in crucian carp and produced an LD50 of 1.99×106 CFU/ml. Antimicrobial susceptibility pattern of strain CAV-134 showed it was susceptible to most antimicrobial agents tested but resistant to ampicillin, amoxicillin, carbenicillin, vancomycin, teicoplanin, lincomycin and clindamycin. This is the report on the pathogenic A. veronii isolated from the skin ulcerative syndrome of dragon-eye goldfish.
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ItemFirst Report of Chryseobacterium sp. from Koi (Cyprinus carpio) in Turkey( 2016)In this study, we isolated Chryseobacterium sp. from koi in Turkey. The disease outbreak occurred in fish weighing 10-300g (water temperature 9-10°C) in November 2011- February 2012. The cumulative mortality rate was approximately 55% over 4 months. Infected koi exhibited anorexia, weakness, emaciation, damage to dorsal and caudal fins, grey-white skin discoloration (1-1.5cm) in the head area, large open wounds in skin with disease progression, necropsy findings, paleness of the liver, enlarged spleen and kidney, acidic fluid in the body cavity. Samples for bacteriological examinations were collected from the kidney, liver, and spleen using sterile swabs; these samples were streaked onto Anacker ordal Agar and incubated at 18°C for 48 h. Five bacterial isolates were obtained from diseased fish. Phenotypic characteristics of the isolates were determined by conventional methods and rapid identification kits, API 20NE, and API ZYM. Comparative 16S rRNA gene sequence analysis demonstrated that isolate Sin57 belonged to the genus Chryseobacterium, with highest sequence similarity (98.5 %) to C. aahli T68T and C. limigenitum SUR2.
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ItemUse of Fermented Soybean Meal with Whey as a Protein Source for Feeding Juvenile Tilapia (Oreochromis niloticus)( 2016)In this study, the effect of fish meal substitution with fermented soybean meal in juvenile tilapia (Oreochromis niloticus, L.1758) diets was investigated. Six experimental diets were prepared by replacing 0 (FM, control), 10% (FSM10), 20% (FSM20), 30% (FSM30), 40% (FSM40), and 50% (FSM50) of the fish meal protein in the control diet by fermented soybean meal with whey (FSMW). The control diet contained no fermented soybean meal. The isonitrogenous and isocaloric diets were fed to juvenile tilapia (initial average weight 0.74 g) for 90 days. Each diet group was fed in triplicate to 24 fish per aquarium. At the end of the experiment, highest growth, feed efficiency, and protein digestibility were found in the group fed the FSM30 diet. Tilapia fed diets containing fermented soybean meal up to 50% fish meal exhibited similar growth, feed conversion ratio (FCR), protein efficiency ratio (PER), and protein digestibility compared with the control diet. However, feed efficiency (FE) was reduced in tilapia fed FSM50 diet. Body composition, hepatosomatic index (HIS) and viscerosomatic index (VSI) were unaffected by the dietary treatment. Results of this study showed that FSMW could replace up to 40% of fish meal protein in juvenile tilapia diets
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ItemEffect of Partial Substitution of Fish Meal with Sunflower Meal on Feed Utilization, Intestinal Digestive Enzyme, Hematological Indexes, Intestinal, and Liver Morphology on Juvenile Turbot (Scophthal musmaximus L.)( 2016)A 70-day feeding trial was conducted to evaluate effects of partial substitution of fish meal (FM) by sunflower meal (SFM) on juvenile turbot (Scophthal musmaximus L.). Five isonitrogenous and isoenergetic diets were formulated with 0%, 15%, 25%, 35%, and 45% replacement of FM protein with protein from SFM. Triplicate groups of juvenile turbot (30 fish per group), were hand-fed twice daily to apparent satiation. Final body weight (FBW), specific growth rate (SGR), and weight gain rate (WGR), were not significantly influenced by type of plant protein at the 15% level (P>0.05), while higher levels showed significant reduction of FBW, SGR, WGR. Feed efficiency ratio (FER) and feed intake (FI) were significantly influenced when FM protein was replaced up to 45% (P<0.05). Body composition parameters were not affected by SFM substitution but body crude lipid was lowest and ash was highest at 45% (P<0.05). Trypsin and diastase values did not vary with experimental diets but lipase activity was significantly reduced (P<0.05). Catalase (CAT) values were significantly lower than the control (P<0.05) when substitution level reached or exceeded 35%; no significant differences were observed in total antioxidant capacity (T-AOC) and malondialdehyde (MDA) values (P>0.05). In the SFM diet groups, all superoxide dismutase (SOD) values were significantly higher than the control (P<0.05); villi length and enterocytes were significantly reduced (P<0.05), but there was no significant difference (P>0.05) in microvilli height between diets; parenchyma structure of liver was severely damaged; smaller hepatocyte areas and areas with high levels of hepatocyte vacuolization and disorganization were present. All results indicated that SFM protein can partially replace FM protein in juvenile turbot diets without adverse effects.
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ItemMolecular Cloning and Response to Water Temperature and Nutrient Manipulation of Insulin-like Growth Factor (IGF) Genes in Golden Pompano Trachinotus ovatus (Linnaeus 1758) Larvae( 2016)In this study, insulin-like growth factor I (IGF I) and IGF II in golden pompano larvae were cloned and analyzed. In the first trial, IGF expression during ontogeny of larvae in the first 18-days of their life was explored, and then the response of IGFs to water temperature (23, 26, and 29oC) on 12 day post hatching (DPH) and 18 DPH were compared. On 28 DPH, the response of IGFs to the manipulation of nutrients was evaluated. The expression of IGF I increased with the increase of fish age, and was not significantly affected by water temperature. The expression of IGF II was affected by water temperature on 12 DPH and 18 DPH. The expression of IGF II at 23oC was significantly higher than at 26oC and 29oC. The expression of IGFs in fish larvae on 28 DPH was not concomitant with nutrient manipulation. This study detected the gene expression of IGFs at the early stage of golden pompano larvae. The time dependent expression of IGF genes in fish larvae is important to understand the ontogenetic development and growth of fish larvae in early life.
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ItemEffect of Extender Supplemented with Different Sugar Types on Post-thaw Motility, Viability and Fertilizing Ability of Cryopreserved Common Carp (Cyprinus carpio) Spermatozoa( 2016)The influence of various sugar types supplemented to the extender on post-thaw motility, viability, and fertilizing capacity of cryopreserved common carp (Cyprinus carpio) semen were investigated. The results indicated that types of sugar significantly influenced motility, motility duration, and viability rates (P<0.05). Glucose, maltose, sucrose, and trehalose provided higher motility compared to the sugar-free control in post-thaw samples. Trehalose provided highest progressive motility duration, and higher viable sperm rates were obtained with all sugar types except xylose. Xylose exhibited the lowest post-thaw progressive motility duration (35.2±1.4s). The mean highest fertilization (78.2±1.4%) and eyed egg rates (94.3±1.5%) were determined using trehalose in the extender, and differences between the treatments in the fertilization and eyeing rates were significant (P<0.05). Finally, the present study showed that sugars, especially maltose and trehalose (disaccharide), improved post-thaw spermatozoa motility and fertility in common carp semen.
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ItemMicrosatellite-Based Analysis of Genetic Diversity and Relationship of Artificial Hybrid Jiyan-1 Puffer and their Parents, Takifugu flavidus and Takifugu rubripes( 2016)In this study, the genetic diversity and relationship of artificial hybrid Jiyan-1 puffer and their parents (T. flavidus ♀ and T. rubripes ♂) were evaluated using 15 microsatellite markers. The average number of alleles (Na), observed heterozygosity (Ho), and expected heterozygosity (He) of T. flavidus were higher than the average values of T. rubripes. Jiyan-1 puffer showed a relatively high level of genetic diversity, with an average allele number of 6.467 and mean observed and expected heterozygosity of 0.560 and 0.592, respectively. UPGMA cluster analysis indicated that Jiyan-1 puffer inherited more genetic information from female parents. This study indicates that the microsatellite markers will be useful for investigation of genetic background of puffer fish, as well as better conservation and sustainable utilization of puffer fish in aquaculture.
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ItemUse of Oyster Processing Byproduct to Replace Fish Meal and Minerals in the Diet of Nile Tilapia Oreochromis niloticus Fry( 2016)A byproduct from processing oysters (Crassostrea iridalei) for human consumption was evaluated as a possible protein source to replace fishmeal in the Nile tilapia diet. In an 8 week-feeding trial, fish were fed 7 experimental diets containing various inclusion levels of oyster byproduct (OBP) which replaced fish meal. Diet 1 contained 0% OBP, while Diets 2-6 contained 5%, 10%, 15%, 20%, 25% OBP respectively; Diet 7 was a fishmeal-based diet with OBP as the only source of dietary minerals. The optimum amount of OBP inclusion levels producing maximal responses i.e. final average body weight (FABW), weight gain (WG), specific growth rate (SGR), food conversion rate (FCR) and protein efficiency rate (PER) was estimated using the Broken Line Model of analysis. Average optimum level was 17.0% of dietary OBP (fishmeal replacement of 63.8%). Diet 4 (15% OBP= 56.4% fishmeal replacement) resulted in statistically similar growth and feed efficiency parameters to Diets 1-3 and were closest to the estimated optimum inclusion level. Total mineral replacement by OBP (Diet 7) resulted in differing results; SGR values were statistically similar to those of the other dietary treatments; however FABW was inferior, and values for WG, FCR and PER were intermediate. In conclusion, OBP could replace as much as 63.8% by weight of dietary fishmeal and probably a large proportion of the mineral mix in the diet of Nile tilapia fry.
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ItemEvaluation of Crinkle Grass Rhizoclonium riparium in a Diet for Pacific White Shrimp Penaeus vannamei Post Larvae( 2016)A feeding experiment to evaluate the inclusion of Rhizoclonium raw meal (RM) in diets for growth and feed efficiency in Pacific white shrimp, Penaeus vannamei was conducted. Five diets were formulated containing increasing levels of RM inclusion: 0%, (control), 5.25%, 10.50%, 15.75%, and a diet with 15.75% RM totally replacing the mineral mix. The diets were fed to shrimp post larvae for 60 days with 4 replicates. Survival rates were excellent (98-93%) and similar for all treatments. Final average body weight (FABW) was highest in shrimp fed the diet containing 5.25% RM, and lowest with the 10.50% RM diet; FABW of the other groups were either statistically similar or lower than the control group. A similar pattern was also observed for specific growth rate (SGR) and protein gain (PG). Food conversion efficiency (FCE) was highest in shrimp fed the diet containing 5.25% RM; protein efficiency ratio (PER) was higher in all groups fed diets containing RM than the control group. Replacing the dietary mineral component with RM did not significantly affect the growth, feed efficiency, and survival rate. The present study demonstrated that Rhizoclonium riparium var. implexum is a possible complementary protein source and could replace from 15%-45% imported soybean meal (SBM) in the P. vannamei post larvae diet. An additional 1% RM could replace the dietary minerals.
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ItemAeromonas hydrophila: a Causative Agent for Tail Rot Disease in Freshwater Cultured Murray Cod Maccullochella peelii( 2016)Tail rot disease is the cause of significant economic damage in freshwater farmed Murray cod Maccullochella peelii. Only scarce information is available on Aeromonas hydrophila as a possible causal agent for this disease. In this study, a virulent strain, temporarily named XY3, was isolated from diseased codfish suffering from tail rot disease, and identified as A. hydrophila through phylogenetic analysis and phenotypic characteristics. A. hydrophila possesses multiple virulence genes including aerA, ahpA, alt, ast and hlyA genes. In addition, it appears that isolate XY3 has developed multiple resistances to cephalosporin, chloromycetin, glycopeptides, macrolides, nitrofuran, and penicillin drugs, as well as to aminoglycosides, sulfonamides, and tetracyclines antibiotics for veterinary uses in aquaculture as revealed when screened against a range of common antibiotics. To the best of our knowledge, this is the first report of tail rot disease caused by A. hydrophila in freshwater farmed codfish.