Volume 68, 2016

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https://hdl.handle.net/10524/54924

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Aeromonas veronii, Associated with Skin Ulcerative Syndrome, Isolated from the Goldfish (Carassius auratus) in China
(2016) Aijun Lü; Yajiao Song; Xiucai Hu; Jingfeng Sun; Li Li; Chao Pei; Chao Zhang; Guoxing Nie
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.
First Report of Chryseobacterium sp. from Koi (Cyprinus carpio) in Turkey
(2016) Behire Işıl DİDİNEN; Ertan Emek ONUK; Türkay ÖZTÜRK; Seçil METİN; Meryem ÖZ; Özge ÇAYLI; Ayşegül KUBİLAY
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.
Use of Fermented Soybean Meal with Whey as a Protein Source for Feeding Juvenile Tilapia (Oreochromis niloticus)
(2016) Yigit Nalan Ozgur; Demir Tulay
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
Effect 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) Huihui Zhou; Chaoqun Li; Fuyun Bian; Mingsan Man; Kangsen Mai; Wei Xu; Gen He
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.
Molecular 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) Zhenhua Ma; Jing Hu; Yajuan Liu; Rui Yang; Jian G. Qin; Dianrong Sun
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.
Effect of Extender Supplemented with Different Sugar Types on Post-thaw Motility, Viability and Fertilizing Ability of Cryopreserved Common Carp (Cyprinus carpio) Spermatozoa
(2016) Yusuf Bozkurt; İlker Yavaş; Cengiz Yıldız
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.
Microsatellite-Based Analysis of Genetic Diversity and Relationship of Artificial Hybrid Jiyan-1 Puffer and their Parents, Takifugu flavidus and Takifugu rubripes
(2016) Kezhi Xing; Qingkui Wang; Chengxun Chen; Xueliang Sun; Han Zhang
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.
Use of Oyster Processing Byproduct to Replace Fish Meal and Minerals in the Diet of Nile Tilapia Oreochromis niloticus Fry
(2016) Ernestina M. Peralta; Barry Leonard M. Tumbokon; Augusto E. Serrano, Jr.
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.
Evaluation of Crinkle Grass Rhizoclonium riparium in a Diet for Pacific White Shrimp Penaeus vannamei Post Larvae
(2016) Mary Grace Sedanza; Augusto E. Serrano, Jr
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.
Aeromonas hydrophila: a Causative Agent for Tail Rot Disease in Freshwater Cultured Murray Cod Maccullochella peelii
(2016) Chunlei Gai; Weicheng Ye; Liqun Lu; Yi Li; Xianle Yang; Haipeng Cao
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.
Effects of Time after Hormonal Stimulation on Milt Properties in Waigieu Seaperch Psammoperca waigiensis
(2016) Minh Hoang Le; Paul B Brown
The objective of the present study was to assess the effects of time after stimulation with domperidone (DOM), luteinizing hormone releasing hormone analog (LHRHa), and human chorionic gonadotropin (HCG), on features of spermiation including milt physical properties, sperm motility parameters, and sperm morphology, in Waigieu seaperch Psammoperca waigiensis. Male broodfish were injected with either 0.9% saline solution (control), or a single dose of DOM [20 mg/kg body weight (BW)], LHRHa (20, 50, or 80 μg/kg BW), or HCG (500, 1000, or 1500 IU/kg BW). Milt samples were collected before hormone induction (0 h) to assess original milt condition, and at 24 h, 48 h, and 72 h post injection (p.i.). Results showed that treatment with saline solution, DOM, or LHRHa did not significantly alter milt physical properties, sperm motility parameters, or sperm morphology. Treatment with HCG at a dose of 1000 IU/kg BW significantly increased milt volume, total sperm production, and sperm motility parameters, but decreased spermatocrit and sperm concentration at 48 h p.i. These parameters were significantly reduced at 72 h p.i. In conclusion, our results suggest that Waigieu seaperch milt should be collected 48 h after hormonal stimulation with a single dose of HCG (1000 IU/kg BW) to ensure high properties of milt such as milt volume, total sperm production, and sperm motility parameters.
Acinetobacter lwoffii: an Emerging Pathogen for Red Head Disease in Farmed Channel Catfish Ictalurus punctatus
(2016) Haipeng Cao; Weidong Ye; Shan He; Yi Li; Yibin Yang
Red head disease has become a significant emerging cause of economic damage in the farming of channel catfish Ictalurus punctatus. Only scare information is available on this disease caused by Acinetobacter lwoffii in channel catfish. In this study, a virulent strain, temporarily named R21, was isolated from diseased channel catfish suffering from red head disease, and identified through phylogenetic analysis and phenotypic characteristics. A phylogenetic tree was constructed to examine isolate R21 and compare it to other known isolates. In addition, isolate R21 appears to be resistant to azithromycin, ciprofloxacin, erythromycin, norfloxacin, and oxacillin, but is still susceptible to aminoglycosides, amphenicols, sulfonamides and tetracycline drugs for veterinary uses in aquaculture as revealed when screened against a range of common antibiotics. This study confirms A. lwoffii as an emerging pathogen for red head disease in farmed channel catfish.
Evaluation of Dietary Anti-nutritional Factors and Amino Acids Supplementation on Growth, Feed Efficiency Ratio, and Apparent Digestibility of Japanese Flounder (Paralichthys olivaceus) at Equal Feed Intake
(2016) Wei Chen; Kangsen Ma; Yanjiao Zhang; Qinghui Ai; Rantao Zuo; Houguo Xu
A 30-day feeding trial was conducted to evaluate the anti-nutritional factors in fish meal-based diets, and limiting amino acids in soybean meal-based diets on growth, feed efficiency ratio (FER), and nutrient apparent digestibility (AD) of Japanese flounder (Paralichthys olivaceus) at equal feed intake. Four isonitrogenous and isoenergetic diets were formulated: Diet 1 contained fish meal as the main dietary protein source; Diet 2 was based on Diet 1 and supplemented with anti-nutritional factors; Diet 3 contained both fish meal and soybean meal as main protein source; Diet 4 was based on Diet 3 and supplemented with crystalline amino acids. All diets were assigned to triplicate groups of 5 fish per aquarium. Results from Diet 1 showed that force-feeding was a possible method to rear Japanese flounder with high FER and 100% survival rate. In the first three periods (4 days/period), weight gain (WG) and FER of fish fed Diets 2, 3 & 4 were significantly lower (P<0.05) than in fish fed Diet 1. After 30 days of the feeding trial, WG and FER of fish fed Diets 3 & 4 were significantly lower than in fish fed Diet 1 (P<0.05). No significant difference in WG and FER was observed either between fish fed Diets 1 & 2, or between fish fed Diets 3 & 4. The AD of dry matter and crude lipid of fish fed Diets 3 & 4 were significantly lower than those of fish fed Diet 1 (P<0.05). Results indicated that supplementation of anti-nutritional factors in a fish meal-based diet, or supplementation of crystalline amino acids in a soybean meal-based diet did not significantly affect growth performance of Japanese flounder by force feeding.
Optimal Dietary Protein Level for the White Shrimp (Litopenaeus vannamei ) in Low Salinity Water
(2016) Weihua Gao; Luo Tian; Wei Hu; Mingzhong Luo; Jiashou Liu; Qiaoqing Xu; Juan Tian
In order to find the optimal dietary protein level for Litopenaeus vannamei in low salinity water, isolipid and isocaloric diets with different protein levels (25%, 30%, 35%, 40% and 45%) were tested to feed L. vannamei juveniles (mean weight 0.31 ± 0.02 g) for 56 days in salinity 2 g/L water. The results showed that: (1) as the dietary protein level increased, the final body weight, weight gain and specific growth rate increased at first and then decreased. In the 35% protein level group, significantly better results were obtained as compared to other groups (P<0.05). Through quadratic regression analysis of dietary protein level and weight gain and specific growth rate, we found that shrimps had the highest weight gain when dietary protein level was between 33.51%–34.35%; (2) as the dietary protein level increased, the shrimp moisture content decreased and the protein content increased while lipid and ash content did not significantly change; (3) as the dietary protein level increased, the activity of trypsin increased at first and then decreased, and the 35% protein level group had the highest trypsin activity, significantly higher than other groups (P<0.05). There were no significant differences in lipase or amylase activity.
Substitution of Krill meal for Fish Meal in Feed for Russian Sturgeon, Acipenser gueldenstaedtii
(2016) Yang-yang Gong; Yan-qing Huang; Lu-jiao Gao; Jian-xue Lu; Hong-liang Huang; ong-tao Xi
Krill meal (KM) is a potential feed ingredient that can replace fish meal (FM) in aquaculture. To better understand the efficacy of krill meal, a 200-day feeding trial was conducted with Russian sturgeons (Acipenser gueldenstaedtii). Four extruded diets in which KM replaced 0%, 10%, 20%, or 30% of FM in the formulation were fed to 481 g sturgeons for 200 d. Russian sturgeons that were fed diets containing KM grew as fast as or even better than fish fed with FM control diet. No differences were observed in terms of dorsal muscle composition in the fish fed with diets including KM and those fed with FM control diet. Meanwhile, the fluoride concentrations in the dorsal muscle, liver, and kidney, as well as swim bladder in all dietary groups were below detectable limit. In the gills, skin, vertebral bone and dorsal scutes, the fluoride content from the KM groups progressively increased with dietary fluoride concentration. In conclusion, KM can partially substitute for FM in the diets of Russian sturgeon without affecting normal growth performance.
In Vitro Testing of Potential Probiotic Bacteria against Vagococcus salmoninarum in Rainbow Trout (Oncorhynchus mykiss, Walbaum 1792)
(2016) Didinen B.I.; Onuk E.E.; Sayi H.
In this study, probiotic properties of endogenous microbiota of rainbow trout against Vagococcus salmoninarum isolated during an outbreak of vagococcosis in a trout farm in the Mediterranean region were evaluated. The candidate probiotic bacteria were isolated from rainbow trout intestines. A total of 157 isolates were obtained and screened for antagonistic activity against V. salmoninarum via the Well Diffusion Agar method. Six isolates were determined for antagonistic activity against V. salmoninarum. Conventional microbiological tests and API 20 Strep tests (bioMe´rieux) were used for further phenotypic characterization of all six antagonistic isolates. For molecular identifications of isolates, L. garvieae specific PCR and 16S rRNA gene sequence analysis were used. Antagonistic strains were identified including TUB/2013/V47 (L. garvieae), TUB/2013/V27 (L.garvieae), TUB/2013/V10 (L. garvieae), TUB/2013/V2 (L. garvieae) TUB/2013/V1 (L. lactis) and TUB/2013/V4 (L. lactis). The strains were then tested for hydrophobicity, bile salts and acid tolerance and antimicrobial activity. All isolates were congo red-positive, indicating the presence of hydrophobic structures in their cell walls. It was determined that whole antagonistic strains were resistant to low pH conditions and 0.6-1.5% bile concentrations. Antimicrobial test results showed that most of the strains are susceptible in vitro to amoxicillin/clavulanic acid ampicillin, doxycycline, erythromycin and florfenicol, which are frequently used in aquaculture. As a result, it was found that strains have in vitro probiotic properties (hydrophobic, tolerant to bile salts and low pH conditions). Further study is needed to explore their in vivo probiotic effects against vagococcosis
Effects of Dietary Lecithin, Nucleoside, and Krill Supplementation to a Fishmeal Based Diet on Growth and Feed Utilization of Sharpsnout Sea Bream (Diplodus Puntazzo)
(2016) Stavros Chatzifotis; Manuel Sala-Pérez; Elena Guerra; Lionel Santos Rodrígue; Ana Ruiz-Navarro
The aim of this 96 day feeding trial was to investigate the effects of the addition of different combinations of dietary lecithin, nucleosides, and krill to a fishmeal-based diet on the growth, feed utilization, feed consumption, and body composition of sharpsnout sea bream (Diplodus puntazzo). Six hundred (600) fish (average weight 21.21 ± 0.06SD g) were divided into 8 groups (triplicate treatments) and fed eight isoenergetic fishmeal-based diets, (C-control, L-lecithin, N-nucleosides, K-krill, L+N-lecithin+nucleosides, N+K-nucleosides+krill, L+K-lecithin+krill, L+N+K-lecithin+nucleosides+krill). The effects of the dietary regimes were evaluated in terms of specific growth rate (SGR), feed conversion ratio (FCR), daily feed intake (DFI), and whole body chemical composition (moisture, crude ash, crude protein and crude lipid). At the end the trial the fish had tripled their initial weight. SGR, FCR and DFI were 1.17-1.24 %, 0.95-1.01, and 1.03-1.14% respectively. Although differences were observed between some groups, none of the tested feed additives improved SGR, FCR, and DFI, compared to the control diet. Analysis of whole body proximate composition showed that moisture, crude ash, crude protein, and crude lipid ranged 61.45-64.00%, 3.96-4.26%, 15.44-17.26% and 14.87-18.82% respectively. Crude lipid concentration was higher in whole body of fish fed the nucleoside supplemented diet compared to control, lecithin, and krill groups. No other effects of the dietary regime on the whole body composition of sharpshout sea bream were observed.
The Effect of Dietary Lipid on the Growth Performance of Meagre (Argyrosomus regius Asso, 1801).
(2016) Ali Yıldırım Korkut; Sait Cenk Sert; Aysun Kop; Kutsal Gamsız; Bilge Karahan
The aim of the study was to investigate the effects of dietary lipid on the growth and feed utilization of Meagre (Argyrosomus regius Asso, 1801), taking into account their feeding behavior of collecting food from the bottom of the cages. The fish (141.07±0.5g, average weight ± SD; 22.18±0.53 cm, average total length± SD) were fed three isonitrogenous experimental diets (45% crude protein, dry matter) containing 16% (group A), 18% (group B), and 20% (group C) crude lipids for 570 days. The fish were stocked into 9 net cages (16 m diameter; 7 m deep) at a density of 16000 fish per cage with 2 replications. At the end of the experiment fish in the A, B, and C groups reached 1054.59±5.9, 1026.32±4.3, 955.31±2.3 mean live weight (g) and 45.78±1.6, 44.43±1.4, 43.88±1.4 mean total length (cm) respectively. FCR and CF values were 1.99, 2.07, 2.14 and 1.999, 1.131, 1.170 respectively for each group, at the end of the study. VSI, HIS, and GSI values were also calculated. Growth rate in fish from group A (fed the lowest lipid diet) was superior to the other dietary groups. Cross sections of their liver were checked and were found to have less lipidosis.
Effects of Dietary Carbohydrates with Different Molecular Complexity on Growth Performance, Feed Utilization, and Metabolic Responses of Juvenile Turbot Scophthalmus maximus
(2016) Shuyan Miao; Qin Nie; Huijun Miao; Wenbing Zhang; Kangsen Mai1
A 9 week study was conducted to evaluate the ability of juvenile turbot Scophthalmus maximus (initial body weight: 8.06 ± 0.08 g) to utilize carbohydrates of different molecular complexity (glucose, sucrose and dextrin) diets. Triplicate groups of fish were hand-fed each of the diets in a re-circulated water system. Results showed that weight gain rate and feed efficiency of fish fed dietary dextrin and the control diets were higher than those fed dietary glucose and sucrose diets (P<0.05). Fish fed dietary sucrose had significantly higher daily feed intake than those fed the other three diets (P<0.05). The apparent digestibility coefficients of carbohydrates were glucose > dextrin > sucrose with the lowest occurring in fish fed dietary sucrose. Lipid content in muscle and liver was significantly higher in fish fed the control diet, and muscle glycogen was significantly highest (P<0.05) in fish fed dietary glucose. The order of the liver glycogen was glucose > sucrose > dextrin > control. Insulin was significantly highest (P<0.05) in fish fed dietary dextrin plasma. In fish fed the control diet total cholesterol in plasma was highest (P<0.05), and triacylglycerols in plasma of fish fed the control and dietary dextrin diets were significantly highest (P<0.05). In conclusion, the present study suggests that turbot can utilize dextrin more efficiently than glucose and sucrose.
Hafnia alvei: a Pathogen Causing Infectious Intussusception Syndrome (IIS) in Farmed Channel Catfish Ictalurus punctatus
(2016) Haipeng Cao; Shan He; Yi Li1; Yibin Yang; Xiaohui Ai
Infectious intussusception syndrome (IIS) is a serious problem, causing severe economic losses in farmed channel catfish Ictalurus punctatus. Limited information is available on Hafnia alvei as a causal agent for this disease. In this study, a virulent strain, temporarily named HN01, was isolated from diseased channel catfish suffering from infectious intussusception syndrome, and identified through phylogenetic analysis and phenotypic characteristics. A phylogenetic tree was constructed to examine isolate HN01 and compare it to other known isolates. Isolate HN01 has also been found to be susceptible to aminoglycosides, quinolones and sulfonamides drugs for veterinary use in aquaculture when screened against a range of common antibiotics. To the best of our knowledge, this is the first report of infectious intussusception syndrome caused by Hafnia alvei in farmed channel catfish.

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