Showing papers in "Aquaculture Research in 2009"
TL;DR: It is concluded that L. acidophilus can be used as a probiotic agent in African catfish culture, to enhance fish health, survival and better feed efficiency and growth performance.
Abstract: This experiment was carried out to evaluate the effects of the probiotic, Lactobacillus acidophilus, on the growth performance, haematology parameters and immunoglobulin concentration in African catfish Clarias gariepinus fingerling. Two experimental diets were formulated to contain 35 g kg−1 crude protein and 10 g kg−1 lipids accordingly and fed three times daily for 12 weeks to 25 C. gariepinus fingerlings per fibreglass tank in 12 replicates each. The control diet was prepared with no probiotic supplementation whereas the second diet was prepared supplemented with a probiotic, L. acidophilus, containing about 3.01 × 107 colonies/g of diet. The results show that growth performance [specific growth rate (SGR) and relative growth rate (RGR)], nutrient utilization [protein efficiency ratio (PER) and feed conversion ratio (FCR)] and survival were significantly (P 0.05). From the results of this experiment, we conclude that L. acidophilus can be used as a probiotic agent in African catfish culture, to enhance fish health, survival and better feed efficiency and growth performance.
213 citations
TL;DR: The data showed that dietary organic acids can exert strong anti-microbial effects and have the potential to exert beneficial effects on growth, nutrient utilization and disease resistance in tilapia.
Abstract: A 14-week feeding trial was conducted to determine the effects of dietary organic acids. The experimental diets were added with 0, 1, 2 or 3 g kg−1 of a novel organic acid blend or with 2 g kg−1 of potassium diformate and fed to triplicate groups of red hybrid tilapia (Oreochromis sp.). Upon completion, tilapia were challenged by immersion with Streptococcus agalactiae. There was no significant difference (P>0.05) in the growth, feed utilization and nutrient digestibility among treatment groups despite a trend towards improved results with fish fed organic acid-supplemented diets. Diet pH decreased, causing a reduction in the digesta pH of the stomach and gut. Total bacteria per gram of faeces were significantly (P<0.05) reduced from 1.81 × 108 colony-forming units (CFU) (control group) up to 0.67 × 108 CFU in the fish fed organic acid diets. A similar trend was observed for adherent gut bacteria. Cumulative mortality of fish fed no organic acids was higher compared with fish fed organic acid-supplemented diets at 16 days post challenge. The data showed that dietary organic acids can exert strong anti-microbial effects and have the potential to exert beneficial effects on growth, nutrient utilization and disease resistance in tilapia.
157 citations
TL;DR: Most faecal settling data used in published salmonid waste dispersal models are rudimentary and recent information suggests that such models are highly sensitive to this input, according to limited information on particle size, digestibility, settleable and non-settleable mass fractions of salmonid faeces at cage environments.
Abstract: Knowledge of the quantitative and qualitative properties of salmonid faeces is necessary for aquaculture waste dispersal models, and the design of integrated multi-trophic aquaculture (IMTA) systems. The amount and proximate composition of salmonid faeces can be estimated using a mass-balance, nutritional approach. Indigestible components of salmonid diets have the potential to aiect faecal‘cohesiveness’or ‘stability’. Nutrient content and density of faeces can vary depending on diet and submersion time. Faecal density has a greater in£uence on settling velocity than faecal size. Published settling velocity data on salmonid faeces are highly variable due to diierences in ¢sh size, rearing systems, collection time, water density, methodology, the mass fraction tested and diet. Most faecal settling data used in published salmonid waste dispersal models are rudimentary and recent information suggests that such models are highly sensitive to this input. The design of open-water IMTA systems and estimation of nutrient capture and recovery from co-cultured ¢lter feeders is di⁄cult due to limited information on particle size, digestibility, settleable and non-settleable mass fractions of salmonid faeces at cage environments. Implications of faecal properties on the accountability for the eiects of aquaculture nutrient loading are discussed.
156 citations
TL;DR: Spirulina supplement is promising as an alternative method to antibiotics for disease prevention in tilapia aquaculture, and the optimum level of Spirulina in the fish diet should be 5.0–10.0 g kg−1 diet.
Abstract: The use of antibiotics to control fish disease is one of the constraints in tilapia farming. Hence, the use of probiotic and live organisms as alternative strategies has received much more attention. This study was undertaken to evaluate the use of Spirulina (Arthrospir platensis) as a growth and immunity promoter for Nile tilapia, Oreochromis niloticus (L.). Fish (1.88 g) were randomly distributed at 20 fish per 100 L aquarium and fed a diet containing either 0.0, 1.25, 2.5, 5.0, 7.5 or 10.0 g Spirulina kg−1 diet for 12 weeks. After the feeding trial, fish of each treatment were challenged by pathogenic Aeromonas hydrophila, which was given by an interperitoneal injection, and they were kept under observation for 10 days to record any abnormal clinical signs and the daily mortality rate. The growth-promoting influence of Spirulina was observed with fish, and the optimum growth and feed utilization were obtained at 5.0 g Spirulina kg−1 diet. No significant changes were observed in fish survival among the different treatments. Spirulina supplementation improved the protein and lipid contents in fish bodies without significant differences among them, especially when fed 2.5–10.0 g kg−1 diet, but no significant differences in the moisture and ash contents were observed among different treatments. The physiological parameters were improved when fish were fed a Spirulina-enriched diet. However, the highest red blood cells, white blood cells and nitro blue tetrazolium values were obtained at 5.0–10.0 g Spirulina kg−1 diet; meanwhile, the lowest value was obtained in the control. Total fish mortality due to A. hydrophila infection decreased with an increase in the Spirulina level in fish diets. These results indicate that Spirulina supplement is promising as an alternative method to antibiotics for disease prevention in tilapia aquaculture, and the optimum level of Spirulina in the fish diet should be 5.0–10.0 g kg−1 diet.
124 citations
119 citations
TL;DR: Isolation and enumeration of amylase, cellulase and protease-producing autochthonous bacteria in the proximal intestine (PI) and distal intestine (DI) of three species of Indian major carps, catla (Catla catla), mrigal (Cirrhinus mrigala) and rohu (Labeo rohita), were investigated using the conventional culture-based technique.
Abstract: Isolation and enumeration of amylase, cellulase and protease-producing autochthonous bacteria in the proximal intestine (PI) and distal intestine (DI) of three species of Indian major carps, catla (Catla catla), mrigal (Cirrhinus mrigala) and rohu (Labeo rohita), were investigated using the conventional culture-based technique. Population levels of amylolytic strains were the highest in the PI of catla and the lowest in the DI of rohu. The highest viable count of cellulase and protease-producing bacteria was recorded in the DI and PI of mrigal respectively. Among the bacteria isolated, 10 strains (five from PI and five from DI) were selected as potent enzyme producers according to a quantitative enzyme assay. The chosen strains were further identified by 16S rRNA gene sequence analysis. The five strains isolated from catla showed high similarity to Citrobacter sp. clone W2, Enterobacter sp. JA24, Bacillus coagulans strain TR, uncultured bacterial clone Hel3bc04 and Bacillus cereus strain UST2006-BC004. The four strains isolated from mrigal were most closely related to Bacillus sp. KCd2, uncultured bacterial clone Hel3bd09, B. cereus strain BU040901-020 and Citrobacter freundii strain YRL11, while the strain isolated from rohu probably belonged to Bacillus sp. GV.
116 citations
TL;DR: Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin, and this beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology.
Abstract: The aim of this paper is to provide explanations of how dietary phospholipid (PL) globally improves fish larval development, including growth and survival, digestive functions and skeletal development, and to propose optimal PL levels and sources in fish larval diets. Dietary incorporation of 8–12% PL related to dry matter (d.m.) promotes growth and enhanced survival in various species. Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin. This beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology. Nevertheless, 1.5–2.5% highly unsaturated fatty acids related to diet d.m. supplied by PL improved growth, survival and skeletal development, while 5% induced different skeletal deformities. The high incidence of deformities was associated with the down-regulation of genes involved in development, such as RXRα, RARα, RARβ and BMP-4, observed in the early stages in larvae fed a high highly unsaturated fatty acids level.
113 citations
TL;DR: The study highlights the complexity of resident microbial communities that have not been fully explored in previous rainbow trout studies; this is especially true with probiotic/prebiotic investigations.
Abstract: Bacterial communities from the intestinal tract of rainbow trout were investigated to assess transient and resident microbial communities using both culture-based and culture-independent techniques. Viable counts attached to the intestinal mucosa were in the range of log 4.77–5.38 and log 6.67–6.79 CFU g−1 in the intestinal contents. Pseudomonas spp. and Enterobacteriaceae constituted nearly 80% of the allochthonous population but <60% of the autochthonous populations. This coincided with an elevated mucosal level of a group of Gram-positive rods from ∼2% in the digesta to 25–35% on the mucosa. This group was identified by 16S rRNA as Arthrobacter aurescens and Janibacter spp. HTCC2649. Analysis of denaturing gradient gel electrophoresis banding patterns showed complex communities in all intestinal regions. Similarity coefficients showed that mucosal communities were ∼70% similar to digesta communities and yet due to the presence of bands found uniquely either in the digesta or on the mucosa, the communities are distinctly different. Scanning electron microscopy confirmed mucosal bacterial populations and highlighted a possible localized colonization between mucosal folds. The study highlights the complexity of resident microbial communities that have not been fully explored in previous rainbow trout studies; this is especially true with probiotic/prebiotic investigations.
104 citations
TL;DR: Animals fed diet supplemented with bacilli and LAB had good survival and the best growth performance, suggesting that bacteria are appropriate growth-stimulating additives in tilapia cultivation.
Abstract: This study examined the eiect of potential probiotic bacteria on growth and survival of the tilapia Oreochromis niloticus, under high density and suboptimum temperature Presumptive Bacillus and lactic acid bacteria (LAB) were isolated from tilapia and from their culture system and were characterized for haemolytic and enzymatic activity, and antagonism against Vibrio Selected strains were included in the diet of juvenile tilapia and evaluated during a 134day assay The experiment was conducted with four treatments: (1) ¢sh fed with commercial feed plus Dry Oil s ; (2) ¢sh fed with commercial feed plus LAB; (3) ¢sh with bacilli in water; (4) ¢sh with a mixture of treatments 2 and 3 Tilapias in all treatments, including bacteria, grew signi¢cantly better than ¢sh fed with commercial feed plus Dry Oil s (control group) Survival was similar in all treatments The physicochemical parameters of the culture system were maintained within the optimal ranges for the species, with the exception of temperature (199^24821C) Animals fed diet supplemented with bacilli and LAB had good survival and the best growth performance, suggesting that bacteria are appropriate growth-stimulating additives in tilapia cultivation
96 citations
TL;DR: The white shrimp demonstrated a high capacity to utilize phosphorus in the ingredients, except that in MBM, for which the availability of some amino acid was lower, possibly due to protein damage during processing.
Abstract: Apparent digestibility coefficients of dry matter (DM), crude protein, crude lipid, gross energy, phosphorus and amino acids in Peruvian fish meal (FM), fermented soybean meal, extruded soybean meal, soybean meal, peanut meal, wheat gluten meal, corn gluten meal, shrimp byproduct meal, meat and bone meal (MBM), poultry meat meal and plasma protein meal (PPM) were determined for white shrimp (Litopenaeus vannamei). A reference diet (RF) and test diets (consisting of 70% RF diet and 30% of the feedstuff) were used with 0.5% chromic oxide as an external indicator. A total of 1440 shrimp (initial mean body weight 1.05 ± 0.01 g) were randomly stocked into thirty-six 500-L fibreglass tanks with 40 shrimp per tank and three tanks per diet. Faeces were collected from triplicate groups of shrimp by a faecal collection vessel attached to the shrimp-rearing tank. The shrimp were fed to apparent satiation four times a day and the feeding experiment lasted for 6 weeks. Statistics indicate that apparent DM digestibilities for white shrimp (L. vannamei) were the highest for FM, ranged 52.83–71.23% for other animal products and 69.98–77.10% for plant products. The protein and lipid from plant and animal sources were well digested by white shrimp. Apparent protein and lipid digestibility were in the range 87.89–93.18% and 91.57–95.28%, respectively, in plant products, and 75.00–92.34% and 83.72–92.79%, respectively, for animal products. The white shrimp demonstrated a high capacity to utilize phosphorus in the ingredients. The apparent phosphorus digestibility ranges of animal feedstuffs and plant feedstuffs were 58.90–71.61% and 75.77–82.30% respectively. Amino acid availability reflected protein digestibility, except that in MBM, for which the availability of some amino acid was lower, possibly due to protein damage during processing. Digestibility information could promote the use of ingredient substitution in least-cost formulated diets for white shrimp.
93 citations
TL;DR: β-(1,3) glucan and whole cell yeast protect the fish from pathogens by enhancing the cellular and humoral immune response in C. carpio.
Abstract: The effects of dietary β- (1,3) glucan and whole cell yeast (Sacharomyces uvarum) on the immune response and disease resistance to Aeromonas hydrophila were investigated in Cyprinus carpio. β-(1,3) glucan was extracted from the yeast. Both β-(1,3) glucan and whole yeast were incorporated into the diet at 1% level and fed to common carp C. carpio for a period of 60 days. Control and treated fish were exposed to A. hydrophila on the 30th and the 60th day of the experimental period. Dietary supplementation of glucan significantly increased the white blood cell count in fish on the 60th day (2.91±0.04 × 104), and the highest nuetrophil nitro blue tetrazolium (NBT) activity was also observed in glucan-fed fish (30th day). A consistent increase in neutrophil (NBT) activity was also observed in whole cell fed fish until the end of the experiment. Similarly, β-(1,3) glucan and whole cell yeast enhanced the serum lysozyme activity from the 15th day onwards but higher activity was reported on the 30th day in glucan and the 60th day in whole cell yeast-fed fish. Suplementation of β-(1,3) glucan protected the fish from A. hydrophila infection. Nearly 75–80% of the fish survived pathogen exposure (relative percentage survival). However, only 54–60% survival was observed in the whole cell-fed fish. β-(1,3) glucan and whole cell yeast protect the fish from pathogens by enhancing the cellular and humoral immune response in C. carpio.
TL;DR: Inositol improved growth, digestive capacity and intestinal microbial population of juveniles Jian carp, and the dietary inositol requirement for PWG of juvenile Jian carp is 518.0 mg MI kg−1 diet.
Abstract: A 60-day feeding trial was carried out with juvenile Jian carp (Cyprinus carpio var. Jian) to study the effects of myo-inositol (MI) on the growth, digestive enzyme and intestinal microbial population. Diets with seven levels of inositol (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3 mg MI kg−1 diet) were fed to Jian carp (initial weight 22.28±0.07 g). Per cent weight gain (PWG) was improved with increasing inositol levels up to 535.8 mg MI kg−1 diet (P 0.05). The protein production value, lipid production value and ash production value were increased with increasing dietary inositol levels up to 384.2, 838.8 and 838.8 mg MI kg−1 diet respectively (P 0.05), chymotrypsin, lipase and amylase activities in intestine were the lowest for fish fed the MI-unsupplemented diet (P<0.05). Alkaline phosphatase, Na+, K+-ATPase, γ-glutamyl transpeptidase and creatinkinase activities in the intestine were increased with an increase in the inositol levels up to 384.2–687.3 mg MI kg−1 diet (P<0.05). Intestinal Aeromonas hydrophila and Escherichia coli decreased with an increase in the levels of dietary inositol up to 232.7 and 687.3 mg MI kg−1 diet respectively (P<0.05), while Lactobacillus in the intestine increased with an increase in inositol levels up to 990.3 mg MI kg−1 diet (P<0.05). In conclusion, inositol improved growth, digestive capacity and intestinal microbial population of juvenile Jian carp, and the dietary inositol requirement for PWG of juvenile Jian carp is 518.0 mg MI kg−1 diet.
TL;DR: The results showed that applications of the probiotics resulted in no significant difference in the SGR and survival of the prawns, but significantly decreased the food conversion ratios compared with the control where no probiotics were applied.
Abstract: The effects of two selected probiotics (Pseudomonas synxantha and Pseudomonas aeruginosa) on the specific growth rate (SGR), survival and immune parameters of juvenile western king prawns (Penaeus latisulcatus) were examined for 84 days. Pseudomonas synxantha and P. aeruginosa were either applied into the rearing medium or supplemented in the formulated feed at a concentration of 105 colony forming unit (CFU) mL−1 for each probiotic. The results showed that applications of the probiotics resulted in no significant difference (P>0.05) in the SGR and survival of the prawns, but significantly decreased the food conversion ratios (P<0.05) compared with the control where no probiotics were applied. The supplement of the probiotics with the formulated feed enhanced the probiotic numbers in the intestines of the prawns and low bacteria numbers in the haemolymph. The prawns were significantly (P<0.05) healthier, as indicated by the immune response obtained when both probiotics were given in combination compared with when individual probiotics were used. When applied singly, P. aeruginosa resulted in a higher health status of the prawns compared with P. synxantha. Overall, equal combinations (105 CFU mL−1) and volumes of P. synxantha and P. aeruginosa used as a supplement in the formulated feed resulted in an improvement in the health of the juvenile western king prawns.
TL;DR: It can be concluded that dietary supplementation of MOS at a 1% dietary level promotes growth and survival and higher inclusion levels of immunostimulants led to an immunosuppressive effect in L. rohita fingerlings.
Abstract: The present study was conducted for 60 days to delineate the efficacy of various dietary immunomodulators like mannan oligosaccharide (MOS), yeast extract (YE), protein hydrolysate (PH) and chlorella (CL) in Labeo rohita fingerlings. Five hundred and eighty-five L. rohita fingerlings (average weight: 4.15 ± 0.07 g) were randomly distributed in 13 treatment groups with each of three replicates. Thirteen semi-purified isonitrogenous (crude protein 324.7–332.5 g kg−1) and isocaloric (17.66–17.80 MJ kg−1) diets were prepared with three graded levels (1%, 2% or 4%) of immunostimulants, except the control. At the end of the feeding trial, weight gain%, specific growth rate, feed conversion ratio, leucocyte count, erythrocyte count, haemoglobin content, serum protein, globulin, albumin–globulin ratio, nitroblue tetrazolium (NBT) value and survival percentage were evaluated. Growth was significantly higher in the MOS-fed group. All the immune parameters studied were also recorded higher in the MOS 1%-supplemented group. The survival percentage after challenging with Aeromonas hydrophila was higher (P<0.05) in the MOS-, YE- and PH-fed groups and the lowest in the CL-treated group. It can be concluded that dietary supplementation of MOS at a 1% dietary level promotes growth and survival in L. rohita fingerlings. In contrast, higher inclusion levels of immunostimulants led to an immunosuppressive effect in L. rohita fingerlings.
TL;DR: Eugenol-based anaesthetics appear to be promising as a stress-reducing sedative for Atlantic salmon smolts, and, if used properly, this chemical could improve animal welfare and survivability during and after common aquaculture-related incidents.
Abstract: The purpose of this study was to determine the eiect of clove oil (4.0 mg L � 1 ) sedation, compared with nonsedation, on the primary (plasma cortisol), secondary (osmoregulation) and tertiary (mortality) stress responses in Atlantic salmon smolts during transport and transfer to sea. Clove oil sedation during on- and oi-loading su⁄ciently reduced the primary stress response to lower mortality (2.1%) during transfer to sea compared with unsedated ¢sh, which experienced a mortality rate above 12.2%. The unsedated ¢sh experienced an acute mortality that stabilized only 6 days after the transport. None of the secondary stress responses measured in this experiment could contribute towards explaining this phenomenon, with the possible exception of plasma magnesium (Mg 21 ). Plasma Mg 21 diiered between the groups; while plasma Mg 21 in the clove oil sedated group returned to pre-stress levels 72 h after transport, the unsedated group showed no such recovery even 1 week after transport, which may indicate a disturbance in the hydromineral balance, and provides a plausible explanation for the delayed mortality in this group. Eugenol-based anaesthetics appear to be promising as a stress-reducing sedative for Atlantic salmon smolts, and, if used properly, this chemical could improve animal welfare and survivability during and after common aquaculture-related incidents.
TL;DR: It was concluded that dietary administration of Ergosan can influence some growth and haematological parameters in great sturgeon, H. huso juveniles.
Abstract: Growth performance, carcass quality, survival and haematological responses were determined when Huso huso juvenile (41.7±1.8 g) fed diets containing Ergosan (an algal product) at 0, 2.0, 4.0 and 6.0 g kg−1 for 60 days. Each diet was fed to triplicate groups of fish at 10-day intervals (1–10, 20–30 and 40–50 with non-supplemented diets and 10–20, 30–40 and 50–60 with supplemented diets). Results showed that fish fed diets containing Ergosan had significantly higher growth than the control group (P 0.05). Food conversion ratio in the fish fed a diet containing 4.0 and 6.0 g kg−1 Ergosan was significantly better than the other treatments (P 0.05) but body protein in the fish fed a diet containing Ergosan at the level of 2.0 and 4.0 g kg−1 was higher than the other treatments. Whole body ash content was higher in the control group. It was concluded that dietary administration of Ergosan can influence some growth and haematological parameters in great sturgeon, H. huso juveniles.
TL;DR: Higher dietary starch levels (32-40%) significantly decreased the growth of gibel carp in the present study.
Abstract: An 8-week growth trial was carried out in a semi-recirculation system to investigate the effect of high dietary starch levels on the growth performance, blood chemistry, starch utilization and body composition of gibel carp (Carassius auratus var. gibelio). Five isonitrogenous and isocarloric experimental diets were formulated to contain different starch levels (24%, 28%, 32%, 36% and 40% respectively). Triplicate groups of fish (24 fish per tank with an average body weight, of 8.5 g) were assigned to each diet. The results showed that dietary carbohydrate levels significantly affected the growth performance, hepatopancreatic lipid content, pyruvate kinase (PK) activity and whole-body lipid content. Growth performance, body crude lipid and plasma glucose concentrations showed a decreasing trend with an increase in dietary starch from 24% to 40%. Pyruvate kinase activities and hepatopancreatic lipid content showed an increasing trend with the dietary starch increasing from 24% to 32%, and then a decreasing trend with the dietary starch increasing from 32% to 40%. No significant difference in the hepatopancreatic hexokinase (HK) activity, plasma triglyceride contents, body crude protein, ash and calcium (Ca) and phosphorus (P) contents was observed between different treatments. In conclusion, higher dietary starch levels (32-40%) significantly (P < 0.05) decreased the growth of gibel carp in the present study.
TL;DR: The observed results are able to conclude that the probiotic Efinol®L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes.
Abstract: The objective of this experiment was to test the probiotic Efinol®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz). For the transportation, fish were distributed in 18 plastic tanks, of which nine contained the Efinol®L (10 mg L−1; probiotic treatment) and the remaining had no probiotic (control treatment). Transport lasted 24 h and three different boxes of each treatment were sampled at 3, 12 and 24 h. Up to the 12-h sampling period, no significant difference in the survival was observed; on the other hand, survival was higher at the end of the transport (24 h) in the probiotic treatment. No significant difference was found in dissolved oxygen and temperature between treatments. Conductivity, pH and alkalinity increased along the transport, but without a difference between treatments. Ammonia increased in all treatments, although it was significantly lower in the probiotic group at 24 h. Cortisol levels were significantly higher in all transported fish when compared with the basal values. At 24 h, cortisol levels in control fish were significantly higher than those in the probiotic treatment. With the observed results, we are able to conclude that the probiotic Efinol®L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes.
TL;DR: Three candidate probiotics, Bacillin foraminis, Bacillus cereus biovar toyoi and Bacillus fusiformis, were isolated from hydrogen-producing fermented solution and identified using 16S rRNA sequence analysis and continuously applied in the larviculture system of Litopenaeus vannamei.
Abstract: Three candidate probiotics, Bacillus foraminis, Bacillus cereus biovar toyoi and Bacillus fusiformis, were isolated from hydrogen-producing fermented solution and identified using 16S rRNA sequence analysis. Bacillus foraminis and B. cereus biovar toyoi exhibited strong antagonism against Streptococcus iniae and Photobacterium damselae subsp. piscicida in in vitro co-culture for competitive exclusion assay and then were conducted in the larviculture system of Penaeus monodon reared from zoea 1 to postlarva 1. The daily addition of B. cereus biovar toyoi resulted in significantly deleterious effects on survival (P<0.01) whereas the daily addition of B. fusiformis showed highest survival rate (88.7±0.7%) but no statistically significant difference from control (73.3±12.1%). Bacillus fusiformis was continuously applied in the larviculture system of Litopenaeus vannamei. Administration of B. fusiformis significantly increased survival (P<0.01) in both treatments added daily (87.9±1.7%) and every other day (54.7±1.2%), respectively, at a concentration of 105 CFU mL−1 over control (41.2±1.3%).
TL;DR: Mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish, opening up the possibility of using them to evaluate stress in fish.
Abstract: Plasma cortisol is the most commonly used indicator of stress in fish but, as the blood sampling procedure itself can be a source of stress, it would be helpful to measure cortisol using less invasive matrices. It is also necessary to find alternative matrices as stress indicators in dead fish in which blood sampling is impossible. In the present study, we investigated transport stress in three aquaculture species, European sea bass (Dicentrarchus labrax L.), common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin mucus, gut content, lateral muscle and caudal fin). Cortisol significantly increased after transport in all species and matrices, except in the sea bass gut content, where it remained unchanged. The three species responded to transport stress by producing different cortisol levels. In conclusion, the significant correlation found between plasma cortisol and most of the other matrices opens up the possibility of using them to evaluate stress in fish: mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish.
TL;DR: This studyamines the viability of replacing ¢sh meal inshrimp production diets with alternative proteinsources (combinations of vegetable proteins) in in-land low salinity waters of west Alabama and suggests that PM, pea meal and DDGS can serve as alter-natives to ¢ sh meal as a protein source for shrimpreared in lowsalinity environments.
Abstract: The replacement of marine proteins with vegetableproteins orterrestrialanimalbyproductsinaquacul-ture diets has been gaining momentum. This studyexamines the viability of replacing ¢sh meal inshrimp production diets with alternative proteinsources (combinations of vegetable proteins) in in-land low salinity waters of west Alabama. The testdiets were formulated to contain 36% protein and8% lipid.Thebasaldietcontained10% ¢sh meal.The¢sh meal was then replaced (on a weight to weightbasis) with poultry meal (PM), pea meal or distiller’sdried grain with solubles (DDGS). Two separate ex-periments (laboratory trial and farm trial) were de-vised to test the e⁄cacy of the diets for Litopenaeusvannamei reared in low salinity waters. The labora-tory trial was conducted at the E.W. Shell FisheriesResearchStationinAuburn,Alabama,USA,whereasthefarmtrialexaminedthesamedietsinanoutdoor£ow-throughsystematalowsalinityshrimpfarm inwest Alabama. Results indicate no signi¢cant diier-encesinshrimpgrowth,weightgain,survivalorfeedconversion ratio among dietary treatments, suggest-ing that PM, pea meal and DDGS can serve as alter-natives to ¢sh meal as a protein source for shrimpreared in lowsalinityenvironments.Keywords: poultry meal, distiller’s dried grainwithsolubles,peameal,lowsalinity,¢shmeal,Lito-penaeusvannameiIntroductionFarmers of the Paci¢c white shrimp Litopenaeus van-nameiin inland lowsalinity wellwaters (LSWW) arefaced with the challenge of rearing animals in lessthan ideal environments (Saoud, Davis & Rouse2003; Roy, Davis, Saoud & Henry 2007a,b). Depend-ingontheirsource,inlandLSWWavailabletocultureshrimp can be of varied ionic composition and sali-nity (Boyd & Thunjai 2003; Saoud et al. 2003). Ionicimbalances, which are often found in LSWW, cangenerallybe solvedthroughadditionsof speci¢c ions(e.g. K and Mg) to culture water (McGraw & Scarpa2003; Roy etal.2007a).CommercialfarmersutilizinginlandLSWWare mitigating theproblemby increas-ing levels of Kand Mg in their pond waters throughthe addition of muriate of potash and/or KMag(McNevin, Boyd, Silapajarn & Silapajarn 2004). Un-fortunately,addinglargeamountsofagriculturalfer-tilizers to ponds is an additional expense to inlandfarmers. Increased production costs, competitionfromforeignmarketsandtheincreasingcostofdieselfuelareadditional burdens onfarmers.The cost of feed generallyaccounts for 50^60% oftotal production costs and, thus, west Alabamashrimpfarmers are interested in reducing feed costs.One strategy to reduce feed costs is by reduction in¢sh meal with alternative plant and animal proteinsources.Fishmealis consideredamongthemostsui-table protein sources for shrimp feeds. In spite of itsimportance, a considerable reduction in the use of¢sh meal is expected in the near future. Among thechief concerns include limited availability, variablesupply and cost. Given the growing demand by ani-mal production industries for ¢sh meal and its lim-ited supply, prices are likely to continue to increase,therefore, restraining future use as the main proteinsource in shrimp feeds. Likewise, emerging environ-mental and safety issues associated with the use of
TL;DR: The highest phytase activity was observed in the bacterial strains LF1 and LH1 isolated from the fore and the hindgut regions of rohu respectively, and both the strains were identified as Bacillus licheniformis on the basis of phenotypic characteristics as well as 16S rDNA sequence analysis.
Abstract: Isolation and enumeration of phytase-producing bacterial flora in the foregut and hindgut regions of the gastrointestinal tracts of 10 culturable freshwater teleosts of different feeding habits, namely rohu (Labeo rohita), catla (Catla catla), mrigal (Cirrhinus mrigala), bata (Labeo bata), kalbasu (Labeo calbasu), Nile tilapia (Oreochromis niloticus), climbing perch (Anabas testudineus), common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and grass carp (Ctenopharyngodon idella), have been carried out. Microbial culture of the gut mucosa on selected nutrient media following the enrichment culture technique was performed for bacterial isolation. The bacterial isolates were screened on the basis of their enzyme-producing ability. The bacterial population on the tryptone soya agar (TSA) plate was maximum in the hindgut region of bata, followed by mrigal and minimum in the foregut region of Nile tilapia. In modified phytase screening medium (MPSM), phytase-producing strains were recorded at higher densities in the foregut region of mrigal and grass carp and minimum in the foregut region of bata. In case of the hindgut, maximum phytase-producing strains were present in grass carp and mrigal and minimum in rohu. In general, in MPSM, the bacterial population was lower in the hindgut region of all the 10 species of fish examined. The phytase-producing ability of the selected 31 strains (16 from the foregut and 15 from the hindgut region) was determined by clearing zones on phytate-containing plates. Among these isolates, 22 strains (12 from the foregut and 10 from the hindgut region) were selected as potent phytase producers according to a quantitative enzyme assay. The highest phytase activity was observed in the bacterial strains LF1 and LH1 isolated from the fore and the hindgut regions of rohu respectively. Both the strains were identified as Bacillus licheniformis on the basis of phenotypic characteristics as well as 16S rDNA sequence analysis.
TL;DR: The results suggested that MI could inhibit oxygen radical generation, increase enzymatic antioxidant capacity and prevent oxidative damage of carp.
Abstract: This study was conducted to evaluate the effects of dietary myo-inositol (MI) on the antioxidant status of juvenile Jian carp (Cyprinus carpio var. Jian). A total of 1050 Jian carp (22.28±0.07 g) were randomly distributed into seven groups of three replicates each, feeding diets containing graded levels of MI (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3 mg kg−1 diet) for 60 days. Results indicated that the malondialdehyde content was the lowest for fish fed diets containing ≥384.2 mg MI kg−1, and the highest for fish fed the MI-unsupplemented basal diet (P<0.05). The protein carbonyl content was decreased with increasing dietary MI levels up to 535.8 mg kg−1 diet, and no differences were found with a further increase in the MI concentration. The anti-superoxide anion capacity (ASA) and anti-hydroxyl radical capacity (AHR) were increased with increasing MI levels up to 535.8 mg kg−1 diet, and plateaued thereafter. The superoxide dismutase and glutathione-S-transferase activities showed the same tendency with the ASA capacity. Catalase, glutathione peroxidase and glutathione reducase activities were improved with increasing MI levels up to 838.8, 384.2 and 687.3 mg kg−1 diet, respectively, and remained nearly constant thereafter. These results suggested that MI could inhibit oxygen radical generation, increase enzymatic antioxidant capacity and prevent oxidative damage of carp. Dietary MI requirements for ASA and AHR activities of juvenile Jian carp were 567.94 and 517.22 mg MI kg−1 diet respectively.
TL;DR: It is indicated that intramuscular administration of the tri-herbal compound Az+Ca+Cu at a concentration of 100 ppm could augment the immune response in C. mrigala against A. invadans in vitro.
Abstract: The antibacterial activity of individual and mixed medicinal plant compounds, azadirachtin (Az), camphor (Ca) and curcumin (Cu), was tested at 100, 200, 300, 400, 500, 600 and 700 ppm (mg L−1) against fungal fish pathogen, Aphanomyces invadans, in vitro. At the lower concentrations between 100 and 300 ppm, the mixture of the tri-herbal (Az+Ca+Cu) compound yielded a higher (P>0.05) zone of inhibition (ZI) of 7 mm than the positive control; the maximum ZI values (8–15 mm) were realized between 400 and 700 ppm (P<0.05). At the lowest minimum inhibitory concentration (MIC) the tri-herbal compound (100 ppm) yielded 13 colony-forming units; hence, this dose can be effectively used at the lowest concentration of 100 mg L−1 to ward off the growth of A. invadans in vitro. In Cirrhina mrigala, intramuscular administration (100 μL) of the selected doses of 100, 400 and 700 ppm (mg L−1) significantly enhanced (P<0.05) the serum lysozyme activity (Ly), production of reactive oxygen species and reactive nitrogen species (RNS or NO) by peripheral blood leucocytes on the 10th, 20th and 30th day. A priori administration of the compound in the fish (100 ppm on 30th day) decreased the percentage mortality when challenged with the pathogen while in the untreated group the mortality increased (P<0.05). This study indicates that intramuscular administration of the tri-herbal compound Az+Ca+Cu at a concentration of 100 ppm could augment the immune response in C. mrigala against A. invadans.
TL;DR: The use of increasing levels ofbrown propolis extract (BPE) as a growth promoter in Nile tilapia ¢ngerling feeds and the results in-dicatethepotentialtousethebrownpropolis extract asagrowthpromoter toNiletilapia¢ngerlings are assessed.
Abstract: This study assessed the use of increasing levels ofbrown propolis extract (BPE) as a growth promoterin Nile tilapia ¢ngerling feeds. In a complete rando-mizeddesign,75 Nile tilapia ¢ngerlings with 60 daysonaverageandweighing4.1 0.1gwereassignedto25 aquaria (60L) and subjected to 5 treatments in5 repetitions for 30 days. Propolis from SerradoAra-ripe, Cariri Region, South CearaŁ State ^ Brazil wasused to produce the BPE. The treatments involvedthe addition of BPE to feed samples (0.91, 1.83, 2.74and3.65gkg 1 ) and feed control (without BPE).The¢nal meanweightandthepercentage of weightgainvaried quadratically with the increase in BPE(Po0.01),withamaximumof2.22gkg 1 .Theotherevaluated parameters were not aiected by the treat-ments (P40.05).The level of best performance para-meters was 2.22gkg 1 , between the levels of 1.83and 2.74gBPEkg 1 feed inclusion.These results in-dicatethepotentialtousethebrownpropolis extractasagrowthpromoter toNiletilapia¢ngerlings.Keywords: aquaculture, feed additive, ¢sh nutri-tion,OreochromisniloticusIntroductionFishculturehasbeenthefocusofconsiderableatten-tion in Brazil due to its great potential all over thecountry, due to the appropriate climate, large avail-abilityof waterand the excellent nutritionalvalue of¢sh in general. The species most cultivated include¢shofexoticoriginsuchastheNiletilapia,Oreochro-misniloticus.Despitethelow rainfall inthe Semi-AridNortheast,this region has aneconomic potential for ¢shculture.Thepresenceofsomerivers,particularlytheSaoFran-cisco River and its dams, irrigation canals and lakes,presentssuitableconditionsfordevelopingsystemsfor¢shproduction.Theclimate,favourableforthecultureoftropical¢sh,andtheproximitytothesitesknownasproducers of raw materials and manufacturers of ¢shfeeds (West of Bahia State) are alsopositive factors forthedevelopmentof¢shcultureintheregion.Fromthesocialviewpoint,¢shculturemaybecomean important source of income for the local popula-tion, particularly thoselivingonriverbanks, throughboth large¢rmsandsmallproductionassociationsorlocal cooperatives. The culture of exotic ¢sh species,suchastheNiletilapia,isanimportantregionalalter-nativeasitsculturetechniqueisfullymastered.Fishdiseases causelosses in ¢shculture, thus hin-deringeconomicaldevelopment(Gram,Melchiorsen,Spanggard,Hubner&Nielsen1999).InBrazil,theoc-currence of pathologies in ¢shculture has increasedwith the intense growth (Costa 2003), especiallypathologies caused byAeromonasgenusbacteria.Growth promoters that result neither in bacterialresistance norleave residues in ¢sh £esh have driventhe research towards natural products. Investiga-tionsoftheantibioticpropertiesofpropolishavebeen
TL;DR: It is indicated that dietary pyridoxine supplementation at 100 mg PN kg−1 diet reduces the endosulfan-induced stress and triggers immune response in L. rohita fingerlings.
Abstract: A 60-day experiment was carried out to delineate stress mitigating and immunomodulatory role of dietary pyridoxine (PN) in Labeo rohita fingerlings exposed to endosulfan. Two hundred and seventy fingerlings were randomly distributed into six treatments in triplicates. Five iso-caloric and iso-nitrogenous purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T0 (10 mg PN+without endosulfan), T1 (0 mg PN+endosulfan), T2 (10 mg PN+endosulfan), T3 (50 mg PN+endosulfan), T4 (100 mg PN+endosulfan) and T5 (200 mg PN+endosulfan). The role of pyridoxine on stress mitigation and immunomodulation was assessed by biochemical and haemato-immunological parameters like aspartate aminotransaminase, alanine aminotransaminase, lactate dehydrogenase, malate dehydrogenase, superoxide dismutase and catalase were significantly (P<0.05) lower while acetylcholinesterase was significantly (P<0.05) higher in pyridoxine-fed groups. Erythrocytes count, haemoglobin content and total serum protein, albumin, globulin, nitroblue tetrazolium and lysozyme activity were significantly (P<0.05) higher while cortisol and blood glucose were decreased significantly (P<0.05) in pyridoxine-fed groups. Percentage survival after challenge with Aeromonas hydrophila was highest in T0 group. The results obtained in present study indicate that dietary pyridoxine supplementation at 100 mg PN kg−1 diet reduces the endosulfan-induced stress and triggers immune response in L. rohita fingerlings.
TL;DR: Using macroalgae meal in rainbow trout diets do not enhance the quantity of protein and lipid contents at muscle level but an addition of 3–6% might contribute to increase the level of PUFAs, specially EPA, DHA and LIN.
Abstract: The use of macroalgae as an additional component in animal feeding has been studied. However, information on how it could influence muscle composition of fish body is scarce. This study evaluates four diets with different macroalgae inclusion levels (0%, 1.5%, 3% and 6%) to test the effect on body fatty acid composition of rainbow trout. Tanks with a volume of 600 L were stocked with 60.6 ± 7.9 g fish at a density of 45 individuals tank−1 and fed for 124 days. At the end of the experiment there were not significant differences (P<0.05) in muscle proximate composition among fish fed the different treatments. However, it was determined that inclusion of 3% and 6% of macroalgae meal resulted in a significant increase (P<0.05) of polyunsaturated fatty acids (PUFAs) in muscle. In summary, macroalgae meal in rainbow trout diets do not enhance the quantity of protein and lipid contents at muscle level but an addition of 3–6% might contribute to increase the level of PUFAs, specially EPA, DHA and LIN. Thus, use of macroalgae meal might help to increase lipid quality content in the final product due the beneficial effects of PUFAs for human health.
TL;DR: In this article, the Leuciscus idus L. was collected from five experimental groups, and selected parameters of its quality were analysed for 36-h (group II), 60-h, 60-hour, 84-hour and 108-hour periods, respectively.
Abstract: Milt of the Leuciscus idus L. was collected from five experimental groups, and selected parameters of its quality were analysed for 36 h (group II), 60 h (group III), 84 h (group IV) and 108 h (group V), respectively, after hormonal stimulation with Ovopel (1 granule kg−1 of body weight). The control (group I) fish were not subjected to hormonal stimulation. The highest milt volume was obtained from the fish in group IV (0.70 ± 0.55 mL), where the largest volume of milt expressed per kilogram was also obtained (3.03 ± 1.94 mL kg−1). Significant differences were also found in milt volumes obtained between group I and groups III (P<0.01) and IV (P<0.05). The highest percentage of motile spermatozoa was found in the milt of group IV (59%); significant differences were found between group I and groups II (P<0.01) and III (P<0.001). The value of osmotic pressure of seminal plasma was the highest in group IV (203.19 ± 37.63 mOsm kg−1), and the lowest in group I (118.31 ± 41.13 mOsm kg−1). Parameters determining milt quality and quantity indicate that the period of 60–84 h after hormonal stimulation with Ovopel is optimal for obtaining milt from ide.
TL;DR: The values determined in the present study suggested that internal organs and tissues of perch were slightly altered by MS 222, clove oil and 2-phenoxyethanol anaesthesia, but not by Propiscin anaesthesia.
Abstract: This study investigated the feasibility of using clove oil, 2-phenoxyethanol, or Propiscin as an alternative to tricaine methane sulphonate (MS 222) as a fish anaesthetic, particularly in regard to reducing fish stress. The biochemical blood profiles of perch Perca fluviatilis L. anaesthetized with either MS 222 (100 mg L⁻¹), clove oil (33 mg L⁻¹), 2-phenoxyethanol (0.40 mL L⁻¹) or Propiscin (1.0 mL L⁻¹), and a non-anaesthetized control group were compared. Biochemical profiles were determined from blood samples collected before treatment in controls. For each anaesthetic tested, fish were divided into two groups, one sampled immediately after 10-min anaesthesia and a second, sampled 24 h after 10-min anaesthesia. The values determined in the present study suggested that internal organs and tissues of perch were slightly altered by MS 222, clove oil and 2-phenoxyethanol anaesthesia, but not by Propiscin anaesthesia.
TL;DR: E egg characteristics, oocyte surface ultrastructure and histology of larval ontogenesis until whole yolk resorption were described for the first time for this species, indicating a need for exogenous feeding in R. quelen culture and management.
Abstract: The silver cat¢sh, Rhamdia quelen, is endemic to North, Central and South America with high aquaculture potential and wide acceptance in the market. Breeder ¢sh were subjected to induced reproduction through hypophysation using a crude common carp pituitary extract. Egg characteristics, oocyte surface ultrastructure and histology of larval ontogenesis until whole yolk resorption were described for the ¢rst time for this species. Oocytes and semen were obtained by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators at 241C. The embryonic development was monitored using a stereomicroscope every 10 min until hatching. To analyse the larval development, larvae samples were collected from incubators daily until the ¢fth day, ¢xed in Bouin’s £uid and subjected to routine histological techniques. The oocyte extrusion occurred 8 h after the second hormone dose at 261C. The oocytes were spherical, non-adhesive and yellow, with a diameter of 1471.75 � 47.63 mm. Scanning electron microscopy revealed a thin jelly coat covering the zona radiata in the animal pole around the micropyle. The blastopore closure occurred within 8 h after fertilization, and the fertilization rate was 79.9 � 5.2% at 24 1C. Embryonic development was completed within 25 h 30 min after fertilization. The complete resorption of the yolk and the formation of the digestive system organs and the mouth opening occurred on the ¢fth day, indicating a need for exogenous feeding. The results of this study provide information important for improvement in R. quelen culture and management.