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Feeding trials with Anguilla marmorata during the nursery culture were conducted to establish optimized protocols for transitioning from live to formulated diets. This study evaluated different weaning schemes over three phases of the nursery culture: from live feed (Artemia) to raw fish meat-based mash (FMT), from FMT to dry fish meal-based mash (FML), and from FML to dry formulated crumble diet. Specific growth rate (SGR), percent weight gain (%WG) and survival of A. marmorata elvers were assessed across treatments. The optimized weaning scheme for transitioning A. marmorata glass eel feeding from Artemia to FMT requires a 6.25% reduction of live feed daily for 16 days, resulting in the highest growth performance (SGR=4.49, %WG=109.25%) and survival (98.37%). Dietary transition from FMT to FML feeding, a 5% daily reduction of FMT with FML, over 20 days was found optimal. This treatment yielded superior growth performance with an SGR of 1.59, %WG of 68.80%, and survival of 62.00% (p<0.05). The final phase, transitioning from FML to a formulated crumble diet, was optimized with a 25% daily reduction of FML over 4 days. Elvers on this feeding regime exhibited the highest growth (SGR=2.49, %WG=41.81%) and survival (100.00%). These weaning protocols effectively facilitated the dietary transition of A. marmorata during the nursery stage from live feed to dry-formulated diets within a 40-day period, enhancing the growth and survival of A. marmorata cultured in the brackish water nursery system. [ABSTRACT FROM AUTHOR]

Experiments were conducted to optimize transport conditions of nursery-reared juvenile milkfish in a closed-bag transport system. Combined effects of temperature (25°C–27°C, 20°C–22°C, and 15°C–17°C) and anesthetics (2-phenoxyethanol at 80 mgL−1 for transport sedation) on the survival of juvenile milkfish, Chanos chanos, were evaluated. Another experiment evaluated transport densities of 200, 400, 600, 800, and 1,000 gL-1 for 4-, 8-, 12-, 16-, and 20-h duration. The study showed that a temperature of 20°C–22°C in combination with anesthetic (2-phenoxyethanol) application was the optimum condition for long-duration confinement of milkfish juveniles in transport bags. Milkfish density of 600 gL−1 was found to be optimum for 12 h, 400 gL−1 for 16 h, and 200 gL−1 for 20 h of transport duration. These results provide a practical protocol for the high-density transport of juvenile milkfish from nursery to the growout production facilities. [ABSTRACT FROM AUTHOR]

The present study evaluated the influence of acidic polysaccharide extracted from Sargassum polycystum (SAPE) on growth, immunological responses and resistance to Vibrio harveyi infection of juvenile Penaeus monodon. Five experimental diets supplemented with 100, 500, 1000 and 1500 mg/kg SAPE including a control (0 mg/kg) were formulated and fed to juvenile P. monodon for 50 days. Following the feeding trial growth indices including weight gain and specific growth rate were significantly enhanced, (P < 0.05), in treatment groups fed with diets containing 2000 mg/kg SAPE. Highest survival (46.67±11.54%, P < 0.05) following the infection challenge test with the pathogenic V. harveyi was observed in the treatment group receiving the 2000 mg/kg SAPE supplementation while all shrimp died in the group receiving the control diet. The enhanced resistance to bacterial infection of SAPE treatment groups was further supported by improved immune responses (P < 0.05) including total hemocyte counts and serum antibacterial activities. The present study indicates that dietary supplementation of acidic polysaccharide extracted from Sargassum polycystum at a dose of 2000 mg/kg could enhance growth performance, elevate immune responses and significantly improve resistance of juvenile P. monodon against V. harveyi infection. [ABSTRACT FROM AUTHOR]

The present study evaluated the potential of squid by-product hydrolysate as fishmeal replacement in the plant-based diet of juvenile black tiger shrimp, Penaeus monodon Fabricius, 1798. Five experimental plant protein-based diets were formulated containing squid by-product hydrolysate to replace fishmeal at 0, 25, 50, 75 and 100 %. These experimental diets were fed to triplicate groups of P. monodon for 8 weeks. Results revealed that 25 % fishmeal replacement with squid by-product hydrolysate resulted in growth enhancement, attributable to increased feed intake and gut lactic acid bacteria proliferation. The shrimp fed with 100 % replacement level exhibited a similar growth response with the control group. Protein retention was not affected by the fishmeal replacement levels, but lipid retention was found higher in all treatments with squid by-product hydrolysate than the control. Digestive protease activity decreased with increasing levels of hydrolysate while α-amylase and lipase activities were not affected. Hepatopancreas histology showed that B-cells dominated the control group while R-cells proliferated with increasing inclusion of dietary squid by-product hydrolysate. These results collectively indicate that fishmeal could be totally replaced with squid by-product hydrolysate and 25 % fishmeal replacement could promote the growth of juvenile P. monodon. [ABSTRACT FROM AUTHOR]

The establishment of protein and lipid requirements for growth of penaeid species is essential in maximizing productivity but information on the effects of these nutrients on gonad maturation is still lacking. Indian white prawn, Penaeus indicus (H. Milne Edwards) broodstock, were fed formulated maturation diets containing varying levels of dietary protein (35, 45 and 55%) and lipid (6, 12 and 18%) combinations following a 3×3 factorial design. Control group was fed with fresh mussel, squid and polychaete. Results indicate that treatment groups receiving diets of 45/18 and 55/12 protein/lipid combinations and the control exhibited higher maturation rates than the other treatments (p = 1.9 × 10−4). Shrimp broodstocks fed diets containing the lowest protein or lipid levels exhibited poor gonad maturation. Hepatopancreas damage and gonadal atresia were apparent in treatments with high dietary lipid based on histological and biochemical analyses. The diet with 55/12 protein/lipid combination is therefore best recommended for P. indicus gonad maturation. This study demonstrated that a well‐formulated diet that satisfies the protein and lipid requirements can support successful gonadal maturation comparable with feeding the broodstocks fresh maturation diets. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to evaluate the combined effects of mannan oligosaccharide (MOS) + ß-glucan (BZT® PRE-GE) supplementation administered at different frequencies on the immune responses and resistance of Penaeus vannamei against Vibrio parahaemolyticus, the causative agent of Early Mortality Syndrome (EMS) disease. Four experimental treatments were run with shrimps fed with a control basal diet (TCo), fed daily with diet containing 0.2% MOS+ ß-glucan (Td), fed every 3 days with diet containing 0.2% MOS+ ß-glucan (Td3) and fed every 7 days (Td7) with diet containing 0.2% MOS+ ß-glucan. Following the 30-day feeding trial, shrimp immunological responses were quantified. Infection challenge test was also conducted to evaluate the influence of the treatments on the resistance of P. vannamei against V. parahaemolyticus infection. Results indicate that the immunostimulant application frequency did not affect shrimp survival and overall growth performance. Immunostimulant application every 3 days was found optimum to enhance the immunological responses including total hemocyte count, prophenol oxidase and serum antibacterial activities. Moreover, significant improvement in survival following the infection challenge with V. parahaemolyticus was observed in treatment fed with the immunostimulant every 3 days. Overall these findings suggest that 0.2% MOS+ ß-glucan supplementation applied every 3 days could enhance the immune responses and improve the resistance of P. vannamei against Vibrio parahaemolyticus infection. Administration of 0.2% MOS+ ß-glucan once every 3 days could be a practical immunoprophylactic strategy to manage and prevent outbreaks of mass mortalities caused by V. parahaemolyticus infection in P. vannamei farming. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the influence of dietary soybean lecithin (SBL) on the growth performance, feed utilization, and survival of early juvenile milkfish. Five experimental diets containing increasing levels of SBL (0 g, 0.75 g, 1.5 g, 3.0 g and 6.0 g/100 g diet) were formulated and fed to triplicate groups of early juvenile milkfish (9.0 mg) for 50 days. Results showed that dietary lecithin inclusion improved Weight Gain (WG), Specific Growth Rate (SGR), Survival, Feed Conversion Ratio (FCR) and Protein Efficiency Ratio (PER) of milkfish juvenile. Polynomial regression analysis showed that the optimum dietary level of SBL to promote optimum growth in milkfish early juvenile is 3.56g/100g diet. Beyond this inclusion level, growth performance indices tend to decline. Higher carcass total protein and lipid contents were observed in treatment groups fed diets with optimum inclusion levels of SBL compared to the other treatments. Collectively the findings suggest that incorporating SBL at an optimum dose of 3.56g/100g diet enhances survival, overall growth performance, and improves carcass composition of early juvenile milkfish. Dietary SBL inclusion could be a practical approach in improving the efficiency of juvenile milkfish nursery production to meet the requirements of the expanding cage aquaculture production systems. [ABSTRACT FROM AUTHOR]

We studied the phylogeny, population structure, and demographic history of Scolopsis taenioptera in the western Pacific Ocean. Using the 80 samples collected from four locations, we obtained the nucleotide sequences of mitochondrial cytochrome c oxidase subunit I and cytochrome b genes. We identified two distinct lineages showing a clear phylogeographic break that was possibly due to the Pleistocene sea-level change. One lineage was distributed in Iloilo (Philippines) and the other in Terengganu (Malaysia), Rayong (Thailand), and Ha Long Bay (Vietnam). The Terengganu and Rayong populations showed clear signs of demographic expansion; the Iloilo and Ha Long Bay populations were relatively stable or spatially expanded as geographically subdivided populations. [ABSTRACT FROM AUTHOR]

The potential of water hyacinth leaf protein concentrate ( WHLPC) as an alternative protein source to soybean meal in formulated diets for the white shrimp Litopenaeus vannamei (Boone) postlarvae, was assessed. Isonitrogenous and isolipidic diets were formulated containing 40% protein and 8% lipid. WHLPC replaced 0%, 25%, 50% and 75% of soybean meal protein in the formulated diets. Twenty postlarval Litopenaeus vannamei weighing 5.0 ± 0.00032 mg were randomly assigned to twelve 30-L aquarium tanks and were fed experimental diets for 70 days. Results show that the overall biological performance of shrimp in terms of specific growth rate ( SGR), protein efficiency ratio ( PER), feed efficiency ( FE) and survival in treatment receiving the 25% WHLPC replacement is comparable to that of the control diet. Replacement levels beyond 25% exhibited significant depression in terms of growth performance of the shrimp. Collectively, these findings indicate that WHLPC can replace 25% of soybean meal protein in the formulated diets of L. vannamei. [ABSTRACT FROM AUTHOR]

In order to understand the digestive physiology of Sepia pharaonis Ehrenberg 1831 (Sepiidae) paralarvae, and to formulate appropriate feeding strategies, the activity patterns of major digestive enzymes in relation to larval development were investigated. Trypsin, leucine aminopeptidase, alkaline phosphatase, alpha-amylase, and lipase were analyzed for 25 days from hatching. Results revealed that all digestive enzymes were present even prior to exogenous feeding, and each enzyme exhibited a distinct activity pattern. Leucine aminopeptidase, an enzyme involved in intracellular digestion, was found to be dominant and highly active at early developmental stages and declined with larval maturation. Lipase activity, involved in lipid metabolism, increased in the early stages of development but declined 10 days after hatching (DAH). Secreted enzymes (trypsin and amylase) and alkaline phosphatase (an indicator of larval gut maturity) exhibited low activity prior to 10 DAH and 13 DAH, respectively. However, these enzymes became highly active in the late developmental stages. These findings suggest the gradual gut maturation of S. pharaonis based on intracellular and secreted enzyme activities. The findings also indicate that paralarvae after hatching are wellequipped with digestive enzymes necessary to digest complex food items, and that the larval gut matures 13 to 20 DAH. [ABSTRACT FROM AUTHOR]