军曹鱼仔鱼饲料营养成分需求探讨

军曹鱼是广东、海南、福建沿海的重要海水养殖对象,被称为海水网箱养殖中最有养殖前景的鱼类之一。近年来,有关军曹鱼的研究取得了长足发展,本文就军曹鱼营养需求方面的研究作一综述,以期为军曹鱼的进一步开发利用提供参考。     

军曹鱼人工繁殖与池塘生态苗种培育技术研究

军曹鱼（Rachy centron Canadum）亦称海鲡，隶属鲈形目军曹鱼料、军曹鱼属，分布于大西洋，印度洋和太平洋（东太平洋除外）等热带水域，我国南海沿海亦有分布，但产量较低。为热带海水鱼类，不耐低温，广盐性，由于它具有食性杂、易饲养、病害少、肉质鲜美，可以与大西洋鲑媲美，经济价值高。经一周年养殖当年增重可达6kg-8kg，是海水网箱养殖中生长最快，最具产业化前景的鱼类之一。近年来已成为我国广东、海南沿海的重要海水网箱养殖品种。军曹鱼天然苗种大小不均，数量少，不能满足水产养殖发展的需求，制约了军曹鱼养殖的产业化进程，2003-2006年，笔者根据天然水体中军曹鱼的繁殖习性，摸索军曹鱼人工催产池塘生态育苗技术，连年来取得较好的经济效益，现将主要技术介绍如下。     

配合饲料养殖军曹鱼幼鱼效果分析

军曹鱼亦称海鲡,隶属鲈形目、军曹鱼科、军曹鱼属,为热带海水性鱼类,主要分布于大西洋、印度洋和太平洋(东太平洋除外)等海域,我国沿海亦有分布,但产量较低。军曹鱼生长速度快,是海水网箱养殖中最具产业化前景的鱼类之一。为了降低养殖生产成本,提高经济效益,广东恒兴集团有限公司于2005年6月~11月使用膨化配合饲料进行了军曹鱼幼鱼饲养试验,以期寻找符合军曹鱼营养需求的配合饲料,为军曹鱼规模化养殖提供依据。一、材料与方法1、试验材料试验在广东恒兴集团“863”海水种子工程南方基地进行;养殖用水族箱体积分别为0.5m3和1.0m3;试验用水为…     

军曹鱼Rachycentron canadum（Linnaeus）的生物学特征及网箱养殖技术

本文描述了军曹鱼的形态学,解剖学及其养殖习性,近年来,军曹鱼驯养在我国南方一些海湾网箱养殖中,初步显示出其适应性广,食性杂,生长快,产量高,病害少等特点,当年鱼种养殖６－８个月可达４－５Ｋｇ,养殖１２个月,个体重可达６－８Ｋｇ是一种极有驯化养殖前景的海水鱼类。     

军曹鱼海水网箱养殖技术

介绍了军曹鱼海水网箱养殖中饲养管理和病害防治的主要方法,内容包括:养殖海区的选择;网箱的准备;鱼种的放养;日常的饲养管理;淋巴囊肿病和弧菌病的防治;安全生产等。     

军曹鱼高位池育苗技术研究

军曹鱼(Rachycentron canadum)隶属鲈形目、军曹鱼科、军曹鱼属,亦称海鲡,英文名Cobia.分布于大西洋、印度洋和太平洋等热带水域.最大个体长达1.5米、体重43千克,是目前海水网箱养殖鱼类中生长最快、最有养殖产业化前途的品种之一.……     

人工海水工厂化养殖军曹鱼试验

为了探索军曹鱼在北方地区的内陆养殖技术,我们在长春市进行了人工海水工厂化循环水养殖试验。在小网箱,利用鱼糜、人工配合饵料混合投喂。养殖过程中,水温平均为26.2℃,上下温差不超过2℃;溶氧始终保持在6.3mg/L左右,最低未低于5.5mg/L;盐度始终保持在29‰左右,上下不超过1‰。经过约5个月的养殖,将平均体重为0.44g、平均体长为5.59cm的军曹鱼鱼苗养到平均体重为133g、平均体长为33.4cm,最大个体体重为335g、体长为42.5cm的军曹鱼商品鱼。试验证明,军曹鱼完全可以在内陆用人工海水养殖。     

广东海水网箱养殖的发展及抗风浪网箱的推广

本文回顾了广东海水网箱养殖和深水抗风浪网箱发展历程,介绍了2002年全国水产技术推广总站"南海区升降式深水抗风浪网箱养殖技术示范"项目的实施情况,筛选出军曹鱼、高体鰤两个适宜养殖品种,制订了<军曹鱼深水网箱养殖技术操作规范>和<高体鰤深水网箱养殖技术操作规范>,并对深水抗风浪网箱在广东的广阔发展前景进行了展望;论述了大面积推广抗风浪深海网箱养殖所必需解决的海域养殖容量与环境管理、苗种繁育、配合饲料与投喂技术、病害防治、从业者素质等问题.     

近海浮绳式网箱养殖军曹鱼技术

近海浮绳式网箱养鱼，就是指在港湾外的近海设置浮绳式的网箱，选择优质鱼类，进行高密度、集约化的养殖。近海浮绳式网箱系统是由主缆绳、副缆绳与拖网浮子连接的框架及网片、吊脚绳与沉架等缝制而成，然后采用铁锚和锚绳将其固定在近海养殖海区进行养殖生产。１ 军曹鱼的经济价值及生活习性 军曹鱼，属鲈形目，军曹鱼科，军曹鱼属，海南省地方俗称“海甘楚”。军曹鱼特点为个体大、生长快、抗病力强、产量高、肉厚质细、味嫩滑鲜美、且无细刺骨、营养价值高、经济效益佳，是目前海水网箱养殖鱼类中的优良新种之一。军曹鱼为肉食性鱼类，性…     

海水养殖常见病害防治（上）

1海水养殖概况目前我国沿海地区主要的海水养殖动物品种有：海参、大菱鲆、石斑鱼、龙胆鱼、诺参鱼、金鲳鱼、牙鲆、海鲈鱼、军曹鱼、真鲷,黑鲷、大黄鱼、中华乌塘鳢、梭子蟹、日本对虾等.其中海参养殖主要分布在山东省沿海地区,辽宁省大连市、河北省唐山市等沿海地区.大菱鲆、牙鲆、日本对虾养殖主要分布在山东省沿海地区.大黄鱼、中华乌塘鳢养殖主要分布在福建省邻德市和漳州市沿海地区.而石斑鱼、龙胆鱼、诺参鱼、金鲳鱼、海鲈鱼、军曹鱼、真鲷、黑鲷养殖主要分布在广东省、海南省及广西沿海地区.     

Nutritional requirements of cobia, Rachycentron canadum (Linnaeus): a review

Cobia culture has been rapidly gaining in popularity since the early 1990s; however, the relative success of modified commercial diets in aquaculture has delayed the need for specific research into the nutritional requirements of cobia. Recent work has determined optimum dietary protein and lipid levels in juvenile cobia at 45 and 5–15% dry weight respectively. Maximum growth and feed conversion ratios have been recorded at 27–29 °C in juvenile cobia with an optimum ration level determined at 9% initial body weight per day. There is limited information on amino acid and essential fatty acids (EFA) requirements in cobia. Several studies have explored alternate protein sources in juvenile cobia with relative success observed with meat meal, yeast-based protein and various plant based sources including soybean meal. There is no literature on the vitamin or mineral requirements of cobia or the nutritional requirements of larger fish. Therefore future research should focus on the amino acid, EFA, vitamin and mineral requirements of cobia while the protein, lipid and energy requirements of larger cobia should be addressed. Additional work on feed ingredients, choice and palatability would also aid in maximizing culture production while minimizing costs thereby producing a more sustainable product.     

Study on regional production and economy of cobia <Emphasis Type="Italic">Rachycentron canadum</Emphasis> commercial cage culture

In recent years, cobia has become an emerging farmed species in Asia due to its quick growth and high economic value. This study collects biological and economic data affecting the economic performance of cobia farming in three countries, namely Taiwan, China, and Vietnam. The data are collected by questionnaire sampling and analyzed by multivariate statistical analysis in order to compare the key factors affecting the production and economy of cobia farming in these three countries. The results show that Taiwan, China, and Vietnam have significant differences in input intensities and profitability. China has the highest input intensity (3372.42 TWD/m³), as its high stocking density increases feed input. Taiwan has the highest unit input cost (103.44 TWD/kg), as the high quality of the product increases the price of cobia in Taiwan, which offsets the high product costs. In terms of profitability, the benefit–cost ratio is over one in all three countries, indicating that the profitability of cobia farming is good in all three countries. Profitability analysis shows that fingerlings in China achieve 36.50, which is the highest among the three countries; whereas Taiwan has the highest feed profitability of 0.78, which reveals that the fingerlings produced in China are competitive in both price and quality, while Taiwan has the best feed management efficiency. The production costs and profitability of Vietnam fall between those of Taiwan and China. Feed cost is the main expenditure in cobia culture; thus, good feed management could effectively reduce production costs and increase business performance. The feed quality and input management model of Taiwan, in conjunction with the fingerling quality and stock model of China, could provide future reference for farming management in such areas as feed input and selection of fingerling.     

Optimization of Enzymatic Protein Hydrolysis from Cobia (Rachycentron canadum) Frame Using Alcalase®

The combined effects of hydrolysis time, temperature, pH, and ratio of enzyme to substrate on the degree of hydrolysis (DH) of cobia frame were determined using Response Surface Methodology. The effects of these factors were employed using a three-level factors face-centered central composite design. The proximate compositions of cobia frame and cobia hydrolysate powder were determined as well. The generated model equation gave a quadratic fit with experimental data. It is suggested that hydrolysis conditions for obtaining the optimum DH using Alcalase® were: temperature of 58°C, hydrolysis time of 134 min, pH of substrate at 9.4, and an enzyme concentration of 8.3%. Proximate analyses revealed that cobia frame contained 47.0% protein, 27.6% fat, and 24.8% ash; whereas cobia frame hydrolysate powder contained 88.8% protein, 0.58% fat, and 5.05% ash. The high protein content indicated that cobia frame hydrolysate is a potential ingredient for food and feed.     

Feeding of juvenile cobia,Rachycentron canadum: Evaluation of practical feeds,comparison of commercial fishmeal replacers,and estimation of essential amino acid requirements

Three studies were conducted with juvenile cobia, Rachycentron canadum: (Study 1) a 10‐week feeding trial within floating net cages to test the nutritional efficacy of different dietary feeding regimes (trash‐fish control diet, a semimoist diet, an in‐house dry formulated diet, and a commercial cobia feed); (Study 2) a 10‐week feeding trial within an indoor water‐recirculating tank‐based system to test the nutritional efficiency of different potential dietary fishmeal replacers (poultry byproduct meal, soy protein concentrate, feather meal), a diet without taurine supplementation, and a commercial cobia feed; and (Study 3) estimation of the essential amino acid (EAA) requirements of cobia based on EAA whole‐body composition in fast‐growing cobia fed a trash‐fish‐based diet. Fish performance in terms of growth and feed efficiency was the greatest within the outdoor net‐cage feeding trial, with fish fed the control trash‐fish‐based diet exhibiting the best performance. Although fish growth was poorer within the indoor feeding trials, fish performance was similar for most diets, with apparent crude protein digestibility coefficients of over 75% being obtained in all experimental diets in both feeding trials. The estimated EAA requirements of cobia obtained during this study were similar to those reported for other similar marine carnivorous fish species.     

Establishment,characterization, virus susceptibility and transfection of cell lines from cobia,Rachycentron canadum (L.), brain and fin

Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate‐buffered saline containing 0.25% trypsin at 25 °C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 °C in Leibovitz‐15 medium containing 10% foetal bovine serum. The cells have been sub‐cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamination was detected. Susceptibility to grouper iridovirus was observed for the CB cell line but not the CF cell line. Both cell lines expressed green fluorescent protein after being transfected with green fluorescent reporter gene driven by the cytomegalovirus promoter.     

Efficacy of Concentrated Algal Paste During Greenwater Phase of Cobia Larviculture

ABSTRACT

The purpose of this study was to determine if concentrated algal paste could effectively replace live algae during the greenwater stage of cobia fingerling production without negative impact upon larval growth or survival. Mean cobia survival per tank from 2 dph through post weaning at 28 dph for the live algae treatment was 24.44 ± 2.43% (mean ± SD) as compared to 24.47 ± 2.48% for the algal paste treatment. Furthermore, the number of fish produced per liter for the live algae treatment was 2.44 ± 0.24 fish/L compared to 2.47 ± 0.25 fish /L recorded from the algal paste treatment. Mean fish weight for cobia weanlings from the live algae treatment was 0.417 ± 0.059 g compared to 0.411 ± 0.026 g for the algal paste treatment. These observations demonstrate that during the greenwater stage of cobia larviculture, live algae can be completely replaced with commercially available, concentrated algal paste without negative impact upon cobia growth, survival, or resultant weanling production per unit volume.     

Reproductive biology of the commercially and recreationally important cobia Rachycentron canadum in northeastern Australia

The reproductive biology of 315 cobia, Rachycentron canadum, from northeastern Australia was studied for an 18-month period. Cobia ranged from 181 to 1,470 mm FL (0.06–55 kg). Length–frequency distributions of males and females did not differ significantly. The sex ratio of females to males was 2.18:1. Histological data showed that cobia developed hydrated oocytes during a protracted spawning season between September and June. Gonadosomatic index peaked from October to December, coinciding with the monsoon or “wet” season. Estimated length at first maturity for female cobia was 671 mm FL. Length at 50% maturity (L ₅₀) for females was estimated at 784 mm FL (1–2 years of age). Batch fecundity ranged from 577,468 to 7,372,283 eggs with a mean of 2,877,669 (± SD 1,603,760) eggs. Relative batch fecundity was 249 eggs per g, and no relationship between relative fecundity and fork length was found. There was a significant positive relationship between the total number of eggs produced and fork length. Spawning frequency, estimated by the post-ovulatory follicle method, was 7.6 days. Based on the detection of hydrated oocytes in fish caught at night, cobia most likely spawn at night. Cobia also feed throughout the spawning period. This is the first report on the reproductive biology of cobia in Australian waters, and provides valuable data for future population assessments of cobia throughout the Indo-Pacific.     

Acute responses of juvenile cobia Rachycentron canadum (Linnaeus 1766) to acid stress

Fish are potentially submitted to water acidification when reared in recirculating aquaculture systems. This study evaluated the responses of juvenile cobia Rachycentron canadum after acute exposure to acid water. Juvenile cobia (12.6 ± 0.5 g; 14.2 ± 0.2 cm) were acutely exposed to four pH levels (7.9 (control), 6.5, 6.0, and 5.5). After 24 h of exposure to different pH values, fish were sampled for physiological and histopathological evaluation. Acid water affected physiological parameters and induced morphological histopathologies on gill and skin of juvenile cobia, and these effects were more conspicuous with decreasing pH values. Acid stress induced blood acidosis in juvenile cobia, coupled to a decrease in bicarbonate (HCO₃^?) and saturated O₂ (sO₂) in fish blood. On the other hand, haematocrit, haemoglobin and glucose concentration increased their values (P < 0.01) comparing to control level. Hyperplasia with completely fusion of secondary lamella was observed in all pH treatments (6.5. 6.0 and 5.5), while telangiectasia and proliferation of chloride cells were present for fish exposed to pH 6.0 and 5.5. In skin hyperplasia and hypertrophy of mucous cells, necrosis of these cells for fish exposed to pH 6.0 and 5.5 was observed. The results of this study demonstrate that acute acid water exposition affected physiology and histopathology in juvenile cobia, especially at pH values below 6.5. Accordingly, particular attention must be given to pH during cobia reared in recirculating aquaculture.     

摄食水平对几种重要海水养殖鱼类生长和氮收支的影响

本文研究了不同摄食水平（从饥饿至饱食）军曹鱼幼鱼（平均初始体重10.0g）、青石斑鱼幼鱼（平均初始体重5.5g）和卵形鲳鲹幼鱼（平均初始体重7.7g）的生长和氮收支,建立了生长和氮排泄与摄食水平的回归方程。结果表明,军曹鱼幼鱼特定生长率随摄食水平的增加呈显著增长趋势,在9%和饱食两个摄食水平之间无显著性差异,而青石斑鱼和卵形鲳鲹幼鱼的特定生长率随摄食水平增加呈线性增长趋势;饱食时,青石斑鱼和卵形鲳鲹幼鱼的生长速率接近而明显低于军曹鱼幼鱼的。军曹鱼幼鱼食物转化效率随摄食水平的增加呈先增长后下降的趋势,在9%/d摄食水平组有最大值,而青石斑鱼和卵形鲳鲹幼鱼食物转化效率随摄食水平的增加而持续增长,在饱食摄食水平时有最大值;饱食时,军曹鱼和青石斑鱼幼鱼的食物转化效率接近而明显高于卵形鲳鲹幼鱼的。3种海水鱼摄食氮、排粪氮、生长氮和氮排泄均随摄食水平的增加呈显著增长趋势;比较可知,军曹鱼幼鱼的摄食氮和氮排泄均最大,而青石斑鱼幼鱼的最小。军曹鱼、青石斑鱼和卵形鲳鲹幼鱼饱食和次饱食摄食水平时的氮收支方程分别为100CN = 7.7(6.0)FN + 22.6(31.31)GN + 69.7(62.68)UN、100CN = 2.7(2.8)FN + 20.9(8.4)GN + 76.4(88.8)UN和100CN = 1.8(1.4)FN + 12.8(9.3)GN + 85.4(89.3)UN（氮收支方程括号中的为次饱食数据）;3种海水鱼饱时和次饱食时摄食氮中用于排粪的比例较小且变化不大,军曹鱼次饱食时摄食氮中用于生长的比例较饱食时的大而用于排泄的比例较饱食时的小,青石斑鱼和卵形鲳鲹幼鱼的则相反。因此,鱼类的氮排泄率和氮收支方程存在种间差异,而当食物中氮含量较为接近时,摄食量增大是导致鱼类氮排泄增加的主要原因之一。综合考虑生长、食物转化效率、氮排泄和氮收支方程各因素,可得出在实验的生长阶段,3种海水养殖鱼中,军曹鱼幼鱼的最佳摄食水平为次饱食摄食水平（9%/d或约为饱食摄食水平的70%）,而青石斑鱼和卵形鲳鲹幼鱼的最佳摄食水平为饱食摄食水平。     

Effects of shrimp waste meal on growth performance and chitinase activity in juvenile cobia (Rachycentron canadum)

The effects of replacing fish meal (FM) with shrimp waste meal (SWM) in diets fed to juvenile cobia (Rachycentron canadum) were investigated through a 6‐week trial. SWM was added to replace FM at fractions of 0%, 10%, 20% and 25% of the diet. The result showed the survival rates of the fish were higher than 86.7%. The weight gain and feed conversion rate showed an increasing trend as the SWM proportion in diet increased from 0% to 25%, but the protein efficiency ratio showed a decreasing trend in efficiency. In addition, the hepatosomatic index increased significantly when the SWM percentage was 20% and 25%. There were no significant differences in the protein and ash concentration of the muscle among all dietary groups. However, the muscle lipid content was low when fish fed in diets with high SWM level. Chitinase activity was extremely high in the pyloric caeca tissue of cobia, and increased specific activities of chitinase were only found in the foregut of cobia fed diets containing 10% SWM for a 6‐week period. A challenge test showed that SWM could not enhance cobia resistance to Photobacterium damselae ssp. piscicida infection. Our results suggest that the administration of a 10% SWM diet could potentially reduce the use of FM in the diet of cobia.