网箱培育海参苗技术

随着海参增养殖业的发展,对海参苗的需求量也在不断增加。目前,海参养殖的苗种来源是通过工厂化育苗来提供,而工厂化育苗的生态环境比较稳定,同时也就保护了弱势群体,人为地减少了海参苗的自然淘汰,在这种条件下繁育的海参苗,成活率比较高,但是,把在这种条件下繁育的海参苗投放到自然环境中养殖,成活率偏低,只有5%～15%。     

我国海参池塘养殖存在的问题及应对措施

进入21世纪我国在经历了以海带、对虾、扇贝、海洋鱼类为代表的四次海水养殖浪潮之后,海水养殖业迎来了以海参为代表的第五次浪潮。目前我国海水养殖业正朝着多品种、多元化的可持续方向发展,海参养殖已发展成为我国海水养殖业中的一个重要产业。近年来,随着海参养殖业的高速发展,出现了多种海参养殖方式:围堰养殖、池塘养殖、网箱养殖、室内工厂化养     

一元二氧化氯在海参苗种培育中的应用

近年来,海参育苗与养殖在北方地区发展很快,育苗场不断增多,有关育苗技术也得到了深入的研究,笔者在2006年海参工厂化育苗过程中使用了稳定性一元二氧化氯,对育苗池水进行消毒杀菌处理,取得了较好的效果,培育出的海参苗规格整齐,体质健壮,生长较快,用户购买后反映良好。     

浅谈我国海参工厂化养殖技术

<正>随着经济的发展和人们生活水平的提高,对海参的需求量越来越大。自然产的海参越来越少,人工养殖得到了空前的发展。尤其是近年来,养殖企业和养殖户越来越多地尝试工厂化养殖,克服现有养海参方式的缺点和弊病,完善海参养殖工艺,降低海参养殖成本,缩短海参养殖周期,以推进海参养殖业的快速发展。     

江苏赣榆县青口刺参工厂化人工育苗获成功

近日,江苏省赣榆县青口镇榆城集团刺参工厂化人工育苗获得成功,填补了江苏省刺参工厂化人工育苗的空白。目前,青口镇拥有刺参育苗水体3万米3,年销售额可达1700多万元。2009年以来,榆城集团与连云港市海洋与渔业局,赣榆县海洋与渔业局共同承担了刺参工厂化人工育苗项目。为引导好这一产业的发展,科研人员从苗种、水质和管理三大方面加大管理力度,严格加强海参关键技术和新模式研发,健全海参养殖病害防治体系。     

棘皮动物的免疫防御机制

近年来,棘皮动物养殖业得到了迅速发展,尤其是海胆、海参这两个商业品种,不仅满足了国内消费者的需要,还出口国外。但是随着棘皮动物养殖快速发展,人工育苗规模不断扩大,病害问题频繁发生造成巨大的经济损失,如海参的烂皮病、海胆的黑嘴病等,在一定程度上阻碍了养殖业的健康稳定发展。     

海参养殖之二海参养殖中存在的问题及其对策

近年来,沿海地区海参养殖业蓬勃发展,但随着养殖规模的不断扩大,海参养殖中存在的问题日益凸现。从2004年水产养殖病害测报中可以看出,海参病害以2月份~4月份最为严重,7月份~9月份趋于平缓,进入12月份以来又有爆发迹象。海参病害的发生对海参养殖业产生了一定冲击,影响了海参养殖业健康、有序的发展。笔者结合生产实际谈以下几点看法:一、海参养殖中存在的问题1.苗种问题全人工育苗成功解决了海参养殖的苗种数量问题,但随之而来的苗种质量问题一直困扰着广大养殖者。育苗生产不规范,造成苗种质量下降,直接影响了海参养殖生产的全过程。2.环…     

南方工厂化鲍参混养试验

正红刺参具有生长速度较快、抗病能力强、较耐高温、体壁厚、胶原蛋白、粘多糖等营养物质丰富等特点,经济价值为刺参的2~3倍。随着红刺参繁殖驯化的成功,成功打破了海参增养殖的海区限制,将海参增养殖海域扩展到南方海域,利用南方冬春季进行海参养殖能有效避免海参冬眠现象,缩短了海参的生长周期。另一方面,由于近年来鲍鱼养殖业的畸形扩张导致了鲍鱼养殖业饱受病害困扰,养殖成功率急剧下降,工厂化养殖更甚,如何优化     

昌黎县海湾扇贝养殖信息采集与分析

<正>昌黎县拥有64.9km海岸线,浅海及滩涂资源丰富。近年来,昌黎县以渔业增效、渔民增收为核心,以养殖结构调整为主线,进一步实现由规模渔业向生态效益渔业、由传统渔业向现代渔业的转变,重点发展了浅海筏式扇贝养殖、滩涂养殖、工厂化养殖和人工渔礁养殖等,特色水产品有扇贝、海参、对虾、河鲀、牙鲆、大菱鲆、半滑舌鳎等。随着浅海养殖业的兴起,水产品加工、育苗、销售     

海参饲料研究的现状与发展方向

自20世纪80年代以来,随着海参人工育苗与养殖产业的迅速发展,海参用饲料研究越来越受到业内人士的关注。海参用饲料的好坏,直接影响海参育苗与养殖生产的成败。特别在目前,苗种生产与成参养殖迅速发展,海参用饲料需求量不断增加,而原料又十分短缺、饲料市场比较混乱,海参饲料开始成为限制海参苗种与养殖生产业发展的潜在因素。为此,笔者将综合叙述海参用饲料研究的发展过程、现状,并探讨其存在的问题以及今后发展的方向,供广大从事海参研究、教学、生产者参考。1海参用饲料的发展过程1.1国外海参饲料的研究工作始于刺参人工育苗方面的研究,…     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.