两种饲料对海上筏式吊笼养殖仿刺参生长的影响

以福建冬季海上筏式吊笼养殖的仿刺参为对象,采用传统海带饲料和市面销售的凝胶状海参配合饲料对三种规格的仿刺参幼参(平均体质量分别为105.57、73.15和52.89 g)进行了为期60 d的投喂试验,比较了两种饲料对仿刺参幼参生长的影响。结果表明,传统海带饲料投喂组大、中、小三种规格仿刺参的特定生长率分别为(0.69±0.04)、(0.87±0.05)和(0.99±0.02)%·d-1,凝胶状海参配合饲料投喂组的特定生长率分别为(0.65±0.03)、(0.86±0.05)和(0.81±0.10)%·d-1。传统海带饲料投喂组小规格仿刺参的平均个体增重率和特定生长率均显著大于凝胶状配合饲料投喂组(P0.05),而两种饲料投喂组大、中规格间的差异不显著。因此,传统海带饲料可用于仿刺参海上筏式吊笼养殖生产,而凝胶状海参配合饲料可作为传统海带饲料的辅助饲料。     

刺参浅海筏式养殖技术

刺参通常称作海参,在分类上属于棘皮动物门、海参纲、楣手目、刺参科、仿刺参属。在我国,刺参主要盛产于辽宁、山东、河北等地。刺参养殖方式有池塘养殖、工厂化养殖、围网养殖、浅海筏式养殖等。近些年,随着“北参南养”技术上的突破,刺参浅海筏式养殖在我省尤其在闽东地区海域悄然兴起,取得了良好的经济效益（最好的投入产出比超过1：2）,促进了刺参养殖产业的迅猛发展,有望成为福建省继鲍鱼之后又一大海水养殖产业。现将刺参浅海筏式养殖技术要点总结如下：     

“胃萎缩症”仿刺参幼体及亲参组织中病毒观察

海参含有丰富的蛋白质和粘多糖,营养和药用价值极高.全世界海参约有1200种,在我国海域分布的有140多种,其中以黄、渤海的仿刺参(Apostichopus japonicus)品质最佳[1].近几年,仿刺参(俗称"刺参")人工养殖已成为辽宁、山东沿海水产业重要的养殖品种之一和新的经济增长点.     

海星棘皮投喂仿刺参(Apostichopus japonicus Selenka)的效果

在饲料中添加海星棘皮,与两组商品饲料分别投喂体重为5.0–6.7 g的仿刺参(Apostichopus japonicus Selenka),进行60 d养殖试验,研究其对仿刺参平均增重率(AWGR)、特定生长率(SGR)、饲料系数(FCR)、摄食率(FR)和蛋白表观消化率(APD)的影响。结果显示,各组仿刺参生长良好,成活率无显著差异(P>0.05);60 d时,各组仿刺参的AWGR和SGR变化趋势相同,由高到低依次为市售2组、海星组、市售1组;海星饲料组仿刺参的FCR最低,与其他两组间差异不显著(P>0.05);海星饲料组与市售1组的FR间差异不显著(P>0.05),与市售2组FR间有显著差异(P<0.05);海星饲料组仿刺参的饲料转化率(FE)明显高于其他两组(P<0.05);海星饲料组仿刺参的APD最高,为67.28%,与市售1组的APD差异显著(P<0.05)。研究表明,添加海星棘皮可以较好地促进仿刺参的生长和提高饲料的利用,可添加到仿刺参幼参饲料中用作饲料源。     

刺参南方海上筏式养殖技术研究

刺参（Stichopus,japonicus）属棘皮动物门,海参纲,刺参属,是海参种类中营养价值最高、最受市场喜爱的一种。在我国,海参主要产自山东、辽宁等地。刺参养殖方式有池塘养殖、沉箱养殖、室内控温养殖、围网养殖、浅海筏式养殖等。 随着“北参南养”技术上的突破,刺参养殖在我国南方海域也逐步兴起。福建省福州市连江县的养殖户引进北方的刺参在海上进行海参筏式养殖。2010年11月10Et投苗10万只,苗平均体长12cm,     

饲料对吊笼养殖仿刺参生长及体成分的影响

在水温16.6~11.6℃、盐度29.3~27.6的海域环境条件下,将1 080 cfu初始体质量为(51.8±6.9)g的仿刺参(Apostichopus japonicus)放养于4组共36个网箱吊笼(规格为72 cm×39 cm×31 cm,分为6层),每个吊笼30 cfu(每层5 cfu),分别投喂海带(A组)、海带+鲜杂鱼糜(B组)、海带+扇贝边粉(C组)和仿刺参粉状配合饲料(D组),研究了不同饲料对仿刺参生长和体成分的影响。84 d的饲养结果表明,各处理组仿刺参成活率(SR)和脏壁比(VBWR)均差异不显著(P0.05),但增重率(WGR)、特定生长率(SGR)、饲料系数(FCR)和蛋白质效率(PER)却不同。各组WGR、SGR分别介于172.3%~79.6%和(1.19~0.70)%·d-1之间,B、C两组WGR、SGR均差异不显著(P0.05),但显著高于A、D两组(P0.05),D组最小。B组FCR最低,D组最高,各处理组之间差异显著(P0.05)。A组PER最高,D组最低,各处理组之间差异显著(P0.05)。饲料影响仿刺参体成分,D组水分含量显著低于其它3组(P0.05),其它3组之间差异不显著(P0.05);各组粗蛋白含量变化在40.0%~48.1%之间,C组显著高于其它3组(P0.05),其它3组之间差异不显著(P0.05);粗脂肪含量变化较大,为1.3%~3.8%之间,B组最高,C组最低,各处理组之间差异显著(P0.05);A组灰分含量显著高于其它3组(P0.05),B组显著高于C、D两组(P0.05),而C、D两组之间无显著差异(P0.05)。综合仿刺参各生长指标,在试验饲料组中,饲喂海带与鲜杂鱼糜搭配饲料(B组)对网箱吊笼养殖仿刺参效果较好。     

仿刺参池塘养殖对极端高温的敏感性评估与预测

夏季极端高温是制约我国仿刺参(Apostichopus japonicus)池塘养殖发展的关键环境因素。本研究基于文献拟合了北方养殖区仿刺参存活率与水温的关系, 确定了仿刺参半致死温度; 收集了 1980—2020 年夏季每小时气温数据, 分析了仿刺参养殖区域极端高温的时空特征和仿刺参池塘养殖受灾频次; 根据受灾频次判定了仿刺参池塘养殖敏感区, 最终预测了 2046—2050 年 3 种 CMIP5 典型浓度路径(RCP)情景模式(RCP2.6、RCP6.0 和 RCP8.5)下仿刺参养殖高温敏感性。结果显示, 仿刺参半致死温度(LT₅₀), 即致灾温度, 为(31.7±0.15) ℃; 中国北方沿海区域是气候变暖的显著响应区, 2011—2020 年中国北方沿海区域平均温度和最高温度分别以 1.27 ℃/10 a 和 2.15 ℃/10 a 的速率上升, 导致北方仿刺参养殖区普遍遭遇致灾温度, 其中渤海西南海域受灾频次最高; 在 3 种 RCP 情境下, 渤海大部分海湾仿刺参池塘养殖风险加大。结论认为, 仿刺参产业发展需因地制宜制定科学空间发展规划, 建立基于高温预警预报系统的应对策略, 保障产业可持续发展。     

仿刺参基因组大小的测定

仿刺参基因组大小测定采用流式细胞术,以鸡红血细胞DNA含量(2.5 pg/2C)为内标,用夏眠、正常和野生3个群体的仿刺参体腔细胞测定了52只刺参的单倍体基因组含量,其C-值为(0.90±0.06)pg,由此得出仿刺参基因组大小为(880.2±58.68)Mb。其中,夏眠、正常和野生群体C-值分别为(0.93±0.05)、(0.90±0.05)和(0.84±0.02)pg。运用独立样本t检验对比分析显示:(1)夏眠与正常的仿刺参基因组大小之间差异不显著,说明仿刺参基因组大小与夏眠这一生理因子不具有相关性;(2)池塘(围堰)养殖环境下与野生环境下的仿刺参基因组大小之间有显著差异,野生环境下的仿刺参基因组明显小于池塘(围堰)养殖环境下的基因组。据此推测,环境因子的改变可能对仿刺参乃至整个海参类群基因组DNA含量产生影响。实验还对C-值测定的发展和方法作了详尽的描述,同时在综合其他种类海参基因组大小研究的基础上,探讨了C-值与进化地位之间的关系。     

海参池塘养殖中的常见疾病

<正>刺参(Apostichopus japonicus Selenka),在分类上属棘皮动物门、海参纲、楯手目、刺参科、仿刺参属。随着刺参养殖业的快速发展,不正确的养殖造成病害问题日趋突出,出现了多种明显病症和大规模死亡现象,部分养殖区相继出现了刺参腐皮综合征、后口虫病、气泡病、不摄食等病征,且具有一定的传染性,给刺参养殖业者造成了惨重的经济损失,阻止了海参养殖业的快速发展。本次调查统计了池塘养殖海参常见疾病,通过实践案例分析了疾病暴发的致病     

温度和盐度对红刺参(Apostichopus japonicus)耗氧率与排氨率的影响

采用室内实验生态学方法,研究了不同温度(7、12、17、22、27℃)、盐度(23、26、29、32、35、38)对两种体重S组(1.68–3.48 g)和L组(15.78–20.79 g)红刺参(Apostichopus japonicus)耗氧率(OCR)和排氨率(AER)的影响。结果显示,温度对红刺参OCR和AER均有极显著影响(P<0.01);体重对红刺参OCR无显著影响(P>0.05),而对AER有极显著影响(P<0.01)。温度和体重交互作用对红刺参OCR和AER有极显著影响(P<0.01)。S组红刺参的OCR和AER随温度的升高而增加;L组红刺参OCR和AER均随温度的升高而升高,而在22℃有所降低后又升高。盐度、体重对红刺参OCR和AER均有显著影响(P<0.05)。盐度和体重交互作用对红刺参OCR和AER均无显著影响(P>0.05)。S组和L组红刺参的OCR和AER均随盐度的升高而呈M形变化,在盐度为29和32时较低,而在盐度为26和35时较高。红刺参OCR和AER与体重呈负相关的幂函数方程R = aW b。不同温度下S组和L组红刺参O : N范围分别为4.75–11.74和10.71–15.52;不同盐度S组和L组红刺参O : N范围分别为6.37–12.29和8.24–12.10。综上所述,L组红刺参对高温的耐受能力较S组弱;S组和L组红刺参对低盐和高盐的耐受性较差,其最适盐度范围为29–32。     

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.     

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 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.     

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).     

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.     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.