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1.
刺参耳状幼体体长遗传力的估计   总被引：7，自引：2，他引：7  
基于全同胞组内相关法估计刺参(Apostichopusjaponicus Selenka)耳状幼体初中期体长的遗传力.实验中的30个亲参来自人工养殖的成体刺参群体,亲本交配采用巢式不平衡设计,通过人工授精技术,构建了8个半同胞家系和22个全同胞家系.在耳状幼体初期和中期,每个全同胞家系分别测定40～70个后代个体体长.利用SAS软件的GLM过程,计算表型变量的原因方差组分,估算体长遗传力.分析结果显示,雌性遗传方差组分均显著大于雄性遗传方差组分(P＜0.05),雌性遗传方差组分存在显著的母性效应(P＜0.05).基于父系半同胞组内相关法计算的狭义遗传力是刺参耳状幼体初中期体长狭义遗传力的无偏估计值,估计值分别为0.74和0.75.结果表明,基于刺参耳状幼体体长的加性遗传方差较大,选择育种对于刺参幼体早期生长的改良具有较大的潜力.[中国水产科学,2006,13(3):378-383]  相似文献   

2.
本研究基于全同胞组内相关法对9月龄刺参(Apostichopus japonicus)苗种体长、体重、肉刺总数3个性状的遗传力进行了评估.以前期收集、保存的刺参群体为亲本,选取了健康刺参29头,采用不平衡巢式设计方法及人工刺激采卵授精方法,按照1雌配2-5雄的原则,构建了6个母系半同胞家系及23个父系全同胞家系,至9月龄时,分别抽取每个家系30-50个后代测定相应个体的体长、体重及肉刺总数,应用数量遗传学分析和全同胞组内相关法估计刺参9月龄体长、体重和肉刺总数共3个生长性状的遗传力.结果显示,9月龄刺参体长雌性组分遗传力的估计值为0.87,雄性组分遗传力估计值为0.85,全同胞组分遗传力估计值为0.86;刺参体重雌性组分遗传力估计值为0.20,雄性组分遗传力估计值为0.73,全同胞组分遗传力估计值为0.46;肉刺总数雌性组分遗传力估计值为0.43,雄性组分遗传力估计值为0.32,全同胞组分遗传力估计值为0.37.t检验表明,体长、体重的雄性组分遗传力达到显著水平(P＜0.05),全同胞组分遗传力均达到极显著水平(P＜0.01),肉刺总数的遗传力均未达到显著水平.  相似文献   

3.
虾夷马粪海胆早期生长发育的遗传力估计   总被引：10，自引：5，他引：10       下载免费PDF全文
以虾夷马粪海胆(Strongylocentrotus intermedius)为亲本，采用不平衡巢式设计方法和人工授精技术，每个雄性海胆配5个雌性海胆，每个雌性个体产生若干幼体，构成了11个父系半同胞家系和35个母系全同胞家系，分别测定了每个母系孵化后生长到3月龄和5月龄的全同胞幼海胆40-50个后代的体重和壳径，应用数量遗传学原理和半同胞组内相关分析法研究了虾夷马粪海胆早期生长发育性状的遗传力。结果表明，3月龄和5月龄的海胆体重的狭义遗传力估计值为0．339-0．523，壳径的狭义遗传力估计值为0．316-0．487。分析结果显示，雌性遗传方差组分均显著大于雄性遗传方差组分，雌性遗传方差组分存在显著的母性效应，表明由雄性遗传方差组分估计的遗传力准确可取，父系半同胞组内相关法计算的狭义遗传力是遗传力的无偏估计值。  相似文献   

4.
长牡蛎幼体生长性状的遗传力及其相关性分析   总被引：17，自引：7，他引：10  
采用平衡巢式设计方法和人工授精技术,每个雄体配3个雌体,构建了12个半同胞家系和36个全同胞家系.应用数量遗传学的全同胞组内相关分析法,利用SPSS软件的GLM过程计算表型变量的原因方差组分,估算了长牡蛎幼体生长性状的遗传力.结果表明,5～25日龄幼体壳高狭义遗传力估计值为0.161～01771,壳长狭义遗传力估计值为0.139～0.814,其中利用父系半同胞组内相关法估计壳高的遗传力依次为0.387、0.364、0.262、0.378、0.161,壳长的遗传力依次为0.383、0.398、0.302、0.361、0.139,二者均为中等遗传力.雌性亲本间半同胞个体具有较大的变异程度,存在着较大的母性效应;由雄性遗传方差组分估计的遗传力准确可靠,由父系半同胞组内相关法计算的狭义遗传力是长牡蛎幼体遗传力的无偏估计值.长牡蛎幼体不同生长时期壳高和壳长的遗传相关和表型相关均为正相关,相关系数的范围分别为0.091～0.820、0.224～0.360,表明以壳高或壳长为参数进行选育时,均可达到改良生长性状的效果.  相似文献   

5.
本研究基于全同胞组内相关法对9月龄刺参(Apostichopus japonicus)苗种体长、体重、肉刺总数3个性状的遗传力进行了评估。以前期收集、保存的刺参群体为亲本,选取了健康刺参29头,采用不平衡巢式设计方法及人工刺激采卵授精方法,按照1雌配2–5雄的原则,构建了6个母系半同胞家系及23个父系全同胞家系,至9月龄时,分别抽取每个家系30–50个后代测定相应个体的体长、体重及肉刺总数,应用数量遗传学分析和全同胞组内相关法估计刺参9月龄体长、体重和肉刺总数共3个生长性状的遗传力。结果显示,9月龄刺参体长雌性组分遗传力的估计值为0.87,雄性组分遗传力估计值为0.85,全同胞组分遗传力估计值为0.86;刺参体重雌性组分遗传力估计值为0.20,雄性组分遗传力估计值为0.73,全同胞组分遗传力估计值为0.46;肉刺总数雌性组分遗传力估计值为0.43,雄性组分遗传力估计值为0.32,全同胞组分遗传力估计值为0.37。t检验表明,体长、体重的雄性组分遗传力达到显著水平(P0.05),全同胞组分遗传力均达到极显著水平(P0.01),肉刺总数的遗传力均未达到显著水平。  相似文献   

6.
九孔鲍幼鲍生长性状的遗传参数估计   总被引：1，自引：0，他引：1  
采用不平衡巢式设计方法和人工授精技术,1个父本配3个母本,建立九孔鲍(Haliotis diversicolor super-texta)12个半同胞家系和36个全同胞家系.在40日龄、120日龄、180日龄、240日龄时分别对所建36家系个体测量壳长,壳宽与体质量.采用单性状约束最大似然法(Restricted Maximum Likelihood Method, REML)估计九孔鲍(Haliotis diversicolor supertexta)各阶段体质量,壳宽与壳长性状的遗传参数.结果表明,九孔鲍幼鲍在40、120、180、240日龄时壳长遗传力估计值为(0.13±0.09)~(0.56±0.15),壳宽遗传力估计值为(0.13±0.06)~(0.62±0.13),体质量遗传力估计值为(0.18±0.15)~(0.26±0.08),均属于中等遗传力.另外,从性状的表型相关与遗传相关可以得出,九孔鲍稚鲍在不同日龄壳长、壳宽与体质量的表型相关和遗传相关均为正相关(P≤0.05).表型相关系数为0.66~0.94,遗传相关系数为0.85~0.98,研究结果表明,以3个主要生长性状之一作为选育目标,均能达到遗传改良的目的.  相似文献   

7.
紫贻贝生长性状的遗传力估计   总被引：5，自引：2，他引：3  
为估计紫贻贝生长性状的遗传力,采用平衡巢式设计方法和人工采卵授精技术,按照1雄配3雌的原则,构建了紫贻贝13个父系半同胞家系和39个母系全同胞家系,分别测定了每个家系2、3、5、6月龄生长性状壳高、壳长.运用全同胞组内相关法估计紫贻贝2、3、5、6月龄生长性状的壳高、壳长遗传力.结果表明,雌性遗传方差组分均显著大于雄性遗传方差组分(P＜0.05),雌性遗传方差组分存在显著的母性效应(P＜0.05),因此父系半同胞组内相关法计算的狭义遗传力是紫贻贝狭义遗传力的无偏估计值.所测各月龄父系半同胞组分估计的壳高遗传力分别为0.29、0.85、0.84和0.87,壳长遗传力分别为0.27、0.87、0.86和0.85.紫贻贝的生长性状遗传方差较大,2月龄生长性状遗传力为中度遗传力,3、5、6月龄生长性状遗传力较高,因此对紫贻贝进行选择育种具有较大的遗传改良潜力,可以获得较好的选择效果.  相似文献   

8.
研究估计了斑点叉尾基础群体(G0)体质量、体长和存活性状的遗传参数,为制定育种目标、综合选择指数和选择方法提供基础参数。实验利用5个斑点叉尾引进群体,通过双列杂交和巢式交配设计,产生全同胞和半同胞家系。每个家系内的稚、幼鱼经过中间暂养、个体标记等阶段后,混合放入一个池塘进行生长和存活测试。利用两性状动物模型和公母畜阈模型分别估计生长和存活性状的方差组分和遗传参数。通过最佳线性无偏预测法估计所有个体生长和存活性状的育种值。斑点叉尾基础群体收获体质量和体长遗传力分别为0.41±0.074和0.32±0.064,属于高遗传力水平,并且统计检验显著(P0.05)。尽管在两性状动物模型中设置标记体质量和标记体长作为协变量进行校正,但是由于加性遗传效应和共同环境效应混淆在一起无法剖分,遗传力估计值偏高。收获体质量和收获体长的表型和遗传相关系数分别为0.93和0.97,表现为高度线性正相关。存活性状的遗传力为0.037±0.016,表现为低遗传力,但统计检验仍达到显著水平(P0.05)。家系生长(收获体质量和收获体长)和存活性状育种值间的相关系数分别为0.065和0.100,表现为低度线性遗传正相关,并且统计检验不显著(P0.05)。因此在制定育种方案时,生长和存活性状都可纳入育种目标,利用多性状选择指数方法同时选择。  相似文献   

9.
红鳍东方鲀(Takifugu rubripes)生长性状的遗传参数估计   总被引：1，自引：0，他引：1       下载免费PDF全文
通过人工受精的方法获得红鳍东方鲀8个半同胞家系(16个全同胞家系),共测量了790尾红鳍东方鲀8个半同胞家系(16个全同胞家系)135日龄和200日龄的体质量和体长。将135日龄生长性状作为协变量构建3个动物模型,模型(1)包含加性遗传效应、母本遗传效应和全同胞效应;模型(2)包含加性遗传效应和母本遗传效应;模型(3)包含加性遗传效应和全同胞效应。利用DMU软件,采用平均信息约束极大似然法估计各模型中性状的方差组分,用似然比检验法进行不同模型的差异检验。选择最优模型估计红鳍东方鲀200日龄生长性状的遗传参数。结果表明,母本遗传效应对200日龄红鳍东方鲀生长性状无显著影响,确定模型(3)为最优模型。200日龄红鳍东方鲀,体质量和体长的遗传力分别为0.16和0.14,全同胞效应比率分别为0.12和0.13。研究表明,红鳍东方鲀生长性状具备一定的选择潜力,应用家系选育方法能够获得较好的遗传进展。  相似文献   

10.
凡纳滨对虾生长性状遗传参数的估计   总被引：6，自引：3，他引：3  
采用平衡巢式设计方法和人工授精技术,每个雄体配3个雌体,构建了18个父系半同胞家系和54个母系全同胞家系.分别测定了每个母系生长到5月龄60个全同胞个体的体质量、全长、体长、头胸甲长、头胸甲宽、头胸甲高、第一腹节背高、第三腹节背高和第一腹节背宽9个生长性状,应用数量遗传学原理,采用方差和协方差分析的方法,估算了5月龄凡纳滨对虾生长性状的遗传力及各性状间的遗传相关及表型相关.结果表明,利用父系半同胞组内相关法估计的遗传力是凡纳滨对虾各生长性状遗传力的无偏估计值.其中,体质量、全长、体长、头胸甲长、头胸甲宽、头胸甲高、第一腹节背高、第三腹节背高和第一腹节背宽狭义遗传力的估计值分别为0.460、0.392、0.303、0.234、0.251、0.330、0.282、0.321和0.356,属于中高等遗传力范围,显示出较高的选择育种潜力.基于父系半同胞遗传协方差组分及表型协方差分别估计的各性状间的遗传相关及表型相关表明,各个性状间均表现出高的正相关,其中遗传相关在0.750 ～0.976,体质量—全长的遗传相关为最大(0.976),全长—第三腹节背高的遗传相关为最小(0.750),表型相关为0.507～0.947,体质量—全长为最大(0.947),第一腹节背高—头胸甲高为最小(0.507).经t检验,各性状间遗传相关及表型相关均达到极显著水平,表明以任意一个生长性状为参数进行选育,均可达到改良凡纳滨对虾生长情况的效果.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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).  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO2 and ions should be more often evaluated. Plasma Na+ and Cl‐ are very useful markers of acidosis, due to their respective exchange for H+ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.  相似文献   

20.
Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.  相似文献   

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