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1.
为研究鲈鲤(Percocypris pingi)苗种的生长特性,开发鲈鲤育苗技术,采用水泥池流水单养模式,在自然水温条件下,开展了10日龄至110日龄鲈鲤苗种培育试验。经过100 d的培育,鲈鲤鱼苗体质量从(46.45±4.03)mg增加到(2600.09±105.18)mg,平均体长从(16.22±0.46)mm增长到(50.78±2.97)mm,平均成活率为82.00%;体质量变异系数在4.05%~24.80%,体长变异系数在2.49%~7.32%,体质量变异系数大于体长变异系数;体质量变异系数整体呈现先升高后降低的变化趋势,体长变异系数整体变化较为平缓,在整个培育阶段,鲈鲤种群生长离散呈现从加剧到减弱的变化规律;体质量特定生长率在(0.91±0.49)%/d~(7.75±2.18)%/d,体长特定生长率在(0.47±0.29)%/d~(1.94±1.46)%/d,体质量特定生长率大于体长特定生长率;在水温16.8~23.0℃条件下,鲈鲤生长状况良好,特定生长率相对较高,当水温高于23.0℃之后,特定生长率呈降低趋势,表明16.8~23.0℃是鲈鲤鱼苗适宜的生长水温范围;肥满度变化范围在(1.09±0.10)~(2.85±0.18)g/cm^3,肥满度变化呈现先升高后降低的变化趋势;体长(x)和体质量(y)的拟合方程为y=0.0015x^3.7566(R^2=0.9806),b值为3.7566;全长(y)和体长(x)的拟合方程为y=1.223x-0.5055(R^2=0.9908)。试验结果表明,鲈鲤苗种在水泥池流水单养模式及自然水温条件下生长状况良好,16.8~23.0℃是鲈鲤苗种的适宜生长水温。  相似文献   

2.
在2013年1—12月渔业资源调查数据的基础上,研究了流沙湾海域勒氏枝鳔石首鱼的体长分布、体长-体质量的关系、肥满度月变化、饵料组成、摄食强度和营养级等生物学特性。结果表明:流沙湾海域枝鳔石首鱼体长82~145 mm,优势体长组为116~125 mm和106~115 mm;体长(L)-体质量(W)关系方程为:W=0.0242L~(2.9564)(R~2=0.9471);肥满度最大值出现在2月份,最小值出现在7月;枝鳔石首鱼的饵料组成以甲壳类为主要类群。枝鳔石首鱼的空胃率随季节变化显著(P0.05),在冬季最大,春季达到最小,饱满度指数在秋季最高,冬季最低;营养级变化范围在2.69~3.11,平均营养级为2.94。  相似文献   

3.
为了解池塘养殖条件下1龄异育银鲫“中科3号”的生长特性,在池塘自然水温(18.5~30.6℃)条件下,对体长(4.53±0.18)cm、体质量(2.73±0.17)g的1龄异育银鲫“中科3号”的生长性能进行了研究。试验结果:经过125 d培育,异育银鲫“中科3号”体长增长237.53%,体质量增长3312.45%;体长与体质量呈幂函数关系,关系式为W=0.0356L2.8885(R2=0.985),属等速生长型;体质量日增长量从试验开始到100 d始终呈增高态势,75~100 d的平均体质量日增长量为最高值(1.346 g/d),之后随着水温下降而降低;体质量相对增长率在0~25 d为最高(269.60%),而后逐渐降低,至125 d试验结束时为30.37%;生长指数(0.1054~0.4647)和生长常数(1.318~5.809)随着试验的进行逐渐降低;肥满度为2.6062~2.9480 g/cm^3,呈先降低、后升高、再降低的小幅波动;生长离散逐渐小幅增加。  相似文献   

4.
为完善美洲鲥池塘养殖技术,对美洲鲥1~+龄亚成鱼在池塘保温大棚条件下越冬的生长特性进行了研究。在上海市水产研究所奉贤科研基地开展了美洲鲥池塘保温大棚越冬养殖试验,放养密度为4 682尾/hm~2。试验结果:在水温11.2~20.6℃条件下,经150 d的越冬养殖,越冬成活率98.0%,美洲鲥体长增长26.6%,体质量增加96.2%,体质量与体长呈幂函数关系:W=0.012 3L~(3.076),R~2=0.922 8,接近于匀速生长,体长、体质量日均增长量随养殖天数的增加呈n形变化,肥满度在1.55~1.71,最大值出现在越冬养殖中期。结果表明:美洲鲥1~+亚成鱼的适宜越冬水温在12℃以上,最佳越冬水温在15℃以上。  相似文献   

5.
二龄拉氏鱥在池塘养殖条件下的生长特性   总被引:2,自引:0,他引:2  
为丰富二龄拉氏鱥(Phoxinus lagowskii Dybowskii)的生长生物学资料,研究了二龄拉氏鱥在池塘养殖条件下的生长特性。对平均体长(8.56±0.78)cm,平均体质量(9.62±0.82)g的拉氏鱥,在水温变幅19.4~27.6℃条件下,经过120 d的养殖试验,体长增长36.76%,体质量增长179.63%。体长与体质量呈幂函数关系:W=0.008 1 L3.299 2,R2=0.988 3。体质量日增重在试验60~90 d时最高(0.237 g),体质量相对增长率在试验30~60 d时最高(48.26%)。试验期间,生长常数和生长指标变化趋势一致,在试验30~60 d时最高;试验鱼肥满度从试验初到结束一直小幅升高,变幅为1.528 4~1.671 0;生长离散60~90 d较大,试验末期较小。结果表明,池养二龄拉氏鱥生长为异速生长型,其体质量增长快于体长增长;特定生长率与水温变化关系密切,水温23.5~27.6℃为生长适宜水温。  相似文献   

6.
对室内养殖的1龄和2龄褐菖鲉的生长特性进行了初步研究和比较。1龄褐菖鲉的初始体长、体质量分别为(5.91±0.74)cm、(7.15±2.44)g,2龄褐菖鲉的初始体长、体质量分别为(11.18±0.54)cm、(41.56±6.23)g。经63 d培育,1龄褐菖鲉体长增至(8.64±0.54)cm,日均增长量0.043 cm/d,体长相对增长率为46.19%;体质量增至(19.95±3.39)g,日均增长量0.203 g/d,体质量相对增长率为179.02%。体质量(W)与体长(L)呈幂函数关系,关系式为:W=0.052 5L~(2.737 4)(R~2=0.922 1),b值接近于3,属于等速生长型。体长(L)与日龄(t)的相关关系式为:L=0.0389t+0.4734(R~2=0.937 3,P0.01)。体质量(W)与日龄(t)的相关关系式为:W=0.199 9t-22.487(R~2=0.986 3,P0.01)。2龄褐菖鲉经63 d培育,体长增至(12.32±0.61)cm,日均增长量0.018 cm/d,体长相对增长率为10.19%;体质量增至(56.56±7.68)g,日均增长量0.238 g/d,体质量相对增长率为36.09%。体质量(W)与体长(L)呈幂函数关系,关系式为:W=0.075 5L~(2.624 5)(R~2=0.801 7),b值接近于3,属于等速生长型。体长(L)与日龄(t)的相关关系式为:L=0.014 7t+3.607 5(R~2=0.897 4,P0.01),体质量(W)与日龄(t)的相关关系式为:W=0.226 1t-76.214(R~2=0.977 9,P0.01)。  相似文献   

7.
于2017—2019年采用在池塘上方搭建简易保温大棚的方式开展了美洲鲥当年鱼种越冬养殖试验,研究探讨了越冬养殖相关的技术参数。结果显示:搭建保温大棚后,冬季池塘水温可保持在10℃以上,在美洲鲥当年鱼种(0+龄鱼种,平均体长12.45~16.65 cm,平均体质量27.29~66.41 g)放养密度为1518~2970尾/亩(15亩=1 hm^2,下同)和81.04~100.78 kg/亩的条件下,在越冬前中期(12月至次年3月中旬),日投饲量在0.8~1.6 kg/亩,越冬后期(次年3月中旬至4月上中旬),日投饲量也由2.0 kg/亩左右迅速增加到4.0~5.0 kg/亩。经过125~130 d的越冬养殖,鱼种平均体长达17.48~21.19 cm,增长28.04%~40.40%,平均体质量77.57~137.96 g/尾,增加了106.53%~184.24%,鱼种的体长和体质量特定生长率分别为(0.193~0.261)%/d和(0.585~0.804)%/d,日均增长量和日增重分别为0.036~0.039 cm/d和0.387~0.572 g/d;收获时美洲鲥鱼的肥满度为1.42~1.43 g/cm3,养殖成活率为89.29%~94.81%,饲料系数为1.50~1.65,亩产量为198.50~205.68 kg。试验结果表明,在江浙地区,养殖池塘上方搭建保温大棚后,冬季池塘水温(10~20℃)在美洲鲥当年鱼种的适宜水温范围,能获得较理想的越冬养殖效果。  相似文献   

8.
鄱阳湖日本沼虾捕捞种群生长与结构分析   总被引:2,自引:0,他引:2  
日本沼虾为鄱阳湖的优势种群,在全湖均有分布,2013年4月至11月对鄱阳湖日本沼虾进行了调查,调查结果表明:在采集的标本中,最大体长8.1cm,最小体长1.7cm,其捕捞群体以体长为2.0~4.9cm为主,占85%以上,5cm以上青虾个体不足10%,其捕捞群体小型化比较明显;其体长和体重关系式为W=0.00517 L2.3959(r=0.96,p﹤0.05);鄱阳湖湖区青虾的肥满度(K)变异范围在1.04%~5.25%,平均为2.76%,雌虾与雄虾肥满度无显著差异(p﹥0.05);6~8月为青虾的捕捞高峰,日平均单船捕捞量为21.89kg。  相似文献   

9.
根据北部湾渔港采样及海上调查生物学测定与数据分析,研究了北部湾多齿蛇鲻(Saurida tumbil)春季生物学特征及其年际变化。结果显示,2008~2018年春季,多齿蛇鲻个体呈小型化趋势,各年度平均体长范围为15.8~16.9 cm,平均体质量范围为48.8~77.5 g,2018年的平均体长和平均体质量比2008年分别降低了6.5%和34.5%。体长–体质量关系式中的异速生长参数b的范围为3.03~3.42,表明春季群体主要呈正异速生长状态(b>3)。性成熟体长年际变化分析表明,北部湾多齿蛇鲻存在性成熟提前的现象,雌性群体50%性成熟体长从2008年(19.0cm)至2018年(16.6cm)整体呈减小趋势,10年间减小比例为12.6%,其中,2011~2015年海上采样的样品对比显示,50%性成熟体长减小比例为3.8%。2008~2018年北部湾多齿蛇鲻的肥满度整体呈下降趋势,均值变化范围为1.09~1.29,渔港采样样品和海上采样样品的肥满度年际变化皆呈下降趋势。  相似文献   

10.
杨骏  何兴恒  孙治宇 《水产科学》2020,39(2):209-217
对采自四川省广元市旺苍县东河的113尾中华花鳅的生长和繁殖生物学进行研究。结果显示,旺苍县东河的中华花鳅体长34.92~102.85 mm,体质量0.34~9.84 g,净体质量0.31~8.09 g。分为5个年龄组,以2~4龄个体为主。生长以3龄为分界,3龄前生长速度快,3龄后生长速度减慢。体长(m1)与体质量(L)呈幂函数关系:m1=0.00001215L2.896,r2=0.939,接近等速生长。肥满度<1,雌性和雄性的Fulton肥满度差异不显著,雄性略小于雌性;而除1龄的个体外,其他年龄的雄性Clark肥满度均略大于雌性。雌、雄性比为1∶1.69。雌、雄鱼最小性成熟年龄均为2龄。精子在蒸馏水中的平均寿命为14 s;随NaCl溶液质量分数的增大,中华花鳅精子平均寿命先增后减,在NaCl溶液质量分数为0.25%时寿命最长,达184 s。绝对繁殖力为427~4047粒/尾,平均1949.82粒/尾;相对繁殖力为107.56~566.09粒/g,平均356.07粒/g。6月中旬至8月中旬为产卵盛期。分批产卵,且各批次生殖力大致相同。受精卵为微黏性的沉性卵。  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.
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   

13.
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   

14.
15.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
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.  相似文献   

16.
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   

17.
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   

18.
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   

19.
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   

20.
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.  相似文献   

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