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1.
鱼类早期发育阶段消化系统的研究进展   总被引:1,自引:0,他引:1  
本文综述了鱼类胚胎发育阶段和仔稚鱼发育阶段消化器官变化过程,以及个体发育水平、饵料因素和环境因子对仔稚鱼消化酶的影响,有助于正确了解和掌握鱼类早期阶段消化系统的发育规律,为仔稚鱼初期饵料的开发提供消化生理学上的理论依据.  相似文献   

2.
辛玉文 《海鲜世界》2005,(3):48-48,50
达氏鳇为肉食性凶猛鱼类,具有个体大、生长速度快、抗病力强等特点,市场前景看好,越来越成为理想的养殖对象.但苗种培育技术并不成熟,苗种成活率不高,特别是仔稚鱼阶段.笔者对达氏鳇仔稚鱼培育做了研究,并取得了76%的成活率.现把达氏鳇仔稚鱼培育技术措施介绍如下,供养殖者参考.  相似文献   

3.
尖吻鲈仔、稚鱼异速生长研究   总被引:3,自引:0,他引:3  
以16日龄尖吻鲈(Lates calarifer)为仔、稚鱼发育的区分节点,采用Auto CAD 2014软件对尖吻鲈(孵化后1~36 d)关键器官进行测量和分析。研究发现,在尖吻鲈仔、稚鱼的感觉、呼吸、摄食和游泳等重要器官分化的过程中,均表现出异速生长现象。头部器官中,吻长、口宽在仔、稚鱼期表现出生长速率不同的正异速生长;眼径在仔鱼期为等速生长,稚鱼期转化为负异速生长;仔鱼期的头高为正异速生长,稚鱼期转为负异速生长。在躯干部分器官中,头长在仔、稚鱼阶段均为快速生长,体高及躯干长为等速生长。游泳器官中,仔鱼期,尖吻鲈胸鳍保持等速生长,稚鱼期转为正异速生长;尾鳍在仔鱼期为负异速生长,稚鱼期转化为等速生长,而稚鱼期起始分化的背鳍、臀鳍、腹鳍为快速生长。  相似文献   

4.
使用显微镜和解剖镜对史氏鲟仔鱼期、稚鱼期发育过程进行连续观察,使用目微尺测量仔鱼多项数量性状,利用观察到的形态和数据统计分析结果进行生态学研究。实验结果表明,史氏鲟的早期发育分两个阶段,即胚后期孵出仔鱼(体长10.4~11.2 mm)到开食阶段(体长21.1~22.3 mm)和稚鱼阶段(指外源营养阶段到体态形成阶段)。仔鱼期较稚鱼期和幼鱼期在形态发生和分化上更强烈。优先发展重要的器官,然后发展次要器官是一种真骨鱼类共有的发育模式,我们把这种发育模式称之为异速生长模式。通过研究史氏鲟仔鱼的异速生长模式,讨论了异速生长的生态学意义,证明了早期生命阶段的形态发育和增长模式与当前需要有着密切关系的假设。  相似文献   

5.
海水养殖鱼类仔、稚鱼骨骼发育与畸形发生   总被引:2,自引:1,他引:1  
骨骼畸形可导致鱼类运动困难、摄食能力降低、生长缓慢、成活率低,因此,畸形鱼苗的出现将增加生产成本、影响养殖的经济效益。在海水鱼类人工育苗阶段,骨骼畸形现象普遍存在,严重制约了海水鱼类养殖产业的可持续发展。本文首先系统总结了卵形鲳鲹、黄尾鰤、尖吻鲈等经济海水鱼类颌骨、脊柱、尾骨的早期发育时序及特点,比较了仔、稚鱼骨骼畸形发生的部位、时间及发生规律。之后针对仔、稚鱼阶段影响骨骼发育的主要因素,从遗传、环境、营养等方面进行了剖析,以期为寻找降低人工养殖条件下海水鱼类仔、稚鱼的骨骼畸形提供启示。  相似文献   

6.
综述了海水养殖鱼类消化酶活性研究的以下三方面:(1)消化酶活性的研究,内容包括消化酶的活性分布,温度、pH、外界环境及季节变化对消化酶活性的影响;(2)不同生长阶段消化酶活性的变化,内容包括与仔鱼生长发育相对应的消化酶形成的时间,稚鱼、幼鱼在生长进程中,消化酶的变化规律;(3)鱼类的食物组成对消化酶活性的影响,内容包括饲料的种类和性质,以及饲料不同成分对鱼类消化酶的分泌、活性的影响,进而对饲料利用率的影响。本本对海水养殖鱼类消化酶的活性进行了较为系统的综述,为海水养殖鱼类饲料的开发提供参考数据。  相似文献   

7.
为丰富细鳞鲑(Brachymystax lenok)早期幼鱼培育的基础生物学资料和规模化人工养殖提供理论指导,探究了不同温度(9、13、17、21、25℃)、不同盐度(0、3、6、9、12)及在不同盐度下温度变化对细鳞鲑仔、稚鱼存活和生长的影响。结果表明,温度25℃和盐度9、12条件下,细鳞鲑仔、稚鱼存活率显著低于其他各组(P0.05),温度17℃对细鳞鲑仔、稚鱼末重和特定生长率显著高于其他温度水平(P0.05);随着盐度的升高,细鳞鲑仔、稚鱼末重和特定生长率显著降低(P0.05);在不同盐度的水体中,水温升至19℃时,盐度6、9、12时细鳞鲑仔、稚鱼开始死亡。试验显示,在细鳞鲑仔、稚鱼培育阶段,在9~17℃范围内可适当提高水温,增加其生长速度和增重效果,缩短养殖周期;在一定的盐度水环境中,细鳞鲑仔、稚鱼对温度的适应范围缩小,适应能力减弱。  相似文献   

8.
为丰富细鳞鲑(Brachymystax lenok)早期幼鱼培育的基础生物学资料和规模化人工养殖提供理论指导,探究了不同温度(9、13、17、21、25℃)、不同盐度(0、3、6、9、12)及在不同盐度下温度变化对细鳞鲑仔、稚鱼存活和生长的影响。结果表明,温度25℃和盐度9、12条件下,细鳞鲑仔、稚鱼存活率显著低于其他各组(P<0.05),温度17℃对细鳞鲑仔、稚鱼末重和特定生长率显著高于其他温度水平(P<0.05);随着盐度的升高,细鳞鲑仔、稚鱼末重和特定生长率显著降低(P<0.05);在不同盐度的水体中,水温升至19℃时,盐度6、9、12时细鳞鲑仔、稚鱼开始死亡。试验显示,在细鳞鲑仔、稚鱼培育阶段,在9~17℃范围内可适当提高水温,增加其生长速度和增重效果,缩短养殖周期;在一定的盐度水环境中,细鳞鲑仔、稚鱼对温度的适应范围缩小,适应能力减弱。  相似文献   

9.
为查明许氏平鲉(Sebastes schlegelii)仔、稚鱼消化酶活性随日龄的变化过程,探讨消化酶的发育特性与饥饿的影响,以其初产仔鱼为研究对象,设置6个实验组,分别在1、2、3、4、5d时开始初次投喂(即C、D1、D2、D3和D4组)和完全不投喂(S组)。结果显示,仔鱼前期的许氏平鲉消化酶的比活力波动较大,进入仔鱼后期(22d后),消化酶比活力逐渐稳定;而总活力在仔、稚鱼阶段均不高,变化不显著,进入稚鱼后期后(26d后)随日龄显著升高;存活的各实验组仔、稚鱼消化酶活力在相同日龄时差异并不显著,但由于前期的饥饿,实验结束时D2、D3组仔稚鱼的全长、体重和特定生长率均显著低于C、D1组。结果表明,延迟投喂时间对许氏平鲉的生长发育有显著影响,而且这种影响在生长后期很难恢复。  相似文献   

10.
卵形鲳鲹仔稚鱼异速生长的研究   总被引:2,自引:0,他引:2  
以传统的理论生物学研究方法,对孵化后卵形鲳鲹1~36日龄仔、稚鱼各器官测量和分析,研究其在早期环境适应上的异速生长及其生态学含义,以期为卵形鲳鲹的人工繁殖、育苗提供参考。试验结果表明,卵形鲳鲹仔、稚鱼的感觉、呼吸、摄食和游泳等器官快速分化,均存在异速生长现象。在头部器官中,吻长、口宽、眼径和头高在仔鱼期均为正异速生长,稚鱼期头高为等速生长,吻长、眼径和口宽为负异速生长。在身体各部位中,仔鱼期头长、体高和尾长为正异速生长,躯干长为负异速生长;稚鱼期各部分皆为等速生长;在游泳器官中,仔鱼期卵形鲳鲹胸鳍长、尾鳍高和臀鳍长为正异速生长,尾鳍长为等速生长,背鳍长为负异速生长;稚鱼期背鳍长和臀鳍长为正异速生长,胸鳍长、尾鳍长和尾鳍高为等速生长。卵形鲳鲹这些关键部位的快速发育,使外源性营养开始后以最小的代谢损耗获得了生存能力的显著提升,对适应复杂的生存压力具有重要的生态学意义。  相似文献   

11.
To investigate the impact of changing environmental conditions in the North Sea on the distribution and survival of early life stages of a marine fish species, we employed a suite of coupled model components: (i) an Eulerian coupled hydrodynamic/ecosystem (Nutrients, Phyto‐, Zooplankton, Detritus) model to provide both 3‐D fields of hydrographical properties, and spatially and temporally variable prey fields; (ii) a Lagrangian transport model to simulate temporal changes in cohort distribution; and (iii) an individual‐based model (IBM) to depict foraging, growth and survival of fish early life stages. In this application, the IBM was parameterized for sprat (Sprattus sprattus L.) and included non‐feeding (egg and yolk‐sac larval) stages as well as foraging and growth subroutines for feeding (post‐yolk sac) larvae. Sensitivity analyses indicated that the angle of visual acuity, assimilation efficiency and the maximum food consumption rate were the most critical intrinsic model parameters. As an example, we applied this model system for 1990 in the North Sea. Results included not only information concerning the interplay of temperature and prey availability on larval fish survival and growth but also information on mechanisms underlying larval fish aggregation within frontal zones. The good agreement between modelled and in situ estimates of sprat distribution and growth rates in the German Bight suggested that interconnecting these different models provided an expedient tool to scrutinize basic processes in fish population dynamics.  相似文献   

12.
Variability in the high mortality rate during early life stages is considered to be one of the principal determinants of year‐class variability in fish stocks. The influence of water column stability on the spatial distribution of fish larvae and their prey is widely acknowledged. Water column stability may also impact growth through the early life history of fishes, and consequently alter the probability of survival to maturity by limiting susceptibility to predation and starvation. As a test of this concept, the variability in condition and growth of dab (Limanda limanda) and sprat (Sprattus sprattus) larvae was investigated in relation to seasonal stratification of the water column in the north‐western Irish Sea. RNA/DNA ratios and otolith microincrement analysis were used to estimate nutritional status and recent growth rates of larvae captured on four cruises in May and June of 1998 and 1999. Dab and sprat larvae were less abundant in 1999 and were in poorer condition with lower growth rates than in 1998. Dab larvae of <13 mm also exhibited spatial variability with higher RNA/DNA ratios at the seasonal tidal‐mixing front compared with stratified and mixed water masses. However, the growth and nutritional status of sprat larvae was uncorrelated to water column stability, meaning the more favourable feeding conditions generally associated with the stratified pool and tidal‐mixing front in the Irish Sea were not reflected in the growth and condition of these larvae. This suggests that the link between stability, production and larval growth is more complicated than inferred by some previous studies. The existence of spatio‐temporal heterogeneity in the growth and condition of these larvae has implications for larval survival and the recruitment success of these species in the Irish Sea.  相似文献   

13.
The aim of this paper is to provide explanations of how dietary phospholipid (PL) globally improves fish larval development, including growth and survival, digestive functions and skeletal development, and to propose optimal PL levels and sources in fish larval diets. Dietary incorporation of 8–12% PL related to dry matter (d.m.) promotes growth and enhanced survival in various species. Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin. This beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology. Nevertheless, 1.5–2.5% highly unsaturated fatty acids related to diet d.m. supplied by PL improved growth, survival and skeletal development, while 5% induced different skeletal deformities. The high incidence of deformities was associated with the down-regulation of genes involved in development, such as RXRα, RARα, RARβ and BMP-4, observed in the early stages in larvae fed a high highly unsaturated fatty acids level.  相似文献   

14.
Early life survival is critical to successful replenishment of fish populations, and hypotheses developed under the Growth-Survival Paradigm (GSP) have guided investigations of controlling processes. The GSP postulates that recruitment depends on growth and mortality rates during early life stages, as well as their duration, after which the mortality declines substantially. The GSP predicts a shift in the frequency distribution of growth histories with age towards faster growth rates relative to the initial population because slow-growing individuals are subject to high mortality (via starvation and predation). However, mortality data compiled from 387 cases published in 153 studies (1971–2022) showed that the GSP was only supported in 56% of cases. Selection against slow growth occurred in two-thirds of field studies, leaving a non-negligible fraction of cases showing either an absence of or inverse growth-selective survival, suggesting the growth-survival relationship is more complex than currently considered within the GSP framework. Stochastic simulations allowed us to assess the influence of key intrinsic and extrinsic factors on the characteristics of surviving larvae and identify knowledge gaps on the drivers of variability in growth-selective survival. We suggest caution when interpreting patterns of growth selection because changes in variance and autocorrelation of individual growth rates among cohorts can invalidate fundamental GSP assumptions. We argue that breakthroughs in recruitment research require a comprehensive, population-specific characterization of the role of predation and intrinsic factors in driving variability in the distribution and autocorrelation of larval growth rates, and of the life stage corresponding to the endpoint of pre-recruited life.  相似文献   

15.
Red porgy, Pagrus pagrus, is a candidate species for aquaculture diversification. The aim of this work was to assess whether an early supply of enriched Artemia (D1) or a direct step to dry diets (D3) would be advantageous weaning strategies for red porgy larvae, compared to a later supply of Artemia followed by dry diets (D2). Direct weaning to dry diet resulted in significantly lower growth, survival, pancreatic (trypsin and lipase), and intestinal (alkaline phosphatase) enzyme‐specific activity, with the exception of leucine‐alanine peptidase. The direct weaning strategy presented severe nutritional restrictions from early weaning stages with an associated delay of the maturation of digestive system. The two‐step strategy presented in D1 and D2 resulted in comparable results in most parameters, including survival. Weaning using enriched Artemia as an intermediate step is confirmed as the most adequate strategy for red porgy larvae. Digestive enzymes and selected fatty acids correlated well with performance responses to dietary regimes, thereby supporting the use of these parameters as sensitive and reliable indicators of red porgy nutritional or physiological status during larval stages.  相似文献   

16.
Abstract –  Relationships between fish length, otolith size, age and weight were assessed for a population of wild Australian smelt ( Retropinna semoni ) larvae and juveniles captured over a 4-year period to aid further interpretation of growth and condition during the early life history of the species. Nonlinear smoothed generalized additive models best described the fish–otolith size relationship during the larval and juvenile period, indicating that the proportionality between fish length and otolith size varies in relation to size. It is proposed that back-calculated predictions of fish size at a previous age or otolith size, accounting for individual variation is possible by assuming a body proportional hypothesis. Growth rate of larval and juvenile Australian smelt was best described using the Gompertz model that indicated a steady decline in growth rate after around 30 days of age. The allometric growth of larval and juvenile Australian smelt established from the length/weight relationship can subsequently be used to assess the condition of fish within this population using a relative condition or relative weight condition index. The results of the study have provided significant information to enable more precise growth reconstruction and condition assessment for the species in Australian lowland rivers.  相似文献   

17.
黄伟  曹亮  窦硕增 《水产学报》2016,40(8):1272-1288
鱼类早期生活阶段对外界环境极为敏感,即使低浓度的污染物暴露也可能对其胚胎发育、仔鱼生长存活造成损害,导致种群数量和质量的降低。研究污染物对鱼类早期生活阶段的毒理效应和机制是揭示污染物对生物种群和水生生态系统潜在风险的有效途径。重金属对鱼类的影响在精、卵发生时即可显现。例如,抑制卵(精)母细胞成熟和精子活力降低,使受精率降低;影响受精卵吸水膨胀过程,改变胚胎发育速率、引起胚胎畸形、影响胚胎心率、改变孵化时间、降低孵化率;影响初孵仔鱼体长、造成仔鱼畸形、影响卵黄囊吸收和胚后仔鱼发育生长、摄食行为等。重金属对鱼类早期发育阶段的毒性效应主要取决于金属种类、暴露浓度和受试鱼种及其发育阶段。此外,外界环境条件等因素也会对重金属的毒性产生显著影响。本研究综合分析国内外关于重金属污染物对鱼类精卵、胚胎、仔鱼等早期发育过程生态毒理效应的研究进展,并结合相关报道阐述了其毒性机制。  相似文献   

18.
以美洲西鲱(Alosa sapidissima)仔鱼(孵化后10 d)为实验对象,在室内进行为期30 d的摄食生长试验,分别投喂不同的饵料[单独投喂卤虫(Artemia)、单独投喂微颗粒饲料、卤虫与微颗粒饲料混合投喂],分析不同饵料的投喂对存活、生长、消化酶活性、非特异性免疫相关酶活性以及体脂肪酸组成的影响。结果表明:(1)混合投喂组的存活与生长表现都要显著优于卤虫组和微颗粒饲料组(P0.05),微颗粒饲料组与卤虫组相比差异不大,而试验后期(20~30 d)微颗粒饲料组的存活与生长表现要优于卤虫组;(2)消化酶的结果显示,胃蛋白酶和淀粉酶活力在各组中无显著性差异(P0.05),胰蛋白酶、糜蛋白酶和脂肪酶在卤虫组中活力最低,显著低于其他两组(P0.05),其中糜蛋白酶和脂肪酶活性在微颗粒饲料组中要显著高于混合投喂组(P0.05);(3)碱性磷酸酶和超氧化物岐化酶活力在各组中无显著性差异(P0.05),过氧化氢酶和溶菌酶活力在微颗粒饲料组中最高,卤虫组中最低,两者之间差异显著(P0.05);(4)鱼体脂肪酸受饵料脂肪酸组成影响较大,微颗粒饲料中n-3HUFA和DHA含量较高,其投喂后在鱼体中的含量也高。综上所述,不同饵料投喂对美洲西鲱仔稚鱼存活、生长、消化酶活性、非特异性免疫相关酶活性以及体脂肪酸影响显著,在试验20 d之前使用卤虫与微颗粒饲料混合投喂,20 d后完全转食微颗粒饲料,可以降低成本,同时提高生产效率。  相似文献   

19.
Egg Quality in Wild and Broodstock Cod Gadus morhua L.   总被引:1,自引:0,他引:1  
Problems concerning egg viability or egg quality have received increasing attention, in relation to cultivation as well as to the assessment of reproduction of wild fishes. One important aspect of this paper is to discuss the use of cell morphological characteristics as indicators of egg quality in cod. Early cellular malformation rates in egg batches show a positive correlation with their later egg and larval survival, and can be used as a rough prediction of normal development and mortality rates.
The natural mortality rate offish eggs is not well understood, and observed egg viability of captive cod is are discussed in relation to egg viability in the wild. Results from recent work indicated that approximately 10% of naturally spawned cod eggs from both wild fish (planktonic samples) and from a broodstock had abnormal cleavages at the 2–128 cell stage. Eggs with observed early abnormal cell-cleavage showed very poor survival and hatching rates. For broodstock cod, egg viability was highest during the peak of the spawning season.
The North Atlantic cod may provide a good model species for studies of egg viability variations in wild and captive individuals, as its reproductive biology is well studied. It is now documented that the egg production in cod is dependent on fish age, nutritional status, batch number, and stress factors.  相似文献   

20.
Marine Fish Larvae Feeding: Formulated Diets or Live Prey?   总被引:7,自引:0,他引:7  
In the rearing of larval marine fish, any diet that reduces dependance on live prey production is of technical and economic interest. Weaning juveniles with a completely developed digestive tract to a conventional diet, (i.e., "late weaning") can be successful in any marine fish species. For example, weaning one-month-old sea bass (20 mg) to the study's reference diet, Sevbar, resulted in over 85% survival (40% from hatching) and 1.25 g fish at day 90 (at 19 C)
In contrast, "early weaning" of larvae to special microdiets during the first month is still difficult. The best way to reduce live prey utilization in sea bass is to wean larvae at about 3–4 mg in size (day 20). If weaning could be accomplished 15 days earlier, Artemia savings could be as high as 80%. However, this introduces risks relative to growth retardation (30% weight loss) and lower juvenile quality, including greater size variability and skeletal abnormalities. Similar results have been obtained with commercial microparticles (Fry Feed Kyowa) and experimental microbound diets (MBD) made from raw materials (alginate MBD) or preferably from freeze-dried protein sources (zein MBD).
Total replacement of live prey is still impossible in marine fish. Sea bass larvae fed formulated diets exclusively from first feeding (0.3 mg larval wet weight), or even from their second week of life onwards, exhibited low survival and poor growth. Better results can be obtained when formulated diets are used in combination with live prey from first feeding, although the optimal ratio of live prey to formulated diet is still to be specified.  相似文献   

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