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1.
温度、盐度对条斑星鲽胚胎发育的影响   总被引:1,自引:0,他引:1  
就温度、盐度对条斑星鲽胚胎发育的影响作了初步探讨。实验表明,胚胎发育的适宜温度为6~12℃,最适水温为8~10℃,在适温范围内胚胎孵化速度与温度呈正相关关系(N=65.925T^-0.9672)。盐度低于27,受精卵下沉,27~30之间悬浮于水体中,盐度高于35,受精卵浮于水面。胚胎孵化的适宜盐度范围、最适盐度范围分别为25~40和28~36;盐度低于25或高于40,孵化率都降低。研究表明,条斑星鲽胚胎发育的生物学零度(阈温度)为-0.1℃,有效积温值为1726.48℃.h。另外,根据其Q10值推算的胚胎发育的适宜水温与实验结果相似。  相似文献   

2.
温度与盐度和缢蛏幼体生存、生长及发育的关系   总被引:12,自引:0,他引:12  
林笔水  吴天明 《水产学报》1990,14(3):171-178
本文以长期生活在较高盐度(26—28‰)海域的亲蛏所繁衍的幼体为材料,探索温度和盐度单因子及双因子结合与幼体生存生长、发育的相互关系。浮游幼虫期适盐范围为8.4—32.4‰,最适盐度为12.4‰,稚贝适盐范围为8.4—28.4‰,最佳盐度为12.4‰。温度对幼体的影响,是受盐度高低所支配。在盐度为28.4‰生境中培育,浮游幼虫期适温范围为17—25℃,最适温度为21℃,稚贝适温范围为13—25℃,最适温度为17℃,幼体对25℃以上的较高温度的忍耐力较差。若在最适盐度(12.4‰)中培育,浮游幼虫期最适水温为25℃,稚贝最适水温为21℃。幼虫对较高盐度的忍耐力比对较低盐度的忍耐力来得强。  相似文献   

3.
温度和盐度对日本黄姑鱼胚胎发育的影响   总被引:2,自引:0,他引:2  
为了确定日本黄姑鱼(Nibea japonica)胚胎孵化的最适水温和盐度,采用不同水温和盐度对日本黄姑鱼受精卵进行了孵化试验。结果显示,在盐度为30的条件下,日本黄姑鱼受精卵在14~28℃范围内均能正常孵化,最适孵化水温为18~20℃。孵化时数与温度呈幂函数相关,孵化时间随温度升高而缩短。盐度试验表明,在水温为18℃的条件下,日本黄姑鱼受精卵在盐度25—32的海水中呈悬浮或者半悬浮状态,在盐度14~45范围内均能孵化,适宜孵化盐度为26~32。盐度对初孵仔鱼全长有显著影响,盐度较低组仔鱼全长显著大于高盐度组(P〈0.05)。  相似文献   

4.
温度和盐度同缢蛏稚贝存活及生长的关系   总被引:3,自引:0,他引:3  
本文阐述在室内控制的温度和盐度条件下,采用单因子和结合的方法,研究温度和盐度同缢蛏稚贝存活及生长的关系。缢蛏稚贝的适盐范围为4.50‰至28.30‰,最适盐度为12.40‰至16.30‰。在25℃时,它对低盐(1.80‰以下)有较强的忍耐性,对高盐度(33.50‰至40.00‰)也有一定的忍耐性。缢蛏稚贝的适温范围为10℃至35℃。但最适温度随盐度的不同而异,若在最适盐度的生境中,它的最适水温为27℃至30℃;如果稚贝在最适盐度以外的适盐范围内,经方差分析表明,它的最适温度是22℃。稚贝对低温(5℃至2℃)有很强的忍耐性,致死温度上限是40℃。缢蛏稚贝对盐度的敏感性,比它对温度的敏感性来得强。在22℃以下的温度组中和最适盐度范围内,盐度与温度的相关性不太明显;而在27℃以上的较高温度和适盐范围的上下极限时,其相关性显著,它们相应的适盐或适温范围明显地变窄。  相似文献   

5.
温、盐度对鲻鱼胚胎发育和孵化的影响   总被引:3,自引:0,他引:3  
本文探讨了不同温度、盐度条件下鲻鱼胚胎发育和孵化情况,结果表明:(1)鲻鱼胚胎发育的适宜水温为18—25℃;(2)适宜盐度为25—40;(3)最适孵化条件为温度25℃和盐度30—35。  相似文献   

6.
探讨了温度、盐度对褐牙鲆(♀)×犬齿牙鲆(♂)杂交子一代(杂交F1)胚胎和初孵仔鱼发育的影响。结果表明,杂交F1受精卵孵化适宜温度范围和最适温度分别为15~21℃和18℃,在适宜温度范围内胚胎发育时间随温度的升高而缩短,二者符合乘幂函数关系式N=115.99T-0.7668(R2=0.9769)。胚胎发育的生物学零度和有效积温分别是7.54℃和540.1℃.h,积算温度(A)与试验水温间呈乘幂函数相关,表达式:A=1328.1T-0.3149(R2=0.9624)。胚胎发育的最低盐度界限为10,孵化的适宜盐度范围和最适盐度范围分别为10~45、25~35;初孵仔鱼生存发育的适宜盐度范围、最适盐度范围分别为10~40和10~20。  相似文献   

7.
在水温14~33℃(盐度34)、盐度18-40(水温25.5-26℃)范围内各设12个梯度,采用突变法进行温、盐度对方斑东风螺[Babylonia areolata(Link)]卵囊孵化及幼虫生长实验。结果显示:(1)方斑东风螺胚胎发育适宜水温为23~31℃,最适水温为25-30℃;适宜盐度为28-38,最适盐度为30~38。在适宜水温和盐度范围内,孵化速度随水温和盐度升高而加快,但以水温的影响效应最明显;温度或盐度超过其适宜范围时,孵化率明显下降或幼虫畸形率明显增大。(2)幼虫适宜水温及最适水温与胚胎发育的基本一致;适宜盐度和最适盐度存在向高盐度延伸的现象,其适宜和最适盐度下限分别为30和32。温盐度超过适宜范围时,死亡率明显增大,生长受到抑制。  相似文献   

8.
条石鲷人工育苗及养殖技术   总被引:2,自引:0,他引:2  
论述了条石鲷的工厂化人工育苗和养殖技术。在水温18~22℃下,通过“控温+控光+强化营养”的方法,3龄以上的亲鱼可以达到性成熟,在培育池内自然产卵受精,产卵时的水温控制在23±1℃为好。条石鲷受精卵为浮性,在孵化水温23±0.5℃的条件下,受精卵大约27.5~32小时孵化出仔鱼。条石鲷的生存水温为6~32℃,最适宜水温为18~26℃;生存盐度5—35,最适宜盐度25左右:  相似文献   

9.
温度、盐度对似刺鳊鮈胚胎发育过程的影响   总被引:1,自引:0,他引:1  
设置10℃、15℃、20℃、24℃、27℃、30℃6个温度组和0‰、2.5‰、5‰、10‰、15‰、太湖湖水组6个盐度组,探讨了温度和盐度对似刺鳊鮈(Paracanthobrama guichenoti)胚胎发育的影响。温度实验结果表明:似刺鳊鮈胚胎发育的起始温度(生物学零度)为9.5℃,适宜的发育水温为20~24℃。水温10℃时胚胎卵裂异常,未能进入原肠期;水温升至30℃时胚胎在发育至原肠期前后死亡。水温度为24℃时孵化时间仅为73.5 h,孵化率高达80%,畸形率为0,为最适孵化水温;水温对胚胎发育速率的影响后期较前期大。盐度实验表明:似刺鳊鮈胚胎对盐度有一定的耐受力,各盐度梯度下的胚胎发育速率差异不大,但孵化率的差异极显著。在水温18℃、盐度为2.5‰的水体中胚胎的孵化率为81.67%,高于太湖湖水组的孵化率,此盐度应为似刺鳊鮈胚胎发育较适盐度。  相似文献   

10.
研究了盐度、温度对条石鲷胚胎发育的影响和初孵仔鱼对饥饿的耐受力。结果表明,胚胎发育的适宜盐度范围为20~35,最适盐度范围为25~30,孵化率都在89%以上,盐度低于20或高于35,孵化率都降低。盐度对孵化时间有一定影响,盐度高于35或者低于15条件下孵化时间都延长。胚胎发育的适宜温度范围为21~27℃,孵化率都在77%以上,最适温度范围为23~25℃,孵化率达89%以上,低于19℃或者高于27℃时孵化率降低且初孵仔鱼畸形率升高。胚胎孵化时间与温度成负相关关系,胚胎发育速率与温度成正相关关系。条石鲷胚胎发育的生物学零度(阈温度)为10.06℃,有效积温值为405.3℃·h。对胚胎发育的Q10值进行了计算。饥饿条件下,条石鲷初孵仔鱼8日龄全部死亡,半数死亡时间出现在第6天,饥饿对初孵仔鱼生长具有明显的抑制作用。  相似文献   

11.
对双棘黄姑鱼催产、孵化和育苗技术进行了试验,并观察描述了其仔、稚鱼及幼鱼早期发育的主要特征.通过对饵料强化及水质控制等育苗关键技术的改进,在水温24.5~28.5℃、盐度26~30的条件下,共培育出平均全长30.92 mm的鱼苗约2.45×105尾.  相似文献   

12.
Abstract.– Parameters associated with optimum larval-rearing conditions are important in developing the culturing protocol of potential aquacultural species, and have yet to be addressed in terms of water temperature and salinity for Spisula solidissima similis , the southern Atlantic surfclam. Hatchery spawned S. s. similis larvae were reared to late pediveliger stage in five simultaneously conducted water temperature and salinity treatments. This larval growth and survival experimentation consisted of three salinity treatments (15, 25 and 30 ppt) in conjunction with a water temperature of 20 C, and two water temperature treatments (15 and 25 C) in conjunction with a salinity of 25 ppt. In the 20 C temperature treatment, significantly higher larval survival and greater growth occurred (both, P < 0.0001) as compared to the 15 C and 25 C treatments by day 22. Complete larval mortality occurred in the 20 C, 15 ppt salinity treatment by day 4. No significant differences in larval survival occurred between the 25 ppt, 20 C and 30 ppt, 20 C treatments by day 22 (P = 0.714). However, significantly greater larval growth occurred in the 25 ppt, 20 C compared to the 30 ppt, 20 C treatment (P = 0.009). The optimum rearing temperature and salinity for hatchery spawned S s. similis larvae to late pediveliger stage are 20 C and 25 ppt, respectively, within the temperatures and salinities tested.  相似文献   

13.

Larvae of Japanese smelt Hypomesus nipponensis have unique salinity adaptability and a small gape size; consequently, no system has been developed to feed them for stable high growth and survival. Therefore, suitable conditions for larval growth of Japanese smelt remain to be studied. In an earlier study, we developed a Japanese smelt rearing method using a closed recirculating system. Using that system for this study, we examined recirculation rate effects on Japanese smelt larval growth because the recirculation rate can affect larval feeding opportunities through regulation of the rotifer retention time in the rearing tanks. Using 0.2–0.3% salinity and water temperatures of less than 20 °C, we fed Japanese smelt larvae with SS-type rotifer and commercial feed. Results indicated that larval growth with a recirculation rate of less than 648% per day (LR) is superior to that achieved at a rate of over 2160% per day (HR). Moreover, rotifer density under the LR condition declines more slowly than under the HR condition. These results demonstrated that the recirculation rate affects their growth, perhaps by affecting the opportunities for larvae to ingest the rotifers. Furthermore, SS-type rotifers are available for feeding teleosts in a wide range of water temperatures and salinities.

  相似文献   

14.
Along the Atlantic coast black sea bass occur from the Gulf of Maine to Florida and support important commercial and recreational fisheries. Interest in commercial production of black sea bass has increased in recent years due to high demand and limited seasonable availability. Efforts towards large-scale production have been hampered by a high incidence of early larval mortality. Two of the most important environmental variables affecting hatchery production of marine finfish larvae are temperature and salinity. In the wild, larval black sea bass are found in waters with temperatures of 12–24 C and salinity levels of 30–35 ppt. Studies were conducted to define the temperature and salinity ranges that support growth and development of black sea bass during early life stages. Three developmental phases were investigated: 1) fertilization to hatch: 2) hatch through yolk sac absorption: and 3) during the initial exogenous feeding stage (5–14 days post hatch: DPH). Fertilized eggs were obtained by manual spawning of fish following administration of LHRHa. Fertilized eggs were transferred to 300-mL glass Petri dishes or 500-mL beakers to assess the effects of salinity and temperature through hatch and yolk sac absorption, respectively. To determine environmental effects on growth and survival during initial exogenous feeding 400 actively feeding larvae were cultured in green water and fed enriched rotifers for a 9-d period. For investigation of the effect of salinity, sea water (35 ppt) was diluted gradually to 15, 20, 25, and 30 ppt and maintained at 21 C. For examination of the effect of temperature, seawater was adjusted from 21 C to 12, 15, 21, 27, or 30 C at a rate of 3 C/h. No eggs hatched at 12 C or when salinity was maintained at 0 or 5 ppt. Hatching was uniformly high (≥ 85%) at temperatures between 15 and 27 C and at salinities ≥ 15 ppt. Survival through yolk sac absorption was greatest at temperatures between 18 and 27 C and at salinities ≥ 20 ppt. Survival through first feeding stage was highest at temperatures ≥ 18 C and 30 ppt salinity. Larval growth through first feeding was not significantly affected by salinity level but did increase with rearing temperature. The results indicate that survival and development of black sea bass during early life stages are most favorable at temperatures >18 C with salinity levels approaching full strength seawater.  相似文献   

15.
Effects of temperature and salinity on eggs and yolksac larvae of Polydactylus sexfilis (Cuvier and Valenciennes) were examined in laboratory experiments. Data on developmental rates as influenced by temperature are presented. Larval length at 95% yolksac absorption was maximized between 23.8 and 28.6°C. Based on the development of functional eyes and jaws, larvae were judged capable of feeding before the yolk was completely absorbed. Larvae incubated at intermediate temperatures also had larger amounts of yolk remaining when eyes and jaws were judged functional. Temperature and salinity effects on hatching success, survival at the end of the yolksac stage, and morphological abnormalities were studied in a 10 × 5 (temperature × salinity) array of treatments. In 34‰ sea water, normalized larval survival at the end of the yolksac stage was greater than 50% between temperatures of 21.9 and 28.0°C. Larval survival decreased at lower temperatures and salinities. Proportions of abnormal larvae increased at temperature and salinity extremes, and normal development was maximized between 26 and 34‰. Larvae (74 h after fertilization) were more tolerant to extreme high temperatures than were newly fertilized eggs. Upper salinity tolerance limits of 42-h larvae were greater at 26.2°C than at 23.5 or 29.2°C, and lower salinity was less tolerated at the two extreme temperatures. Based on the results, recommended temperatures and salinities for rearing P. sexfilis eggs and early larvae are 24–28°C and 26–34‰.  相似文献   

16.
Responses to variations in light, temperature and salinity by sea bass larvae are described here. Massive mortality of larvae has been common in Mediterranean culture efforts. This mortality, associated with swim bladder malfunction, has been analysed regarding its association with individual stresses.Optimum temperatures for sea bass growth are clearly unsuited to larval rearing, while brackish sea water (25‰) just as clearly improves growth and survival. Light and nutritional regimes as well as water quality are other sources of environmental stress that may induce the swim bladder stress syndrome (SBSS) and reduce growth and survival. SBSS should not be confused with “gas bubble” disease and its most effective treatment depends on an understanding of larval environmental requirements.Larval growth was enhanced by both decreased salinity and increased temperature, but not by increased light. SBSS and mortality were avoided only when larvae were held at ambient temperature (12.5°C), natural light, and reduced salinity (25‰). Larvae dying with distended swim bladders also had other symptoms of environmental stress—spinal abnormalities, calculi in the urinary bladders, copious mucous and opaque (edemous) tissues. Elevations of temperature and light, as well as ambient sea water (36‰) are environmental stressors and induce SBSS.  相似文献   

17.
The combined effects of temperature and salinity on larval survival and development of the mud crab, Scylla serrata, were investigated in the laboratory. Newly hatched larvae were reared under 20 °C temperature and salinity combinations (i.e. combinations of four temperatures 25, 28, 31, 34 °C with five salinities 15, 20, 25, 30, 35 g L−1). The results showed that temperature and salinity as well as the interaction of the two parameters significantly affected the survival of zoeal larvae. Salinity at 15 g L−1 resulted in no larval survival to the first crab stage, suggesting that the lower salinity tolerance limit for mud crab larvae lies somewhere between salinity 15 and 20 g L−1. However, within the salinity range of 20–35 g L−1, no significant effects on survival of zoeal larvae were detected (P>0.05). The combined effects of temperature and salinity on larval survival were also evident as at low salinities, both high and low temperature led to mass mortality of newly hatched larvae (e.g. 34 °C/15 g L−1, 34 °C/20 g L−1 and 25 °C/15 g L−1 combinations). In contrast, the low temperature and high salinity combination of 25 °C/35 g L−1 resulted in one of the highest survival to the megalopal stage. It was also shown that at optimal 28 °C, larvae could withstand broader salinity conditions. Temperature, salinity and their interaction also significantly affected larval development. At 34 °C, the mean larval development time to megalopa under different salinity conditions ranged from 13.5 to 18.5 days. It increased to between 20.6 and 22.6 days at 25 °C. The effects of salinity on larval development were demonstrated by the fact that for all the temperatures tested, the fastest mean development to megalopa was always recorded at the salinity of 25 g L−1. However, a different trend of salinity effects was shown for megalopae as their duration consistently increased with an increase in salinity from 20 to 35 g L−1. In summary, S. serrata larvae tolerate a broad range of salinity and temperature conditions. Rearing temperature 25–30 °C and salinity 20–35 g L−1 generally result in reasonable survival. However, from an aquaculture point of view, a higher temperature range of 28–30 °C and a salinity range of 20–30 g L−1 are recommended as it shortens the culture cycle.  相似文献   

18.
Temperature and salinity are two factors known to influence the growth potential and survival of the Pacific white shrimp, Litopenaeus vannamei, acclimated to low salinity waters. In west Alabama, farmers suspect low water temperatures at stocking, in conjunction with low salinity and suboptimal ionic profiles, might be responsible for reduced survival and production at harvest. To determine the influence of temperature and salinity on post‐larval (PL) L. vannamei, a series of bioassays were conducted at the E.W. Shell Fisheries Research Station in Auburn, Alabama and Claude Peteet Mariculture Center in Gulf Shores, Alabama. PL L. vannamei of ages 11, 13, and 20 (PL11, PL13, and PL20) were acclimated down to salinities of 12, 4, 2, 1, 0.5, and 0.2 ppt at different temperatures ranging from 17.6 to 24.0 C. During the acclimation bioassays survivals were assessed at 24 and 48 h. PL survival of the three age groups examined were significantly reduced at salinities of 1, 0.5, and 0.2 ppt. These results correspond well to those reported at higher temperatures confirming that across the tested temperature range salinity endpoint was the driving factor in determining survival and that suboptimal temperatures had a minimal influence on survival.  相似文献   

19.
Heavy rainfall on a brackish water pond used to culture larval barramundi, Lates calcarifer, resulted in the stratification of the pond (average depth 1.5m) into freshwater and saline layers. The saline monimolimnion (ca.22 ppt salinity) accumulated heat from solar radiation, reachign a maximum water temperature of 38°C, while the fresher mixolimnion (ca.5ppt salinity) reached only 31°C during the same period. The probable causes of the total mortality of barramundi in this trial were water conditions resulting from ectogenic meromixis, i.e., the high temperature of the monimolimnion and the low salinity of the mixolimnion, which made both layers unsuitable for larval survival.  相似文献   

20.
赵明日  孙世春 《水产科学》2007,26(8):449-452
用5种富含EPA、DHA等高不饱和脂肪酸的海洋微藻强化褶皱臂尾轮虫、卤虫无节幼体,用强化后的轮虫和卤虫无节幼体投喂红鳍东方鲀仔鱼。结果显示:n-3HUFA(尤其是DHA、EPA)对提高仔鱼的成活率、生长率和耐高盐能力都有重要作用,DHA效果好于EPA,用EPA代替部分DHA是可行的,但过量的AA对仔鱼生长有抑制作用,并降低仔鱼的耐高盐能力。5种微藻中,H24、H61和H24 C95组效果较好,C95效果一般,B222、R165效果较差。  相似文献   

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