Influence of Colored Light on Growth rate of Juveniles of Fish

The main aim of our experiments was to study the influence of colored light on juveniles of Carassius carassius, Perccottus glenii and Poecilia reticulata. The species of fish used for studies differ in their biotopes and feeding behavior. The results of experiments demonstrated that different species of fish can have different response to light quality. Thus crucian carp developed better by green light, rotan-by blue and green, guppy - by blue light. By red light the growth rate in all species decreased. The response in different species of fish to the light environment appears to be governed by changes in energy metabolism and hormone disproportionation.     

Recruitment abundance index of Pacific bluefin tuna using fisheries data on juveniles

ABSTRACT:   The recruitment abundance index of Pacific bluefin tuna Thunnus orientalis was estimated from 1980 to 2003 fishing year by using the troll fishery data in Nagasaki Prefecture, western Japan. It has been shown that the troll fishery in Nagasaki Prefecture operates with good time–area coverage of the species habitat, and that the fishing power slightly changed during the period analyzed, based on fisheries statistics, published information, and interviews with the fishers. Average catch per unit effort (CPUEs) were standardized by a generalized linear model (GLM) considering the effects of fishing year, season and landing area. Standardized CPUE of age-0 bluefin tuna showed larger fluctuations year by year than the nominal CPUE combined for all ages. High CPUEs in fishing years of 1981, 1994, 1996 and 1999 were observed. Data from these years agreed with the higher recruitments estimated by virtual population analysis (VPA) or higher catch of age-0 fish reported for the Pacific side. The age-specific standardized CPUE of age-0 bluefin tuna in this study was judged to be a useful indicator of recruitment.     

Factors influencing migration of Penaeus indicus in the Negombo lagoon on the west coast of Sri Lanka

Juveniles of Penaeus indicus (Milne Edwards) occur in the Negombo lagoon Sri Lanka and on maturing they return to the sea for reproduction. Cohort analysis indicated pulses of immigration to the nursery areas in February and June. The growth rates for juveniles were relatively high compared with that of adults. Three groups of prawns were identified in the lagoon: `small quick movers', `larger long stay individuals' and an `intermediate group'. There were few identifiable emigration pulses from the lagoon towards the offshore areas. It appears that osmotic stress caused by low salinity waters in the lagoon during the periods of high precipitation may be the strongest influence triggering the onset of emigration.     

拉萨裂腹鱼仔、稚鱼的异速生长模式

采用实验生态学的方法对拉萨裂腹鱼（Schizothorax waltoni Regan）0~90日龄的异速生长模式进行研究。结果显示：拉萨裂腹鱼仔、稚鱼全长由慢速生长到快速生长的转折点为28日龄;其多数外部器官均具有异速生长特点,头部和尾部的生长快于躯干部,头长、肛前长、肛后长分别在24～25日龄、36～37日龄、37～38日龄出现生长拐点,头高和体高分别在40～41日龄、49～50日龄出现生长拐点;眼径在18～19日龄较早出现生长拐点,促使眼睛充分发育,以提高早期仔鱼在开口期摄食外源食物的能力;吻长在42～43日龄出现生长拐点,促进了口的充分发育,以适应不同阶段的饵料环境;胸鳍、背鳍、臀鳍、腹鳍和尾鳍分别在18～19日龄、39～40日龄、43～44日龄、46～47日龄、37～38日龄出现生长拐点,其中臀鳍和腹鳍长在拐点前后相对全长均呈现正异速生长,但是拐点后生长指数明显降低,各鳍在仔鱼早期的快速生长使拉萨裂腹鱼仔鱼的游泳能力得到大幅提高。拉萨裂腹鱼仔、稚鱼的异速生长模式,保证了各重要功能器官的充分发育,有效地保障了其开始摄取外源性营养后的生存能力,同时对早期野生资源保护和苗种生产有重要的指导意义。     

长江口南支水域刀鲚仔稚鱼数量变动的研究

为了探明长江口南支刀鲚仔稚鱼的丰度和分布变化,2014年3-9月在长江口南支设置8个站点,采用大型仔稚鱼网(口径1.3 m,网目0.5 mm)在每月大潮期间按月进行表层水平拖网。共拖网91网次,采集刀鲚仔稚鱼1 270尾,体长范围为3.56~50.88 mm,发育阶段由卵黄囊期仔鱼期到稚鱼期。其中涨潮期间采集刀鲚仔稚鱼1 013尾,平均密度0.27 ind/m3,平均体长10.00 mm。其中St.8密度最高,达0.268ind/m3,平均体长为9.44 mm。退潮期间采集刀鲚仔稚鱼163尾,平均密度0.01 ind/m3,平均体长为20.08 mm。St.8昼夜调查表明,夜间采集刀鲚94尾,涨潮期间密度为0.056 ind/m3,小于白天涨潮密度,退潮期间密度为0.003 ind/m3,小于白天退潮密度,涨潮平均体长为13.86mm,大于白天;夜间退潮平均体长为22.01 mm,与白天相当。比较沿岸碎波带研究结果,长江口南支出现的刀鲚仔稚鱼个体较小,有必要加强对江面刀鲚早期资源漂流水域的保护。     

乐清湾塘养泥蚶的生长

1998年6月至2000年7月对浙江省乐清湾塘养泥蚶的生长进行了详细的观察。刚孵化变态的D形幼虫壳长92-100μm，经10d培育达到180.5-201.5μm，平均每日增长8.9-10.2μm；稚贝附着后16d平均壳长从191.3μm增长到634.1μm，平均每日增长27.7μm；出库稚贝放养于围塘内，培育9个月平均壳长达到8.34mm，成为商品贝苗，平均每月增长0.86mm，其中9－10月份增长可达1.65mm；再经15个月培育达到成品贝，平均壳长28.57mm，平均每月增长1.35mm。泥蚶是一种慢生型贝类。对室内浮游幼虫、稚贝、中间暂养贝苗、成蚶养殖期间的多项生长指标进行测量和称重，获得的相关关系非常显著。     

Advance in the Culture Research of Small-Eye Flounder,Paralichthys microps,and Chilean Flounder,P. adspersus,in Chile

ABSTRACT

Over 71% of the aquaculture production of Chile is based on salmonids, and given the recents problems in the world salmon industry, it is necessary to investigate the culture of new species as a vital priority to maintain an industry of great social and economic impact for Chile. Small-eye flounder, Paralichthys microps, and chilean flounder P. adspersus, are native, high-value flatfish present off the coasts of Perú and Chile, that are commonly exploted by artisanal fishermen. Since 1986 both species have been objects of research studies for culture based on techniques developed for Japanese flounder. This paper is a review of current knowledge of this species and to identify research needs for the near future. Natural spawning of small-eye flounder and chilean flounder broodstock in captivity is already possible, but the manipulation of spawning using photoperiod and hormonal inducement, as well as the role of broodstock nutrition in egg and larval quality, needs to be explored. Successful incubation and larval culture protocol for both species have been developed, with larval survival over 24% from certain egg batches. Nutritional characterization and requirements for chilean flounder eggs and larvae during the culture period, optimal temperature, density, light intensity and green-water culture, are all subjects of ongoing research. Efforts to improve early culture protocol continues with emphasis on causes of larval mortality, early use of dry feed, microbial ecology of culture tanks and water quality. Weaning from live to formulated diets has been investigated, demonstrating survival of 30-50%. Presently only about 1-5% of hatchery raised flounder show a pigment disorder. Research on formulated diets and the weaning process are under way to ameliorate these results. Juveniles are being grown experimental in tanks and net pens systems and their performance (growth, survival, health) in both systems is being evaluated. Chilean flounder require approximately 2.8 years to reach 1 kg. Effort is also focusing on improving juvenile growing protocol, including recirculation systems, culture environment and diet formulation. Much future research will be required to attain optimal production of the species, such as species-specific nutritional requirements, optimum stocking density, disease and health management and growing protocols with new systems (shallow raceway). At present there is enough known about chilean flounder to begin a pilot-stage that will be the key for future development of its culture.     

二硫氰基甲烷及其分解产物对根结线虫幼虫作用方式的研究

 二硫氰基甲烷及其分解产物对根结线虫二龄幼虫具有很高的生物学活性,LC₅₀和LC65分别为0.7220和1.6527μg/mL;1μg/mL二硫氰基甲烷处理二龄幼虫10min以上,二龄幼虫致病力下降;0.5μg/mL二硫氰基甲烷处理0~5min时,能增加线虫的呼吸作用,但随药剂处理时间延长(5min~12h),线虫呼吸作用受到抑制,2.5μg/mL二硫氰基甲烷对线虫呼吸的抑制作用高于0.5μg/mL;药剂处理的线虫悬浮液的电导率明显高于对照,且药剂浓度越高,悬浮液的电导率越大,这种变化在药剂处理的15~120min内保持稳定。     

水温和饵料对宝石鲈稚、幼鱼生长和成活率的影响

通过对宝石鲈稚、幼鱼在不同水温及饵料条件下的生长情况研究,初步确定宝石鲈稚、幼鱼最适生长水温为30℃左右;在试验选用的5种饵料中,卤虫是最适合其稚、幼鱼期生长发育的饵料.在最适条件下,宝石鲈稚、幼苗表现出最快的生长速度和较高的成活率.为宝石鲈的苗种培育提供了重要资料,直接指导了生产实践.     

江苏沿岸中华小公鱼仔稚鱼的分布特征及其与环境的关系

根据2006-2007年"苏通渔01110"渔船按季度对江苏省沿岸海域(119°00′-123°00′E 、31°40′-35°50′N)进行仔稚鱼种类组成及数量分布的调查.从中对筛选出的中华小公鱼(Stolephorus chinensis)仔稚鱼资源空间分布及其与环境关系进行了探讨.结果表明:夏季共采集到443尾,平均每站为36.9尾,以前弯曲期仔鱼为主;秋季共采集417尾,平均每站为34.8尾,以后弯曲期仔鱼和稚鱼为主.结合环境数据和历史调查资料分析表明,低盐度的水域更适合中华小公鱼的个体生长;水温和盐度的变化影响了该调查海域优势种鳀鱼的分布,显示了中华小公鱼在该海域内的数量优势作用.