马拉硫磷和甲氰菊酯对萼花臂尾轮虫生殖的影响

研究了不同浓度马拉硫磷(malathion)(0.03、0.3、3.0、30.0、300.0、3000.0μg/L)和甲氰菊酯(fenpropath-rin)(0.004、0.04、0.4、4.0、40.0、400.0μg/L)对萼花臂尾轮虫(Brachionus calyciflorus)3d种群增长率、携卵雌体数/非携卵雌体数、混交雌体百分率、混交雌体受精率及7d休眠卵产量影响。结果表明,马拉硫磷、甲氰菊酯对种群增长率、混交雌体百分率、混交雌体受精率及7d休眠卵产量有显著影响;马拉硫磷对携卵雌体数/非携卵雌体数无显著影响,但甲氰菊酯有显著影响。马拉硫磷对轮虫休眠卵产量最低效应浓度(LOEC)为0.3μg/L,对混交雌体百分率LOEC为30.0μg/L,对种群增长率和混交雌体受精率LOEC为300.0μg/L;甲氰菊酯对轮虫休眠卵产量最低效应浓度0.04μg/L,对混交雌体百分率和携卵雌体数/非携卵雌体数LOEC为4.0μg/L,对种群增长率和混交雌体受精率LOEC为40.0μg/L。试验显示,马拉硫磷和甲氰菊酯对轮虫生殖存在差异,轮虫休眠卵产量可以用来监测和评价2种杀虫剂潜在的影响。     

冷冻对轮虫休眠卵上浮率的影响↑（*）

本文报道了冷冻对轮虫休眠卵在水中上浮率的影响，一次冷冻（２４小时）可使各种轮虫休眠卵在水中的上浮率平均提高近５０％，使晶囊轮虫休眠卵的上浮率提高９０％左右。多次反复冷冻能使各种轮虫休眠卵的上浮率提高８５％左右，冷冻时间在８～１０４小时间，延长冷冻时间不会影响轮虫休眠卵的上浮率，并分析了冷冻处理后的休眠卵在水中和糖盐高渗液中上浮率提高的机理，讨论了冷冻处理在轮虫休眠浮选，定量以及土池轮虫生产中的意义     

投喂酵母和扁藻类培养褶皱臂尾轮虫的效果试验

实验室条件下，分别以面包酵母和扁藻为饵料培养褶皱臂尾轮虫（以下简称轮虫）。结果表明，轮虫摄食扁藻的生长繁殖效果要好于摄食酵母。以扁藻为食物，其带卵率和带卵数分别为45．5％和3．1个，而以酵母为食物，其带卵率和带卵数仅分别为32．5％和2．2个。在轮虫接种密度情况下（经一个培养周期7天），轮虫密度分别为54个／ml、32．5／ml。     

不同饵料对褶皱臂尾轮虫生长繁殖的影响

为了探讨不同饵料对褶皱臂尾轮虫种群生长繁殖的影响,通过在浓缩小球藻的基础上分别添加蛋黄、鱼肝油、三文鱼油、鱿鱼油和维生素,采用6种不同饵料(或组合)培养轮虫20 d,分析比较各组在轮虫的密度、怀卵量、抱卵率以及水质指标(p H、DO、氨氮)等方面的差异。结果表明,投喂不同的饵料,轮虫密度各组间存在差异,鱼肝油组轮虫密度最大,达到466个/m L,其次是鱿鱼油组和三文鱼油组,单独投喂浓缩小球藻的对照组轮虫密度最小;轮虫怀卵量各组间差异极显著(P0.01),鱼肝油组显著高于其它组(P0.05),最高达到908个/m L,其次为鱿鱼油组,对照组最低;鱼肝油组的抱卵率和日平均增殖率最高,其次是鱿鱼油组;对照组和维生素组的轮虫培养水体水质保持较好,蛋黄组水质最差。研究表明,投喂鱼肝油对轮虫的生长繁殖有显著促进作用,采用浓缩小球藻和鱼肝油混合投喂培养轮虫,可提高轮虫质量和营养价值。     

两种消毒剂处理对萼花臂尾轮虫休眠卵萌发的影响

在特定条件下形成的轮虫休眠卵,经过一定时间的储藏保存,其萌发率均有不同程度的降低[1,2]1)。已有研究表明,大量的细菌污染是导致褶皱臂尾轮虫(Ｂｒａｃｈｉｏｎｕｓｐｌｉｃａｔｉｌｉｓ)休眠卵萌发率降低的主要因素之一;使用适宜种类和浓度的消毒剂处理可显著地提高其萌发率[3]。有关淡水轮虫休眠卵的报道较少,为此我们使用扫描电子显微镜对萼花臂尾轮虫(Ｂｒａｃｈｉｏｎｕｓｃａｌｙｃｉｆｌｏｒｕｓ)休眠卵进行观察,并用不同种类和浓度的消毒剂对其进行消毒实验,旨在为轮虫休眠卵的有效保存和使用提供依据。1　材料和方法1.1　轮虫休…     

温度对超小型轮虫生长、繁殖及营养成份的影响

实验观察了8℃～44℃水温范围内超小型(SS型)轮虫生长繁殖情况。结果表明:温度对轮虫生长影响极显著,室温(21.5℃～24.7℃)～38℃为SS型轮虫最适的生长温度范围,轮虫繁殖速度从小到大排列顺序为35℃组(32℃组(29℃组(26℃组(38℃组(21.5℃～24.7℃组。经48小时培养,轮虫增长倍数为6.67～22.0倍,组间差异极显著(p0.01)。实验对不同水温条件下培养的SS型轮虫体内脂肪酸含量进行分析表明:培养温度对轮虫体内高度不饱和脂肪酸(EPA、DHA)含量无规律性影响;饵料对轮虫体内高度不饱和脂肪酸(EPA、DHA)含量影响极显著,小球藻培养组EPA含量为0.19%～1.22%,DHA含量为0.032%～0.08%;酵母培养组EPA、DHA含量分别为0.028%和0。     

饵料中添加鱼油型HUFA强化剂对褶皱臂尾轮虫生产及营养价值的影响

分别以酵母、80%酵母与20%光合细菌混合物为基本饵料,研究褶皱臂尾轮虫(Branchionus plicatilis)半连续培养过程中持续添加5 mg/(L·d)的鱼油型HUFA强化剂对轮虫生产及其营养的影响.结果表明,投喂80%酵母与20%光合细菌混合物的轮虫组,其最高密度、平均抱卵率、种群维持高密度的时间、总产量等指标在4个处理中最低;而持续添加5mg/(L·d)的鱼油型HUFA强化剂的轮虫组,其平均抱卵率、总产量与酵母组无显著差异,但高密度情况下种群的稳定性显著增加.饵料对所培养的轮虫的营养价值也有影响.日饵中添加HUFA强化剂,增加了轮虫的总脂含量,降低了轮虫的粗蛋白及氨基酸含量.添加HUFA强化剂培养的轮虫的脂肪酸组成也发生了变化.     

维生素B12对圆型臂尾轮虫种群增长、繁殖和个体大小的影响

为了解维生素B 12 对海水圆型臂尾轮虫( Brachionus rotundiformis )种群增长、繁殖和个体大小的影响,采用四种不同浓度的维生素B 12 (0、0.3、0.6、1.2 μg/mL)强化培养轮虫7 d。每天测定轮虫的种群密度和怀卵率,每隔一天测定轮虫背甲长和宽。试验结果显示:0.3 μg/mL维生素B 12 组轮虫的种群增长、怀卵率显著高于其他组( P<0.05);0.3 μg/mL维生素B 12 组轮虫的背甲长和宽均显著小于其他三组( P>0.05),而其他三组差异不显著。试验结论:在本试验条件下,维生素B 12 对圆型臂尾轮虫种群增长、繁殖和个体大小影响的最适浓度为0.3 μg/mL。     

辛基酚对萼花臂尾轮虫毒性效应的研究

应用生态学毒理学方法,研究了环境雌激素辛基酚(OP)对萼花臂尾轮虫毒性效应。包括24h急性毒性、慢性浓度(0.01~0.16mg/L)对轮虫发育阶段、2d的种群增长率r及7d休眠卵产量影响。结果显示:OP对轮虫24h的急性毒性LC50为0.91mg/L;OP浓度0.08、0.16mg/L显著降低轮虫的生殖前期、生殖期和寿命历时,0.04mg/L以上降低轮虫的生殖量;OP浓度0.08、0.16mg/L显著降低轮虫2d的r,0.01mg/L及以上浓度显著降低轮虫7d的休眠卵产量。以上研究表明:OP对轮虫的生殖具有干扰作用,其中轮虫7d休眠卵产量为监控水体OP污染最敏感的指标。     

冷冻对轮虫休眠卵萌发率的影响

对在不同冷冻时间和冷冻强度下臂尾轮虫休眠卵的萌发率进行了测试,结果显示,褶皱臂尾轮虫（ Ｂｒａｃｈｉｏｎｕｓ ｐｌｉｃａｔｉｌｉｓ） 休眠卵在－ １８ ℃冷冻２０ ｄ ,萌发率提高１３ ．９ ％ ;－ ３０ ℃冷冻６０ ｄ ,萌发率提高１４ ．４ ％ ;室外经整个冬季冻后,萼花臂尾轮虫（ Ｂ．ｃａｌｙｃｉｆｌｏｒｕｓ） 、壶状臂尾轮虫（ Ｂ．ｕｒｃｅｕｓ） 休眠卵的萌发率平均提高了１ ～３ 倍,而角突臂尾轮虫（ Ｂ．ａｎｇｕｌａｒｉｓ） 的萌发率却降低了近１ 倍。－ ８０ ℃强冷冻２ ｄ,褶皱臂尾轮虫休眠卵萌发率从３９ ．５ ％ 降至１ ．６ ％ 。同时,本文探讨了冷冻影响轮虫休眠卵萌发的机理以及冷冻处理在北方轮虫土池生产中的实际意义。     

不同开口饵料对江鳕仔鱼生长及存活率的影响

采用海水皱褶轮虫（Brachionus plicatilis）、淡水臂尾轮虫（Bruchionus sp.）（维持有小球藻（Chlorella sp.））、超微粒子饵料、水丝蚓（Tubifex sp.）肉糜、摇蚊幼虫（Chironomus sp.）肉糜五组不同饵料进行江鳕仔鱼开口饵料选择试验。经15 d培育,结果表明：淡水轮虫是江鳕仔鱼最佳开口饵料,生长速度最快,成活率最高（95.42%）。     

Larval rearing and development of Siganus lineatus (Pisces: Siganidae) from hatching through metamorphosis

Larvae of Siganus lineatus were hatched and reared through metamorphosis in a 7 000-1 tank covered with a translucent roof. The larvae were fed phytoplankton (mixed cultures), rotifers (Brachionus plicatilis), copepods (Oithona sp.), and Artemia nauplii. Thirty-five days were required for all the larvae to metamorphose; survival was 800 out of 5 000 (16%). The rearing period and rearing criteria are identical to those required for S. canaliculatus. Three important developmental stages were identified: the dark-head carnivorous stage (the gut is a simple coil), the brown-head omnivorous stage (the gut is elongated and convoluted), and the juvenile herbivorous stage (the gut is highly elongated and convoluted into a complex coil). Over-feeding on Artemia nauplii may result in deaths among brown-head and juvenile fishes; adjustment of the feeding regime when larvae begin to develop into the brown-head stage is considered important. Copepods are an excellent substitute for Artemia nauplii during this period     

在人工海水条件下，利用面包酵母培养褶皱臂尾轮虫（Brachionus plicatilis）的研究

在充气、以面包酵母为饵料、盐度为20的条件下,进行人工海水培养褶皱臂尾轮虫的实验。结果表明,不同人工海水中,用速溶海水晶配制成的海水和自然海水稀释的海水培养褶皱臂轮虫的效果明显地优于粗盐配制的;用速溶海水晶配制成的海水培养褶皱臂尾轮虫时,最大密度能达1710个／ml。不同营养强化剂中,绿色巴夫藻、扁藻以及胶囊肝油 蛋黄的效果较好。添加剂4ppm氯霉素时,培养褶皱臂尾轮虫的效果较好。     

Comparison of rotifer Brachionus plicatilis as a choice of live feed with dry feed in rearing Coregonus lavaretus fry

This experiment, designed for the first time in the Middle East region to sustain Coregonus lavaretus production, examined the efficacy of a live organism ( Brachionus plicatilis ), an artificial diet (48% crude protein) and a mixed feed for the first 3 month of rearing fry. Nine rearing cages were floated on the surface of a natural pond supplied with hyporheic-zone river water, each containing 150 numbers of white fish fry, where they were treated with each of the three diets in triplicates. The fry were fed eight times daily starting at the onset of exogenous feeding. Results showed that fry utilized live organisms more efficiently than the artificial and mixed diets. Rotifer-fed group consistently showed higher growth rate during the entire experiment. Length increment (29.6 mm), weight gain (572.3 mg) after 12 weeks of feeding were higher ( P  < 0.05) in this group. Also, their mean weekly specific growth rate (4.97% day⁻¹) was the highest and feed conversion rate (2.97) was the lowest among all treatments. Survival rates of the fry declined from 75% to 61.4%, from 74.3 to 45.8% and from 72.7 to 54.5% for live feed, mixed diet and artificial diet, respectively.     

Unicellular algae as a food for turbot (Scophthalmus maximus L.) larvae — The importance of dietary long-chain polyunsaturated fatty acids

The production of juvenile turbot in research and commercial practice still involves the use of live foods for the early larvae. The rotifer Brachionus plicatilis is used for the first few days followed by nauplii of the brine shrimp, Artemia salina. During this live food phase, the addition of live unicellular algae to the rearing tanks improves the growth and survival of the turbot larvae.Within 10 days of the start of feeding, large differences in growth rate become apparent depending on the presence or absence of particular algae. The use of Dunaliella tertiolecta in particular results in stunted growth and high mortalities. Evidence is presented in this paper that Dunaliella tertiolecta is not toxic, and that its failure to support turbot larval growth is probably due to a deficiency of long-chain polyunsaturated fatty acids. These compounds have been shown by other workers to be an essential dietary requirement in O-group turbot.     

褶皱臂尾轮虫对提高暗纹东方鲀鱼苗成活率的作用

利用褶皱臂尾轮虫和暗纹东方鲀鱼苗在5‰的咸淡水中都能够存活的特点,用面包酵母培育褶皱臂尾轮虫经海水小球藻强化培育后在5‰的盐度条件下投喂暗纹东方鲀鱼苗,结果表明,褶皱臂尾轮虫较之淡水轮虫可使暗纹东方鲀鱼成活率显著提高。     

Reproduction,early development and larviculture of the barber goby,Elacatinus figaro (Sazima,Moura & Rosa 1997)

The barber goby, Elacatinus figaro, is a cleaner species of ecological importance and of keen interest to the aquarium trade. Endemic to Brazil, it is a threatened species and so aquaculture is a potential solution for reducing pressure on the natural stocks. This study describes the reproductive behaviour, the embryonic and larval development and the general breeding and rearing conditions. Ten wild fish initiated the formation of breeding pairs 20 days after acclimation to captivity. Spawning started 12 days after the first pair was formed, with one female from each pair spawning from 140 to 700 eggs (n=15 spawnings). The average period of incubation of the eggs was 6.8 days at 25 °C. The best hatching rate was 99.5% (n=10 spawnings). Larval rearing used Nannochloropsis oculata with rotifers (Brachionus rotundiformis) as the first food (day 0–25); nauplii and meta‐nauplii of Artemia were fed from day 18 until larval metamorphosis with subsequent weaning using commercial marine fish diets. The transformation to juveniles started at around the 30th day post hatch. The best larval survival rate until complete metamorphosis was 30.6% (n=4 larvicultures). After this period, the mortality was insignificant. This study demonstrated that the cultivation of barber goby is feasible.     

An intensive hatchery rearing protocol for larvae of the bullseye puffer,Sphoeroides annulatus (Jenyns)

In this study bullseye puffer, Sphoeroides annulatus larvae were reared from hatching through to 1 or 2 months after weaning on an experimental scale in three replicate 600 L tanks and on three occasions during the spawning season (nine tanks in total). The rearing protocol used was green water (Nannochloropsis oculata and Isochrysis sp.) 100 000 cells mL^?1 from 0 to 11 days after hatch (DAH), 5–10 rotifers, Brachionus rotundiformis mL^?1 from 2 to 26 DAH, 0.1–1 Artemia mL^?1 from 21 to 34 DAH and weaning from 29 to 34 DAH. Survival to a month after weaning was 1%, a total of 3153 juveniles were produced with an average wet weight of 0.29 ± 0.07 g and a length of 27.5 ± 0.82 mm.     

Development of Improved Feeding Methods in the Culture of Yellow Tang,Zebrasoma flavescens

Yellow tang, Zebrasoma flavescens, are one of the most heavily traded marine aquarium fish species, with nearly 400,000 individuals collected annually from Hawaii's reefs. Despite recent success culturing this species, significant challenges in the rearing processes remain to be overcome before commercialization is feasible. This study compared two feeding regimens, an original diet treatment, which was initially used to successfully culture yellow tang, and a revised diet, which differed in the timing of the introduction of feed items and weaning periods. Both diet regimens consisted of Parvocalanus crassirostris nauplii, enriched Brachionus rotundiformis rotifers, and Artemia nauplii, followed by a transition to dry and frozen feed items. The revised feeding regimen aimed to considerably reduce the amount of copepods and rotifers needed in the rearing process. Eggs were stocked at 40/L into replicate (n = 3) 200‐L tanks for the feeding regimen trial. A follow‐up rearing study, in which eggs were stocked at 19/L in a single 1000‐L tank, tested the revised feeding method at pilot scale. Fish reared on the revised feeding regimen were observed to grow faster in body length and body depth after 2 wk in culture and transitioned more quickly to juveniles as 41% had completed their transition to juvenile coloration by 70 d after hatch. None of the fish reared under the original feeding regimen attained full juvenile coloration during the study period. Survival was not significantly different between treatments and was 0.13% ± 0.13 and 0.29% ± 0.17 in the original and revised feeding regimens, respectively. In the pilot‐scale study, growth was comparable to that of both treatments in the 200‐L scale trial, but survival was much better at 1.9%. This study successfully shortened the copepod and rotifer feeding periods for yellow tang, while not jeopardizing growth or survival. This outcome enhances the commercialization potential for this and likely other Acanthuridae species.     

Larval rearing of hilsa shad,Tenualosa ilisha (Hamilton 1822)

Hilsa, Tenualosa ilisha has received much attention for culture due to decline of the natural population. Lack of knowledge on larval rearing is the bottleneck for its culture. This study was aimed at developing larval rearing protocols for hilsa shad. Hilsa larvae (4 days old, 4.76 ± 0.06 mm/0.49 ± 0.01 mg) were stocked in fibreglass‐reinforced plastic tanks (1.7 m³ water volume) at 300, 600 and 1,200 nos/m³ in triplicates in three experimental systems viz., E‐I (circular, 0.567 m water depth), E‐II (circular, 0.962 m water depth) and E‐III (rectangular, 0.567 m water depth) and reared for 46 days. The larvae were supplied with Chlorella vulgaris, Brachionus calyciflorus, mixed phytoplankton and mixed zooplankton during 4–50, 6–25, 8–50 and 26–50 days of their age respectively. In each system, higher (p < 0.05) fry survival at 300 nos/m³ than in higher densities indicates density dependent stress. Circular tanks showed higher survival (13.3%–61.31%) than in rectangular tanks (6.88%–27.26%) in each stocking density, indicating the importance of tank shape for rearing. Water depth affected fry survival in circular tanks (E‐I and E‐II) at 300 nos/m³; at 0.962 m depth, survival was higher (61.31%, p < 0.05) than that of 0.567 m depth (49.93%). Good fry survival was achieved through feeding the larvae initially with Chlorella followed by co‐feeding with Brachionus, mixed phytoplankton and zooplankton and rearing in circular tanks at 300 nos/m³ densities at 1 m depth. This first‐ever larval rearing protocol is useful for mass production of fry to support hilsa aquaculture in future.