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1.
采用投喂小球藻、角毛藻、鱼腥藻、螺旋藻以及小球藻和角毛藻5组饵料分别投喂扁玉螺浮游幼虫,每天测定壳宽和存活率,结果表明,8天后,投有角毛藻的2组存活率较高,生长较快。笔者认为,角毛藻是扁玉螺浮游幼虫的适合饵料。  相似文献   

2.
In this study, partial and total replacement of live diets (microalgae and Artemia nauplii) with microencapsulated diets (MED) are demonstrated for larval culture of P. indicus . Slower growth and lower survival rate of larvae fed experimental MED were significantly improved by a supplement of 15 cells/μL frozen mixed algae (1:2, Tetrtaselmis and Skeletonema ) during protod stages (PZ1–PZ3). This low level of algal supplement to MED resulted in survival (85–92%) equal to that obtained from control live diets (91%) during protod stages. These significant improvements in larval growth and survival are likely to be due to higher larval digestive enzyme activities and hence more efficient digestion of the artificial diet by the larvae. Like other penaeids, P. indicus larvae show high total and tissue trypsin activities during PZ stages, with a peak at mysis stage 1 (M1), and a decrease during subsequent stages when fed on conventional live diets of algae followed by Artemia during mysis stages. Larvae fed 15 ceUs/μL mixed frozen algae in addition to MED demonstrated a significantly higher trypsin activity throughout herbivorous larval stages in comparison to larvae fed solely on MED. A freeze dried alga Rhinomonas reticulata incorporated into a MED at 23Vo (v/v) induced larval trypsin activity equal to that produced by live algae. Hence, the algal substances, which trigger digestive enzyme production, may be retained within the microcapsules. At mysis stages, however, addition of live prey (one Artemia/ mL) to cultures fed with MED significantly improved growth and survival although it depressed trypsin activity. For mysis stages it appears that the use of predigested ingredients is necessary to improve the digestibility of formulated diets.  相似文献   

3.
An experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low-HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids—HUFA). Seven tanks were set up for each diet. After the rotifer stage, approximately seven days after hatching, the larvae were fed newly-hatched Artemia salina nauplii (AT-1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tanks was further subdivided and the larvae fed Arternia nauplii enriched with one of four enrichment diets: Dry Selco, Protein Selco, ICES low-HUFA or Super Selco. The rotifer enrichments had no significant effect on larval growth and survival. The nutritional value of the Artemia stage (day 13 to 26) was more important for the overall larval survival.  相似文献   

4.
Intact microencapsulated protozoeal diets (MED), added to 5 m filtered hatchery water at the recommended concentration of 4 mg L-1 gave no significant difference in bacterial numbers after 6 h, over a 48 h period compared to control groups in autoclaved hatchery water. Disruption of the MED resulted in a significant increase in bacterial numbers up to 12 h compared to controls with intact microcapsules. Protein leach rates were similar in sterile water and 5 m filtered water, indicating that leaching was independent of microbial activity. MED leached significantly less dietary solubles compared to a microparticulate diet (MPD). There was no evidence to suggest significant attachment of bacteria to diet particles for at least 48 h.In low-quality water after algal blooms, survival of white shrimp (Penaeus indicus) larvae was poor when reared in both sterile and 5 m filtered water. The addition of bacteria filtered from xenic algal cultures together with the algal exudates to such water gave significant improvements in survival to larvae fed MED in 5 m filtered water but not in autoclaved culture water. Live algal diets promote high larval survival and growth irrespective of the inclusion of bacteria.It is suggested that algal exudates act as selective bacteriocides and total replacement of algae with MED requires a balanced bacterial community which can be attained at times from natural sea water, or when the natural bacterial community balance is disturbed, corrected by the use of algal exudates.  相似文献   

5.
Early weaning in spotted sand bass larvae, Paralabrax maculatofasciatus, was evaluated, testing a combination of two weaning times, 17 and 22 d after hatching (d.a.h.), and three different microparticulate diets. Protein in diets was mainly from sardine meal and from 15% squid meal, beef blood meal, or fish protein hydrolysate. Anatomical (standard length), histological (gut development), and biochemical (highly unsaturated fatty acids) parameters were measured in larvae, as well as survival and resistance to a stress test measured 40 d.a.h. For larvae weaned at 17 d.a.h., the best growth and survival were obtained with diets containing fish protein hydrolysates; for larvae weaned at 22 d.a.h., best results were obtained with squid meal and fish protein hydrolysate. Growth and survival were significantly lower when using beef blood meal in both weaning treatments. The best relative and total survival were for larvae weaned at 22 d.a.h. After the resistance test, 100% survival occurred in larvae fed on any microparticulate diet and either weaning treatment. No significant differences in arachidonic acid, eicosapentaenoic acid, or docosahexaenoic acid concentrations in fish fed on any diet occurred. Results suggest that weaning at 22 d.a.h. with diets containing fish protein hydrolysate or squid meal is preferred by this species.  相似文献   

6.
底质对小褐虾生长和存活率影响的实验研究   总被引:3,自引:1,他引:3  
本研究的目的在于通过小褐虾(Crangon uritai)的人工饲养,以观察栖息底质对其存活率和生长的影响。实验小褐虾样本来自韩国釜山Dadaepo(35°02′N,128°57′E)附近4 m水深海域的桁杆拖网渔获,共选取80尾样本进行实验,其中雌性40尾、雄性40尾,并分别被独立饲养在40个有沙和40个无沙的2 L容器中。为便于分析,将实验样本设为每组20尾,分别为无沙饲养的雌性组NSF和雄性组NSM,以及有沙饲养的雌性组SAF和雄性组SAM。实验环境条件为水温14℃、盐度32.5、光周期L∶D为12∶12。饲养期间,每天投喂新鲜的冷冻虾肉,投喂24 h后将残饵虹吸排除,海水每3天更换1次,整个实验持续100 d。实验前测定每尾实验小褐虾样本的体长和性别。实验中每天检查每个容器中的小褐虾蜕皮、死亡和残饵情况,并记录蜕皮时间以便计算其蜕皮间隔。结果表明,在各组最初样本的甲长分布之间没有显著性差异(P>0.05)的情况下,经过整个实验周期,小褐虾NSF和NSM的存活率分别为28%和10%,而SAF和SAM分别为38%和25%。各对照组个体平均甲长的增长量NSF为1.22 mm、SAF为1.43 mm、NSM为0.6 mm、SAM为0.9 mm。有沙饲养条件下,雌性和雄性的蜕皮间隔分别为15.0 d和15.3 d,而无沙饲养的雌雄的蜕皮间隔分别为16.0 d和16.0 d。无论雌性还是雄性在有沙饲养条件的蜕皮间隔均比无沙饲养的短。有沙饲养的雌、雄个体蜕皮增长率分别为5.2%和4.8%,无沙饲养的蜕皮增长率分别为3.7%和3.2%,在有沙饲养条件下雌、雄的蜕皮增长率均较无沙饲养的要大。有沙饲养的雌雄个体生长速度均较无沙饲养的要快,有沙饲养的雌性个体绝对增长率相对于雄性个体要更高。在提供沙质底质的条件下,小褐虾的存活率提高,蜕皮间隔明显缩短,蜕皮增长率增大,更有利于小褐虾的生长。[中国水产科学,2007,14(1):90-98]  相似文献   

7.
将初始体质量为(0.006±0.0005)g的仔鱼,随机分为4组,每组3个平行,分别投喂4种饵料:人工配合饵料、轮虫、蛋黄和轮虫+人工配合饵料.试验周期为28 d.结果表明,(1)轮虫+人工配合饵料和人工配合饵料组生长较快,特定生长率分别为0.014 %/d和0.013 %/d, 绝对生长率达到0.150、0.142 g/d,二组差异不显著(P>0.05);蛋黄组生长最慢,与其他各组差异显著(P<0.05).(2)轮虫+人工配合饵料与轮虫组仔稚鱼的成活率达到90.3%和 89.7%,大部分个体发育进入幼鱼阶段,二组差异不显著(P>0.05);蛋黄组存活率较低,只有40.7%,与其他各组差异显著(P<0.05).(3)投喂不同饵料对奥尼罗非鱼仔稚鱼的消化酶具有显著影响,蛋黄组的淀粉酶和脂肪酶活力显著高于其他各组(P<0.05);轮虫+人工配合饵料组的胃蛋白酶活力较高,天然饵料(轮虫)组较低.  相似文献   

8.
试验分延迟0d、1d、2d、3d、4d、5d、6d、7d投饵和完全饥饿9个试验组,研究了延迟投饵对泥鳅仔鱼摄食、生长和存活的影响。结果显示:水温27℃±1℃时,泥鳅仔鱼3日龄开口,混合营养期2d,4日龄卵黄囊消失。开口当日初次摄食率为36%,最高初次摄食率出现在5日龄,达98%,饥饿不可逆点(PNR)在8~9日龄。延迟0d(正常投饵)和1d投饵组仔鱼体长一直呈增长趋势,至11日龄,两组仔鱼体长没有显著差异(P>0.05);随延迟投饵天数的增加,仔鱼体长生长速度明显降低;完全饥饿组仔鱼3~5日龄呈正增长,随后转为负增长。延迟0d和1d投饵组,11日龄时仔鱼存活率分别为82.67%和89.33%,且两者无显著差异(P>0.05);随延迟投饵天数的增加,11日龄时仔鱼存活率明显降低;完全饥饿组,11日龄时仔鱼全部死亡。  相似文献   

9.
The effect of four stocking densities (30, 60, 100, and 150 lobsters/m2) on the growth and survival of Panulirus cygnus postpueruli was determined over a 112‐d grow‐out trial. Agonistic behavior at each experimental density was recorded using infrared filming. Survival and growth decreased with increasing density, although this trend was only significant between the lowest (30/m2) and the highest densities (150/m2) (P < 0.05) at the conclusion of the grow‐out trial. Density had no significant effect on apparent feed intake but significantly affected food conversion ratios (FCR) across all four densities, with FCR being best at 30/m2 and worst at 150/m2. The number and frequency of agonistic encounters per tank differed significantly with density, with agonistic encounters being highest at 150/m2 and lowest at 30/m2. Agonistic encounters coincided with the crepuscular foraging pattern of postpueruli. The reduction in survival and growth of postpueruli at the highest density (150/m2) can be attributed to the significant increase in the number of agonistic encounters. This study supports that P. cygnus postpueruli should be stocked at densities less than 100/m2 in order to minimize the negative effect of density on growth and survival.  相似文献   

10.
在水温8.9~14.2℃下,在平列糟(长3m,宽0.4m,高0.2m)中采用A、B和C组三种投喂方式驯养刚开口摄食、体质量0.129±0.07g的哲罗鱼(Huchotaimen)苗60d,以探讨驯化方式对哲罗鱼仔、稚鱼生长、存活和种群变异系数的影响:A组以浮游动物开口,投喂浮游动物3d,投喂水蚯蚓15d后,改投人工饲料;B组以水蚯蚓开121,投喂水蚯蚓15d后,改投人工饲料;C组直接以人工饲料开口。结果表明:C组体质量特定生长率(3.577±0.78%/d),明显大于A组(3.132±0.87%/d)和B组(3.024±0.91);A、B、C组的成活率分别为75.67%、74.87%和84.36%,C组明显大于A、B组;A、B和c组鱼体质量变异系数依次为21.47%、22.59%和11.32%,实验表明,直接以人工饲料开口是哲罗鱼规模化养殖中合理的驯化投喂模式。  相似文献   

11.
The palm ruff, Seriolella violacea (Cojinoba), is a potential new species for Chilean aquaculture. To approach Cojinoba larviculture, an experimental Artemia enrichment emulsion, containing docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) = 2.5, supplemented with vitamin E, astaxanthin, and β‐glucan, was evaluated in both Artemia and Cojinoba larvae, 30–50 d.a.h. This study tested an experimental enrichment emulsion versus a commercial emulsion, with an integral approach of multicompound emulsions. After 23 h enrichment, experimental emulsion (EE)‐enriched nauplii reached DHA and EPA concentrations of 23.8 and 18.7 mg/g dry weight (dwt), respectively, while in Cojinoba larvae they were 18.4 and 19.7 mg/g dwt. Control emulsion (CE)‐enriched nauplii exhibited lower DHA and EPA (6.1 and 7.7 mg/g dwt), while only DHA decreased in the control larvae (12.6 mg/g dwt). Vitamin E was higher in EE‐enriched nauplii (29.2 mg/100 g dwt) than in the control (8.4 mg/100 g dwt). Larvae fed EE‐enriched Artemia exhibited 8% increase in survival and 19% in growth compared with the control. Astaxanthin was detected only in larvae fed EE‐enriched nauplii. The tumor necrosis factor‐α concentration was not significantly different between larvae fed EE‐ and CE‐enriched nauplii. EE looks promising as an Artemia enrichment and experimental diet to assess palm ruff larval requirements, and has a positive impact on fish larvae performance.  相似文献   

12.
在盐度为5‰,水温(28±0.5)℃的条件下,对延迟投饵0~7d的奥尼罗非鱼(Oreochromis niloticus×O.aureus)仔鱼摄食、生长与存活进行了研究,并确定了仔鱼的饥饿不可逆点(PNR)。试验于仔鱼开口的当天开始试验。结果显示:仔鱼于3日龄开口;延迟投饵0~7 d组,投饵2 h后仔鱼摄食发生率分别为20%、100%、83.3%、36.7%、13.3%、6.7%、3.3%和0%,各组之间差异显著(P<0.05);延迟投饵在2 d以内,10日龄仔鱼体长和体重与对照组无显著差异(P>0.05),延迟投饵超过2 d,体长和体重显著低于对照组(P<0.05);奥尼罗非鱼仔鱼存活率随延迟投饵天数增加而降低,延迟0~2 d的10日龄仔鱼的存活率相差不大,介于78.6%~79.3%,各组差异不显著(P>0.05),延迟投饵超过2 d的仔鱼存活率较低,介于0%~33.3%;奥尼罗非鱼仔鱼的不可逆点出现在仔鱼开口后第4 d,开始投喂的最佳时间在仔鱼开口后的3 d之内。  相似文献   

13.
One alternative to contribute to the reduction of the pressure on coral reef ecosystems brought about by an increasing demand for marine aquarium ornamentals is to improve and further develop the culture of desirable species for trade. Peppermint shrimp from the genus Lysmata are among the most intensively traded decapod in the trade and while several studies have been conducted to improve its culture, individuals obtained from culture facilities are generally paler than those collected from the wild. Because color is a fundamental component of the price tag on most marine ornamental live species, poorly colored animals command a lower price, reducing competitiveness. In this study, we evaluate the influence of tank background color (reflected light) on the morphological coloration change of Lysmata boggessi. In a 15‐d experiment, 30 individuals were exposed either to reflected‐red or white light and the relative change of coloration between initial and final moments was quantified with photography (RGB color model). At the end of the experimental period, shrimp exposed to red‐reflected light presented a more intense red coloration than those exposed to white‐reflected light. These results demonstrate that a simple change in background tank color can enhance shrimp external coloration. Such a cheap‐to‐implement procedure can support the culture of more colorful, hence more valuable ornamental shrimp that can compete with those captured from the wild.  相似文献   

14.
ABSTRACT

The aim of the present study was to evaluate the survival and growth of larvae (L) of pintado, Pseudoplatystoma corruscans, fed different Artemia sp. proportions: 50, 200, 350, 500, 650, 800, and 950 Artemia nauplii per larva per day, in a complete randomized design. Water salinity was 1.7%, and larviculture lasted for a period of 15 days, which was divided into three individual 5-day trials. Larvae were stocked at a density of 15 per liter and kept in the dark. The concentrations of un-ionized ammonia-N and nitrite-N were directly proportional to the increase in prey density (P < 0.05). Regression analysis showed increased survival and growth rates up to 200, 350, and 500 nauplii/L/day, for the first, second, and third trials, respectively. These results indicate that larval food intake is related to ontogenetic development stage.  相似文献   

15.
The influence of tank wall color and up‐welling water flow on growth and survival of Eurasian perch larvae (Perca fluviatilis) was tested in an intensive culture system. Newly hatched larvae were fed Artemia nauplii, later combined with dry feed, and reared for 5 wk in either black tanks with up‐welling water flow or in gray tanks with or without up‐welling water flow. The perch larvae grew significantly faster in black tanks than in gray tanks regardless of water flow. Two weeks after hatching, a significantly higher mean weight was shown in larvae reared in black tanks compared to larvae reared in gray tanks with up‐welling water flow, and after 4 wk, the mean weight was significantly higher than in both of the other treatments. The difference in growth was further enhanced during the last week of the experiment, and the final mean weights were 51.1 ± 1.9 mg in black tanks with up‐welling water flow, 23.8 ± 2.1 mg in gray tanks with up‐welling water flow, and 23.7 ± 2.2 mg in gray tanks without up‐welling water flow. The cumulative mortality at the end of the experiment averaged 75% in all treatment groups. Taken together, the enhanced growth of Eurasian perch larvae in black tanks could be explained by high prey contrast and increased prey consumption. Up‐welling water flow had no impact on growth and survival of the perch larvae in gray tanks, indicating that the availability and consumption of the prey were independent of water movement.  相似文献   

16.
The aim of this experiment was to determine the optimal initial food for hatchling cuttlefish and to investigate the influence of dietary composition on the growth, survival, and nutritional composition of cultured juvenile cuttlefish, Sepia pharaonis. Six experimental food groups were designated: Artemia nauplii, Calanus sinicus, frozen Hyperacanthomysis brevirostris, Ampithoe valida, H. brevirostris, and subadult Artemia. The results showed that survival, growth body biochemical composition of juvenile cuttlefish were significantly affected by experimental diets (P < 0.05). The optimum initial food was H. brevirostris, yielding a growth rate as high as 6.39%/d and survival rate reaching 81%. Growth rate was significantly positively correlated with dietary protein, Lys, Met, Phe, Iie, Leu, Trp, Arg, Gly, Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and 16:0 (P < 0.05). Survival was significantly positively correlated with dietary protein, Lys, Met, Phe, Val, Thr, Iie, Leu, Trp, Arg, Gly, EPA, DHA, and 16:0 (P < 0.05). The dietary protein, lipid, Met, Val, Thr, Leu, 18:0, and EPA were prone to accumulation within the body of juvenile cuttlefish (P < 0.05). These results demonstrate that juvenile cuttlefish exhibited the best growth rates and survival when fed a diet that supplied high‐protein, low‐fat, and larger quantities of Lys, Met, Phe, Val, Thr, Iie, Leu, Trp, Arg, Gly, EPA, DHA, and 16:0.  相似文献   

17.
杂交鳢和乌鳢池塘养殖对比试验   总被引:1,自引:0,他引:1  
对杂交鳢和乌鳢进行池塘养殖对比试验.前者投喂人工饲料,后者投喂冰鲜鱼,结合水质调控和病害防治等技术,杂交鳢成活率80.9%,乌鳢53.9%;杂交鳢平均单产为5.2 kg/m~2,饵料系数1.367;乌鳢1.8 kg/m~2,饵料系数4.29.整个养殖过程杂交鳢塘换水2次,乌鳢塘换水6次.  相似文献   

18.
温度对墨西哥湾扇贝幼虫和稚贝生长与存活的影响   总被引:9,自引:2,他引:9  
为研究墨西哥湾扇贝人工育苗的适宜温度,2000年4月和2001年4月在浙江省玉环县抛西水产育苗场,通过设置不同温度梯度,研究了海水温度对墨西哥湾扇贝浮游幼虫和稚贝生长与存活的影响。结果表明:墨西哥湾扇贝浮游幼虫的适宜温度为20-33℃,最佳生长温度为25-30℃。稚贝的适宜温度为15-33℃,最适生长温度为25-30℃。  相似文献   

19.
The aim of this study was to evaluate two new types of experimental weaning microdiets for fish larvae, using the same formulation, but with different manufacturing processes, microextrusion marumerization (MEM) and particle‐assisted rotational agglomeration (PARA). Both microdiets were compared to a commercial microdiet, Otohime? (OTO), during the weaning of the fine flounder, Paralichthys adspersus . Weaning was achieved by cofeeding with live food from 40 to 50 d after hatch (d.a.h.). Thereafter, only the microdiets were fed to the end of the study (60 d.a.h.), where the total length, dry weight, and survival rates were 15.9 ± 3.20, 14.3 ± 1.72, and 14.4 ± 2.28 mm; 8.83 ± 3.40, 5.53 ± 2.85, and 7.10 ± 3.56 mg; 18.1, 16.3, and 15.2%, for OTO, MEM, and PARA, respectively. The dry weight and total length were significantly higher (P < 0.05) for larvae fed OTO compared with those fed MEM. There were no differences between the other comparisons. Based on these results, any of the two experimental microdiets can be used for future investigations. However, we recommend the PARA microdiets because the manufacturing process produces less‐dense and smaller particle size diets, reducing sinking rates and increasing the probability of the larvae in detecting and ingesting the diet.  相似文献   

20.
鳗鲡仔鱼微型胶囊饵料的初步研究   总被引:5,自引:0,他引:5  
邓岳松 《水产科学》2001,20(5):8-10
制备了囊心物为液态的,含脂溶性营养物(lipidic solubility nutriment,LSN)及水溶性营养物(water solubility,WSN)的明胶(GT)-羧甲基纤维素(CMC)微型胶囊饵料。制备方法为将WSN和LSN分别溶入适量水和鱼油中,再将水与鱼油制成W/O乳剂,最后以GT、CMC为囊材将乳滴包裹成微囊。平均囊径为41.2μm。对鳗鲡(Anguilla japonica)仔鳗的投喂实验表明,微囊饵料加上天然饵料可使仔鳗存活15d,而只投喂天然饵料的仔鳗只存活了8d。  相似文献   

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