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1.
根据鲍育苗中常用的6种底栖硅藻氨基酸的组成分析结果,选择15种人工合成氨基酸作为诱导物质,进行鲍浮游幼虫附着、变态的影响实验,发现天冬氨酸组附着率最高,谷氨酸组次之,但均略低于底栖硅藻组,明显高于对照组。变态率实验,天冬氨酸和谷氨酸组结果基本一致,均略高于底栖硅藻组,明显高于对照组。不同氨基酸浓度对附着、变态的影响实验结果表明:无论是天冬氨酸还是谷氨酸,实验浓度为10-5mol·L-1组的附着率和变态率最高。 相似文献
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R W Hickman 《Aquaculture Research》2000,31(6):529-536
The New Zealand dredge oyster Tiostrea lutaria Hutton is an incubatory ostreid species that produces fully developed pediveliger larvae, which typically settle shortly after release from the parent. Broods of larvae obtained by opening incubating oysters provide a potential method of spat production, but only a small proportion of the broods obtained in this way are the late‐stage, ready‐to‐settle pediveligers. The majority of the broods are gastrula‐, trochophore‐ and veliger‐stage larvae. Experiments were undertaken to determine whether these early stages, as well as the pediveliger stage, could be reared through to settlement, and so make spat production based on opening incubating oysters much more efficient. Experiments conducted at three temperatures (ambient, ambient + 3 °C and ambient + 6 °C) and under three food regimes (with and without cultured microalgae and without dissolved organics) were unsuccessful in ex‐parent rearing of early larvae (gastrulae and trochophores). Later stage larvae, both veligers and pediveligers, were successfully reared, and high (> 75%) but variable levels of settlement were achieved. Ex‐parent rearing did not benefit from elevated temperatures or the presence of food, and settlement of spat from these prematurely released larvae may be reduced in the presence of food. The ability to rear veliger larvae, as well as pediveligers, greatly increases the potential to use the opening of incubating adult oysters during the breeding season as a source of dredge oyster spat. 相似文献
5.
为探究脂多糖（LPS）对海洋细菌生物被膜形成、海洋贝类幼虫变态所产生的作用,深入了解影响厚壳贻贝附着变态的因素,本实验使用不同浓度的LPS直接刺激厚壳贻贝幼虫,观察其对幼虫附着变态的直接作用;同时在海假交替单胞菌形成生物被膜的过程中添加不同浓度的LPS,分析生物被膜生物学特性的变化,及变化后的生物被膜对厚壳贻贝幼虫附着变态的影响。结果显示,3种浓度的LPS均可直接诱导厚壳贻贝幼虫的变态;10.0mg/L浓度LPS处理后的生物被膜其细菌密度、膜厚度明显降低,且膜厚度降低了12.1%,胞外产物中多糖、脂类显著增加,其中代表性多糖可拉酸的含量增加了35.4%,同时其对幼虫变态的诱导作用也提高了53.3%。因而,在厚壳贻贝幼虫的附着变态过程中,LPS具有直接诱导作用,同时还可以通过调控生物被膜胞外物质,特别是可拉酸的生成,间接影响厚壳贻贝幼虫的附着变态。本研究成果对海洋细菌互作关系研究、厚壳贻贝养殖产业的改善以及海洋防污技术研发具有重要推动价值。 相似文献
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In order to optimize Pecten maximus larval performance and post-larval yield, larvae were fed five algal concentrations in the range 3–20 cells μL?1 in 2,800-L flow-through tanks without prophylactic antibiotics. Competent larvae were transferred to a commercial hatchery for settlement and provided uniform conditions for 4 weeks to observe effects. Increased diet concentration increased the sum of fatty acids (FA) in the total larval population, reaching 7 and 25 ng FA larvae?1 at 3 and 16 cells μL?1, respectively. The FA level in competent larvae was not affected by diet concentration and ranged from 30 to 46 ng larvae?1. Increased diet concentration increased larval growth rate, and the larvae were ready to settle 5 days earlier when fed 16 cells μL?1 compared to 3 cells μL?1. Larval ingestion rate increased during life span and with increased larval diet concentrations, but a considerable amount (40–60 %) of the added algal cells was lost from the larval rearing tanks due to the seawater flow. There was no effect on larval survival, final post-larval shell height, % of competent larvae transferred to settlement, or total yield of post-larvae. Final mean post-larval shell height was 509 μm and 25.5 % of competent larvae settled, resulting in a final post-larval yield between 6.9 and 17.6 % of the initial number of d3 larvae. Competent larvae with similar FA content produced similar numbers of post-larvae independent of diet concentration, even if higher diet concentrations resulted in higher rates of larval development and metamorphosis. 相似文献
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《Aquaculture (Amsterdam, Netherlands)》2006,251(2-4):549-557
A volatile chemical, dibromomethane (DBM), produced from red coralline algae is known as a chemical inducer of larval metamorphosis of the sea urchin Strongylocentrotus nudus. We performed experiments exposing DBM to the larvae of S. nudus and Strongylocentrotus intermedius through a hydrophobic membrane. Metamorphic rates resulting from different diluted DBM solutions and exposure times were ascertained. The highest metamorphic rate, more than 80% in both species, was found after 1 h exposure to 1/2 diluted DBM. With this dilution, more than 80% of S. nudus and S. intermedius larvae metamorphosed 1 h after start of the experiment after only 10 and 5 min exposure, respectively, which corresponded to the low concentrations of 52–61 ppm and 34–43 ppm DBM by GCMS analysis, respectively. These findings suggest that DBM has an instantaneous effect on high success of metamorphosis of larvae of S. nudus and S. intermedius. 相似文献
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ABSTRACT: As a possible factor leading to the low recruitment level of sea urchins in kelp forests, the inhibitory effect of 2,4-dibromophenol (DBP) and 2,4,6-tribromophenol (TBP) released from the large perennial brown algae Ecklonia kurome and Eisenia bicyclis on survival and metamorphosis of eight-armed larvae of the sea urchin Strongylocentrotus nudus was examined. The percentage of larvae that underwent metamorphosis in filtered sea water after 1 h exposure to one-half dilution of saturated dibromomethane solution (∼60 ppm) as a chemical inducer reached approximately 100% after 1 h, while that in filtered sea water containing 1 ppm TBP was reduced to 73%. This was further reduced to less than 40% in the presence of 10 and 20 ppm TBP after 2 h. In filtered sea water containing 1 and 10 ppm DBP, the proportion of metamorphosed larvae was reduced markedly to 43 and 5% after 2 h, respectively. All larvae exposed to 50 ppm TBP and to 20 and 50 ppm DBP died after 1 h. These findings suggest that DBP is more toxic than TBP for sea urchin larvae, strongly inhibiting their metamorphosis. 相似文献
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为研究胆碱受体在厚壳贻贝幼虫变态发育过程中的作用,通过药理学手段调查胆碱类神经递质乙酰胆碱、氯甲酰胆碱及其拮抗剂六甲双铵和阿托品对厚壳贻贝幼虫变态发育调控作用。结果显示:在24 h暴露实验中,氯甲酰胆碱在10-5~10-4mol/L浓度表现出诱导活性,乙酰胆碱则无诱导活性。在持续暴露实验中,氯甲酰胆碱在10-5~10-4mol/L浓度表现出诱导活性,乙酰胆碱在10-6~10-4mol/L浓度表现出诱导活性。在拮抗剂实验中,在10-4mol/L氯甲酰胆碱或10-4mol/L乙酰胆碱存在时,N型胆碱受体拮抗剂六甲双铵对厚壳贻贝幼虫的变态均无抑制效果,表明N型胆碱受体可能并不在幼虫的变态发育过程发挥主导作用。M型胆碱受体拮抗剂阿托品在10-4mol/L氯甲酰胆碱存在时表现出抑制作用,且测试液中幼虫的变态率降为0%,表明M型胆碱受体可能参与调控厚壳贻贝幼虫变态发育过程。在整个药理学实验过程中无死亡幼虫出现,因而氯甲酰胆碱和乙酰胆碱可作为有效诱导物来促进厚壳贻贝幼虫的变态发育,尝试应用于该种的水产养殖过程;同时本研究为厚壳贻贝变态发育调控机制的研究提供有效理论依据。 相似文献
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Jun Hayakawa Tomohiko Kawamura Toyomitu Horii Yoshiro Watanabe 《Fisheries Science》2007,73(2):371-377
ABSTRACT: The settlement of larval top shell Turbo ( Batillus ) cornutus in response to seven macroalgal and three benthic diatom species was examined in the laboratory. The percentages of larval settlement differed significantly among algal species, and were significantly higher on two red algal species ( Marginisporum crassissima , an articulated coralline alga, and Gelidium elegans , an agarophyte) than on the green algae, brown algae and benthic diatoms tested. Marginisporum crassissima induced larval settlement most strongly throughout the experiments. The percentage of larval settlement on a crustose coralline alga (unidentified species), which is known as a suitable substratum for abalone larvae, was much lower than on M. crassissima and G. elegans , which have morphologically complex growth forms . The percentage of settled individuals on ethanol-killed M. crassissima was much lower than on intact M. crassissima . The results indicate that physical structure is unlikely to be the main inducer of settlement; therefore, settlement of top shell larvae seems to be strongly induced by chemicals from the two red algal species. The specific distribution of juvenile top shell in the field may be at least partly determined by the strong induction of larval settlement by articulated coralline and gelidiacean algae. 相似文献
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为了探讨斧文蛤(Meretrix lamarkii Deshayes)的繁殖规律和胚胎发育过程,自2012年1月至2013年1月,每月采集样品,采用组织学方法对浙南海区移养的斧文蛤性腺发育、生殖周期和性成熟率周年变化进行了研究,并结合室内人工育苗试验对其胚胎发育过程进行了显微观察。结果表明,该地区斧文蛤的性腺发育以1年为1个周期,可分为增殖期、生长期、成熟期、排放期和休止期5个时期,雌雄性比约为1:1,性腺发育时间基本同步,均始于2月,随着水温的升高而发育,大部分个体在6月至7月发育成熟,7月下旬至8月底是繁殖盛期,可用阴干加流水刺激方法诱导其排放精卵,受精卵在水温29℃、盐度28、p H 7.8~8.5条件下,经16~20 h孵化成D形幼虫,壳长为100~110μm,浮游幼虫经5~6 d培育进入匍匐幼虫期,壳长约200μm,最后发育变态为稚贝。本研究为斧文蛤的人工繁育、养殖开发以及种质资源保护提供了基础资料。 相似文献
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Alfredo Salas‐Garza Griselda Parés‐Sierra Rodrigo Gómez‐Rigalt Eugenio Carpizo‐Ituarte 《Journal of the World Aquaculture Society》2009,40(4):460-471
This work presents the embryonic, larval, and postlarval development of Lithopoma undosa (L. undosa) (20 ± 2 C and the effect of natural inducers on the larval metamorphosis. Embryonic development until hatching of the trochophore larva took 15 h. Early veliger larvae with well‐developed shell were after 24 h. At 48 h, the operculum was completely formed. Cephalic tentacles were visible after 72 h. Larvae reached competence 6 to 7 d after fertilization, and was characterized by the presence of branched cephalic tentacles. The effect of natural inducers was evaluated. The percentage of metamorphosis with diatoms and adult mucus was 94% and 58% respectively, differing from the 25% without inducer. When was repeated, the metamorphosis was 100%, and 16% with benthic diatoms. The initial mean size of the postlarvae was 0.316 ± 0.02 mm. After 264 d the juveniles had attained a mean size of 5.98 ± 0.16 mm. These results will not only be of use in the evaluation of the culture of L. undosa, but also in studies on the characterization of inducers. 相似文献
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《Aquaculture (Amsterdam, Netherlands)》1986,55(1):5-22
The role of the symbiotic alga Symbiodinium microadriaticum (= zooxanthellae) in growth, development, and survival of larval and juvenile tridacnid clams was investigated. The zooxanthellae were not present in eggs released from adult Tridacna gigas and Hippopus hippopus, but were ingested by veliger larvae after development from the trochophore stage. Growth of veligers of the clam H. hippopus fed freshly-isolated S. microadriaticum was significantly higher than the growth of starved veligers. In contrast, veligers fed cultured strains of S. microadriaticum and 1–5-day-old isolates of S. microadriaticum from H. hippopus had growth and survival rates not significantly different from starved veligers. These results suggest that translocated photosynthetically-fixed carbon from the ingested freshly-isolated algae was responsible for increased veliger growth and survival.The presence of zooxanthellae in the stomachs of veligers before metamorphosis facilitated establishment of a symbiosis with S. microadriaticum and a concurrent increase in growth after metamorphosis. The establishment of the symbiosis with S. microadriaticum entailed passage of the algae from the stomach, through the digestive gland, and into the developing haemal sinuses. The contribution of photosynthetically-fixed carbon from the symbiotic zooxanthellae could theoretically account for the respiratory demand of 6-week-old juveniles of H. hippopus, corroborating positive growth of unfed symbiotic juvenile clams maintained in filtered seawater.When offered a variety of free-living and symbiotic species of algae, juvenile H. hippopus established a symbiosis only with strains of S. microadriaticum. Other species of algae were apparently digested if small enough to be ingested. Less than 7% of the free-living phytoplankton species Isochrysis galbana and Platymonas subcordiformis that were ingested by symbiotic juvenile Tridacna gigas (3–12 months old) were passed intact through the digestive system after 3 days. In contrast, when freshly-isolated zooxanthellae from T. gigas were offered to symbiotic juvenile T. gigas, up to 76% of the zooxanthellae ingested passed through the clam's digestive system and were released in faecal pellets intact. The symbiotic dinoflagellate Amphidinium klebsii and the diatom Phaeodactylum tricornutum were not ingested by veliger or juvenile clams. 相似文献
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To examine the hypothesis that EDTA increases hatching rates and survival of penaeid shrimp larvae by decreasing the toxicities of heavy metals through chelation, the toxicity of cadmium, a highly toxic metal, was compared to the toxicities of calcium and phenol in both the presence and absence of EDTA. In addition, the toxicity of EDTA at higher concentrations was examined. The toxicities of EDTA, cadmium, calcium, and phenol were evaluated in terms of the percentage of nauplii surviving after 24 hours of exposure and the percentage of nauplii which metamorphosed to protozoea. The toxicities of cadmium, calcium, and phenol were also determined in the presence of EDTA. EDTA concentrations of 1.34 mM were lethal to nauplii. At 0.67 mM, EDTA reduced the percentage of nauplii which metamorphosed to protozoea but below 0.3 mM neither survival nor metamorphosis were affected. Cadmium, phenol, and calcium were lethal to nauplii at concentrations of 20 μM, 7 mM, and 400 mM, respectively. Metamorphosis was blocked by concentrations of 1 μM, 0.9 mM, and 200 mM, respectively. However, in the presence of 0.3 mM EDTA, the toxicities of cadmium and calcium were reduced. Cadmium concentrations of 20 μM did not affect either survival or metamorphosis in the presence of EDTA. In calcium concentrations of 50 and 100 mM, the percentage of nauplii that metamorphosed to protozoea was increased by the addition of EDTA. The interaction of EDTA and phenol toxicity was not significant. 相似文献
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Growth,settlement and survival of Dicathais orbita (Neogastropoda,Mollusca) larvae in response to temperature,diet and settlement cues 
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下载免费PDF全文 The southern Australian whelk, Dicathais orbita, is a potential candidate for aquaculture, as both seafood and for bioactive compound production. Larval rearing experiments to determine the effects of temperature and diet on the growth and survival of D. orbita larvae under laboratory conditions comprised five different unicellular algal diets of two brown algal species; Isochysis galbana and Chaetoceros muelleri, two green algae; Tetraselmis seucica and Nannochloropsis oculata, and a mixture of all four strains for larvae maintained at 16 and 22°C. Absolute growth, specific growth rate (SGR) and survival were determined regularly. Larvae reared at 22°C on a mixed diet, or brown algae, performed significantly better than those reared on green algal diets alone. Preliminary trials with settlement cues were undertaken on different aged larvae to determine when larvae become competent. An array of natural cues (carrion, Xenostrobus pulex, adult mucus and Ulvella lens), as well as concentrations of KCl was tested. KCl(concentration of 20 mM) induced the greatest settlement, however, no larvae metamorphosed under the conditions provided. This study confirms long‐lived planktotrophic larval development for Dicathais orbita with higher development rates at the higher water temperatures. Further studies will optimize culture conditions and cues for settlement and metamorphosis. 相似文献
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Effect of neuroactive compounds on larval metamorphosis of New Zealand geoduck (Panopea zelandica) 下载免费PDF全文
下载免费PDF全文 Dung V Le Tim Young Andrea C Alfaro Ellie Watts Nick King 《Aquaculture Research》2017,48(6):3080-3090
We present here the first laboratory study on the effects of pharmacologically active compounds on the larval metamorphosis of the New Zealand geoduck, Panopea zelandica (Quoy and Gaimard, 1835). Two batches of competent hatchery‐reared larvae were exposed to acetylcholine chloride, epinephrine hydrochloride and excess potassium ions in the form of KCl and K2SO4. None of the tested chemicals increased the proportion of metamorphosed geoducks, and in some cases, the chemical caused significant mortality, despite having been used extensively with other species, such as mussels and oysters. This might indicate that geoduck larval physiology and development differs from other bivalves. Geoducks may have evolved distinct chemoreceptor patterns that facilitate metamorphosis under environmentally favourable conditions for subtidal soft sediment habitats suitable for burrowing. Thus, further research is needed to identify alternative cues (e.g. conspecific adults, sediment characteristics and surface biofilm) and understand their role in settlement and metamorphosis. This information will aid the design of reseeding methods and contribute to the development of reliable hatchery production of geoduck spat. 相似文献
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《Aquaculture (Amsterdam, Netherlands)》2005,243(1-4):357-366
The impact of starvation on larvae of Ivory shell Babylonia formosae habei was studied in a laboratory experiment. Newly hatched veligers showed considerable tolerance to starvation due to their endogenous yolk material, and time to the point-of-no-return (PNR; the threshold point during starvation after which larvae can longer metamorphose even if food is provided) was calculated to be 104.5 h. However, starvation still affected larval growth, survival, and metamorphosis. Mean shell length of larvae increased 49.77 μm day−1 for nonstarved, but only 11.13 μm day−1 for larvae starved for 108 h. After larvae began feeding, their growth rates rapidly recovered to the level of the nonstarved following short periods of starvation (less than 48 h), but were inhibited and unable to ever reach the level of the nonstarved when being starved beyond 48 h. Percent metamorphosis was 53.75% for the nonstarved, but all larvae died before 10 days for those starved for 108 h. Starvation not only affected larval time to reach metamorphosis, but also caused the delay in the time to metamorphosis. For the nonstarved, larvae took only 11.5 days to reach spontaneous metamorphosis, but they took 20 days to reach spontaneous metamorphosis when starved for 96 h, and this duration of delayed metamorphosis reached 8.5 days. Furthermore, the importance of yolk material for maintaining larval survival of B. formosae habei during starvation periods is also discussed. 相似文献
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Addison L. Lawrence Joe Fox Frank L. Castille 《Journal of the World Aquaculture Society》1981,12(1):271-280
Although ethylenediaminetetraacetic acid (EDTA) is used routinely in the intensive culture of penaeid shrimp larvae to increase both the percentage of eggs that hatch and the survival of larvae, the mode of action is not known. To explain EDTA's beneficial effect this study compares the toxicities of copper and manganese divalent ions in the presence and absence of 10 mg EDTA/liter seawater. Toxicity was evaluated in terms of the percentage of Penaeus stylirostris nauplii surviving after 12 and 24 hours of exposure to either copper or manganese and in terms of the percentage of nauplii that metamorphose to the protozoeal stage. In the absence of EDTA, copper and manganese ions were toxic to nauplii with copper causing 100% mortality at a much lower concentration (20 μM) than manganese (20,000 μM). In the presence of EDTA, survival of nauplii exposed to copper was increased but survival of nauplii exposed to manganese was not affected. At concentrations lower than the levels that reduce survival, copper ions (0.2 μM) and manganese ions (2 μM) reduce the percentage of nauplii that metamorphose to protozoea. In the presence of EDTA, the percentage of nauplii that metamorphose to protozoea is increased with both nauplii exposed to copper ions and nauplii exposed to manganese ions. The beneficial effects of EDTA are probably due to the chelation of copper and manganese ions by EDTA. Chelation lowers the free concentration of these ions and thus reduces their toxicities. 相似文献
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僧帽牡蛎幼体附着和变态的诱导 总被引：6，自引：1，他引：6
采用外加人工化学物质检验对僧帽牡蛎眼点幼体的附着和变态诱导活性,结果表明去甲肾上腺素、野上腺素和L-多巴可有效诱导幼体不固着变态.在药物持续作用下,肾上腺素的最佳诱导浓度为10-5mol@L-1(变态率67.4%),去甲肾上腺素的最佳诱导浓度为5×10-5mol@L-1(变态率52.2%),L-多巴的最佳诱导浓度为10-5mol@L-1(变态率43.0%),而对照组变态率为0.幼体大多在药物作用12～24h之间完成变态.三种药物诱导的变态个体中有85%以上是不固着变态.比较多种附着基和EPI的变态诱导活性,显示同种贝壳的活性较肾上腺素还高.去甲肾上腺素诱导幼体变态效应对低盐海水有较强耐受能力,而对高盐海水适应性差. 相似文献
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用添加了不同含量Vc-2-多聚磷酸酯(600 mg/kg,3000 mg/kg、6000 mg/kg,对照)的饲料分别投喂中国对虾幼体(Z1-P5),测定其对幼体生长、变态、非特异性免疫以及体内Vc积累量的影响。结果显示:6000 mg/kg处理组显著促进了幼体的生长和变态(P<0.05);超氧化物岐化酶和抗菌活力较对照组和600 mg/kg处理组均达到了显著水平(P<0.05)。第20 d用副溶血弧菌攻毒,3000、6000mg/kg处理组均显著提高了幼体存活率;高效液相色谱法检测幼体体内的Vc含量发现,其体内Vc含量随着饲料中Vc-2-多聚磷酸酯含量的增加而增加。以生长、变态、超氧化物岐化酶、抗菌活力为评价指标,建议中国对虾幼体饲料中Vc-2-多聚磷酸酯的添加量为6000 mg/kg。 相似文献