僧帽牡蛎幼体附着和变态的诱导

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.     

5-羟色胺诱导刺参幼虫附着变态

采用不同浓度的5-羟色胺（5-HT）溶液诱导刺参幼虫附着变态,处理不同时间后,计算附着变态率。结果表明：使用浓度为0．001、0．01、0．1和1mmol／L的5-HT溶液诱导刺参幼虫12和24小时均可不同程度地提高刺参幼虫附着变态率。以浓度为0．1mmol／L的5-HT溶液诱导刺参幼虫24小时效果最好,附着变态率提高12．8％。     

化学物质诱导九孔鲍幼虫变态附着的初步研究

用KCl、尿素[CO(NH2)2]、乙二胺四乙酸二钠(EDTA-Na2)诱导九孔鲍幼虫变态附着,分析同种化学物质的不同质量浓度以及不同的化学物质对变态附着的影响,并对他们的诱导效果进行了对比.试验结果表明,质量浓度为0.075 g/L的KCl和0.35 g/L 的EDTA-Na2的诱导作用最显著,而尿素的诱导效果较差,尿素诱导九孔鲍幼虫变态附着的最佳质量浓度是0.1 g/L.不同的诱导物及同一种诱导物在不同的质量浓度下对九孔鲍幼虫变态附着的诱导作用有较大的差异.     

肾上腺素对岩牡蛎幼虫变态的诱导

为了得到壳型规则、大小均一的单体牡蛎,本研究采用肾上腺素对岩牡蛎单体苗种生产的诱导条件进行研究,阐明了岩牡蛎单体苗种的最适诱导浓度、诱导时间和诱导密度。结果显示,肾上腺素能显著诱导岩牡蛎幼虫的不固着变态,最适诱导浓度为5×10–5 mol/L,最适诱导时间为1 h,提高诱导浓度和延长诱导时间导致岩牡蛎幼虫的不固着变态率、稚贝壳高和存活率显著降低;肾上腺素对低于8个/mL幼虫密度的诱导效果差异不显著,但稚贝壳高和存活率在8个/mL的培育密度下显著低于0.5～4个/mL,研究表明利用肾上腺素诱导岩牡蛎单体时,可大批量处理眼点幼虫,但稚贝充气培养的最适培养密度应不高于4个/mL。     

诱导皱纹盘鲍浮游幼虫附着和变态的物质

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。     

GABA受体拮抗剂荷包牡丹碱和CGP52432对厚壳贻贝幼虫附着变态的影响

为研究GABA及其受体拮抗剂荷包牡丹碱（GABA_A受体）和CGP52432 （GABA_B受体）在厚壳贻贝幼虫附着变态中的调控作用,实验通过分析厚壳贻贝不同发育阶段幼虫转录组数据获得GABA受体相关蛋白基因（GABARAP）和GABA_B2受体基因(GABA_B2R),发现GABA_B2R在变态前期的眼点幼虫阶段相较于其他阶段幼体显著高表达。通过实时荧光定量PCR验证也得到相似的表达模式,显示GABA_B2R可能参与调控厚壳贻贝幼虫变态发育。药理学实验结果显示,10^-4 mol/L GABA对厚壳贻贝幼虫的变态具有诱导活性（27.2%±3.0%）。在拮抗剂实验中,10^-6～10^-4 mol/L荷包牡丹碱和CGP52432均显著抑制了厚壳贻贝幼虫变态,且抑制作用随浓度升高而增强。实验还发现GABA及其受体拮抗剂都抑制了厚壳贻贝幼虫的游泳行为。研究表明,GABA_A或GABA_...     

几种化学物质对西施舌幼虫附着和变态的诱导技术

采用添加不同化学诱导物的方法,研究了肾上腺素（EPI）、氨基丁酸(GABA)、L-多巴（L-DOPA）、Ca²⁺对西施舌眼点幼虫附着和变态的诱导作用,确定了化学诱导物 最佳诱导浓度。结果表明,EPI对西施舌附着和变态的诱导效果最为显著,当EPI浓度为10^-4 mol·L^-1时,附着率及变态率分别为88.3％及92.8％,同时成活率也高达98.14％;GABA亦有较好的诱导效果,当GABA浓度为10^-5 mol·L^-1,附着率及变态率分别为86.9％及87.6％;L-DOPA能诱导西施舌眼点幼虫变态,当L-DOPA浓度为10^-6 mol·L^-1时,变态率达73.3％,附着率达84.9%. Ca²⁺最适宜浓度为20 mmol·L^-1时,附着率、变态率及成活率分别为86.1％、42.8％和87.4％。以上4种化合物最适宜浓度诱导作用时,西施舌幼虫的附着率和变态率均显著高于对照组。实验还对Ca²⁺在西施舌大规模人工育苗中的诱导作用进行探讨。     

化学物质诱导泥蚶幼虫附着变态的研究↑（*）

1996年8～9月间在室内用8种化学诱导物对泥蚶变态前期幼虫进行附着变态诱导实验。结果表明,8种药物对泥蚶幼虫的变态均有一定的诱导作用。其中,3-HT、EPI和NE对幼虫变态的诱导作用极显著,有效浓度范围较广;KCl和Ala的诱导作用较显著,有效浓度范围较窄;而Try、CABA和Ach只有某些浓度组的诱导效果明显,诱导效率对浓度的信赖性较强。从诱导物浓度来看,10-4mol/L的Ala、GABA和10-5mol/L的EPI诱导效果最好,与对照组相比,变态率均提高12%以上。不同处理时间试验表明,处理时间的长短与幼虫的变态率无一致的相关性关系,因药而异;总的来看,处理时间不超过8h的诱导效果较好,时间过长诱导率降低(GABA除外)。其中,用10-5mol/L的Ala处理1～4h或10-5mol/L的EPI处理4h效果最好,与对照组相比,变态率均提高25%以上。8种药物中,只有Try表现出对幼虫明显的毒性影响,Try的浓度越高,处理时间越长,幼虫的死亡率越高,用10-4mol/L的Try处理幼虫3h,死亡率达89%。     

K^＋对几种海胆幼虫变态的诱导效果

K^ 是对海洋底栖无脊椎动物幼虫诱导普遍有效的无机离子。本文探讨了K^ 对红海胆等9种胆的变态诱导效果，分析了其安全使用浓度、处理时间等技术。对有关因子对变态率的影响进行了对比。     

西施舌(Coelomactra antiquata)幼虫附着变态及胚后发育的研究

在1999-2011年间,为了充实西施舌(Coelomactra antiquate)幼虫附着变态生物学理论基础和提高育苗成苗率,采取显微连续观察和活体显微摄影方法,对西施舌的幼虫发育各阶段的形态特征、附着变态及胚后发育的全过程等进行研究。结果表明,西施舌的直线铰合幼虫出现前闭壳肌和3对面盘收缩肌。壳顶幼虫时期开始生成后闭壳肌。足呈舌状,足神经节上方有一对平衡器,面盘中央具顶鞭毛朿。后期壳顶幼虫出现足丝腺、管状内鳃丝。匍匐幼虫足呈棒状,匍匐活动频繁,足丝腺发达,内鳃丝2~3对。面盘萎缩,顶鞭毛朿脱落,开始分泌足丝附着;次生壳生成;器官移位,唇瓣、口、内鳃相连接,以鳃滤食为西施舌幼虫变态的主要生物学标志。初期稚贝唇瓣二指形,内鳃丝2~4对。初期幼贝唇瓣三角形,眼点消失,外鳃丝生成,除性腺外,内部器官发育齐全。此项研究,对于进行西施舌幼虫的诱导附着及完善其产业化育苗工艺都具有重要意义。     

葡萄牙牡蛎的净化及其低温贮藏研究

为保证生食葡萄牙牡蛎(Crassostrea angulata)的安全,在贝水比1∶10、水交换率3次/h、水温28℃、盐度28的条件下,采用流水式紫外线杀菌方法净化48 h,检测净化前后13个卫生指标的变化;净化后的牡蛎在冷藏(4℃)和冷冻(-18℃)两种条件下贮藏7 d以上;检测贮藏过程中菌落总数、大肠菌群和主要营养成分的变化。结果显示,经过48 h净化,菌落总数和大肠菌群含量均大幅下降,重金属、化学污染物等指标变化不大;两种贮藏条件下,菌落总数和大肠菌群都呈先下降再上升的变化,但始终处于安全水平内;蛋白质、脂肪、糖原含量缓慢下降,乳酸含量快速上升。研究表明,葡萄牙牡蛎在紫外线杀菌净化48 h后,至少在冷藏6 d或冷冻11 d内可以保证食品安全。     

冬季单体牡蛎池塘育肥初步实验

为提高牡蛎商品品质,开展了池塘葡萄牙牡蛎(Crassostrea angulata)冬季育肥实验。育肥实验设置4个实验组:3组室内水泥池实验组(水温分别为24℃、20℃和16℃)以及1组室外池塘实验组,室内实验组饵料来自于室外池塘藻水。实验结果表明:经过一个月育肥,室外池塘实验组的牡蛎肥满度由13.1%增加到了19.6%,性腺饱满个体比例由13.3%增加到66.7%;室内水泥池实验组牡蛎肥满度无明显变化。池塘实验组牡蛎糖原含量稍有增加,水泥池实验组下降。池塘育肥葡萄牙牡蛎效果明显。     

Broodstock conditioning of the Portuguese oyster (Crassostrea angulata,Lamarck, 1819): influence of different diets

The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T‐ISO; Diet 2 – P. lutheri, T‐ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D‐larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms‐predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase.     

Influence of gonadal development on metal accumulation in the Portuguese oyster,Crassostrea angulata,in subtropical areas

Metal enrichment makes oyster considered to be an appropriate food source for trace elements, but excessive accumulation can threaten human health. Reproduction is an important biotic factor that affects the metal accumulation in oysters. However, the influence of continuous gonad development model on metal accumulation in some subtropical oysters is still unclear. The present study addresses the concentrations of trace metals and glycogen associated with the gonadal and somatic tissues throughout the reproductive cycle of diploid and triploid Crassostrea angulata cultured in Fujian, China. Cu, Zn and Pb contents of gonads were negatively correlated (p < 0.05) with gonadosomatic index (GSI). The correlation between Cd content and GSI was not significant. There was a positive correlation (p < 0.05) between GSI and Mn content in female gonads while the correlation was negative (p < 0.05) in males, indicating Mn plays an important role in gametogenesis of females. The effects of gonadal maturity and gender on metal accumulation in somatic tissue were not significant (p > 0.05). The concentrations of all metals in sterile triploids were not significantly different from those of the somatic tissue of diploids. Gonadal glycogen content showed a negative correlation with the GSI. However, somatic glycogen content was not affected by gonadal development, indicating that the energy consumed during gametogenesis comes mainly from recently ingested food rather than from energy stored in somatic tissue. The effects of the gonadal development on the metal accumulation in oysters varied according to the metal and tissue type.     

Mitochondrial DNA barcoding for Okinawan oysters: a cryptic population of the Portuguese oyster Crassostrea angulata in Japanese waters

We used mitochondrial (mt) DNA barcoding to evaluate the species diversity of oysters sampled from the coast of Okinawa Island, Japan. Our analysis revealed the presence of a hitherto-unrecognized population of the Portuguese oyster Crassostrea angulata, a putative species closely related to the Pacific oyster C. gigas. Forty-eight Okinawan oyster specimens were collected and subjected to species diagnosis trials based on mtDNA barcodes. Of the 30 Crassostrea specimens, 17 were identified as C. angulata, seven as C. gigas and six as C. bilineata (syn. C. iredalei). The remaining 18 Saccostrea specimens formed several divergent clades in phylogenetic trees, although they could not be identified to species level because of the confounding taxonomy of the Saccostrea species complex. Our results stress the necessity for reviewing the species diversity of Okinawan oysters.     

温度对长牡蛎和葡萄牙牡蛎及其杂交稚贝生长和存活的影响

为比较不同温度下长牡蛎(Crassostrea gigas)和葡萄牙牡蛎(C.angulata)杂交稚贝的生长与存活差异,以正交组GA(长牡蛎♀×葡萄牙牡蛎♂)、反交组AG(葡萄牙牡蛎♀×长牡蛎♂)、自交组GG(长牡蛎♀×长牡蛎♂)和AA(葡萄牙牡蛎♀×葡萄牙牡蛎♂)的稚贝为材料,开展了温度适应性研究.结果 表明,GA...     

Effects of different substrates on settlement and growth of pearl oyster (Pinctada maxima) larvae in hatcheries

Metamorphosis of pearl oyster Pinctada maxima pediveliger is affected by physical and chemical characteristics of the collectors. In the present study, we conducted four experiments to evaluate the effects of collector characteristics on the settlement and growth of hatchery-reared pearl oyster. In the first experiment, black, red, yellow, and white plastic sheets were used as collectors. Settlement of P. maxima larvae in black and red plastic sheets was significantly higher than that in yellow and white plastic sheets (P < 0.05). Mean shell length was not significantly different among the four colored sheets (P > 0.05). In the second experiment, pediveliger larvae were settled onto palm rope and polypropylene rope collectors. The number of spat in the palm rope collector was significantly higher than that of spat in the polypropylene rope collector (P < 0.05). Mean shell length was not significantly different between palm rope and polypropylene rope collectors (P > 0.05). In the third experiment, settlement and subsequent growth were compared between plastic sheets with and without biofilm. The number of spat in the plastic sheets with biofilm was significantly higher than that in the plastic sheets without biofilm (P < 0.05). Mean shell length after settlement were not significantly affected (P > 0.05). In the fourth experiment, pediveliger larvae were stored in tanks with (experimental group) and without collectors (control group). The settlement rate of larvae on the wall was not significantly different between the two groups(P > 0.05). The settlement rates of the larvae on the wall and collectors in the experimental group were significantly larger than those on the wall in the control group(P < 0.05). Mean shell length was not significantly different between the groups (P > 0.05). Our results suggest that appropriate selection of collector types, color, and conditioning can improve the settlement of P. maxima larvae in hatcheries.