0~#柴油中的水溶性石油烃对中华绒螯蟹溞状幼体的急性毒性

以中华绒螯蟹溞状幼体为实验对象,通过48 h半静水式急性毒性试验探究0~#柴油中的水溶性石油烃对中华绒螯蟹(Eriocheie Sinensis)溞状幼体的急性毒性效应。结果发现,水溶性石油烃对5期(Z_1～Z_5)溞状幼体的24 h半致死浓度分别为9.902、10.542、11.596、13.441和15.684 mg/L; 48 h半致死浓度分别为6.249、7.193、8.022、9.889和12.948 mg/L;安全浓度分别为0.813、1.005、1.247、1.606和2.480 mg/L。参照《环境监测技术规范》生物监测(水环境部分),可以看出0~#柴油的水溶性石油烃对中华绒螯蟹各期溞状幼体为高毒。本研究可为科学评价水溶性石油烃对中华绒螯蟹各期溞状幼体的毒性提供依据,同时为河蟹养殖环境风险预警监测提供数据参考,对生产实践具有良好的指导意义。     

一株中华绒螯蟹幼体益生菌的筛选及其种属特性的初步研究

通过单株细菌感染中华绒螯蟹Ⅰ期溞状幼体的方法筛选出2株病原菌,它们对幼体的72 h致死率为100%;获得有益菌1株,与对照组相比提高中华绒螯蟹Ⅰ期溞状幼体的变态率近50%,该菌株有望成为中华绒螯蟹幼体的益生菌株.根据16S rRNA序列同源性分析结果,将其初步鉴定为节杆菌属的一种.     

中华绒螯蟹幼体及仔蟹阶段肝胰腺发育的组织学研究

通过对中华绒螯蟹幼体及仔蟹进行连续采样和组织切片,系统地研究了该阶段中华绒螯蟹肝胰腺的发育情况。结果表明,中华绒螯蟹的肝胰腺前体出现于心跳期胚胎,由卵黄囊特化而来,为1对囊状结构,此阶段首次出现肝胰腺细胞(柱状上皮细胞)。胚胎孵化后,随着幼体的发育,肝胰腺由最初的1对囊状结构逐渐分叶生长。从Ⅰ期溞状幼体至Ⅴ期溞状幼体,肝胰腺分叶数量分别为4-6-8-12-12,肝胰腺细胞高度由(12.63±4.91)μm增至(44.16±13.57)μm。肝胰腺中的细胞组成也随着幼体的发育逐渐完善,Ⅱ期溞状幼体的肝胰腺中首次出现E细胞和B细胞,Ⅲ期溞状幼体肝胰腺中首次出现F细胞,而R细胞直到Ⅱ期仔蟹才首次出现。从大眼幼体到Ⅲ期仔蟹,肝胰腺细胞高度由(44.93±18.27)μm增至(56.38±5.69)μm。     

中华绒螯蟹Timeless基因在不同发育阶段的表达谱分析

Timeless基因是重要内源性的生物钟基因之一,在生物体内周期性表达,保持昼夜节律时间并激活输出途径。本文分析了中华绒螯蟹Timeless基因在其溞状幼体Ⅰ~Ⅴ期、大眼幼体期和仔蟹Ⅰ~Ⅲ期共9个不同发育阶段以及扣蟹、成蟹(性成熟)不同组织间的mRNA表达情况。荧光定量PCR结果揭示Timeless基因在溞状幼体Ⅰ期至仔蟹Ⅲ期9个发育阶段均有表达,在溞状幼体Ⅴ期的表达量最高,显著高于其他时期(P0.05),随后在大眼幼体时期急剧下降,最后仔蟹时期又呈稳步上升趋势。在扣蟹时期的8个组织中,Timeless基因在肝胰腺和肌肉中的表达量较高,与其他组织的表达均呈显著差异(P0.05);在成蟹时期肝胰腺中的表达量最高且与其他组织中的表达水平均差异显著(P0.05)。研究结果表明,中华绒螯蟹Timeless基因在幼体发育阶段均有表达,组织表达主要在肝胰腺和肌肉中,并且在不同性别的成蟹组织间Timeless mRNA表达存在显著差异。推测该基因可能在中华绒螯蟹的生长发育、生理适应和代谢调控过程中具有重要作用。     

六株海洋微藻强化的酵母轮虫对中华绒螯蟹溞状幼体的影响

实验用6株海洋微藻来强化用酵母预培养的褶皱臂尾轮虫,并将强化后的轮虫投喂中华绒螯蟹的溞状幼体,以研究使用经不同食物强化后的轮虫投喂溞状幼体对溞状幼体变态时间及成活率的影响。结果表明：经过直链藻强化的轮虫投喂的溞状幼体的成活率及变态时间均优于其他海洋微藻强化的褶皱臂尾轮虫,海水蒜头藻与海水小球藻次之,酵母轮虫最差。     

中华绒螯蟹胚胎发育及几种代谢酶活性的变化

采用实验室内小规模实验的方法,在水温(16.2±1.5)℃和盐度20的条件下,对中华绒螯蟹胚胎发育过程中的形态学变化和几种重要代谢酶的活性变化进行了系统性研究。实验结果表明,中华绒螯蟹的胚胎发育过程可以分为9个主要阶段:受精卵、卵裂期、囊胚期、原肠期、前无节幼体期、后无节幼体期、原溞状幼体期、出膜前期和孵化期;水温16℃的条件下,整个胚胎发育过程需40 d左右,有效积温达到10 758 h.℃。乳酸脱氢酶(LDH)、总ATPase和苹果酸脱氢酶(MDH)的活性都随胚胎发育时期的变化而变化,LDH活性呈现出先上升后下降的趋势,在囊胚期中活性最高;总ATPase活性在原溞状幼体期最高,在原肠期最低;MDH活性在原溞状幼体期最高,在囊胚期最低。     

草甘膦对中华绒螯蟹幼蟹的毒性影响

为研究水稻种植过程中常用除草剂草甘膦对中华绒螯蟹幼蟹的毒性作用,通过48 h半静水法测定草甘膦对中华绒螯蟹的半致死浓度(LC₅₀)和安全浓度(SC),并据此结果设定28 d慢性试验浓度,测定中华绒螯蟹的死亡率、蜕壳率和平均蜕壳天数,以及肝胰腺组织学变化。试验结果表明,急性毒性试验中,草甘膦12、24、36、48 h对中华绒螯蟹的半致死浓度分别为18.91、16.67、13.99、12.09 mg/L,安全浓度为1.9 mg/L;慢性毒性试验中,相比对照组,试验组草甘膦浓度达到0.6 mg/L后中华绒螯蟹的死亡率显著升高,草甘膦浓度达到0.3 mg/L时中华绒螯蟹的蜕壳率显著降低,各组间平均蜕壳时间统计学显示无明显差异,但组织学试验表明,中华绒螯蟹长时间暴露于低于安全浓度的草甘膦中依然会造成肝胰腺的损伤。     

敌百虫对中华绒螯蟹幼体的毒性研究

采用实验室小型水族箱,每组设1个空白对照、2个平行组,研究敌百虫对中华绒螯蟹不同生长期幼体的急性毒性。结果表明:中华绒螯蟹Ⅱ期蚤状幼体(Z2)24 h和48 h LC50分别为0.0052和0.0045 mg/L,安全浓度为0.00101 mg/L;Ⅲ期蚤状幼体(Z3)24 h和48 h LC50分别为0.0061和0.0051 mg/L,安全浓度为0.00262 mg/L;Ⅳ期蚤状幼体(Z4)24 h和48 h LC50分别为0.0053和0.0039 mg/L,安全浓度为0.00063mg/L;大眼幼体(M)24 h和48 h LC50分别为0.0104和0.0087 mg/L,安全浓度为0.00202 mg/L。     

中华绒螯蟹超氧化物歧化酶的初步研究

对自然状态下长江水系的中华绒螯蟹成蟹血淋巴和大眼幼体组织匀浆上清液中超氧化物歧化酶(SOD)的活性进行了初步研究。结果表明,在中华绒螯蟹成蟹血淋巴中均检测出超氧化物歧化酶的活性,为182.96±45.66 U/mL(n=29),而在中华绒螯蟹大眼幼体组织匀浆上清液中亦检测到超氧化物歧化酶的活性,为94.29±15.65 U/mL(n=4)。超氧化物歧化酶在河蟹的自身防御系统中起着重要的作用。     

中华绒螯蟹神经系统及其胚后发育的组织学观察

为完善中华绒螯蟹神经系统组织学相关资料,文章采用石蜡切片和苏木精—伊红染色技术对中华绒螯蟹神经系统及其胚后发育组织学特点进行了研究。结果表明,中华绒鳌蟹中枢神经系统在Ⅰ期溞状幼虫已见雏形,但前、中、后脑未愈合,前脑较小;Ⅱ期溞状幼虫前脑体积增大;Ⅲ期溞状幼虫中、后脑向上迁移与前脑愈合,到Ⅴ期溞状幼虫,前脑、中脑、后脑完全愈合并迁移到两眼之间;大眼幼虫和稚蟹脑具备了六边形形态。食道下神经节与胸神经节的两条神经索在Ⅰ期溞状幼虫呈分离状态,Ⅱ期溞状幼虫时开始愈合,至Ⅳ期溞状幼虫完全结合。腹神经链在Ⅰ期溞状幼虫发育不完全,Ⅲ期溞状幼虫形成两条神经索,Ⅳ期溞状幼虫两条神经索联系紧密。Ⅴ期溞状幼虫食道下神经节与胸神经节高度愈合,腹神经链发育完全,并在大眼幼虫期开始与胸神经节愈合。胸腹神经团的3个组成部分在稚蟹期达到完全愈合。     

中华绒螯蟹(Eriocheir sinensis)种苗土池培育技术研究Ⅰ-Ⅰ期溞状幼体的适宜密度

在６口海水土池（计１．９ｈｍ２）中分别按下列密度（万／ｍ３）布苗：３，４，５，３，４和０．２７，比较研究了中华绒螯蟹（Ｅｒｉ－ｏｃｈｅｉｒｓｉｎｅｎｓｉｓ）Ⅰ期氵蚤状幼体（Ｚ１）的密度对幼体变态率和成活率的影响。结果表明，Ｚ１的密度为４万／ｍ３时，大眼幼体的变态率（大眼幼体密度占Ｚ５密度的％；２１．６％）和成活率（大眼幼体的密度占Ｚ１密度的％；２．４％）及产量（４２ｋｇ／ｈｍ２）最高。     

梭子蟹全人工工厂化育苗技术

2000年笔者在日照市水产研究所利用1450m^3水体进行梭子蟹全人工工厂化育苗生产，共出Ⅱ-Ⅲ期幼蟹512．7万只，创造了出苗量为3500只／m^3，总产为150多万元的直接经济效益，同时对幼体培育的密度进行了初步试验，结果表明，从Z1至M期幼体培育密度10－15万/m^3为宜，M期以后密度为0．8－1．5万/m^3为宜。     

Ingestion Rate and Feeding Behavior of the Peppermint Shrimp Lysmata wurdemanni on Artemia Nauplii

A laboratory study was conducted to examine the effects of food level and water temperature on the ingestion rate in the larvae of the peppermint shrimp Lysmata wurdemanni , a popular aquarium spe cies. Artemia nauplii were used as the food item. Number of newly hatched Artemia nauplii consumed by the larvae (from zoea II to zoea VII, zoea I can metamorphose to zoea II without exogenous nutrition in about one day) was measured daily at four food concentrations (2, 5, 10 and 20 Artemia nauplii/mL) and two temperature levels (25 C and 28 C). The experiment was conducted in 500-mL beakers with three replicates for each treatment. The results show that the shrimp consumed significantly more food at 28 C than at 25 C (P < 0.01). Ingestion rate increased with increasing food concentration in all larval stages and with larval development except for the lowest food level ( 2 Artemia nauplii/mL) where insufficient food supply limited the ingestion rate to around 35 Artemia nauplii/ larva per d after zoea IV stage. The larval development rate was significantly lower (P < 0.05) in the shrimp subjected to the two lowest food concentrations (2 and 5 Artemia nauplii/mL) in the 500-mL beakers. But in a separate experiment conducted in the 1,400-mL beakers, the results were reversed: both survivorship and development rate were significantly lower at the two higher food levels (6 and 12 nauplii/mL) than those at 3 nauplii/mL level. During molting period, ingestion rate decreased significantly, followed by a sharp rise to the normal rate the following day.     

Ontogeny of feeding apparatus and foregut of mud crab Scylla serrata Forsskål larvae

The development of the feeding apparatus of the mud crab Scylla serrata larvae was studied using electron microscopy for mandibles and light microscopy for other paired mouthparts and the foregut. The six paired mouthparts, which consisted of the mandibles, maxillules, maxillae, first maxillipeds, second maxillipeds and third maxillipeds, were dissected from specimens representing each larval stage. The first five paired appendages were already present in newly hatched larvae while third maxillipeds appeared only at the megalopa stage. Mandibles displayed complex incisor and molar processes at early zoeal stages, which became simple in morphology at megalopa. Mandibular palp buds were observed at the zoea 5 stage and these became fully developed as three‐segmented mandibular palps at the megalopa stage. Endopods of other paired mouthparts exhibited increased number of setae and size as the individual metamorphosed from zoeal stages to megalopa and crab instar. The foregut appeared as a continuous cavity at zoea 1 where the cardiopyloric valve was indistinct while the filter gland was clearly identifiable. Zoea 2 and succeeding zoeal stages exhibited a setose foregut; the gastric mill and its lateral and median teeth were prominent at zoea 3 stage. The significance of these morphological changes is discussed in terms of its implication in larval feeding management.     

氨氮对红星梭子蟹早期幼体的急性毒性

在盐度30、pH 8.5、温度28.8～29.8℃、投喂扁藻和轮虫的条件下,设置10、20、40、80、160mg/L共5个氨氮梯度和1个对照组(天然海水),进行了氨氮对红星梭子蟹早期幼体(第Ⅰ期溞状幼体,Z1)的急性毒性试验。结果发现,氨氮暴露12～72h,红星梭子蟹早期幼体活力组间差异显著(P<0.05),当氨氮继续暴露至84～96h,早期幼体活力组间差异不显著(P>0.05);氨氮暴露12～96h,红星梭子蟹早期幼体存活率组间差异显著(P<0.05),但对照组与10mg/L试验组差异不显著(P>0.05);红星梭子蟹早期幼体的氨氮暴露12、24、36h时的半致死质量浓度分别为80.94、27.96、14.43mg/L,红星梭子蟹早期幼体暴露36h的氨氮安全质量浓度为1.44mg/L。     

氨氮对锈斑蟳早期幼体的急性毒性

在pH 8.5、水温(28.5±0.5)℃、盐度30条件下,用500 ml烧杯设置10、20、40、801、60 mg/L5个氨氮(总氮)质量浓度梯度和1个对照组(天然海水),研究氨氮对锈斑蟳早期幼体(Z1)急性毒性试验。结果表明,氨氮暴露12 h,40 mg/L以下质量浓度组毒性作用不显著,但80 mg/L以上质量浓度组与对照组差异显著(P<0.05);氨氮暴露24 h,20 mg/L以下质量浓度组毒性作用不显著,但40 mg/L以上质量浓度组与对照组有显著差异(P<0.05);氨氮暴露36～96 h,0、10 mg/L组间差异不显著,但20 mg/L以上质量浓度组与对照组有显著差异(P<0.05)。12、24、36、48、60、72 h氨氮暴露的半致死质量浓度分别为85.566、36.171、22.880、12.485、8.299、4.313 mg/L。锈斑蟳早期幼体培育的安全质量浓度为0.431 mg/L。     

4种水产药物对蓝点笛鲷幼鱼急性毒性试验

采用半静水法生物测试，以蓝点笛鲷（Lutjanus rivulatus）幼鱼为受试生物，研究了甲醛、苯扎溴铵、聚维酮碘和高效氯氰菊酯对其的急性毒性。结果表明，毒性大小依次为高效氯氰菊酯〉聚维酮碘〉苯扎溴钱〉甲醛。甲醛、苯扎溴铵和聚维酮碘为低毒物质，安全质量浓度（SC）分别为19．8800mg·L^-1、7．5710mg·L^-1和2．8429mg·L^-1；高效氯氰菊酯为剧毒物质，SC为0．0028mg·L^-1；甲醛、苯扎溴铵、聚维酮碘和高效氯氰菊酯对蓝点笛鲷幼鱼的24h半数致死质量浓度（LC50）分别为81．3240mg·L^-1、40．7619mg·L^-1、15．2077mg·L^-1和0．0153mg·L^-1；48hL C50分别为75．9587mg·L^-1、34．7413mg·L^-1、12．9894mg·L^-1和0．0129mg·L^-1。根据试验结果，建议菊酯类不宜作为蓝点笛鲷育苗药物使用，聚维酮碘和苯扎溴铵要慎用。     

Survival of blue king crab Paralithodes platypus Brandt, 1850, larvae in cultivation: effects of diet, temperature and rearing density

Blue king crab (Paralithodes platypus) larvae were cultivated to test the effects of diet, temperature and rearing density. Dietary treatments included no feeding (unfed), Artemia nauplii enriched with diatoms Thalassiosira nordenskioeldii (THAL), unenriched Artemia fed in addition to Thalassiosira (A+THAL) and a control diet of Artemia enriched with frozen Isochrysis paste (ISO 6). Trials were conducted at 6 °C, and a rearing density of 10 zoea L^?1, with six replicates per treatment. The ISO 6 diet was also tested at 3 °C (ISO 3) and 9 °C (ISO 9), and at densities of 20 (ISO 20) and 40 (ISO 40) zoea L^?1. Survival of zoea larvae fed the A+THAL diet (91.7%) was significantly higher than all others, whereas unfed zoea larvae died within 2 weeks. Temperature and rearing density had no significant effects on survival. Time required to reach stage C1 was significantly greater at 3 °C (109 days) than at 6 °C (70 days), but did not decrease further at 9 °C. After reaching the postlarval (glaucothoe) stage, half of the replicates in the ISO 20 and ISO 40 treatments were fed continuously, but survival did not differ significantly from unfed glaucothoe. We conclude that blue king crab larvae are not lecithotrophic and can be cultivated with high survival using the proper diet. These techniques can be used to produce large numbers of juvenile crab for laboratory research, or could be modified for use in stock‐enhancement programmes.     

Effects of Starvation and Feeding on Lipid Class and Fatty Acid Profile of Late Stage Mud Crab,Scylla serrata,larvae

Lipid class and fatty acid (FA) analysis were conducted on newly molted, fed, and starved zoea V and megalopa of the mud crab, Scylla serrata (S. serrata). Larvae starved for 4 d showed a substantial decrease in total FA content, from 49.67 μg/mg to 13.94 μg/mg ash‐free dry weight (AFDW) at the zoea V stage, and from 38.47 μg/mg to 10.40 μg/mg AFDW at the megalopa stage. This depletion indicates that S. serrata larvae effectively utilize stored lipid reserves for energy during periods of food deprivation. Megalopa subjected to longer starvation periods, however, did not utilize lipid as the major energy source after day 4, suggesting increased reliance on protein catabolism during prolonged starvation. At both larvae stages the major FAs were 18:1n‐9, 16:0, 20:5n‐3 (eicosapentaenoic acids, EPA), 18:3n‐3 (linolenic acid, LNA), 18:0 and 22:6n‐3 (docosahexaenoic acid, DHA) and this FA profile persisted in both fed and starved larvae. The highly unsaturated fatty acids (HUFA), EPA, DHA, and arachidonic acid (20:4n‐6, AA) were not conserved in tissue during starvation, indicating that HUFA requirements might be lower for S. serrata larvae than shown for other crustaceans. Similarly, a high level of LNA in newly molted zoea V and megalopa were rapidly depleted in unfed larvae, indicating that this FA had an important role as an energy reserve. Throughout the study, FAs from the polar lipid fraction dominated larvae tissues, while FAs from the neutral lipid constituted the largest accessible energy reserve during starvation (depleted from 23.05 to 1.23 μg/mg AFDW in zoea V, and from 19.00 to 1.27 μg/mg AFDW in megalopa). The results of this study provide new insight into lipid utilization of S. serrata larvae during development, an important step toward development of formulated diets for use in mud crab hatcheries.