Ontogeny of the Lymphoid Organs of Japanese Flounder, Paralichthys olivaceus

Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40d was carried out. The pronephric kidney duct appeared early in hatching although the primordial haemopoietic stem cells wereobserved within a week after hatching. The spleen was first seen after 8d of hatching. The thymus appeared after 15d, situated near the pronephric kidney. Small lymphoid cells appeared during the later phase of the post-larval stage in the sequence of thymus, kidney and spleen. During the 40d of observations, there were no distinct inner or outer zones in thymus and no red or white pulp in spleen. These results suggest that the nonspecific defense immune system plays a very important role in the early larval stage of Japanese flounder.     

pH值对大菱鲆生长及鱼体生化组成的影响

研究不同pH对大菱鲆（Scophthal musximus）幼鱼生长及一般生化组成的影响。结果发现：不同时间段内,饲料利用率（FCR）总是随环境pH升高而呈上升趋势,特定生长率（SGR）及增重率（WGR）随环境DH升高而呈下降趋势。在不同时间段,pH83与pH88组的FCR均高于其他组,差异有统计学意义（P〈0.05）,而SGR、WGR均低于其他组,差异有统计学意义（P〈0.05）。各组间鱼体水分差异无统计学意义（P〉0.05）;脂肪含量总体呈下降趋势,pH63组的脂肪含量高于其他组,差异有统计学意义（P〈0.05）,pH6．8至7．3之间时差异不具统计学意义（P〉0.05）,pH78至8．8时降低,差异有统计学意义（P〈0.05）;蛋白含量在pH6．3至7．3之间时差异无统计学意义（P〉0.05）,pH7．8至88时降低,差异有统计学意义（P〈0.05）;灰分含量在DH6．3至7．3之间时差异无统计学意义（P〉0.05）,pH7．8至88时升高,差异有统计学意义（P〈0.05）。结果表明,水环境pH在6．3～7．3范围内有利于大菱鲆幼鱼的健康生长。     

Genetic diversity in two Japanese flounder populations from China seas inferred using microsatellite markers and COI sequences

Japanese flounder is one of the most important commercial species in China; however, information on the genetic background of natural populations in China seas is scarce. The lack of genetic data has hampered fishery management and aquaculture development programs for this species. In the present study, we have analyzed the genetic diversity in natural populations of Japanese flounder sampled from the Yellow Sea (Qingdao population, QD) and East China Sea (Zhoushan population, ZS) using 10 polymorphic microsatellite loci and cytochrome c oxidase subunit I (COI) sequencing data. A total of 68 different alleles were observed over 10 microsatellite loci. The total number of alleles per locus ranged from 2 to 9, and the number of genotypes per locus ranged from 3 to 45. The observed heterozygosity and expected heterozygosity in QD were 0.733 and 0.779, respectively, and in ZS the heterozygosity values were 0.708 and 0.783, respectively. Significant departures from Hardy-Weinberg equilibrium were observed in 7 of the 10 microsatellite loci in each of the two populations. The COI sequencing analysis revealed 25 polymorphic sites and 15 haplotypes in the two populations. The haplotype diversity and nucleotide diversity in the QD population were 0.746±0.072 8 and 0.003 34±0.001 03 respectively, and in ZS population the genetic diversity values were 0.712±0.047 0 and 0.003 18±0.000 49, respectively. The microsatellite data (F_st =0.048 7, P<0.001) and mitochondrial DNA data (F_st =0.128, P<0.001) both revealed significant genetic differentiation between the two populations. The information on the genetic variation and differentiation in Japanese flounder obtained in this study could be used to set up suitable guidelines for the management and conservation of this species, as well as for managing artificial selection programs. In future studies, more geographically diverse stocks should be used to obtain a deeper understanding of the population structure of Japanese flounder in the China seas and adjacent regions.     

Reproductive output of male seahorses,Hippocampus abdominalis,from Wellington Harbour,New Zealand: Implications for conservation

This investigation examines aspects of reproductive output in brooding wild male seahorses, Hippocampus abdominalis, from Wellington Harbour, New Zealand. Previously undocumented, such information is crucial to the management and protection of this species in relation to the CITES Appendix II‐listing of all seahorse species. Brooding males (n = 46) were captured and kept captive until the release of their juveniles, whereupon the number of juveniles was counted and sampled for standard length (SL) and dry weight (DW). SL (mean ± 1SE) of brooding males was 18.1 ± 0.6 cm and wet weight (WW) 17.6 ± 1.6 g. Number (mean ± 1SE) of juveniles released per brood was 271.2 ± 27. The number of juveniles produced was positively correlated with parent SL, WW, and brood pouch volume. Brood pouch volume was positively correlated with male SL. SL (mean ±1SE) of juveniles released was 16.7 + 0.2 mm and DW 1.2 ± 0.1 mg. Mean SL and DW of juveniles were not correlated with the number of juveniles per brood, parent male SL or parent male pouch volume. The percentage of pouch contents which were non‐viable (i.e., premature or non‐viable eggs) upon juvenile release was low (1.1 ± 0.2%; mean ±1SE of the total pouch contents). Based on findings in this study it is suggested that the CITES 10 cm minimum height restriction, which can be used in lieu of non‐detriment findings to allow sustainable exploitation of seahorses, is not suitable for H. abdominalis from Wellington Harbour as it would appear to only protect small males that produce low numbers of juveniles.     

基于层次分析法的莱州湾鱼卵、仔稚鱼评估

作者采用层次分析法对莱州湾鱼卵、仔稚鱼群落结构进行评估,旨在为渔业水域生态环境保护和渔业资源的合理利用提供参考和依据。根据2014年5月、6月和9月对莱州湾鱼卵、仔稚鱼的调查结果,分别以生物、经济、化学3类评价指标构建层次结构模型,最终计算得到各站位评分。结果表明:2014年夏季到秋季的时间变化中,莱州湾鱼卵、仔稚鱼群落结构最优区域的分布存在由近岸向中央区域转移的明显趋势。同时,在评估结果方面,针对评估体系中化学指标的存在与否,莱州湾近岸区域相对于中央区域反应更加敏感。     

In vitro acute cytotoxicity of the neonicotinoid insecticide acetamiprid to FG cells, the gill cell line of flounder Paralichthy olivaceus

1 IntroductionAcetamiprid (( E)-N1-[( 6-chlor-3-pyridyl )methyl]-N2-cyano-N1-methylacetamidine), a cyano-substituted neonicotinoid compound ( Kagabu,1999), is a relatively newclass of insectide, exhibi-ting a broad insecticidal spectrum ( Matsunaka,2000; …     

牙鲆胸腺的组织学研究

牙鲆的胸腺位于鳃腔背面结缔组织膜上,紧贴着肾脏的头部,界限清晰,胸腺不向咽腔突出,胸腺上皮没有粘液细胞。牙鲆胸腺没有明显的外区和内区之分,胸腺细胞和巨噬细胞比较均匀地分布于整个组织中,未能观察到胸腺小体。在胸腺的细胞类型上,首次发现了大量的交错突细胞,常与淋巴细胞相伴,其特点是具有大量的”迷路样”膜结构。同时还发现,牙鲆胸腺可以不对称并存在快速退化现象,在3月龄时最易观察,而6月龄以上的牙鲆即退化消失。     

摄食转基因集胞藻牙鲆的安全性评价

评价转牙鲆生长因子基因集胞藻作为鱼类饲料添加剂的安全性。将摄食转基因集胞藻的牙鲆肌肉以10.0 g/kg.BW.d剂量给小鼠连续灌喂8周,对试验鼠的摄食量、体重、血液常规和血生化指标、脏体系数以及生殖机能进行了检测,对组织器官进行了病理学检查。研究结果显示,灌喂摄食转基因藻牙鲆的小鼠,其摄食量、体重、血液常规、血生化指标及脏体系数与对照小鼠无显著差异(P>0.05),其生殖机能和肝、肾等组织器官未受损害。表明转基因集胞藻作为牙鲆饲料添加剂不能通过食物链对食鱼生物造成不良影响,是安全无毒的。     

鱼类淋巴囊肿病毒靶器官的组织病理研究

探讨病毒传播途径,运用组织病理学技术,对患淋巴囊肿病毒病的牙鲆和鲈鱼的组织进行显微观察,并对病毒感染的靶器官进行了研究。结果表明,在牙鲆体表皮下结缔组织中,当大量成纤维细胞膨大、变圆,大小为10~18μm时,细胞膜外未出现囊壁,少数细胞的细胞质中观察到嗜碱性物质;18~20μm的膨大细胞在细胞膜外出现囊壁,细胞质内出现嗜碱性物质;>20μm的细胞具有了淋巴囊肿细胞的典型特征。另外,在牙鲆鳃、肠上皮下结缔组织和粘膜下层中,脾、头肾边缘组织和表面系膜、肝表面系膜,以及鲈鱼的鳃等部位均观察到淋巴囊肿细胞,并在牙鲆和鲈鱼脾内观察到膨大细胞。因此,淋巴囊肿病毒的靶器官主要是鱼体表皮下结缔组织,其次是鳃、体腔膜、肠、脾和头肾。鱼体表皮下结缔组织是淋巴囊肿病毒病的检测、检疫和早期诊断的最佳样品。