Synopsis of the life cycles of Digenea (Platyhelminthes) from lagoons of the northern coast of the western Mediterranean

The present document reports on the large amount of data relating to digenean parasites recorded from or known to be present in various hosts in lagoons of the northern coast of the western Mediterranean, which has been compiled from the literature of more than a century. In these lagoons, at least 72 nominal species of digeneans have been recorded. This total corresponds to approximately 12% of the 584 “marine” digenean species reported for Europe. Data are provided on the life cycles of 56 digenean species. The life cycle has been totally elucidated for 44 species (25 from fish, 19 from birds), and partly for the other 12 species (seven from fish, five from birds). This means that the life cycle is known for 61.1% of the recorded fauna (44/72) and partly for 16.7%, but remains unknown for 22.2%, making it, in this respect, one of the best understood digenean marine faunas in the world. In addition, a checklist is provided dealing with the cercarial and metacercarial forms recorded from lagoons of the northern coast of the western Mediterranean, which have been described only on the basis of characters of these larval stages and which remain without demonstrated links to a corresponding sexual adult stage in a vertebrate.     

真骨鱼类卵膜孔精子引导系统的数学模型

继１９８７年发现泥鳅成熟卵卵膜孔涡旋状结构后,作者又发现大银鱼卵膜孔区域呈现沟脊放射状结构,通过对大银鱼,鲂鱼卵孔纵切面曲线的数学建模及其对这种给切面曲线成因的研究,     

Nassariid gastropods as destructive agents in preservation and fossilization of marine fishes

Experimental investigations on the feeding activity of the gastropodNassarius moestus in intertidal environments in the Sea of Cortez (Gulf of California) show them to be effective agents influencing processes of marine fish taphonomy. Time-lapse documentation reveals that potential whole-body preservation of fish carcasses is largely prevented through the rapid destruction of soft tissues, muscles, and ligaments, followed by disarticulation and subsequent disassociation of skeletal elements. Dissociated bones are subject to differential dispersal through hydrodynamic transport and physical wear through abrasion. Transformation of whole-body carcasses into thoroughly defleshed and disarticulated skeletons by large groups of scavenging snails was commonly observed to take place within one tidal cycle. The loss of information during taphonomic processes via destructive biological agents may ultimately bias the fossil record in a significant way and thus have implications for the paleoecological interpretation of fossil teleost assemblages.     

硬骨鱼类性别决定与分化相关基因研究进展

鱼类是脊椎动物中最低等但分布最广、种类最多的一类生物.与高等脊椎动物不同,鱼类的性别决定除了受遗传因素的影响,外界环境(激素水平、温度、盐度、氧气等)和自身内分泌调节也发挥了重要作用,因而其性别决定与分化机制极其复杂.尽管如此,遗传因素仍然是鱼类性别决定与分化的关键因素.本文通过对影响硬骨鱼类性别决定及分化的遗传因素(包括sox,dmrt1,amh,gsdf,cyp19a1a,foxl2等性别决定及分化相关基因和Rspo1/Wnt/β-catenin信号通路)的研究动态与进展进行综述,为更深入的探索鱼类性别决定与分化机制提供参考.