褶纹冠蚌钩介幼虫非寄生变态发育观察及早期稚蚌的生长

为揭示褶纹冠蚌钩介幼虫变态发育特征及过程，采用体外培养方法实现了褶纹冠蚌钩介幼虫的非寄生变态发育。运用光学显微镜和扫描电子显微镜对变态发育过程中幼虫外部形态、内部器官发育进行了系列观察，对非寄生变态发育的稚蚌后期生长发育进行跟踪研究，并分析了底泥和光照两种环境因子对稚蚌存活及生长的影响。结果显示:在整个培养过程中，钩介幼虫的外部形态及大小未出现显著性变化，而斧足、鳃丝、外套膜及内脏团等组织器官逐步形成；在培养第3天，幼虫可见斧足雏形，鳃丝、外套膜纤毛尚未发现；在培养第6天，斧足成形，可见斧足侧沟，外套膜纤毛稀疏，鳃丝出现；培养第9天，斧足纤毛、外套膜纤毛增多，鳃丝密集。稚蚌投喂30d后，鳃丝基本成形。养殖试验结果表明:底泥对稚蚌存活和生长具有显著影响（P < 0.01），而光照无显著性影响（P>0.05）。该结果为蚌科钩介幼虫变态发育生物学研究积累了基础资料，也通过对稚蚌生长的评估证实了体外培养是蚌类人工繁育及保护的有效技术途径。

STUDIES ON THE NON-PARASITIC METAMORPHOSIS OF CRISTARIA PLICATA GLOCHIDIA AND THE DEVELOPMENT OF EARLY JUVENILES

In nature, the glochidia of Cristaria plicata must successfully parasitize a suitable host fish to metamorphose into juveniles. The current study investigated non-parasitic metamorphosis of the glochidia mainly focusing on the de-velopment of glochidia in external morphology and internal organs using microscope and scanning electron micro-scope, and analyzed the effects of sediment and light on the survival and growth rate of newly metamorphosed juve-niles. The results showed that the glochidia remained similar in external morphology and size during the transforma-tion process, while the feet, gill filaments, mantles, visceral mass and other inner organs were gradually formed. On the 3rd day of the in vitro culture, the rudiment of foot was firstly observed; on the 6th day, the feet had generally took shape with cilia showing on the surface of foot and the edge of mantle, and gill filaments began to show; on the 9th day, the cilia on feet and mantles increased and gill filaments became more dense; and after 30 days of tank culture, the morpho-logy of juvenile mussel gills was clearly evident and was similar with adult mussels, and three typical different cilia were observed on the surface of branchial filament. The results demonstrated that the sediment has significant effects on the survival and growth of juveniles (P<0.01), whereas the nature light has no effect (P>0.05). These results provide basic insight for researches on the non-parasitic metamorphosis of glochidia of Unionidae species, and confirme that in vitro culture is an effective method for the artificial breeding and conservation of freshwater mussels.