【作者】 焦玉坛；

【导师】 文春根；

【作者基本信息】 南昌大学 ， 水生生物学， 2008， 硕士

【摘要】 本论文对背角无齿蚌中Y纹蚌螨和弯弓蚌螨种群动态进行了调查,结果显示Y纹蚌螨总感染率为45.91%,丰度为18.41±22.49,5月份感染率最高;弯弓蚌螨总感染率为17.47%,丰度为3.41±12.88,6月感染水平最高。两种螨类对体长150-170mm的背角无齿蚌感染率最高,对雌雄蚌无特异性选择。Y纹蚌螨和弯弓蚌螨都偏好选择寄主的外套膜和鳃部。利用卡方对种间关联关系进行检验,表明两种蚌螨之间呈负关联关系(x~2=14.12,V=-0.073)。利用自制趋光性装置研究了三种蚌螨趋光性,结果表明Y纹蚌螨、弯弓蚌螨和簇刺蚌螨的趋光性与光强以及光色有关。在不同光强下,三种蚌螨的趋光性指数差异均显著(P＜0.05);1300Lux,1000Lux,400Lux和100Lux光强下三种蚌螨的趋光性差异极显著(P＜0.01);在700Lux光强下差异显著(P＜0.05)。Y纹蚌螨随着光强增加,趋光指数有随之增加的趋势;簇刺蚌螨在光强度为1000Lux趋光指数达到最大;弯弓蚌螨只有在光强度为700Lux表现为正趋光性,其它条件下均表现为负趋光性。弯弓蚌螨在三种颜色的光下均表现为正趋光性,对于红光的趋光性反应较黄、蓝光更为敏感;簇刺蚌螨只有在黄光条件下表现为正趋光性,在蓝光和红光条件下均表现为负趋光性,而且红光下负趋光性行为相当显著;Y纹蚌螨在红光下表现为正趋光性,在黄光和蓝光条件下表现为负趋光性。由此可见,不同的蚌螨种类对不同光色也具有不同趋向性反应。通过对弯弓蚌螨的连续石蜡切片进行了观察,发现其消化道包括咽、胃、中肠、结肠和直肠。背腺末端浸于中肠附近的组织中,开口于背部。雌性弯弓蚌螨的生殖腺由外膜和内生殖上皮组成,内生殖上皮分布有滤泡细胞。雄性生殖腺有一对精巢,内含许多由血淋巴细胞包围的精囊,精囊或精子通过输精管排出体外。更多还原

【Abstract】 Population dynamics of the water mite U. ypsilophora and U. arcuata was investigated in freshwater bivalve A.woodiana woodiana during the period from August 2006 to July 2007 in Nanchang. A pattern of seasonal variation was observed, with prevalence and abundance of U. ypsilophora and U. arcuata peaked in May and Jun, respectively. The number of mites in individual host was significantly correlated with the size, but not with the sex, of bivalves. The U. ypsilophora and U. arcuata have a site preference for mantles and gill of the host, respectively. Analysis for interspecific association indicated that it was obviously negative association between U. ypsilophora and U. arcuata; it was possible that they were parasitic on different positions or the ecological niches isolated.The phototactic behavior of U. ypsilophora, U. arcuata and U. penicillatus were studied by artificial equipment. The phototactic index, which had been detected under the conditions of different light intensity and varied colour light, was considered as an important performance in phototactic behavior research .The result indicated that there was significant difference in all of three species mites (P<0.05). In all light intensity excluded 700 Lux, there were extremely significant difference (P<0.01). For U. ypsilophora, with the increase of light intensity, the phototactic index increased; U. penicillatus the phototactic index reached the max value on the 1000 Lux; while U. arcuata performanced differently with the former two species, which showed positive phototactic on 700Lux while performanced negative phototactic under otherelse ones. However, U. arcuata showed positive phototaxis in red, blue and yellow light, which become more sensitive under red light than blue and yellow. U. penicillatus holded positive phototaxis only, while under other colour light becomes negative phototaxis. U. ypsilophora performanced positive phototaxis under red light only.The digestive system and gonad of adult U. arcuata are described from serial paraffin sections. The alimentary canal consists of pharynx, stomach, mesenteron, colon and rectum. There were no obvious wall cells in alimentary tract. The gonad of female U. arcuata contains outer membrane and inner epithelium; the gonad of male U. arcuata abounds with spermatophores which were surrounded by hemocytes.更多还原