摘要
2008年7月至2009年7月研究了江西青岚湖圆顶珠蚌(Unio douglasiae)的种群结构与繁殖特征。从其种群结构的周年变动情况来看,该种群趋于稳定状态,壳长40—65mm的个体占大多数。在采集的标本中,最大个体壳长为83.6mm,最小个体壳长为20.3mm。圆顶珠蚌自然种群性比为1:1.20,性成熟最小雌体壳长为27.6mm,体重为2.62g;最小雄体壳长为27.9mm,体重为2.21g;5至6月间繁殖盛期,检测到最小妊娠个体壳长为29.8mm,体重为2.98g,推断一周年的圆顶珠蚌可能达到性成熟。根据圆顶珠蚌生殖细胞的发育规律和滤泡的变化特点,性腺发育分为生长期和成熟期、排放期、恢复期;属多次产卵类型。育儿囊属外鳃型,胚胎在胶质索中发育,钩介幼虫成熟后,胶质索消失成黏液状,成熟钩介幼虫附在新形成的黏液丝上排出体外。妊娠母蚌在受到刺激后,易发生流产,提前排出胶质索。繁殖期为2至7月,4、5、6月为繁殖高峰期,妊娠率分别为80.43%、84.21%和78.05%。平均繁殖力为(183.72±6.43)千粒/个,最大繁殖力为344.64千粒/个,壳长为54.5mm;最小繁殖力为49.95千粒/个,壳长为29.8mm。繁殖力与壳长和体重显著相关。这些结果不仅可以丰富淡水蚌的生物学内容,也能为淡水蚌保护和湖泊与河流的规范管理提供理论依据。
Freshwater mussels are one of the most widespread and imperiled groups of animals in the world, which play a major part in the functioning of many freshwater ecosystems, however, their populations declined continually during the 20th century. Unio douglasiae, one important specie of Unionidae, is widespread in lakes, rivers and impoundments, but little is know about its population structure and reproductive traits. Investigations on the population structure and reproductive traits of Unio douglasiae were carried out in Qinglan Lake from July, 2008 to July, 2009. From the view of population structure, the population tended to be stable and shell length of individuals was mainly from 40 mm to 65 mm in the population. The maximum length and the minimum length of individuals were 83.6 mm and 20.3 mm in the specimens. The sex ratio of natural population was found 1 ： 1.20, the sex ratio of each month was in close agreement with the expected value of 1 ： 1 by X^2 test. The minimum mature female with a shell length of 27.6 mm and weight of 2.62 g, and which of the male with a shell length of 27.9 mm and the weight of 2.21 g were found. The minimum preg-nancy individual was found with a shell length of 29.8 mm and weight of 2.98 g in examined specimens. We concluded that the female and male individuals matured at the age of 1 year. Taking the developmental characteristics gametes in follicles and features of follicles into account, the annual cycle of maturation for both male and female could be divided into the following three periods： （1） growth and maturation period, October to January of next year, （2） spawning period, February to June, （3） recovery period, August to September. The female in maturation could spawn several rounds in one reproduction cycle. Two pieces of outer gills of the female were used as marsupium. Embryo developed in the con-glutinates. In the development process of embryo, the colour of marsupium changed from ivory white to light red, then became cardinal red after matured. Mat
出处
《水生生物学报》
CAS
CSCD
北大核心
2010年第3期473-480,共8页
Acta Hydrobiologica Sinica
基金
国家自然科学基金(No.30860045)
江西省学科带头人和鄱阳湖环境与资源利用教育部重点实验室项目资助
关键词
圆顶珠蚌
种群结构
繁殖力
Unio douglasiae
Population structure
Fecundity
