文章基本信息

标题：Life Cycle and Production of the Exotic Snail Physa venustula (Pulmonata: Physidae) in the Napostá Grande Stream, Southern Pampas, Argentina
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作者：Pablo R. Martin
期刊名称：Journal of Freshwater Ecology
印刷版ISSN：0270-5060
电子版ISSN：2156-6941
出版年度：2001
卷号：16
期号：1
页码：93-104
DOI：10.1080/02705060.2001.9663792
出版社：Taylor & Francis
摘要：The life cycle of Physa venustula Gould, 1848 (Physidae) in Napost Grande stream is semelparous and subannual, with two or three poorly defined cohorts per year. Oviposition and recruitment are almost continuous. Juvenile mortality is high up to the length of 3.5 mm and decreases in subadults and adults. Density fluctuations are tied to hydrodynamic conditions and drift events rather than to reproductive activity. Density and biomass in vegetated bottoms were higher than in sandy-mud ones. Annual somatic production estimated by the size-frequency method was low (0.095 g(dry weight).m -2 ) and turnover rate high (8.10 yr -1 ) when compared to those of other Physidae.