Ecology and Evolutionary Biology Commons^™

Because female Porcellio laevis (Isopoda: Oniscidea) carry eggs and young manca in a ventral marsupium, fecundity and body size are positively correlated. We examined female body size in November and February, a period in which breeding does not occur and changes in body size are unlikely to be attributed to growth. Our results from two consecutive years revealed several general patterns. First, the sex-ratio of individuals collected with baited traps was extremely female biased. Second, body size was significantly larger (as indicated by length of antennae and appendages) in samples collected during November than in those collected during February. Third, …