Elemental composition (C,N, H) and energy in the development of Pagurus bernhardus (Decapoda: Pagurida) megalopa

No differences in development time and mortality were detected between starved and fed laboratory raised megalopa of Pagurus bernhardus. The average time of development in 138 megalopa was determined as 7.3±0.1 (95% CI) days. During megalopa development P. bernhardus loses about 7% in dry weight (DW), 17% in carbon (C), 6% in nitrogen (N) and 17% in hydrogen (H). During development C/N ratio and individual energy content descend about 14 and 22% respectively. Weight specific energy content decreases by 17% in the first 3 d and remains constant at 12.3±0.3 (95% CI) J·(mg DW)^-1 thereafter. About another 25% in individual energy content was lost by molting to crabs. The measured compounds do not follow a steady decrease. The possibility is discussed that a period of low energy cost (about the first half of development) alternates with times of higher energy expenditure mainly based on lipids. A fixed physiological program different from starvation capability is indicated for P. bernhardus megalopae. By comparing megalopae hatched in two different seasons and years reference is given to the variability in growth pattern.