POPULATION-DYNAMICS AND SECONDARY PRODUCTION OF CALLICHIRUS MAJOR (CRUSTACEA, THALASSINIDEA) ON A SOUTHERN BRAZILIAN SANDY BEACH

An intertidal population of Callichirus major from a. sandy Leach in s outhern Brazil was sampled monthly between January 1995 and June 1996. The mean abundance was 10.11 holes.m(-2), with higher values in summe r and in the lower intertidal. The mean biomass of males together with juveniles was 3.65 g.m(-2) dry weighs, and mean biomass of females (e xcluding gonads and eggs) was 4.91 g.m(-2). Population structure varie d across the beach, with larger individuals predominating in the upper intertidal. C. major showed a seasonal pattern of growth, with slowes t growth during the winter. The parameters of the seasonal oscillating von Bertalanffy growth function were L-infinity = 15 mm, K = 0.9, C = 0.8 and WP = 0.55 for males and L-infinity = 16 mm, K = 0.8, C = 0.8 and WP = 0.60 for females. Longevity was nearly 3 years. Berried femal es were found between November and January. Recruitment occurred in au tumn (May), but older adults predominated throughout the year. Egg pro duction was 2.145 g dry weight m(-2).y(-1), corresponding to 36% of dr y weighs of each female. Annual somatic production was 4.21 g.m(-2).y( -1) for males and juveniles and 4.86 g for females. The annual PIE rat io of the population was 1.059 y(-1) (somatic production) and 1.310 y( -1) (total production), respectively.