ABSTRACT
Mellita quinquiesperforata latiambulacra inhabits sandy bottoms, ranging from 0.5 to 6.0 m depth, in the west-central coast of Venezuela in sediments with a high proportion of fine grains. A population at Quizandal Beach was sampled monthly during three years (1979–1982). The maximum recorded density was 2570 ind.sqm−1 for juveniles and 87 ind.sqm−1 for adults. Growth parameters of the von Bertalanffy model were estimated with different methods by the analysis of size-frequency distribution. Cohort separation was done using Bhattacharya (1967) approach. The Elefan (Pauly and David 1981) method gave an estimated infinite length of 82.9 mm and growth rate of 0.66 years−1. Infinite lengths of 82.79, 83.68 and 70.03 mm and a k constant of 0.69, 0.48 and 0.92 were estimated using Gulland and Hold plot (1959), Wetherall et al. (1987) and Ford-Walford plot (1933, 1946) respectively. Nevertheless the Munro’s phi-prime parameter indicate that the calculated growth curves do not differ significantly. Natural mortality is very high and the estimated instantaneous values are 2.28 (Catch curve method) and 2.10 (Beverton and Holt 1956) representing an annual mortality of about 85%. Mellita quinquiesperforata latiambulacra from Quizandal Beach has a mean longevity ranging from 2.8 to 3.4 years, while the age to attempt 95% of infinite size is around 4.8 years.
