POPULATION-DYNAMICS, REPRODUCTION AND GROWTH OF UPOGEBIA-PUSILLA (DECAPODA, THALASSINIDEA) IN THE EVROS DELTA (NORTH AEGEAN SEA)

Monthly samples of Upogebia pusilla were collected from February 1983 to February 1984 in an area of the Evros Delta located close to the se a, where salinity and temperature of the water ranged from 4 to 25 par ts per thousand and 4.3 degrees to 24.5 degrees C, respectively. Popul ation density and wet weight biomass varied greatly, being higher in s ummer. Young shrimps appeared in August and had a maximum life span of approximately three years. Ovigerous females were found from April to August. The frequency of females among the collected individuals was 0.393. The smallest ovigerous female had a total length (TL) of 39 mm, while the maximum TL for females was 82 mm and for males 106 mm. Grow th in age classes I and II was greater in the period from July to Augu st. Mean growth of carapace length (CL) was described by the Von Berta lanffy function. A positive correlation existed between total length a nd CL or wet weight (W).