Reproduction and growth of the freshwater prawn, Palaemon paucidens (Decapoda : Palaemonidae) in a lake of Korea

Abstract

This study analyzed the reproduction and growth of freshwater prawn, Palaemon paucidens De Haan 1844 from Suk-dang lake(Korea). The analysis of the sex ratio showed a higher proportion of males than that of females, The average size of the eggs was 6.12 (+/- 0.55) mm(3) in the non-eyed stage (stage A) and 7.20(+/- 0.86)mm(3) in the eyed stage (stage B). The reproductive output (RO) calculated with the dried-body weight of an incubating female and the weight of the eggs in dried condition was 26.97% (n = 17) of the average females weight. Incubating prawn appeared in April, and the gonadosomatic indices (GSI) showed the highest value during three months from January to March. Based on the month when there was a high proportion of incubating females with a high GSI, the estimated spawning season of P paucidens was April, The maturity of the female was evaluated by the development of the ovaries and the existence of eggs, The average body length when 50% of the females in the group reached maturity was 8.55 (+/- 2.74) mm. The analysis of the length-frequency distribution showed that the life span of P. paucidens ranged from 12 to 13 months. Females mature faster than males.