Reproductive performance of male Argentine red shrimp Pleoticus muelleri
bate (Decapoda, Penaeoidea) in culture conditions
A.C.
Diaz, A.V.F. Gimenez, N.S. Haran, J.L. Fenucci-2001
Journal
of the World Aquaculture Society, 32(2): 236-242
Abstract :
Spermatophore
and sperm quality of male Argentine red shrimp Pleoticus muelleri held under
laboratory conditions was evaluated using compound spermatophore weight,
sperm count and percentage of live sperm as indicators. Thirty-seven males
of 5 to 20 g wet weight were held indoors in a 3-m diameter circular
fiberglass tank for 45 d. They were fed fresh squid, clam and pelletized
diet. Spermatophores were obtained by manual ejaculations. Four shrimps were
re-ejaculated to verify the subsequent spermatophore regeneration.
Spermatophore mean weights were significantly lower for 5-10 g males than
for 15-20 g males (r = 0.998) (P < 0.05). There were no significant
differences in sperm count and percent live sperm among the different weight
classes (5-15 g, 15-20 g, 20-25 g). The sperm count varied from 2.22 to 5.62
million. No change in sperm quality was seen in re-ejaculated individuals.
During the first 2 wk of the experiment, the spermatophores exhibited
healthy morphology and colour; by the fifth week evidence of spermatophore
deterioration was apparent. Despite the degree of melanization, sperm
quality was not affected and the high variability in sperm count indicated
that the artificial ejaculation is adequate in this species.
(CONICET,
Fac Ciencias Exactas & Nat, Funes 3350, B7602AYL, Mar Del Plata,
Argentina)