ARTIFICIAL INSEMlNATION IN PENAEID SHRIMPS

Abstract

Artificial Insemination (AI) is a tool for genetic manipulation in the
shrimp stocks. It is seen as one of the means for propagating shrimp culture to
new areas by controlled reproduction. Attempts at artificial insemination in
the dominant closed-thelycum penaeid shrimps species of the area viz.
Metapenaeus affinis and Metapenaeus brevicornis were induced in wild adult
stocks collected off Mumbai coast. Female specimens were subjected to
unilateral eyestalk ablation by pinching so as to induce moulting and
maturation. AI was performed two days after moulting on these females when
the cuticle was still soft and flexible. Moulting also ensured rejection of initial
spermatophores, if present. Response of males to electrical stimulation for
spermatophore expulsion was spontaneous. Use of tissue glue for
spermatophore retention was found to be unnecessary. Latency period ranged
between10-16 days, while spawning occurred within 10-12 days of spermatophore
transfer. Three partial spawning were recorded viz., two in Metapenaeus
affinis and one in Metapenaeus brevicornis with an average spawning and
hatching rates of 30% and 72.3% respectively. Average survival from first
nauplius (N1) to one-day old post-larva (PLI) was a meager 3.43%. Use of AI in
genetic manipulation of shrimp stocks for aquacultural purposes is indicated.
Keywords : Artificial insemination, electro-ejaculation, penaeid shrimp,
(glue) a-cyanoacrylate