Abstract

Many workers emphasized the usefulness of electroejaculation technique in artificial insemination studies for hybridization and selective breeding programmes in commercially important decapods. Such techniques are also used to improve the seed production. Similar technique is very much lacking in crabs in general and P. pelagicus in particular. So that electrical stimulation on spermatophore expulsion is studied in P. pelagicus. Among six positions the bilateral ejaculation (extruding spermatophores in both sides) was occurred only in positions I & VI. In all three trials the animals were bilaterally ejaculated 100% in position VI. However in position I the bilateral ejaculation was 66.66%. In other four positions (II, III, IV and V) the ejaculation was happened unilaterally (extruding spermatophores in one side) especially in probe attachment side in all three trials. In positions II & IV all the animals were extruded unilaterally in all the three trials whereas in positions III & V the unilateral ejaculation was 66.66% & 83.33% in trial I, 83.33% & 66.66% in trials II & III respectively. The average volts and seconds required for extrusion of spermatophores was ranged from 5.75 to 7.75 volts and 3.83 to 7.70 seconds respectively. Spermatophore weight was ranged from 33.0 to 105.61 mg.

Keywords: Male crabs; P. pelagicus; Electroejaculation; Technique; Spermatophore