Métodos de extrusão manual e elétrica dos espermatóforos de reprodutores selvagens do camarão-rosa Farfantepenaeus paulensis (Decapoda: Penaeidae)

Abstract

The present study compared manual and electrical methods to extrude the spermatophore of the pink shrimp Farfantepenaeus paulensis aiming to analyze their influence on the number of spermatic cells and spermatophore regeneration. The males were extruded in the beginning (day zero) and in the end (43 rd day) of the experiment to evaluate the efficiency of these methods in the regeneration process. For the extrusion, a gentle pressure was applied manually in the fifth pair of pereiopods or electrically by a 9 volt pulse in the same area. Both methods were efficient in removing the spermatophore and no significant differences were found (P>0.05) in the number of sperm cells. Nevertheless, significant decreases (P<0.05) in the body weight, spermatophore weight and spermatosomatic index (ESI) at the end of the experimental period were observed by using the electrical stimulation. The mean values (±SD) of the number of sperm cells were 1.46 (±0.84) and 3.25 (±2.12) millions for the electrical and manual treatments, respectively. Results indicate that both methods may be applied to collect initial samples of spermatophores as well as for sperm quality testing. However, when previously spermatophore-extruded males are to be used, the manual method is indicated as the number of spermatic cells, spermatophore weight, body weight, and ESI are maintained after regeneration.