Natural and artificial reproduction of the river shrimp Macrobrachium carcinus (L.)

In the laboratory the reproduction of the river shrimp Macrobrachium carcin us was undertaken by natural copulation and artificial insemination. The sp ermatophore were obtained by applying electrical stimuli from 3.0 to 7.5 vo lts in the base of the fifth pair of pereiopods in the male. 45 natural cro ssings and 39 by artificial inseminacion were undertaken. Independently of the type of crossing, the females spawned about 20 hours after mating and s pawning lasted between 25 and 30 minutes. The duration of the embrionic dev elopment (time of egg hatch) and the number of larvae hatched by females wa s determined. Larval production ocurred in 26 (57.78%) of the total number of natural crossings, with an average of 39,883 larvae/female; while with t he artificial crossings a production of 31,260 larvae/female in 16 crossing s (41.03%),vas obtained Neither the time to egg hatching nor larval product ion were affected by the type of crossing.