Mating Without Anterior Pleopods in a Simultaneous hermaphroditic shrimp, Lysmata Wurdemanni (Decapoda, Caridea)

Abstract

The effects of copulatory rami removal of male-role shrimp (male-phase (MP) or euhermaphrodi te-phase (EP)) on mating behavior of a simultaneous hermaphroditic shrimp, Lysmata wurdemanni, were investigated in the laboratory. There was no difference in general mating behavior between male-role shrimp with or without ablation of copulatory pleopods. However, ablation highly significantly (P < 0.001) affected copulation frequency. The influence was also sex dependent (P < 0.001). In general, copulation frequency in ablated EP shrimp was significantly higher (P < 0.05) than in ablated MP of the same treatment. Ablation of either pleopod 1 or pleopod 2 in MP shrimp did not affect mating behavior or spermatophore transfer. The success of spermatophore transfer was negatively correlated with the mean copulation frequency (R = ?0.9707, P < 0.001). Normally, spermatophores were deposited on the base of the last two pairs of pereiopods. Ablation of the pleopods may lead to failure of emission or improper deposition of a spermatophore. Some new mating behaviors are described and a possible mating mechanism for the shrimp is proposed.