Gonad characterization and reproductive cycle of Collisella subrugosa (Orbigny, 1846) (Gastropoda: Acmaeidae) in the northeastern Brazil.

Gonad characteristics and reproductive cycle in the acmaeid Collisella subrugosa from Northeastern Brazil were investigated. The individuals were collected monthly from February 1993 to April 1994 at Farol do Mucuripe Beach, Fortaleza, Ceará, Brazil. There is no external characteristic on the shell and the soft body structures except the gonad that allows sex differentiation. The gonad of limpet Collisella subrugosa shown four stages (1) "partially ripe", (2) "ripe", (3) "partially spawned" and (4) "spawned", stages. The reproductive cycle is continuous, with the maturation and spawning running parallell in this population. The temperature was constant during the study period and it did not seem to be important to induce the spawning. The salinity had a weak negative correlation with the spawn process.