Sexual differentiation and size at first maturity of the invasive mussel Perna viridis (linnaeus, 1758) (mollusca: Mytilidae) at La Restinga Lagoon (Margarita Island, Venezuela)

GREGORIO BIGATTI; PATRICIA MILOSLAVICH; PABLO E. PENCHASZADEH

American Malacological Bulletin

AMERICAN MALAC. SOCIETY

Lugar: Chicago; Año: 2005 vol. 20 p. 65 - 69

Abstract: The Asian green mussel Perna viridis was first recorded in the Americas in 1992 at Trinidad Island. In 1995 it was observed in the mainland coast of South America at Sucre State (Venezuela) and in 1998 at La Restinga Lagoon, Margarita Island, Venezuela. We studied the size at sexual differentiation, size at first maturity, and gametogenesis of P. viridis from La Restinga Lagoon using histological sections. One hundred specimens of P. viridis between 8 and 91.2 mm in total shell length were examined. No gonadal development was observed in individuals smaller than 18 mm. Sexual differentiation began at 20 mm with incipient follicular formation. Specimens larger than 25.0 mm had well-developed gonads at different stages of maturation. Size at first maturity was larger than previously reported at other localities. Because the lagunar mangrove system is permanently open to the sea, larval supply could come either from outside or inside the Lagoon, assuring the recruitment of new spat and the dispersal of the species. The introduction of this invasive species into the Lagoon has increased the available hard substrata for settlement of sessile invertebrates.