Perna viridis in La Restinga Lagoon (Margarita Island, Venezuela): Is this population reproductively active?

PENCHASZADEH, P.E; BIGATTI, G. AND MILOSLAVICH, P

Charleston, USA

Congreso; 68th Meeting AMERICAN MALACOLOGICAL SOCIETY,; 2002

The Indo-Pacific green mussel Perna viridis has been recorded in South America since 1992 (in Trinidad Island). In 1995 it was observed in the north coast of Sucre state in Venezuela. Specimens of P. viridis were collected from  Rizophora mangle roots during February 2002 in the coastal lagoon “La Restinga” (Margarita Island, Venezuela). The aim of this work is: To generate knowledge concerning the sexual differentiation size and the first maturation size in this mussel. Does the recruitment depends on the exogenous larval supply, or is the population of  P. viridis inside the lagoon reproductively active? We collected specimens between 18 mm and 91.2mm of total length. Sexual differentiation starts at a size of 23 mm with incipient follicular formation. In the mantle of individuals of a total shell length of 20mm or less no gonad development was observed. Specimens larger than 30mm presented developed gonads, while males were all mature and females had developed gonads with different maturity stages (50% to 100% of follicle development in the mantle). First maturity stages are discussed in relation to other localities, cited by several authors. We concluded that the population of  P. viridis  in La Restinga lagoon is reproductively active. Larval supply could come from outside or inside the lagoon, assuring the recruitment of new spat and the dispersion of this species.