Reproductive cycle of Mytella guyanensis (Lamarck, 1819) in a Marine Reserve (RESEX Bay of Iguape), Bahia, Brazil.

V M A Camilo,J R Luz,S Campiolo,G Boehs,J Da C Souza,E De J Conceição

doi:10.1590/1519-6984.05716

Abstract

Mytella guyanensis, consumed and commercialized in coastal regions of Brazil, is one of several bivalve species of socioeconomic interest for coastal communities. Besides serving as a source of income and subsistence for these communities, it also contributes to their food security as it is a source of proteins and micronutrients. Thus, the reproductive cycle of this species was studied aiming to contribute to food security and its preservation. Samples were collected monthly, between March 2014 and March 2015, in a natural stock (12°38'50"S; 38°51'43"W) in a Marine Reserve (RESEX Bay of Iguape) (community Engenho da Ponte), Bahia, Brazil. Mytella guyanensis is collected by women on site, where the artisanal fishing of this resource is performed without following any specific handling procedure. Also, empirical evidence indicates overexploitation. The specimens collected were measured along the anterior-posterior axis (length), and after macroscopic analysis they were fixed in Davidson solution, processed by routine histology techniques and stained with Harris haematoxylin and eosin (H&E). The macroscopic analysis showed sexual dimorphism, with the male and female gonads presenting a milky-white and orange colour, respectively. A 1:1 sex ratio (M: F) was observed and reproduction of the species was continuous all year round. March, April, July and August were the months with highest values of gamete elimination. We suggest that a M. guyanensis management plan should restrict capture during these months, in order to sustainably regulate exploitation of this food resource in this reserve.

Highlights

Studies on the reproductive biology of economically important aquatic species are essential to comprehend its life history (Garner et al, 1999) and are important in management actions
Considering the economic importance represented by M. guyanensis for the communities from this Reserva Extrativista Marinha Baía de Iguape (RESEX), this study aimed to determine the reproductive cycle of the species in this marine reserve, with a view to contributing to food security of the communities living there, and to preserve it as a resource
Though separate sexes is the dominant situation for mytilids (Coe, 1943), cases of hermaphroditism were reported in the literature on surveys conducted for this species in other Brazilian coastal regions (CarpesPaternoster, 2003; Gomes et al, 2009), which agrees with the findings of this study, and which may be associated with environmental factors, such as sudden variation in salinity and pollution (Ceuta et al, 2010)

Summary

Introduction

Studies on the reproductive biology of economically important aquatic species are essential to comprehend its life history (Garner et al, 1999) and are important in management actions. Mussels may sometimes be the only affordable source of protein available One of these species is Mytella guyanensis (Lamarck, 1819), popularly known as “bacucu”, “bico de ouro”, and “sururu” (Rios, 1994; Pinto and Boehs, 2008). This mytilid is distributed from Mexico to Peru, on the Pacific Ocean, and from Venezuela to Brazil, on the Atlantic (Rios, 2009), inhabiting intertidal regions of mangroves where it uses the byssus to attach to underground roots. I.e., it resists wide variation in salinity and is dioecious (Sibaja, 1986)

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