Reproductive aspects of Brachidontes rodriguezii in the high intertidal; extreme environmental effects

Abstract

In this study we tried to reveal if under conditions of high-stress mussels presented some trade off about reproductive aspects like size/frequency of oocytes and the reproductive cycle of the mussel Brachidontes rodriguezii. This species dominates the rocky intertidal coast of Buenos Aires province, Argentine and is a prey item of several exploited species. Mussels were collected from December 2011 to May 2013 in the upper level of it distribution in the high intertidal coast. Gonad tissue samples were processed according to standard histological procedures. Four gonadal development stages were described for males and females all year round. According to the significant decrease in the frequency of mature oocytes, the spawning events were in February 2012/2013. This study also reports hermaphrodite and parasite mussels in very low frequency. We concluded that the frequency and duration of the post-spawning gonadal development stage were the most notable difference along the vertical distribution, suggesting that the high-stress condition of high intertidal impacts negatively on gonad restoration.