Batch spawning can be seen as a strategy to release eggs over a long period of time increasing the survival probability of offspring (Lambert and Ware, 1984) Also it can be seen as a necessity in highly fecund species where a physical limitation occurs when the hydration phase of oocytes takes place markedly increasing the volume of eggs and expanding the body cavity (Bagenal, 1978; Fordham and Trippel, 1999)