MEPS 274:225-234 (2004)  -  doi:10.3354/meps274225

ABSTRACT: Positive parental effects, defined as the strategies displayed by sardine Sardina pilchardus adults to increase the survival of eggs and larvae, were studied off the coast of the Iberian Peninsula (Spain) by monthly sampling of eggs and larvae in Ría de Vigo, over a period of 4 yr. Two different parental strategies were observed over the spawning period: temporal variations in spawning intensity, and variation of egg quality. Sardine spawn outside the upwelling season, to avoid offshore transport of eggs and larvae to where food is less abundant. There is a negative correlation between the duration of embryonic development and egg organic content. Sardine employ a parental strategy that adapts the biochemical composition of eggs to the evolution of the temperature in the area during the spawning season. Eggs of higher organic content are produced in the coldest months, thereby compensating for the delay in embryonic development time due to low temperatures. This also has the effect of enhancing larval survival.

KEY WORDS: Parental strategies · Reproduction · Fish · Egg · Larva