Fig. 2

Body mass (g ash-free dry mass) cycle for a 30 mm standard individual (calculated from size-mass relationship, Eq. 1) and reproductive cycle of Cardita affinis based on the gonado-somatic index (GSI) and gonadal stages from microscopic observations of smear samples. Spawning events are indicated by black bars on top: Bar size corresponds to the extent of the spawning events indicated by body mass decreases; GSI decreases and spent stage increases between successive months. La Niña 1998–2000 chronology based on data from NOAA/National Weather Center-Climate Prediction Center