Egg production and viability of co-occurring in nature copepods, Calanus helgolandicus and Calanoides carinatus, fed diatom, Thalassiosira rotula, and then switched to dinoflagellate Prorocentrum minimum, were compared in experimental conditions. Egg production of both species on diatom diet was similar (up to 17-22 eggs.female-1.d-1) but no viable nauplii were observed. Development was arrested at different stages depending on degree of anomalies. Abnormal embryos displayed various degrees of deteriorations in pigment distribution and organization of extracellular matrix. Reproductive responses of C.carinatus both to negative (diatom) and positive (dinoflagellate) diets were postponed in comparison with quick responses of C.helgolandicus. After 3 days of... |