Life cycle of Calanus chilensis Brodsky in Bay of San Jorge, Antofagasta, Chile
Tóm tắt
The copepod Calanus chilensis is an endemic component of the zooplankton community in northern Chile. Size distributions of adult females, relative frequency of copepodid stages and relative numbers of adult males and nauplii, suggest the presence of at least 6 generations during the year, although the species seems to continuously reproduce through all seasons. Temperature profiles from 0 to 175 m indicated the presence of the ‘El Niño’ current during March and April. Surface temperature ranged between 21.1 and 13.1 °C. Warm waters during the ‘El Niño’ event seemed to affect the body size of adult females and the normal course of cohort development, although the population tended to recover rapidly through the subsequent months. We discuss the role of oceanographic conditions in controlling the life cycle of this species, as well as its continuous growth through the year compared to other Calanus species.
Tài liệu tham khảo
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