Effects of temperature and food concentration on the survival, development and growth rates of naupliar stages of Oithona davisae (Copepoda, Cyclopoida)

Oithona spp. are probably the most abundant and ubiquitous copepods in the world's oceans. However, knowledge of their development and growth rates is scarce compared to that of calanoid copepods. In the present laboratory study, we determined the survival, development and growth rates of the naupliar stages of Oithona davisae under different temperature regimes and food concentrations. Naupliar survival was reduced to approximately 60% at the lowest food concentration tested (11 mu g C l(-1) after 7 d at 20 degrees C). The development of O. davisae nauplii was equiproportional, but not isochronal. Food concentrations required for maximum development and growth rates were 56 and 87 mu g C l(-1), respectively. The Q(10) values for development and growth depended on the temperature range. O. davisae nauplii showed similar developmental times, but lower growth rates and food requirements than values reported in the literature for calanoid copepods. We suggest that these differences may help to explain the ubiquity of Oithona spp. in oceanic environments.