Development, growth, and egg production of Centropages abdominalis and Neocalanus flemingeri from the eastern subarctic Pacific

Abstract

Copepods dominate oceanic mesozooplankton in terms of abundance and biomass thus contributing a significant source of secondary production. I determined development, growth, and egg production of Centropages abdominalis and Neocalanus flemingeri at temperatures representative of the northern Gulf of Alaska in spring. Median development times from eggs to adults were 42 and 59 days for C. abdominalis at 5 and 7°C, respectively, and 117 days from eggs to copepodite stage five for N. flemingeri at 5°C. Average copepodite growth rates were 0.08 and 0.17 d⁻¹ for C. abdominalis at 5 and 7°C, respectively, and 0.15 d⁻¹ for N. flemingeri at 5°C. In situ egg production of C. abdominalis was 37 ± 22 eggs female⁻¹ d⁻¹ (mean ± S.D.), corresponding to a growth rate of 0.14 d⁻¹. Lifetime fecundity of N. flemingeri determined at 5°C was 535 ± 258 eggs female⁻¹ (mean ± S.D.). Comparing these results to in situ populations reveals that C. abdominalis may be food limited during the summer and fall, while N. flemingeri is likely not food limited in late spring. Overall, this information helps clarify the life history patterns of these two species and allows production to be estimated and models of secondary production created for conditions within the Gulf of Alaska.