Egg production data for the Arctic copepods Calanus glacialis/marshallae, C. hyperboreus and Metridia longa, CASES 2003-04
Ship: CCGS Amundsen CA
Principal Investigator: Louis Fortier
Start Date: 20-10-2003
End Date: 14-08-2004
Citation: Darnis et al. Egg production data for the Arctic copepods Calanus glacialis/marshallae, C. hyperboreus and Metridia longa, CASES 2003-04. Unpublished data
Abstract: The time series was conducted from 20 October 2003 to early August 2004. Live samples for egg production experiments were collected in autumn and summer at different stations making the CASES sampling grid, and at one permanent station once the Amundsen settled in the landfast ice of Franklin Bay for the overwintering period. Females of all three species were present year round and reproduced successfully in the study region. Thirty randomly selected females of each species were placed individually in 45-ml petri dishes filled with filtered sea water and incubated at in situ temperature for 24 h in the dark. At the end of the experiment, eggs produced were counted. Gonad maturation was assessed on the females that did not spawn. The data set provides a time series of egg production rates (EPR), clutch size and gonad maturation index for the three dominant Arctic copepods. The primarily herbivorous copepods Calanus glacialis and C. hyperboreus and the omnivorous Metridia longa make up the bulk of zooplankton biomass in Arctic pelagic ecosystems. They play a crucial role in the trophic flux of energy through the pelagic food web and in the vertical transport of carbon during their ontogenic vertical migration. From studies conducted in the Greenland Sea and northern Norway, the two Calanidae are known to have evolved different reproductive strategies to deal with the strong seasonality of food availability. Despite its importance in Arctic zooplankton assemblages, the annual reproductive cycle of M. longa is hardly documented. This dataset is aimed at studying the reproductive biology of these three dominant copepods over an annual cycle in the Canadian Arctic waters of the Beaufort Sea.