Egg hatching times of Antarctic copepods

Egg hatching times were determined at a range of temperatures for four species of commonly occurring Antarctic copepods. At a given temperature the eggs of Rhincalanus gigas took longest to hatch, up to 9 days at 0°C, followed by those of Calanoides acutus, Calanus propinquus and Calanus simillimus. A Bělehrádeks temperature function with the parameter b fixed at −2.05 accounted for >95% of the variance for each species. There was an approximate doubling in hatching times between 5°C and 0°C for R. gigas and for the other species the increase in embryonic duration was 40–50% at the lower temperature.