Hatching rate of the egg-carrying estuarine copepod Eurytemora affinis

Abstract

The egg-carrying copepod Eurytemora affinis IS cles and detntus are often found in high concentrations often a characteristic and dominant component in the carbon cycles of freshwater influenced marine ecosystems in the Northern Hemisphere. In egg-carrying copepods the specific e g g produclion rate in the field can be calculated from the e g g hatching rate at in situ temperatures, the eggliemale ratio and the carbon content of the eggs and females. To determine the temperature dependent e g g hatching time (HT) of 2 populations of E. affinis, hatching experiments were conducted at 6 different temperatures (T). Hatching times ranged from 14.1 to 1.6 d at 5 and 22"C, respectively. Results from the 2 populations were pooled and fitted to a power function-HT = 187T ' 5 4 (I-' = 0.97; p < 0.001). There is a large range in the hdtch~ng t~rnes versus temperature reported In the 11tei-ature, dnd our results reveal longer hatching times than prev~ously reported To overcome this pronounced vanation in hatching tlmes, we present a significant relationship (r2 = 0.87; p < 0 001) based on all available data: HT = 36.87 'l''