Centropages Kroyeri egg production rate as a function of lagoon summer conditions

Abstract

En
Daily egg production of the neritic calanoid copepod Centropages kroyeri was measured from 4 to 23 August 2003 at a site in North lagoon of Tunis and related to summer environmental variables and food availability. Food availability was evaluated by assuming a direct correlation with concentrations of the Chlorophyll a (Chl a), the particulate organic carbon (POC), and some easily extractable macromolecular compounds such as proteins, carbohydrates and lipids, from the seston. The egg production Rate (EPR) was estimated by incubating mature females with natural filtered seawater. The EPR of Centropages kroyeri ranged from 4.2 (± 2.5) to 8.4 (± 6.2) eggs female–1 day–1. This value was positively affected by salinity (r = 0.501, P<0.01). Among indices of food availability, only seston proteins were positively correlated (r = 0.840, P<0.0001) with the daily EPR of the species.