Enviromental factors on the egg morphology and the hatching rate in the calanoid copepoda

Abstract

Acartia erythraea was sorted from Zooplankton samples taken from Gamak Bay, located in the Southern coastal waters of Korea. A. erythraea produced three morphological types of egg. One with a smooth surface and another with long spines surface and other with short spines. Egg with a short spines surface are considered subitaneous, eggs covered with long spines and smooth egg are diapause. In this study, A. erythraea EPR (egg production rates) ranged between 1 and 25 (mean of 6)eggs female-1 d-1. Canonical correspondence analysis (CCA), performed to examine the relationships among three egg types, DO(dissolved oxygen), and environmental variables, EPR (egg production rates) showed that three egg types and EPR (egg production rates) were positively correlated with temperature, DO (dissolved oxygen), Chl-a concentration.ace and other with short spines. Egg with a short spines surface are considered subitaneous, eggs covered with long spines and smooth egg are diapause. In this study, A. erythraea EPR (egg production rates) ranged between 1 and 25 (mean of 6)eggs female-1 d-1. Canonical correspondence analysis (CCA), performed to examine the relationships among three egg types, DO(dissolved oxygen), and environmental variables, EPR (egg production rates) showed that three egg types and EPR (egg production rates) were positively correlated with temperature, DO (dissolved oxygen), Chl-a concentration.