Embryology and Influence of Temperature and Salinity on Early Development and Survival of Yellowtail Flounder Limanda lerruginea

Abstract

The purposes of this research were to provide a detailed description of the embryonic development of the yellowtail flounder Limanda ferruginea and to determine the influences of temperature and salinity on developmental rates and survlval within the maximal environmental range of these variables (4"-18 "C; 28-38 % S). Embryological categories were described and related to developmental times at different temperatures. This relationship was direct and a series of power function curves were calculated for predictive purposes. Embryo survival to hatching was interactively affected by temperature and salinity. Response surface analyses showed low survival (10-30 %) a t low salinities coupled with low and high temperatures, and high survival (70-90 %) a t intermediate temperatures and higher salinities. The greatest mortality occurred during gastrulation. Time to 50 % hatching was inversely related to both temperature and salinity. Size at hatching (SL) was influenced by temperature and salinity interaction with larger larvae In the mid salinity range at mid to upper test temperatures. Occurrences of anomalies were relatively low (< l 0 %). They were lower at intermediate test temperatures integrated over all salinities and higher a t intermediate test salinities integrated over all temperatures. Experimental results arc discussed with reference to environmental impact on yellowtail early life stayc survival.