Some Effects of Salinity and Temperature on Early Development and Survival of the English Sole (Parophrys vetulus)

Eggs of the English sole were incubated at a number of salinity–temperature conditions within the ranges of 10–40‰ salinity (S) and 2–12 C. Temperatures of 2 C were lethal in all cases. Development time from fertilization to 50% hatch ranged from 3.5 days (12 C) to 11.8 days (4 C) and was shortest at salinities around 25‰ between temperatures of 6–12 C. Larvae were classified as viable (normal) or abnormal on the basis of several subjective criteria.Response surfaces were computed and salinity–temperature conditions were estimated at which several responses were maximized, namely: larval size: 28.1‰, 7.9 C; total hatch, 25.6‰, 9.0 C; viable hatch, 25.9‰, 8.4 C. In general, optimum conditions for survival appeared to be associated with salinities and temperatures of 25–28‰ and 8–9 C. Temperatures associated with the production of 50% viable hatch or better at optimum salinity conditions (25.9‰) were calculated to be those bounded by 4.5 and 12.5 C.Incidental observations were obtained in several cases on e...