Egg size relationships in five species of salmonids and Thymallus thymallus (L.)
Purtscher, Ulrich; Humpesch, Uwe H.
Characteristics of reproductive products, such as egg volume, egg number and alevin size, and their relationships to female size were studied in six fish species in order to detect similar or different life-history strategies. Interspecific variations in fecundity and egg volume were also considered. The positive relationship between alevin dry weight and egg dry weight in all species examined indicates that heavier fry emerge from larger eggs. In Salvelinus fontinalis and Salvelinus alpinus, both absolute fecundity and egg volume increase with body size. Significant relationships between number of eggs and female length were shown for Salmo trutta and Oncorhynchus mykiss and egg volume correlated significantly with parental length in Hucho hucho and Thymallus thymallus, while inverse correlations between egg volume and egg number were found in Salmo trutta, Oncorhynchus mykiss and Thymallus thymallus.