Adult size, longevity and fecundity in the seaweed fly, Coelopa frigida

An inversion polymorphism of chromosome I in the seaweed fly, Coelopa frigida , is known to affect adult size. The relationship between adult size and components of fitness is, therefore, of particular interest. The longevity of males and females, female fecundity and the number of matings achieved by males have been measured using laboratory lines and have all been found to increase with size. The consequences for the maintenance of the inversion polymorphism are discussed.