MULTIPLE PATERNITY AND SPERM STORAGE IN TURTLES

Multiple paternity is the occurrence within a single clutch of offspri ng fathered by more than one male. This pattern may be an an adaptive feature of the mating system of turtles. Mating systems are the adapti ve features of reproduction which contribute to variation in the proba bility of a particular egg being fertilized by a particular sperm. Tur tle populations have rarely been studied specifically in terms of mult iple paternity or mating systems. Five features related to multiple pa ternity are discussed: spacing behaviour prior to courtship, mate-seek ing and mate choice, agonistic encounters between individuals, sperm s torage, and sperm competition. Several studies have examined movements and spacing behaviours in turtles, and have drawn inferences about ma te-seeking. At present, multiple paternity has been detected in clutch es of loggerhead turtles (Caretta caretta), wood turtles (Clemmys insc ulpta), and snapping turtles (Chelydra serpentina). In wood turtles, a relationship between male dominance and paternity has been detected t hrough DNA fingerprinting. Sperm storage has been demonstrated in seve ral species, but studies of sperm competition are lacking. Directions for future research are considered.