REPRODUCTIVE FAILURE OF DOMINANT MALES IN THE POECILIID FISH LIMIA-PERUGIAE DETERMINED BY DNA-FINGERPRINTING

Hierarchical structures among male individuals in a population are fre quently reflected in differences in aggressive and reproductive behavi or and access to the females. In general, social dominance requires la rge investments, which in turn then may have to be compensated for by high reproductive success. However, this hypothesis has so far only be en sufficiently tested in small mating groups (one or two males with o ne or two females) due to the difficulties of determining paternity by conventional methods. DNA fingerprinting overcomes these problems by offering the possibility to determine genetic relationships and mating patterns within larger groups Burke, T. (1989) Trends Ecol. Evol. 4, 139-144!. We show here that in the poeciliid fish Limia perugiae, in small mating groups the dominant male has a mating success of 100%, wh ereas in larger groups its contribution to the offspring unexpectedly drops to zero.