Correlates of male reproductive success in Padogobius martensi (Gobiidae)

Factors affecting male reproductive success were investigated in a natural population of Padogobius martensi, a small freshwater goby showing paternal care. Males were found to be polygynous and their mating success was related both to their body length and to the size of the nest occupied. Body size was a good predictor for the presence of eggs in the nest. The number of egg batches guarded by a male was highly correlated with the area of his nest. Mature males with a total length of 48 mm or less (1-year-old individuals) occupied nest sites in breeding areas but were never found with eggs in their nests. The components of sexual selection which may determine the variance in mating success are discussed.