Correia, C. Reproductive behaviour of redlip blenny, Ophioblennius atlanticus atlanticus (Pisces: Blenniidae), in the Azores: Cannibalism, allopaternal and paternal care.

The objective of this study was to monitor a natural population of Ophioblennius atlanticus atlanticus, in order to study: 1) the existence of allopaternity in the species, 2) variation in mating success in males and relations between mating success, and some territorial and phenotypic characteristics of males, 3) male aggression, with a comparison between different paternities, 4) the occurrence of egg cannibalism, in relation to male territorial and biometric characteristics. A total of 76 nests were used, with the removal of 30 paternal males for the experimental allopaternity study. For the natural allopaternity, a stereotypic design of each occupant was made, in order to monitor the permanence of males in the nests during the spawning season. This method also allowed the measurement of an index of aggression for all the individuals. Female mating choice was analysed on the basis of the number of egg batch development stages and by the spawning sites in the monitored nests. For the egg cannibalism study, stomach contents of 30 individuals, which were removed from original nests, were analysed. The results show that this species is characterised by allopaternal behaviour, with the occurrence of natural allopaternity recorded for the first time. Allopaternal males, experimental and natural, increased their mating success, by means of adoption of new spawning batches. For paternal males, total length was the most important factor determining mating success, which could be related to intra-specific selection. Females also showed a preference for nests with spawning batches in early stages of development. However, once a nest was selected, there was no preference in terms of spawning location within the nest. Aggression was strongly related to male size, with dorsal, pectoral anal and caudal fins showing the most evidence of aggression. Egg cannibalism was directly related to the mean number of spawning batches found in the nest.