Reprodução de Leptodactylus ocellatus (Anura, Leptodactylidae), uma espécie com cuidado maternal à prole

Abstract

In Leptodactylus ocellatus, the tadpoles form schools that are protected by the females until the end of the larval phase. Here we described aspects of the reproduction of this species in areas of Cerrado in the state of Minas Gerais (Brazil). We determined in the field the reproductive period, spawning places, duration of the parental care and differences in the survival (degree of development reached) of protected/unprotected schools. We described the way of action of tadpole predators and the types of reaction of the parental females in the presence of them. The reproduction took place all around the year, with greater activity in the hot/rainy season. Foam nests were circular in format, often presenting a central opening; they were often built in the water surface amidst grass-like vegetation. Permanent and temporary bodies of water were used. The amplexus was axillary and the male beat the foam with lateral movement of the hind limbs. After leaving the foam, the tadpoles remained aggregated, forming dense schools. Females remained with the tadpoles until the end of the metamorphosis, 42 days on average. We observed coalition (fusion) between two or more schools of different females. Parental drove the schools through undulations in the water produced by pelvic movements and built channels interconnecting isolated areas. Females actively defended tadpoles from predators, as co-specific males, jumping, snout hitting, biting and emitting screams. Predators of tadpoles were teleosts, snakes, birds, arthropods and conspecifics. Egg clutches were preyed upon by teleosts and conspecific tadpoles. There was not significant difference in the survival (larger development) between guarded and unguarded schools in habitats with and without teleosts (tadpole predators). Among unguarded schools, the survival was significantly greater in environments without teleosts. The females appear to favor the schools through active defense and through orientation in the environment. The presence of the female was not an absolute warranty or an essential condition for the tadpoles to reach of the metamorphosis in environments without teleosts; Although it increased their survival in the presence of teleosts. In the species, the maternal care can be classified in two categories: attendance to the eggs/tadpoles and tadpoles driving. Functionally, it can be classified as predatory avoidance, including cannibalism. In the species, the maternal care may increases the survival of the offspring but is not an obligatory condition to the development of eggs and tadpoles, as well as the mother absence do not necessarily mean the death of the tadpoles.