Reproductive ecology and behavior of Thoropa miliaris (Spix, 1824) (Anura, Leptodactylidae, Telmatobiinae)

Abstract

Thoropa species are distributed in southern and southeastern Brazil and have semiterrestrial tadpoles on rocky environments. Herein, we provide further data on reproduction, paternal care and tadpole cannibalism in T. miliaris. Guarding males were tested for disturbances in their egg masses. Egg masses were laid in stripes of wet rock; eggs were in a single layer and were adhered to the rock surface, roots, and to one another. The tadpoles hatched between four and six days. The egg number in two egg masses was 750 and 1190; eggs were gray and the yolk were about 1.7 mm in diameter; 2.3 mm with the jelly capsule. Aggressive interactions were observed between males. Males remained with their egg masses during the night and reacted aggressively to the experimental disturbances. Late stage tadpoles were found cannibalizing eggs. An egg mass in a recently formed wet stripe died from drought. The strips of wet rock are the only places where eggs and tadpoles can develop and represent a limiting factor for reproduction because they occur in short supply. For the females, the selection of newly formed wet strips may represent a trade-off between the advantages of using places free of cannibalistic and/or competitive tadpoles and the risks of losing offspring by drought. Our results do not support Cycloramphinae as a valid taxon, indicating that the morphological and behavioral similarities between Thoropa and Cycloramphus species should be interpreted as convergence. Thoropa miliaris, parental care, reproduction, cannibalism, Atlantic forest, Brazil. Resumo Ecologia e Comportamento Reprodutivo de Thoropa miliaris (Spix, 1824) (Anura, Leptodactylidae, Telmatobiinae). As espécies de Thoropa estão distribuídas no sul e sudeste do Brasil e têm girinos semiterrestres em ambientes rochosos. Aqui apresentamos dados complementares sobre reprodução, cuidado paternal e canibalismo por girinos em T. miliaris. Machos guardiões foram testados quanto a perturbações às suas desovas. As desovas foram postas em faixas de umidade na rocha; os ovos foram postos em camada única e estavam aderidos à superfície da rocha, raízes e uns aos outros. Os girinos eclodiram entre quatro e seis dias após a oviposição. O número de ovos em duas desovas foi 750 e 1190; os ovos eram cinza e a porção vitelínica mediu cerca de 1,7 mm em diâmetro; 2,3 mm com a cápsula gelatinosa. Foram observadas interações agressivas entre os machos. Os machos permaneceram com suas desovas durante a noite e reagiram agressivamente às perturbações experimentais. Girinos em estágios tardios foram vistos canibalizando ovos. Uma desova em uma faixa de umidade recém formada morreu por desidratação. As faixas de umidade na rocha são os únicos locais onde os ovos e os girinos podem se desenvolver e representam um fator limitante para a reprodução porque são raras. Para as fêmeas, a seleção de faixas úmidas recém formadas deve representar um balanço entre as vantagens em ocupar lugares livres de girinos canibais e/ou competidores e os riscos de perda de prole por desidr...

Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest

“…or have disappeared in recent times (Heyer et al, 1990), thus most populations are found at or near sea level. Past work on this genus indicates that these frogs have unique natural histories: they live and breed on rocky marine shores (Giaretta and Facure, 2004), tadpoles are semiterrestrial and develop in seeps and streams (Bokermann, 1965;Rocha et al, 2002), they have high tolerance to short exposures to salt water (Abe and Bicudo, 1991) and they eat marine invertebrates and have physiological adaptations for excreting salt (Bokermann, 1965;Sazima, 1971;Brasileiro et al, 2010).…”

“…The patchy distribution of these habitats could play a role in structuring the genetic diversity of this species at fine scales on the landscape. In addition, Thoropa taophora exhibits a polygonous mating system in which related females share breeding sites (Muralidhar et al, 2013) and male Thoropa guard their tadpoles and aggressively defend the developing young from other males (Giaretta and Facure, 2004). This territorial behavior might contribute to increased philopatry and reduced dispersal (Greenwood, 1980;Clobert et al, 2009) and the kin-biased breeding structure likely reduces genetic diversity within population (Muralidhar et al, 2013).…”

Morphological Diversity and Evolution of Egg and Clutch Structure in Amphibians

“…Arrays attached to a single surface are orderly, but the group appears more haphazard if it is deposited on multiple stones or vegetation. The orderliness of the egg arrangement is also likely a function of the female's behavior (e.g., Giaretta and Facure, 2004). Eggs of some Spea form a haphazard array on sprigs of vegetation (Fig.…”

Habitat selection by anurofauna community at rocky seashore in coastal Atlantic Forest, Southeastern Brazil

“…Scinax littoreus is a bromeligenous species (sensu Peixoto, 1995) and have their whole complex life cycle associated to the bromeliads (Alves- . Also, the species T. miliaris is adapted to breed in temporary water films that flow over the rocks after rains where it tadpole grows and metamorphoses into a froglet (Giaretta and Facure, 2004;Haddad and Prado, 2005). Thus, these species reduced the dependence of great water collections for reproduction.…”

“…This species is being commonly associated to these types of habitats (Rocha et al, 2002;Giaretta and Facure, 2004). Sparse vegetation composed by shrubs and small trees was the less used microhabitat by amphibians.…”