Parental care of underwater egg clutches in Andean water frogs (Anura: Telmatobiidae)

Abstract

The most generalized reproductive mode in anurans is the deposition of egg clutches in water that develop into exotrophic aquatic tadpoles. Yet, despite this extended distribution, cases of parental care on submerged egg clutches are poorly documented. Because of its high diversity, its aquatic habits, and reports on males of two species standing next to the clutch, the Andean genus Telmatobius Wiegmann, 1834 offers an excellent model to examine the evolution of such behavior and the factors influencing it. Here, we combine field and laboratory studies to describe the breeding biology and parental care behavior on Telmatobius culeus (Garman, 1876), Telmatobius hintoni Parker, 1940, Telmatobius intermedius Vellard, 1951, Telmatobius jelskii (Peters, 1873), and Telmatobius oxycephalus Vellard, 1946. Our findings indicate that these five species have prolonged breeding season, and use concealed underwater shelters between rocks or macrophytes for mating and egg deposition. We showed that clutches of 35–560 eggs are deposited in these shelters. Males were observed next to the egg clutch and defending it aggressively against intruders, including conspecifics. Females were, on average, larger than males supporting the hypothesis that competition among males does not drive sexual size dimorphism in the genus. Our findings provide meaningful data to use in conservation programs, given that most species of Telmatobius are considered endangered and fill a significant information gap in understanding parental care’s origin in Nobleobatrachia.