Three is a crowd: Conspecific multi-male spawning in the Spotted Toad Rhaebo guttatus (Schneider, 1799)

A case of multi-male spawning between two males and one female of Rhaebo guttatus is reported. An amplectant pair of R. guttatus was observed spawning in an ephemeral puddle located in a flooded area of a stream inside an open ombrophilous forest remnant on 31st January 2019, in the municipality of Cotriguacu, north-western Mato Grosso state, Brazil. To our surprise, a conspecific male (secondary male) was submerged with its belly up, nostrils out of the water and clasping the female by the ventral region, apparently, trying to fertilise the eggs. For Neotropical anurans, multi-male spawning has been reported to occur in eight phyllomedusid and four leptodactylid species. Therefore, it is the first record of conspecific multi-male spawning for R. guttatus. These observations provide new insights into the breeding biology of R. guttatus. Further studies, however, are needed to better understand the reproductive features, focusing on genetic analyses of the offspring produced from multi-male spawning of R. guttatus to determine whether multiple paternity occurs in this toad species.

Automated summary

The case of multi-male spawning between two males and one female of Rhaebo guttatus is reported, with a conspecific male observed attempting to fertilize eggs in an amplectant pair. This is the first record of conspecific multi-male spawning for R. guttatus, and further studies are needed to understand the reproductive features, particularly regarding genetic analyses of offspring produced from such spawning to determine potential multiple paternity.