Systematic Study of A Tree Frog Family Pelodryadidae (Günther 1858) (Amphibia: Anura) from Tanimbar Islands, Moluccas

Abstract

Pelodryadidae is a family known as the Australian Tree Frog, which has a wide distribution in the eastern region of Indonesia and Australia. Colleeneremia capitula was the only species from this family that was described at Tanimbar Islands, Moluccas, Indonesia. The separation and isolation from the adjacent islands may have led to diversification and speciation within the genus. Since the early description of this species and the subsequent molecular studies in 2025, no additional information has been published regarding its morphology. There is also no information about the sympatric species of Pelodryadidae on this islands. In this study, we redescribe Colleeneremia capitula and describe an unidentified species based on specimens from the Museum Zoologicum Bogoriense (MZB) through morphological characters and molecular data. We observed and measured 44 specimens (29 males and 15 females) of Colleeneremia capitula and 31 specimens of an unidentified species, and performed genetic analysis using the 16S rRNA gene. We recognized the specimens of Colleeneremia capitula into two morphotypes based on morphological variation in the coloration, pattern, and especially the color of the iris. Univariate analyses revealed that of the 31 characters, only three were not significant. Principal Component Analysis (PCA) analysis showed clear separation of the morphospatial between these two morphotypes. However, molecular analysis revealed that the genetic divergence among Colleeneremia capitula samples ranges from 0 to 1.4%, indicating that they belong to a single species. We tentatively assigned the unidentified species to the genus Papuahyla based on morphological observation. Whereas, molecular analysis revealed that the unidentified species nested within the Drymomantis subclade, with genetic divergence within the subclade ranging from 8% to 14%. The limited data from the 16S rRNA gene cannot precisely define the taxonomic position of this species. From this study, we can conclude that Colleeneremia capitula in the Tanimbar Islands is confirmed to be a single species with two clearly distinct variants. The unidentified species was tentatively identified as part of the family Pelodryadidae, specifically as Papuahyla sp.