An investigation into the taxonomy of Abavorana luctuosa (Peters, 1871) (Anura, Ranidae) and the resurrection of Rana decorata Mocquard, 1890 from Borneo

Abstract

The taxonomic status of the ranid frog Abavorana luctuosa (Peters, 1871) was investigated using a combination of molecular and morphological data. The analyses revealed that A. luctuosasensu lato is composed of two species in Borneo. One of these species agrees with the description of Rana decorata Mocquard, 1890 which is resurrected in the combination Abavorana decoratacomb. nov. (Mocquard, 1890). Abavorana decorata is recovered as the sister lineage to the remainder of Abavorana and differs by a 16.0–17.0 % uncorrected pairwise sequence divergence from its congeners A. nazgul and A. luctuosa, respectively. It is distinguishable morphologically from A. luctuosa and A. nazgul by its ventral pattern (bold, black and white reticulations on its venter along with bold banding on the underside of hind limbs vs. generally immaculate and spotted in the latter two species), and a prominent white streak beneath the eye and/or tympanum extending to the corner of the jaw. Abavorana decorata further differs from A. luctuosa by having a significantly wider head and snout, larger interorbital and tympanum diameters, longer femur in both sexes, and various combinations of other mensural characters. Both species are sympatric in Borneo and this discovery adds to a growing number of widespread Sundaic species shown to be species complexes with distinct forms in Borneo.