Systematics and Taxonomy
Up to some 55 species are sometimes placed in Huia, including some originally placed into the genera Odorrana and Eburana, which formed a paraphyletic cluster; indeed these two genera are sometimes treated as junior synonyms of Huia. The Long-snout Torrent Frog on the other hand – formerly Huia nasica – is now in Odorrana. But many of the moves to Huia seem to be premature and it is better to treat Odorrana as valid, in a more comprehensive way and including Eburana, than expanding Huia.
For as it seems, even in the revised delimitation the genus is still paraphyletic with Meristogenys. Either the latter genus is included here, or Huia is restricted to the type species (the Hole-in-the-head Frog, H. cavitympanum) and what might be its closest living relatives (e.g. an undescribed species from Sumatra), or some species of Huia - e.g. the Sumatran Torrent Frog (H. sumatrana) - are split off again. The former alternatives seem to be more advisable as long as the interrelationships of Huia and Meristogenys species as well as the closely related Clinotarsus are as badly resolved as they are at present. Meristogenys tadpoles are furthermore characterized by a split and ridged upper lip not found in the Hole-in-the-head Frog, indicating that the genera ought to be kept separate.
New species are being discovered regularly, exacerbating the taxonomic uncertainties.
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