|Martinique volcano frog|
| Allobates chalcopis|
(Kaiser, Coloma, and Gray, 1994)
Allobates chalcopis is the only aromobatid species endemic to an oceanic island. This has led to a suggestion that it is not native but an introduced species, synonymous with some mainland species. However, examination of new specimens with molecular phylogenetics methods suggests it is truly distinct from the mainland Allobates, and highly diverged from its closest relatives. This conclusion is also supported by morphological and ecological evidence, thereby strengthening the position that it is a true endemic.
Allobates chalcopis is a small frog with males measuring about 17 mm (0.67 in) in snout–vent length and females about 16–18 mm (0.63–0.71 in). Its dorsum is light brown with darker markings. Males have a distinctive, black throat, tapering off to a dark gray, whereas females have uniformly pale orange throat and venter.
The tadpoles are terrestrial, free-living, and endotrophic—they do not feed but rely on stored yolk. They grow to a length of at least 12 mm (0.47 in). The body is ventrally flattened.
Allobates chalcopis was originally described from forested ravines of Mount Pelée at an elevation of about 500 m (1,600 ft) asl. Extensive search in 2011 failed to spot the species in this habitat, but it was discovered higher up on the mountain, at about 800–1,400 m (2,600–4,600 ft) asl, that is, to the summit of the mountain. The current range starts from the transition zone between forest and savanna, the latter being the vegetation type found higher up on the mountain.
The International Union for Conservation of Nature assessed Allobates chalcopis in 2010 as a "Vulnerable species". However, in light of its disappearance from the lower altitudes and the very small remaining range (and the evidence of endemicity), Fouquet et al. (2013) argue that it should be considered as "Critically Endangered".
- Hedges, B.; Ibéné, B.; Breuil, M.; Powell, R. (2010). "Allobates chalcopis". IUCN Red List of Threatened Species. IUCN. 2010: e.T55066A11247344. Retrieved 10 September 2016.
- Frost, Darrel R. (2016). "Allobates chalcopis (Kaiser, Coloma, and Gray, 1994)". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 10 September 2016.
- Kaiser, H.; L. A. Coloma; H. M. Gray (1994). "A new species of Colostethus (Anura: Dendrobatidae) from Martinique, French Antilles". Herpetologica. 50: 23–32. JSTOR 3892871.
- Fouquet, A.; Pineau, K. V.; Rodrigues, M. T.; Mailles, J.; Schneider, J. B.; Ernst, R.; Dewynter, M. L. (2013). "Endemic or exotic: The phylogenetic position of the Martinique Volcano Frog Allobates chalcopis (Anura: Dendrobatidae) sheds light on its origin and challenges current conservation strategies". Systematics and Biodiversity. 11: 87–101. doi:10.1080/14772000.2013.764944.
- Dendrobatid in the taxonomy employed by Fouquet et al. (2013).
- Kaiser, H.; Altig, R. (1994). "The atypical tadpole of the dendrobatid frog, Colostethus chalcopis, from Martinique, French Antilles". Journal of Herpetology. 28 (3): 374. doi:10.2307/1564539. JSTOR 1564539.