| Nimbaphrynoides | |
|---|---|
 | |
| Gestating female | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Anura |
| Family: | Bufonidae |
| Genus: | Nimbaphrynoides Dubois [fr], 1987 |
| Species: | N. occidentalis |
| Binomial name | |
| Nimbaphrynoides occidentalis (Angel, 1943) | |
| Synonyms[3] | |
Nectophrynoides occidentalisAngel, 1943 | |
Nimbaphrynoides is amonotypicgenus oftrue toads[4][5] from highlands in theMount Nimba region of theWest African countries ofGuinea,Liberia, andCôte d'Ivoire. The sole species isNimbaphrynoides occidentalis.[3] Along withNectophrynoides,Eleutherodactylus jasperi, andLimnonectes larvaepartus,Nimbaphrynoides is one of the only anurans that combineinternal fertilization withovoviviparity.[6][7]
Nimbaphrynoides occidentalis was firstdescribed asNectophrynoides occidentalis byFernand Angel in 1943. A second species from Mount Nimba,Nectophrynoides liberiensis, was described in 1979. The two were then transferred to a newly erected genusNimbaphrynoides in 1987.[3][8] The two species were similar except for the larger size ofN. liberiensis compared toN. occidentalis and some small colour differences. However, their calls are similar, and the genetic differences are minor. On this basis, they have been judged to be the same species. However, acknowledging the significant differences in size and that small genetic differences do exist,[8] they are still retained assubspecies:[3][5][8]
Adult males ofNimbaphrynoides occidentalis occidentalis measure on average 18 mm (0.7 in) and adult females on average 20.5 mm (0.8 in) in snout–vent length.Nimbaphrynoides occidentalis liberiensis are larger at respectively 22.4 and 28.7 mm (0.9 and 1.1 in). Adult colouration is variable. Thedorsum in most individuals is brown to black backs, without a distinct border between the two colours. It may also be uniform in colouration, or have lighter and darker browns irregularly mixed. There are some lighter areas in the head, at least on the snout and the eye-lids. The legs are light brown with irregularly bordered darker stripes or dots. The venter is typically white, but someNimbaphrynoides occidentalis liberiensis have small to large light brown dots on their venter. Juveniles had brighter coloured backs than adults.[8]
Themale advertisement call is very faint, short, and resembles a metallic "bing".Nimbaphrynoides areviviparous—they haveinternal fertilisation and the female gives birth to fully developed, tiny toadlets.[8] Eggs are small, ranging from 0.5–0.6 mm in diameter.[9]
Nimbaphrynoides occur in montane grasslands at elevations of 1,200–1,680 m (3,940–5,510 ft)above sea level. It is not tolerant to disturbance,[1] and recent observations are from less impacted areas where soil was not compacted or little compacted.[8] It can be locally very common, but the population is severely fragmented.[1] The area has been affected by mining,[1][8] and thetype locality ofNimbaphrynoides occidentalis liberiensis is now an open cast mining pit.[8] Future threats include a proposed iron ore mining concession and the arrival of a large contingent of refugees. Part of the population is protected by theMount Nimba Strict Nature Reserve, although improved management of the site is required.[1]
