Description

SVL is 70mm for males (Passmore and Carruthers 1995). Head broader than long (Laurent 1963). Small, obvious, beady eyes with vertical pupil (Laurent 1963). The snout is bluntly pointed, with a hardened tip used for head-first burrowing (Laurent 1963). This burrowing technique is unlike most other burrowing forms (Passmore and Carruthers 1995). Distance between the nostrils is 2.4 mm (Laurent 1963). There is no tympanum. Bodies appear squat, depressed, and bloated (Passmore and Carruthers 1995). The lower jaw recedes and there are no teeth on the upper jaw (Laurent 1963). The skin is smooth with a transverse fold across the top of the head (Passmore and Carruthers 1995). The limbs and digits are stout. Tibia is 2.5 times longer (18.6 mm) than broad (Laurent 1963). The first, second, and fourth fingers are the same length, while the third finger is the longest (Laurent 1963). Toes are not webbed (Laurent 1963).

The color, as reported by Laurent (1963) is a uniform olive green dorsally, grading to greenish on the sides. The ventral coloration is purplish grey with yellowish spots (Laurent 1963).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Congo, Congo, the Democratic Republic of the

View distribution map in BerkeleyMapper.

This species is found in the northeastern Democratic Republic of the Congo, but its range comes very close to the Ugandan border. It may also occur in Uganda (IUCN 2006). It is found in inland wetlands (bogs, marshes, swamps, peatlands, pools) of lowland tropical forests at elevations of up to 2000 m (IUCN 2006).

Life History, Abundance, Activity, and Special Behaviors

This frog is fossorial. It burrows forward, using the snout to wedge into the soil, rather than the backward (feet first) burrowing which is characteristic of most fossorial species. Hemisus olivaceus uses its front legs to push the soil aside while its back legs push the frog forward (Alexander 2004).

Breeding takes place in both temporary bodies of water and more permanent marshland. The male frogs usually call from the surface, but will also call from within their burrows. Amplexus is inguinal. The female will burrow with the male in tow. The female lays eggs in a breeding chamber inside the burrow and will remain with the eggs and tadpoles until they leave the egg chamber and enter the water (Alexander 2004).

Trends and Threats

The species is thought to be common within its range (IUCN 2006). occurs within at least one protected area, Virunga National Park (IUCN 2006). There are some protected areas, establishment, and management for the species, but more research actions are needed (IUCN 2006).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Long-distance pesticides, toxins, and pollutants

Comments

The species first described by Laurent (1963). The genus Hemisus derives its name from the Greek Hemi meaning half and Ous meaning ear. The species name olivaceus given because of its olive colored dorsal skin.

References

Alexander, J.G. (2004). ''Genus Hemisus Gunther, 1859 (Family Hemisotidae).'' Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. SI/MAB Series #9. Smithsonian Institution, Washington, D.C..

IUCN, Conservation International, and NatureServe (2006). Global Amphibian Assessment: Hemisus olivaceus. www.globalamphibians.org. Accessed on 10 March 2008.

Laurent, R.F. (1963). ''Three new species of the genus Hemisus.'' Copeia, 1963(2), 395-399.

Minter, L. R. (2004). ''Breviceps verrucosus.'' Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. SI/MAB Series #9. Smithsonian Institution, Washington, D. C., 194-195.

Species Account Citation: AmphibiaWeb 2008 Hemisus olivaceus: Olive Snout-burrower <https://amphibiaweb.org/species/1514> University of California, Berkeley, CA, USA. Accessed Apr 16, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 16 Apr 2024.

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