Family Pyxicephalidae

Strongylopus hymenopus (Boulenger, 1920)

Berg Stream Frog, Drakensberg Stream Frog, Drakensbergse Langtoonpadda (A)

By A. Channing

Currently accepted name: Amietia hymenopus (Boulenger, 1920)
Red listing status: Near Threatened (2016)

Photo by Manson A., 2014. URL: FrogMAP: 1630

Distribution

S. hymenopus is endemic to the high slopes of the Drakensberg and Lesotho highlands. The southernmost record from Barkley East (3027DC) appears isolated, but this is probably due to inadequate sampling. The species occurs at altitudes of 1800–>3000 m. Lambiris (1987) presented evidence, based on tadpole specimens, that suggests that two species, namely S. hymenopus and an undescribed species, are confounded under this name.

Very few records were collected during the atlas period. The atlas data are reliable but incomplete.

Habitat

S. hymenopus inhabits Alti Mountain Grassland vegetation, in topography characterized by steep slopes and fast-flowing streams. Annual precipitation is 500–750 mm and occurs as summer thunderstorms and winter snowfalls. Adults forage in grassland on the plateaux and on gentle slopes. When breeding, they may be found in seepage areas, along the rocky banks of gently flowing streams, or near the edges of pools.

Life history

Breeding occurs after the first spring rains in September, through to January. Unlike other members of this genus, S. hymenopus lays its eggs in the water. Clutches of 200–500 eggs are attached to rock in flowing water or deposited in shallow, stagnant pools at the sides of streams. Eggs may also be laid in many smaller batches of 7–15 (Channing 1979). The development of the tadpoles has not been documented.

Conservation

S. hymenopus occupies uplands that are generally free of impacts that would affect it negatively. The species occurs in the uKhahlamba-Drakensberg Park. It is not believed to be threatened, and no special conservation action is recommended. However, the number of atlas records for this species is very limited and it is recommended that additional surveys be conducted to determine the true extent of the species’ range and the size of its populations. The presence of chitrid fungus infections in Ametia vertebralis (see species account), a species that inhabits the same uplands, indicates that S. hymenopus should also be monitored for this pathogen. Little is known of the life history of S. hymenopus and this also handicaps conservation assessment.

Current distribution map

Undated records;  pre-1996;  1996 to 2002;  2003 to present