AMPHIBIAWEB
Anhydrophryne rattrayi
Rattray's frog
family: Pyxicephalidae
subfamily: Cacosterninae

© 2004 Robert C. Drewes (1 of 4)
Conservation Status (definitions)
IUCN (Red List) Status Vulnerable (VU)
CITES
Other International Status None
National Status None
Regional Status None

Country distribution from AmphibiaWeb's database: South Africa

 

View distribution map using BerkeleyMapper.

   

From the Encyclopedia of Life account:

Distribution

Anhydrophryne rattrayi is endemic to the Eastern Cape Province where it has a restricted distribution centered in the Amatola Mountains (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

This is one of southern Africa’s smallest frog species with females attaining a body length of 22 mm (Wager, 1963, 1986; Passmore and Carruthers, 1995; Channing, 2001). The snouts of males are calloused, slightly flattened, usually whitish and presumed to be adapted for excavating nests. Body colour and pattern are variable: the dorsum varies from light grey to dark brown or copper-coloured. Irregular dark mottling and a thin, light vertebral line are sometimes present. A dark mask extends across the eyes from nostrils to armpits. The white ventrum is marbled with dark blotches that do not extend onto the throat (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Habitat and Ecology

The species inhabits Afromontane Forest at altitudes generally >1100 m. It appears to flourish in the grassland/forest ecotone and also occurs in short grass in small open patches of wetland within forests (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Associations

The diet of A. rattrayi includes small leaf-litter crustaceans such as amphipods and isopods (Wager 1986). Springtails (Collembola) appear to form a large proportion of the diet (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Metamorphosis

The species reproduces by direct development. Wager (1986) found larval development and metamorphosis are completed in about four weeks. The newly metamorphosed froglets measure only 4 mm from snout to vent (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Advertisement Call

The advertisement call has been described as a melodious “ping, ping, ping”, repeated rapidly or slowly in bouts of 7–15 notes, or sometimes emitted as single notes (Wager 1986). The notes are 0.05 s in duration with an emphasized frequency of 3500 Hz (Channing 2001). Passmore and Carruthers (1995) recorded a call rate of 4 notes per second, emitted at an emphasized frequency of 3000 Hz. Wager (1986) and Channing (2001) reported that under favourable conditions, that is, mist or rainy weather, hundreds of males may be heard calling throughout the night and sometimes during the day. Calling has been recorded in summer, October–February (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

Reproduction

Once paired, A. rattrayi breeds in moist leaf litter on the forest floor, often near streams and waterfalls. Adults are found in wet situations (e.g. near waterfalls), but the eggs are laid in areas where waterlogging is unlikely to occur. Eggs are laid in small holes excavated in the clay soil beneath leaf litter on the forest floor. Wager (1986) recorded a spherical egg chamber, 21 mm in diameter, with a smooth shiny wall and a 9-mm entrance hole in the 3-mm thick roof. The chamber is, apparently, excavated by males. Additional information on nest building and other aspects of reproductive biology is needed. The pearly white eggs are large, nearly 2.6 mm in diameter, and encased in a 6-mm gelatine capsule. Clutches of 11–20 eggs are laid in a single layer on the floor of the nest and adhere to each other (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/

IUCN Red List Category and Justification of Conservation Status

A. rattrayi is here classified as Endangered owing to its limited and severely fragmented distribution (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Burger, M.
License: http://creativecommons.org/licenses/by-nc/3.0/