AMPHIBIAWEB
Cacosternum plimptoni
Plimpton's Dainty Frog
family: Pyxicephalidae
subfamily: Cacosterninae
 
Species Description: Channing A, Byun C, Burger M, Febvre S, Moyer D. 2005 A new dainty frog from East Africa (Anura: Ranidae: Cacosternum) Afr J Herp 54:139-148.

© 2007 Robert C. Drewes (1 of 2)

Country distribution from AmphibiaWeb's database: Kenya, Tanzania, United Republic of

View distribution map using BerkeleyMapper.


Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
See IUCN account.
CITES
Other International Status None
National Status None
Regional Status None

   

From the Encyclopedia of Life account:

Etymology

This species is named for George Plimpton (1927-2003) who played an important role in generating support for the Tanzania Wildlife Fund and the African Rainforest Conservancy, which funded research in the Usambara and Udzungwa Mountains. He was also an editor and active ornithologist.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Taxonomic Notes

A population of Cacosternum plimptoni was identified from Ethiopia by Zimkus (2008), but it is likely that this is a new species (Scott and Zimkus, unpublished).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Summary

This species of dainty frog is found in northern Tanzania and the highlands of Kenya. It is morphologically similar to Cacosternum boettgeri from the interior of southern Africa, and is distinguished on the basis of an advertisement call with double or treble pulsed notes.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Distribution

This species is known mainly from highland areas in northern Tanzania and southern Kenya (including the Serengeti National Park, Nairobi, Mau Narok and the Kinangop Plateau). There are also records from Kitende in Uganda and the Marungu Plateau in southeastern Democratic Republic of Congo.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

The head is roughly triangular in dorsal view; the head length is approximately 25% of SUL. The eyes are visible from below, and the pupils are horizontally elliptical. The nostrils are one-fifth the distance from the snout tip to the anterior eye, and inter-nostril distance is three-quarters of interorbital distance. The tympanum is not visible. The upper lip is smooth and thin. The relative finger lengths are as follows: I<II<IV<III. The tips of the fingers are rounded; discs are absent. The inner and outer metacarpal tubercles are clearly visible, and the supernumerary tubercles are small, white and round on a pigmented palm. Two supernumerary tubercles are present between the base of the third finger and the outer metacarpal tubercle. The subarticluar tubercles are distinct and rounded. The thighs are well developed. The relative toe lengths are as follows: I<II<V<III<IV. Toe tips are round without discs. The inner metatarsal tubercle is white and slightly elongated. The outer metatarsal tubercle is small, rounded and pale; webbing is absent. In life the dorsum is rough with regular small warts (Channing et al., 2005).

Holotype coloration: In life, the dorsum and head are dark with two lighter stripes on the flank that extend from the armpit to urostyle. There are irregular small dark marks on the head. Black blotches are visible on the venter. A thin white line runs parallel, and just above, the jaw line. The snout is light beige. A thin vertebral stripe runs from the snout to the urostyle. A thin dark line runs from near the snout to the sacrum on the flanks. A dark irregular line runs from the neck to the legs on each side of the midline and divides the flanks into two parts - pale brown at the top and light beige below. Limbs are pale brown with darker blotches. The thigh, tibia and foot have three round dark spots each; four smaller spots are present on the arm. The venter is white with round regular spots on the belly and some smaller spots under the jaw. Dark speckles are present on the limbs (Channing et al., 2005).

Paratypes differ slightly in coloration; four have light beige areas on the flanks that are much wider than the same area of the holotype. Blotches on the throat are also less visible. Some have dark limbs with light spots on the ventral surface, rather than light limbs with dark spots as in the holotype. One has two lines of light dots running between the eyes at the level of the armpit (Channing et al., 2005).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Size

The holotype is an adult female, measuring 19.7 from snout to urostyle; the six paratypes, all adult males, range from 16.4 to 19.2 (Channing et al., 2005).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Diagnostic Description

This species resembles cannot be reliably distinguished from C. boettgeri using external morphology. Its advertisement call has pulse trains that consists predominantly of double or treble pulses (rarely four).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Comparisons

This species can be distinguished from C. striatum by the latter's immaculate white belly. None of the known advertisement calls of other species have a regular series of pulse trains, except for the territorial call of C. namaquense (Boycott et al. 2002), which has trains of four pulses.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Advertisement Call

Males call from shallow water in temporary pools, often at the base of emergent vegetation. The call consists of a regular series of pulse trains with double or treble pulses. Often single pulses are at the beginning and sometimesthe end of the call. The call duration is approximately 0.5 sec, and the pulse rate is approximately 10.2/sec. The summary values for 133 calls from 26 individuals show 3 to 10 pulse trains (mean 6.1), and a mean emphasized frequency of 4.42 kHz (Channing et al., 2005).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/