AMPHIBIAWEB
Phrynobatrachus pallidus
family: Phrynobatrachidae
 
Species Description: Pickersgill, M 2007 Frog Search; results of expeditions to southern and eastern Africa. Edition Chimaira. Frankfurt-am-Main

Country distribution from AmphibiaWeb's database: 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:

Summary

Phrynobatrachus pallidus is a miniature species (SVL < 17.5 mm) of puddle frog distributed in Kenya and Tanzania. Members of this genus are identified by the presence of a midtarsal tubercle, elongate inner metatarsal tubercle, and outer metatarsal tubercle. P. pallidus is characterized by a smooth dorsum, presence of small but distinct digital discs, and pronouced lateral gular folds in the male.


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

Etymology

This species is named for the Latin 'pallidus' meaning pale.


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

Distribution

This species is known from the Tanzanian coast between Dar es Salaam and Tanga, inland to the foothills of the West Usambara Mountains (Pickersgill, 2008). More recently a specimen from Kakoneni in the Coast Province of Kenya was identified as this species (Zimkus et al., 2010). There is also an unconfirmed record from Lake Kenyatta in coastal Kenya (Pickersgill, 2007).


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

Morphology

The body is slender with the head width being 29-33% of the SVL. Members of this genus are identified by the presence of a midtarsal tubercle, elongate inner metatarsal tubercle, and metatarsal tubercle. The tibia is 53-54%, the foot is 47-53%, and femur is 46-47% of the SVL. Scapular warts form a W-shape with an ovular anterior pair and a more elongate posterior pair. No minute asperities are present. The tympanum is hidden or barely discernible. Manual webbing is absent. All toes have discs, and there are discs on the outer two fingers. Pedal webbing is rudimentary with 3-4 digits free of webbing on digit IV. Dorsum is greyish to brown with semi-regular dark brown markings on each side, and an interorbital triangle. A light vertebral line may be present. There is a dark streak along the side of the face but no subtympanal light streak. The upper lip is speckled but not barred, while the lower jaw exhibits weak barring. A dark strip runs from the axilla down the side of the body. Venter is white with some light pigmentation in the pectoral region in both sexes. Males exhibit pronounced lateral vocal folds. There is a weak swelling on the back of the thigh of the male paratype, suggesting femoral glands (Pickersgill, 2007)


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

Size

Phrynobatrachus pallidus is a miniature (snout–vent length < 17.5 mm) puddle frog species. Snout-vent lengths of type material include one male of 15 mm and one female of 17.5 (Pickersgill, 2007). An additional specimen from Kenya (MVZ 234153) measures 17.0 mm (Zimkus, unpublished).


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

Diagnostic Description

This species is easily distinguishable from other dwarf Phrynobatrachus by the presence of small but distinct digital discs and an almost smooth dorsum (Pickersgill, 2007).


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

Comparisons

Phrynobatrachus inexpectatus, P. kakamikro, P. mababiensis, P. minutus, and P. parvulus are morphologically similar to P. pallidus. Toe webbing in P. inexpectatus is almost absent and the throat of males is strongly suffused with dark grey pigment (Largen, 2001). Phrynobatrachus anotis, P. minutus and P. parvulus males in breeding condition can be distinguished by throat colour, yellow in the first two and dark grey in the latter. The foot of P. kinangopensis and P. perpalmatus is well webbed (versus rudimentary to absent webbing in P. pallidus). Phrynobatrachus rungwensis, P. ukingensis, and P. uzungwensis share similar SVL, exhibit well developed digital discs and an indistinct tympanum but are slightly larger. In addition, the throat is heavily pigmented in P. ukingensis, and P. uzungwensis exhibits extensive pedal webbing. Phrynobatrachus breviceps and P. stewartae also exhibit more extensive pedal webbing (at maximum two and a half phalanges of fourth toe free of webbing).


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

Habitat and Ecology

It has been found calling from puddles and pools, occupying areas with denser fringing vegetation than Phrynobatrachus mababiensis. It has also been in sites where dense bush has been cleared for vegetable plots. The little available evidence suggests that it survives well in habitats modified by humans. There are records from very close to sea-level, up to 429m asl in the West Usambara footlhills (Pickersgill, 2008).


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

Associations

P. mababiensis were heard calling at a site in Dar es Salaam (Pickersgill, 2007). P. pallidus occupied pools with denser vegetation at the edges, while P. mababiensis appeared to be less selective. Only when species vocalized at any one time if the two species shared the same pool. P. pallidus also was identified in vegetable plots where Afrixalus sylvaticus but not P. mababiensis occurred.


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

Population Biology

It is locally abundant, but little data are available, as it has probably been confused with other species (Pickersgill, 2008).


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

Advertisement Call

Advertisement calls were recorded by Pickersgill (2007). The voice is a prolonged buzz of variable length, ending in one or more metallic-sounding ticks. Pulse rates of males from Tanga were constant at 26-28 pps and between 3.3-5.2 kHz. Call ends in one or more metallic-sounding ticks, 0.07-0.43 seconds after the buzz.


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

Reproduction

It breeds aquatically, and tadpoles tentatively assigned to this species were collected from a well-vegetated puddle (Pickersgill, 2007).


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

Phylogenetics

Mitochodrial sequence data from 12S rRNA, valine-tRNA, and 16S rRNA fragment, as well as combined sequence data from mitochondrial and nuclear (RAG-1) genes indicate that P. pallidus is the sister species to a clade that includes P. mababiensis B (Kenya and Tanzania), P. ukingensis, and P. ungujae (Zimkus et al., 2010).


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

IUCN Red List Category and Justification of Conservation Status

The IUCN Red List (2009) categorizes this species as Least Concern in view of its wide distribution, probable tolerance of a broad range of habitats, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.


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

Trends

Populations of this species are stable (Pickersgill, 2008).


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

Threats

It is probably an adaptable species that is not facing any significant threats (Pickersgill, 2008).


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