AMPHIBIAWEB
Phrynobatrachus intermedius
family: Phrynobatrachidae
 
Species Description: Roedel M-O, Boateng CO, Penner J, Hillers A 2009 A new cryptic Phrynobatrachus species (Amphibia: Anura: Phrynobatrachidae) from Ghana, West Africa. Zootaxa 1970:53-62.

© 2016 Daniel Portik (1 of 1)

Country distribution from AmphibiaWeb's database: Ghana

View distribution map using BerkeleyMapper.


Conservation Status (definitions)
IUCN (Red List) Status
CITES
Other International Status None
National Status None
Regional Status None

   

From the Encyclopedia of Life account:

Summary

Phrynobatrachus intermedius is a medium sized (snout–vent length < 28 mm) species of puddle frog from primary forest in south-western Ghana. Members of this genus are identified by the presence of a midtarsal tubercle, elongate inner metatarsal tubercle, and outer metatarsal tubercle. Phrynobatrachus intermedius exhibits a combination of unique morphological and color characteristics including a compact body, short and pointed snout, a conspicuous dark face mask, a relatively smooth dorsum with feebly developed dorsal ridges, a black throat with few small white spots, blackish vermiculation on the breast, and moderately developed webbing with approximately 1.5 phalanges free of webbing on toe IV.


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

Etymology

The specific name means 'intermediate' in Latin and refers to the species exhibiting morphological characteristics of both P. liberiensis and P. plicatus, making it a morphological intermediate of the two.


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

Distribution

Phrynobatrachus intermedius is only known from two sites in the Ankasa Reserve in south-western Ghana (Rödel et al., 2009).


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

Morphology

This species have an oval, compact body shape and a short snout, rounded in dorsal and pointed in lateral view. Canthus rostralis is distinct and sharp; loreal is region plain. Nostril is closer to snout than to eye. Tympanum is present but indistinct, and smaller than diameter of eye. Femur is only slightly shorter than tibio-fibulare. Hands have large, oval palmar and thenar tubercles; fingers have small roundish subarticular tubercles. Relative finger length: 1=2>4>3. Palmar webbing is absent. Tarsal tubercle, large ovular inner metatarsal tubercle, and small, round external metatarsal tubercles are present. The inner metatarsal tubercle is approximately one third of shortest toe length. Relative toe length: 1<2<5<3<4. Webbing formula: 1 (1), 2 (1- 0.5), 3 (2-1), 4 (2.5), 5 (1). Toe and finger tips slightly expanded without forming discs. Dorsal skin is grainy, and eyelids are smooth. Back with inconspicuous dorsal ridges that start behind the eyes on the level of the tympani, converge slightly and end shortly posterior to the bases of the forelegs, and no other warts are discernible. Ventral skin is smooth. Overall coloration of the dorsum is reddish-brown, slightly fading towards the belly to a grayish-brown. Small bluish spots are present in the middle of the back, positioned on both sides in line with the dorsal ridges. Dark bars absent from the dorsal parts of forelegs. Three indistinct dark bars present on the femur and tibia dorsally. The outer, posterior parts of thighs are uniform reddish-brown. The anterior parts of thigh are lighter and slightly mottled with brown. Vent in the middle of a black triangle that is dorsally bordered by a fine white line. A very conspicuous dark chocolate-brown to blackish triangular face mask is present, starting at snout tip and covering loreal and tympanal region. Dorsally this mask bordered by fine, irregularly bordered white line. Posterior to tympanum the face mask curves down to bases of forelegs, following fine supratympanal ridge. The upper and lower mandible is slightly darker than the face mask and throat, with very few minute white points. Irregular white spots are present on a dark brown throat. The breast and upper part of belly white are patterned with dark brown vermiculation, and the remainder of belly and ventral part of thighs is white to beige. The dark color of the throat extends to the anterior parts of upper arm. The lower arm and lower leg have fine darker mottling. Color in preservation is slightly faint, otherwise not very different to life, and dorsal bluish spots in life are green.


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

Size

Currently P. intermedius is only known from three specimens, two female adults and one juvenile. The SVLs of the two females are 22.81 mm and 27.76 mm. Males of this species are so far unknown (Rödel et al., 2009).


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

Diagnostic Description

This species is characterized by combination of unique morphological and color characteristics including a compact body, short and pointed snout, a conspicuous dark face mask, a relatively smooth dorsum with feebly developed dorsal ridges, a black throat with few small white spots, blackish vermiculation on the breast, and moderately developed webbing with approximately 1.5 phalanges free of webbing on toe IV.


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

Comparisons

From a number of the smaller West African Phrynobatrachus species, including P. annulatus, P. calcaratus, P. taiensis, and P. villiersi, this species can be distinguished by its size (> 22 mm), the absence of an eyelid cornicle and a different ventral pattern. P. ghanensis and P. pintoi lack an eyelid cornicle, but are also much smaller and have a different ventral coloration. P. tokba, P. gutturosus, and P. fraterculus are smaller, have a more slender body shape and scapular glands that are differently shaped or absent (P. fraterculus). These three species have only very rudimentary traces of webbing. The ridges differentiate P. intermedius from P. brongersmai that has scapular glands that form an X-shaped pattern and brown stippling on the gular and pectoral regions; as well as from P. guineensis, P. phyllophilus, P. accraensis, P. francisci, and P. natalensis that mostly have two pairs of comma shaped scapular glands, but no ridges. Webbing is also more developed in P. accraensis, P. francisci, and P. natalensis than P. intermedius. P. alleni has ridges that resemble P. plicatus (X-shape, see below) but are shorter. These ridges are also much more distinct in P. alleni than in P. intermedius. Furthermore P. alleni has either a white (females), or a yellowish (males) venter, whereas the throat and breast are dark colored in P. intermedius. Yellowish throats are also present in males of P. accraensis and P. fraterculus (Rödel et al., 2009).

P. intermedius differs from all Phrynobatrachus species previously mentioned by the presence of a very distinct blackish-brown face mask. A face mask is also present in P. batesii, P. liberiensis, and P. plicatus. The Central African P. batesii has much less developed webbing compared to the P. intermedius, and P. batesii females have a white throat. Thus, P. intermedius is morphologically most similar, although somehow intermediate to P. plicatus and P. liberiensis. Adult P. plicatus and P. liberiensis males have very distinct folds on a completely black throat; males of P. intermedius are unknown. P. intermedius shares with P. plicatus a more pointed snout and a more conspicuous face mask, compared to P. liberiensis. In P. intermedius the throat bears some small whitish spots or points. Female P. plicatus have a uniform dark throat and the P. plicatus snout is more rounded in lateral and more pointed in dorsal view. Both sexes of P. plicatus can be readily distinguished from the P. intermedius by distinct long and X-shaped dorsal ridges that clearly exceed the middle of the back. These ridges are usually bordered by a color that is either lighter or darker than the rest of the back and thus makes the ridges even more conspicuous. The dorsal ridges are much less conspicuous and shorter in P. intermedius, not exceeding the middle of the back. Few P. plicatus, some sympatric with P. intermedius, may have comparatively short dorsal ridges. However, these are still longer and much more distinct in P. plicatus than in P. intermedius, and the ridges converge and diverge, thus forming an X-like figure. P. intermedius ridges are only slightly converging. P. plicatus further has a less broad head and more developed webbing than P. intermedius. The greenish dorsal spots of the P. intermedius holotype occasionally occur also in P. plicatus. Many P. plicatus posses paired or unpaired black spots in the most caudal quarter of the back, a character not observed in any other West African Phrynobatrachus (Rödel et al., 2009).


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

Habitat and Ecology

All specimens of the new species were collected in swampy parts of primary rainforest within the Ankasa Reserve (Rödel et al., 2009).


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

Associations

Frog species in sympatry with P. intermedius include P. liberiensis, P. plicatus, and P. ghanensis (Rödel et al., 2009).


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. maculiventris is the sister species of P. liberiensis, and these two species are in turn sister to P. tokba (Zimkus, 2010). The analysis of mitochondrial 16S rRNA revealed P. maculiventris differed from P. liberiensis by 4.7 ± 0.7 % (N= 15; Rödel et al., 2009).


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

IUCN Red List Category and Justification of Conservation Status

Phrynobatrachus intermedius is not currently included in the IUCN's Red List assessment of amphibian species. Following the IUCN (2001) criteria, this species should be recognized as Data Deficient because it is currently known from only three specimens collected at the type locality. Rödel et al. (2009) recommend that if the species cannot be recorded in further forests it should be classified as Critically Endangered because of the size of its range.


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

Conservation Actions and Management

All known specimens of this species were collected from the Ankasa Reserve. This reserve is divided into two: the Ankasa Resource Reserve and the Nini-Suhien National Park, collectively called the Ankasa Conservation Area. The two types have been collected in the swamps of the Resource Reserve (Rödel et al., 2009)


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