Pelophryne Barbour (Bufonidae), 1938

Inger, Robert F. & Stuebing, Robert B., 2009, New Species And New Records Of Bornean Frogs (Amphibia: Anura), Raffles Bulletin of Zoology 57 (2), pp. 527-535 : 531-532

Pelophryne Barbour (Bufonidae)

Remarks. – There are two general morphotypes among the Bornean species of this genus—one with the tips of the fingers expanded into truncate discs and one with the tips of the fingers rounded and not expanded. The latter group includes only three species— P. misera (Mocquard) known from high elevations on Mt. Kinabalu, P. api Dring from a wide altitudinal range in northern Sarawak, and the recently described P. linanitensis Das —which are easily distinguished from one another.

Both the recognition of species within the group having expanded finger tips and the association of specimens with named taxa have posed problems. There are six similar, nominal Bornean taxa in this group: guentheri (Boulenger) , macrotis (Boulenger) , signata (Boulenger) , exigua (Boettger) , rhopophilius Inger & Stuebing , and murudensis Das. In the past very small samples and lack of multi-species samples from single localities have made it difficult to decide if differences among the morphotypes represent intraspecific or interspecific variation. Roux (1906), for example, placed exigua in the synonymy of guentheri , stating that the type of exigua was merely a juvenile guentheri ; however, the type of exigua , which we have examined, is an adult male having vocal sac openings and mandibular spinules. Inger (1966) placed both exigua and signata in the synonymy of brevipes (Peters) , a Philippine species; examination of new material calls that decision into doubt (Inger & Tan, 1996). The recently described species, P. rhopophilius , was the first species based on a type series of more than two specimens. The seven frogs constituting this type series show little variation in size, secondary sex characters, coloration, and body proportions (Inger & Stuebing, 1996). Das (2008) has recently described P. murudensis , based on a sample of four specimens that also exhibit little intraspecific variation.

We now have five samples from Sarawak, each consisting of at least five individuals; three of these samples consist of two morphotypes. One of these morphotypes is small: males having vocal sacs, yellowish mandibular spines, and a nuptial pad of fine, light spinules measure 13.5–15.9 mm snout to vent (n = 9) and adult females 15.3–17.6 mm (n = 9). They have two consistent elements of coloration: (1) The venter is cream or yellow with small, isolated black spots; the dark pigment occupies less than one-third of the ventral surface, and the light coloration extends half-way up the side. (2) The side of the head is dark with a wide cream or yellow streak running from below the eye under the tympanum and over the axilla where it is continuous with the light colour of the side. In coloration, size, and secondary sex characters, this morphotype agrees with the types of P. signata (Boulenger) (BM 1947.2.19.25–26), and P. exigua (Boettger) (SMF 3737); we have examined types of both nominal species. We assign this small form to Pelophryne signata (Boulenger) and place Nectophryne exigua Boettger in its synonymy. Pelophryne signata , as here defined, is about the same size as the Philippine species P. brevipes (Peters) : males 16.0–17.8 (n = 5), females 16.6–17.4 (n = 3), but P. brevipes has brown or black pigment covering most of the belly and underside of the hind limb and lacks the uninterrupted light lateral streak present in signata .

The second morphotype in each of these multi-species samples is larger: adult males with nuptial pads and vocal sacs measure 17.0– 24.6 mm and adult females 19.1–24.3 mm. Males do not have conical or spinose tubercles under the mandible. All have the dorsal surface set with small spinose tubercles and scattered larger tubercles that do not form a pattern. Dorsally all are brown (in preservative) with small, irregular darker markings. The side of the head is lighter with dark spots. These frogs fall into two groups. In one ( P. rhopophilius ), snout-vent length of adult males (with nuptial pads) ranges from 21.6 to 24.6 mm (mean ± SE = 22.70 ± 0.26; n = 11); the single adult female measures 24.3 mm. The abdomen in this group is mottled black and white (in preservative), with the light areas elongate and irregular in shape. The second group is slightly smaller with adult males 17.2–20.0 mm (mean ± SE = 18.98 ± 0.65; n = 4) and two adult females 19.1 and 21.6, the last having enlarged, non-pigmented ova. The abdomen is dark with many discreet, small, round, white spots. We treat this second group as a distinct species that we describe below as Pelophryne saravacensis .

The other large form of Pelophryne from Borneo, P. guentheri (Boulenger) , is larger with females 28.3–31.1 mm (n = 4) and a mature male 29.9 mm, the last having a row of mandibular spines. We consider P. macrotis (Boulenger) , its type examined by us, to be conspecific with P. guentheri .

The type series of P. murudensis Das from northern Sarawak consists of males measuring 21.9–25.6 mm ( Das, 2008). These differ from the species described below in several respects (see below) .