Ansonia penangensis Stocliczka 1870
Creators: name: Quah, Evan
name: Grismer, L. Lee
name: Muin, Mohd Abdul
name: Anuar, Shahrul
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Bufonidae
Ansonia
Ansonia penangensis

description: Description
All specimens collected were subadult (<17 mm SVL), as adult A. penangensis may reach 37.2 mm SVL (Dring, 1979; Wood et al. 2008). The limbs and digits are slender; the head is wider than the body; the snout projects over the lower jaw; and the tympanum is visible. No longitudinal bony ridges are present in the interorbital space of the head. The dorsal surface of the limbs and body is tuberculate, covered with small, rounded tubercles that lack a keratinized tip; the tubercles are not arranged in rows; no enlarged tubercles along the dorsolateral fold, temporal or scapular regions or at angles of the jaw. The ventral surfaces of the belly and throat are coarsely granular; the granules are more widely spaced on the ventral surface of the limbs. The fingers are long, slender, unwebbed; have narrowly rounded tips not wider than other phalanges, and not forming discs. The first finger is shorter than second; the tip of the first finger does not reach the base of tip of second when adpressed. Toes slender with rounded tips; do not form discs; the third, fourth and fifth toes have 1.5 phalanges free of webbing. Tarsal ridges are absent.
Coloration. In life, dorsal surfaces are nearly uniformly black with small warts; small orange spots occur along the flank near the base of the limbs (more pronounced on hind leg); a white spot is present below the eye and two white warts occur at the base of the jaw; the upper portion of the limbs are prominently barred in orange (orange barring formed by a confluence of orange spots; Figure 1a). The ventral surfaces are gray with white spotting on the gular region but none on the forelimb; heavy, white spotting on the belly but only light spotting on the ventral surface of hind limbs (Figure 1b). The iris is uniformly red. The smaller specimens (USMHC 0002 0004) look similar to the largest specimen (USMHC 0001) in all aspects of morphology, the only difference being that the spotting on the belly and barring on the limbs are not as pronounced and the colors are not as bright.
Natural history. All individuals were collected between 1900 2100 h, following periods of afternoon precipitation. All specimens were found on the ground amongst leaf litter near a trail in evergreen forest with a thin canopy and gaps in the canopy, approximately 300 m from a river (Figure 1e; N 05.44º, E 100.28º, 263 m elevation). Tadpoles were found, clinging onto the rocks in fast flowing portions of the river (Figure 1c). These observations are similar to the remarks made by Boulenger (1912) and Flower (1899) who noted the tadpoles of A. penangensis can be found in swift-flowing hill-streams. A partially metamorphosed froglet was also observed (Figure 1d). The tadpole and the partially metamorphosed froglet were not collected, but these findings indicate breeding by A. penangensis in this river.
Tadpole. Ansonia penangensis was the only species of Ansonia found at the collection site, and the only larval form found. Provisionally, these tadpoles (USMHC 0005 0010) are assigned to A. penangensis. The tadpoles closely match the description of tadpoles of A. penangensis given by Boulenger (1912). The tadpoles had an average total length (TL) of 28.1 mm, body length (BL) of 8.1mm, body height (BH) of 2.7mm, maximum tail height (MTH) of 2.3mm, tail muscular height (TMH) of 2.1mm, body width (BW) of 4.6mm, internarial distance (IND) of 1.2mm, eyes to nare distance (END) of 0.7mm, eye to tip of snout distance (ES) of 2.9mm, eye diameter (ED) of 0.7mm and inter-orbital distance (IOD) of 1.6mm. Viewed dorsally; the headbody is teardrop-shaped; the snout is very broadly rounded and widest just before the eyes and the body is dorso-ventrally flattened in lateral view. The eye-nares distance is similar to the the eye diameter; the internarial distance is narrower than the interorbital distance. The body starts to taper slightly behind the eyes; before narrowing abruptly posteriorly towards the tail. The eyes are located on top of the head; the nares are closer to the eyes than to the tip of the snout (Figure 2a & 2b). The oral disc is ventral and slightly narrower than the maximum width of the body. Both labia are broadly expanded and the anterior labium is separated by grove from the snout while the posterior labium has two rows of marginal papillae and the edges of the porsterior labium are fringed. The upper jaw has two rows of black uninterrupted minute dermal denticles while the lower jaw has three continuous rows. As such the labial tooth row formula is 2/3. The anterior rows are longer than the posterior rows and separated from the jaw sheaths. The beak is white and there are black diagonal marks on each side of the upper jaw; the lower jaw is edged with black (Figure 2c & 2d). The tail is slender and thickest at the midsection. Both the dorsal and ventral fins are roughly equal in height but the dorsal fin terminates at the proximal two thirds of the tail. The tail musculature gradually tapers posteriorly to the pointed tail tip. The ground coloration on the dorsal surface is grey; darker blotching is present behind the eyes and before the tail. The belly is light cream colored.
description: Published as part of Quah, Evan, Grismer, L. Lee, Muin, Mohd Abdul & Anuar, Shahrul, 2011, Re-discovery and Re-description of Ansonia penangensis Stoliczka, 1870 (Anura: Bufonidae) from Penang Island, Malaysia, pp. 57-64 in Zootaxa 2807 on pages 59-61, DOI: 10.11646/zootaxa.2807.1.4, http://zenodo.org/record/14017098