Bioacoustics of Leptobrachella gracilis

Colouration in life (based on topotypes): Basal colouration of the dorsum variable between individuals and also within a single individual at different times of the day; from light grey, cream-coloured, or yellowish to dark grey or almost black ( Figure 3 ). Basal colouration of the venter is white. Several colour pattern elements present on body. Their colouration is darker than the sourrounding areas and varies from grey to brown or black. Dark dorsal pattern variable but often consisting of a broad, interrupted line running from tympanum to groin on both sides of the body. Another line runs above the spine in some individuals; in others, this line is reduced to a series of irregularly shaped spots. Some individuals lack a dorsal pattern. The lateral sides of the body have large dark spots in most individuals. In some, there are also small, cream-coloured dots. Dark spots are also present on the lateral sides of the thigh and tibia, above the tympanum and in the loreal region. A large, Y-shaped blotch is present between the eyelids in most individuals, as are two oval, anterolaterally directed spots on the snout, one of each side posterior to the nostrils. These spots can be fused with each other partially or completely, forming V-shaped or triangular blotches. The lips are irregularly barred light and dark, with pattern in the supralabial area being continued in the infralabial area. Legs and lower arms are banded. In most individuals, the bands are darker than the surrounding areas; in some individuals, however, they can become light grey during the night and then are about as light as or even lighter than the surrounding areas ( Figure 3 ). The upper arm and the proximal one-fourth of the lower arm are cream-coloured in most individuals without any pattern or with only small dots. In few individuals the upper arm is dark-banded like the lower arm. The ventral sides of foot, tarsus, and lower arm are dark grey or black. Venter, chest and chin are spotted with large dark spots ( Figure 4 ). In some individuals, the ventral pattern can become quite weak during the night, and is more apparent during the day. The iris is bright red in the upper two-fifths and dull greyish red, with a narrow ring of bright red along the pupil in the lower three-fifths. species Leptolalax gracilis Leptolalax gracilis Voucher No. BMNH 72.2.19.35 = 1947.2.25, NMBE 1059912 NMBE 1056599, 1056602, 1056604, 1059903–1059911 sex females males status holotype, topotype topotypes origin Matang Range, Borneo Matang Range, Borneo TFL/SVL 0.50–0.53 0.54 ± 0.02 0.51–0.57 Fot/SVL 0.40–0.42 0.44 ± 0.01 0.42–0.47 TarL/TFL 1.37–1.38 1.37 ± 0.04 1.28–1.43 HW/SVL 0.30–0.36 0.33 ± 0.01 0.32–0.35 HL/SVL 0.32 0.33 ± 0.01 0.31–0.34 KNE/TFL 1.85–1.89 1.86 ± 0.03 1.83–1.91 LEG/SVL 1.55–1.66 1.68 ± 0.06 1.58–1.79 ELB/SVL 0.69–0.76 0.74 ± 0.02 0.70–0.79 HND/SVL 0.24–0.28 0.27 ± 0.01 0.25–0.30 SVL/IO 10.30–11.63 10.65 ± 0.42 9.96–11.27 IO/HW 0.27–0.29 0.28 ± 0.01 0.26–0.30 NN/HW 0.23–0.25 0.26 ± 0.01 0.24–0.28 SVL/NN 12.12–13.58 11.74 ± 0.48 11.14–12.72 HW/HL 0.94–1.12 1.01 ± 0.03 0.96–1.06 KNE/SVL 0.94–0.96 1.00 ± 0.03 0.96–1.05 IO/EW 0.78–0.99 0.79 ± 0.05 0.71–0.89 ED/SL 0.95–1.07 0.98 ± 0.03 0.94–1.04 EN/NN 1.05–1.06 1.03 ± 0.07 0.92–1.17 ED/EN 1.59–1.64 1.63 ± 0.09 1.45–1.78 EN/HL 0.25–0.27 0.27 ± 0.02 0.24–0.29 ED/TD 1.78–2.36 2.09 ± 0.16 1.91–2.42 ED/HL 0.40–0.44 0.43 ± 0.02 0.41–0.47 Colouration in preservative: Similar to that in life but colours are generally paler. Dorsal and ventral patterns are clearly visible. Ecological notes: The species is abundant at the lower elevations (< 500 m ) of Gunung Serapi in the Matang Range. Individuals can be found in the leaf litter of the forest floor from only a few to several dozens of meters from the next stream. They are seldom found on leaves in the vegetation. Males call from the forest floor but sometimes can be found perched on elevated calling sites like a fallen tree, a tree root, or a rock, up to 2 m above the ground. Characteristics of the advertisement call of topotypic specimens have been reported by Matsui (1997) .

Diagnosis: The type species of the genus Leptolalax ( Dubois 1980 ) , distinguishable from its congeners by the combination of the following characters: (1) size large, SVL of males 34.3–39.0 mm, of females 42.4–49.0 mm, (2) interorbital distance less than or subequal to width of upper eyelid, (3) pectoral glands small and low, hardly discernible, (4) ventrolateral, supra-axillary, and femoral glands absent, (5) venter speckled with large, irregularly shaped spots, (6) snout acuminate in ventral view, rounded in lateral view, (7) webbing between toes basal, (8) advertisement call consisting of long series of notes with 3–4 pulses, dominant frequency at 2600–2800 Hz, without frequency-modulation.