(Gray, 1838)
Javan Pipistrelle
External characters (Table 92)
This is a medium-sized pipistrelle with an average forearm length of 33.2 mm (30.0-36.0 mm). Pelage colour varies between individuals; some are a uniform chestnut brown on the dorsal surface, others a darker clove brown with a light frosting of paler brown on the hair tips. The hair tips are buffy brown on the ventral surface with the hair roots black or almost black. The ears and wing and interfemoral membranes are a uniform dark brown and essentially naked. The baculum has a long narrow shaft and strongly bifid tip; the basal lobes are well developed and deflected ventrally (Fig. 205).
Cranial characters
With an average condylo-canine length of 12.4 mm (11.9-13.1 mm), this is a more robust skull than that of P. coromandra . The rostrum is broad and dorsally flattened, with a shallow linear depression in the mid-line and two lateral depressions over the orbits. There is a large V-shaped nasal notch. The supraorbital region is distinctly broadened to produce abruptly incurving lateral margins to the anterior part of the postorbital area. The dorsal profile is almost straight from the nares to the lambda, with a slight depression over the orbits; it is a little flattened at the fronto-parietal suture. The lambda forms the most elevated part of the skull and the convex supraoccipital the most posterior part. The palate is broad, concave and essentially parallel-sided. The basisphenoid pits are moderately developed but not as deep or large as those of P. cadornae . The coronoid process of each half mandible is robust but does not exceed the tip of the lower canine in height.
Dentition
- Upper toothrow length (C-M3) averages 4.9 mm (4.6-5.2 mm). The first upper incisor (I2) is usually bicuspidate, although occasionally the secondary cusp may be indistinct; it usually attains three-quarters the height of the anterior cusp. The second incisor (I3) is large, about as tall as the secondary cusp of I2; it has a larger central and a smaller lateral accessory cusp and is separated from the upper canine by a narrow diastema. The upper canine has a distinct posterior secondary cusp. The first small upper premolar (PM2) is intruded from the toothrow; it is not greatly reduced with its crown area exceeding that of I2. The canine and the second premolar (PM4) are closely adjacent but not in contact.
- The first lower premolar (pm2) is slightly extruded from the toothrow, it is about half to three-quarters the crown area and two-thirds the height of the second lower premolar (pm4). m1 and m2 are about equal in size, with the talonid larger than the trigonid. m3 is two-thirds the size of m2 with the talonid about equal to the trigonid.
Karyology
2n=36; with three pairs of metacentrics, four pairs of submetacentrics, one pair of subtelocentrics and nine pairs of acrocentrics. The X chromosome is a medium sized metacentric, the Y chromosome a small acrocentric (Dulic, 1980).
Variation
Following Corbet and Hill, 1992, the taxa babu , peguensis and camortae have been included in the synonymy of javanicus . Specimens from the mainland of the Indian Subcontinent are referred to P. javanicus babu and those from the Nicobar Islands to P. j. camortae .