A new species in the rhacophorid genus Philautus is described on the basis of five male specimens collected from the Matang Range, a herpetologically well-surveyed area of the lowland of Sarawak, western Borneo. The species possesses a cutaneous pectoris muscle but lacks vomerine teeth, and is assigned to the aurifasciatus group of Philautus. It is superficially similar to some other species of the same group, but can be differentiated from them by a combination of several morphological characters, including lack of a nuptial pad and lingual papilla, and more significantly, by a distinct advertisement call. This discovery underscores the immediate necessity for detailed surveys in the already well-explored lowlands of Borneo.
We describe a new species of torrent-dwelling ranid frog of the genus Meristogenys from the Crocker Range, western Sabah, northern Borneo. The new species, Meristogenys maryatiae, differs from congeners by the combination of: small body, males 31-37 mm and females 65-66 mm in snout-vent length; head narrower than long; eyes moderate, diameter subequal to snout; iris unicolored; legs long; ventral surface of tibia without heavy pigmentation; rear of thigh blotched dark brown and cream; toes fully webbed; outer metatarsal tubercle present; larval dental formula 7(4-7)/6(1).
A new megophryid species is described from southwestern Sarawak, Malaysian Borneo. In appearance, Leptolalax marmoratus sp. nov. is most similar to L. hamidi also from southwestern Sarawak, but differs from it by mtDNA sequence, larger body size, and higher dominant frequency of advertisement call. The assumption that more than one species of Leptolalax coexist at one locality in Borneo is supported. The finding of the new species raises the species number of Leptolalax known from Borneo to nine, and the island is thought to be one of the diversification centers of the genus.
A new megophryid species, Leptolalax kecil, is described from the Cameron Highlands of Peninsular Malaysia on the basis of acoustic and morphological characteristics. It has an advertisement call dissimilar to that of other, congeneric species, and is the smallest of the known Leptolalax. It is similar to L. pluvialis from Vietnam in small body size, but differs from it in ventral color, and in the size and color of the pectoral gland. The distributional pattern of the new species Is discussed.
A new microhylid, Kalophrynus yongi, Is described from the Cameron Highlands of Peninsular Malaysia. Morphologically, the new species differs from all known congeners by having a very stout forelimb with a humeral spine in males. Acoustically, it resembles K. baluensis and K. heterochirus and sharply differs from K. interlineatus, K. pleurostigma, K. palmatissimus, and K. nubicola.
We describe a new species of cascade frog of the genus Rana, from west Malaysia. Rana monjerai, new species is a medium-sized frog of the subgenus Odorrana (SVL of males, 38-43 mm; of one female, 75 mm), and is distinguished from all other members of this subgenus by the combination of: white lip stripe, dorsolateral fold, full web on the fourth toe, vomerine teeth, gular vocal pouch and relatively large tympanum in males, no dorsal marking, no clear light spots on rear of thigh, first finger subequal to second, finely tuberculated dorsum, and unpigmented ova. The significance of finding this species from peninsular Malaysia is discussed.
A new small, semi-arboreal toad of the genus Pelophryne is described from western Sarawak, Malaysian Borneo, on the basis of molecular and morphological evidence. Of the two morphotypes recognized in the genus, the new species belongs to the one in which the tips of the fingers are expanded into truncate discs. Among the species in the morphotype, the new species is most similar to P. murudensis, but differs from it by body size, relative hindlimb length, and dorsal coloration. The new species is currently known only from a limited area on Gunung (= Mt.) Penrissen, and future measures of its habitat conservation are necessary.
A cryptic Bornean torrent frog of the genus Meristogenys, which is divergent genetically and morphologically from all known congeners, is described from mountain streams of western Sarawak, East Malaysia (Borneo). The species occurs sympatrically with the type species of the genus, M. jerboa, but apparently differs from it in adult coloration and larval morphology, such as keratodont formulae and glands in tail fins. Females of the new species possess much larger and fewer eggs than in sympatric M. jerboa, suggesting significantly different reproductive traits between these species. A key to larvae of known species of the genus is provided.
A new fish leech, Branchellion brevicaudatae sp. n., is described based on specimens parasitizing the gills of the short-tail stingray, Bathytoshia brevicaudata (Hutton, 1875), collected from Japanese waters. The new species can be distinguished from other congeners by having: i) pulsating vesicles emerging from posterior base of branchiae, one pair per somite; ii) dorsal white spots, not arranged in longitudinal row; and iii) blackish body. A phylogenetic tree based on partial sequences of the mitochondrial cytochrome c oxidase subunit I gene from the new species and other piscicolid worms showed that the new species is sister to Branchellion torpedinis Savigny, 1822. This is the first record of Branchellion Savigny, 1822 from Japanese waters.
We surveyed natural population of the Drosophila ananassae species complex on Penang Island, Malaysia. Analyses of phenotypic traits, chromosome arrangements, molecular markers, and reproductive isolation suggest the existence of two species: D. ananassae and D. cf. parapallidosa. Molecular marker analysis indicates that D. cf. parapallidosa carries chromosome Y and 4 introgressions from D. ananassae. Thus, D. cf. parapallidosa seems to be a hybrid descendant that recently originated from a natural D. parapallidosa♀× D. ananassae♂ cross. Furthermore, D. cf. parapallidosa behaves differently from authentic D. parapallidosa with respect to its reproductive isolation from D. ananassae. Premating isolation is usually seen in only the D. ananassae♀× D. parapallidosa♂ cross, but we observed it in crosses of both directions between D. ananassae and D. cf. parapallidosa. In addition, hybrid males from the D. ananassae♀× D. parapallidosa♂ cross are usually sterile, but they were fertile when D. ananassae♀ were mated with D. cf. parapallidosa ♂. We attempted an artificial reconstruction of the hybrid species to simulate the evolutionary process(es) that produced D. cf. parapallidosa. This is a rare case of natural hybrid population in Drosophila and may be a useful system for elucidating speciation with gene flow.