太田 英利

We describe a new species of Luperosaurus from first growth, low-elevation, closed canopy rain forest on Mt. Tompotika at the tip of the eastern peninsula of the island of Sulawesi (Celebes), Indonesia. The new species is the first record of the genus Luperosaurus from this island and differs from all known species of Luperosaurus by numerous morphological characters and a unique color pattern. The new species also shares some presumably derived character states with members of the genus Ptychozoon. A phylogenetic analysis of 24 morphological characters is consistent with the previously hypothesized presence of two species groups (putative lineages) within the genus Luperosaurus. The analysis suggests that the new species from Sulawesi may either belong to a clade also including L. brooksi and L, browni or may fall basal to the remaining Luperosaurus. The monophyly of the species currently referred to Luperosaurus is questionable. We consider Luperosaurus serraticaudus a junior synonym of L. browni.

This article compares amphibian and reptile components of the original and revised versions of the Red List of Japan, and analyzes geographic patterns of, and major threats to, species and subspecies now assigned to the threatened categories. The numbers of both amphibians and reptiles categorized as threatened in the Red List of Japan have increased greatly through its revision as a result of recent progress in the taxonomy of these groups in Japan, the introduction of new criteria for risk assessment, and unexpectedly rapid declines in the status of several taxa. Threatened taxa of amphibians and reptiles in the revised list tend to be concentrated in the Ryukyu Archipelago, where deforestation seems to be the major ultimate cause of declines. Reduction in the quality and quantity of inland water environments seems to be the major cause of declines in several endemic amphibians from the main islands of Japan. The importance of conservation was emphasized in the revised list by progress in taxonomy, by new insights and data on the estimation of temporal dynamics of population density or habitat size for threatened taxa, and by the impacts of and need to prevent further deforestation in the Ryukyus and of the ongoing destruction of inland water habitats on the main islands of Japan.

Based on sequence variation in 806 bp of the mitochondrial 12S rRNA gene, phylogenetic relationships were inferred for 14 species of Trimeresurus (sensu lato) including all East Asian members. Samples analyzed also included representatives of all assemblages of species that are frequently treated as separate genera except for T.mangshanensis, a type species of the recently described monotypic genus Ermia. Results support some previous accounts chiefly from morphological studies, such as distinct divergence of T.wagleri from the remainder, and monophyly of T.mucrosquamatus, T.flavovirids,T.jerdonii, T.egans and T.tokarensis. On the other hand, our results negated a putative close affinity of T.monticola and T.okinavensis, and indicated the sister relationship of the latter with T.gracills Phylogenetic relationships revealed in this study suggested that the genus Trimeresurus dispersed into the Ryukyu region at least three times, and that T.flavoviridis and T.tokarensis from the central Ryukyus constitute a relict clade.

An adult male Mabuya, recently collected from Lanyu Island, Taiwan, was identified as Mabuya cumingi, a species hitherto known only from Luzon Island of the Philippines, on the basis of small body size (56.6mm in snout-vent length), embossed dorsal head scales, five scales beneath toe I, and the presence of a dark middorsal stripe. Occurrence of this species on Lanyu Island was also confirmed by additional sighting records. Mabuya cumingi is regarded as a fourth reptile species representing a dispersal to this island from the Philippines.

Morphological comparisons of available types of the two snoutornamented agamids from northern Borneo, Aphaniotis ornata and A. nasuta, failed to show any substantial differences. Careful examination of original descriptions of these nominate taxa also yielded no discriminant characters. Thus, although the holotype of A. nasuta was not detected in our survey of various museum collections, we are sure that it is appropriate to synonymize this nominate species with A. ornata.

We karyotyped five species of the agamid genus Gonocephalus, G. chamaeleontinus, G. liogaster, G. bellii, G. grandis (from Peninsular Malaysia), and G. robinsonii. Of these, karyotypes of the first four species had several chromosomal characteristics exclusively shared with the previously reported karyotypes of G. miotympanum and G. grandis (from Borneo), such as the diploid chromosome number (42) and the presence of 22 biarmed macrochromosomes. This seems to support the monophyly of those four species and G. miotympanum, probably along with some other species of the genus not yet karyotyped. This hypothesis is premised on our finding of distinct chromosomal characteristics that are indicative of highly derived states in the agamid karyotypes. The karyotype of G. robinsonii, while remarkably different from other congeneric karyotypes in exhibiting much smaller diploid (32) and biarmed macrochromosome numbers (12), share these and other chromosomal characteristics with several Australian species. It seems unlikely for the karyotype of G. robinsonii to directly emerge from other congeneric karyotypes or vice versa. We conclude that the inclusion of this species in Gonocephalus would render the genus paraphyletic.

Hemibungarus japonicus (sensu late) is a highly polymorphic member of the Oriental coral snakes distributed in the central part of the Ryukyu Archipelago of Japan and on Taiwan. We analyzed morphological variation of this taxonomically confusing species for the first time on the basis of samples from almost the whole range of its distribution. Results revealed a distinct divergence between populations of the central Ryukyus and Taiwan. For the Ryukyu populations, three subspecies were recognized on the basis of prominent geographic variation in coloration-H, j. japonicus (Gunther, 1868) from Amamioshima and adjacent islets, H. j. boettgeri (Fritze, 1894) from Tokunoshima, Okinawajima and a few islets adjacent to the latter, and H. j. takarai subsp nov. from Kumejima and several other islets north and west of Okinawajima. In Taiwan, two distinct species, H. hatori (Takahashi, 1930) and H. sauteri (Steindachner, 1913), are recognized on the basis of their distinct coloration, nearly distinct ventral counts, and parapatric distribution.

Phylogenetic analyses were carried out for representatives of all eublepharid genera and a few other gekkonoid taxa using sequence data for 879 base pairs of mitochondrial 12S and 16S ribosomal RNA genes. Neighbor-joining (NJ) distance analysis of the data suggested independent great divergences of Coleonyx and Aeluroscalabotes, and monophyly of the remainder within Eublepharidae (bootstrap proportion [BP]=76%). Of the latter, the two African genera, Hemitheconyx and Holodactylus, were almost certainly monophyletic altogether (BP=99%), whereas their sister-group relationship with Eublepharis received a weaker, but still substantial support (BP=68%). Within Goniurosaurus kuroiwae, G. k. splendens first diverged from the remainder (BP=100%), followed by G. k. kuroiwae from the northern part of Okinawajima (BP=100%): G. k. kuroiwae from the southern part of Okinawajima and G. k, orientalis, differing from each other at only seven bases, diverged finally (BP=99%). Parsimony analysis yielded results consistent with those of NJ analysis with respect to the monophyly of the two African genera and relationships within G. kuroiwae, but retained the other relationships within Eublepharidae unresolved. Our results, while showing no serious discrepancies with the relationships among eublepharid genera hypothesized from morphological data, cast a serious doubt to the currently accepted population systematics within G. kuroiwae. Furthermore, results of both analyses suggested a closer affinity of Diplodactylinae (as represented by Rhacodactylus trachyrhynchus) with Eublepharidae, rather than with Gekkoninae. Our study lends a robust support to the Laurasian origin of the family Eublepharidae.

Portions of two mitochondrial genes (12S and 16S ribosomal RNAs) were sequenced to analyze the phylogenetic relationships of the Mabuya group from the Australian region (Corucia, Egernia and Tiliqua). Results indicated the monophyly of these genera and their divergence from Asian and African members of this group. This suggests that the diversity of the Mabuya group in the Australian region has increased through an endemic radiation, not through multiple colonizations from outside. Among the genera from this region, Corucia and Tiliqua were closest to each other. This result contradicts with those of the previous hypotheses on the basis of morphological and immunological data that, respectively, suggested closest affinities between Corucia and Egernia, and Egernia and Tiliqua. We suppose that the morphological characters exclusively joining Corucia and Egernia are actually in plesiomorphic state.

Phylogenetic relationships among 12 species of the genus Draco were inferred from 779 base pairs of mitochondrial 12S and 16S rRNA genes and allozymes for 20 presumptive loci. Results indicated the presence of at least four distinct lineages within the genus. The first lineage consists of D. volans and D. cornutus, whereas the second only of D. lineatus, which exhibits a great genetic divergence between two subspecies. The third is monotypic with D. dussumieri, the only species distributed in southern India. The fourth included all the remaining species. The third and fourth lineages are supposed to exclusively share a common ancestor. It is likely that the common ancestor of whole Draco originally diverged into three groups, the ancestors of the first, second, and third and fourth lineages, by vicariance. In the fourth lineage, D. blanfordii, D. haematopogon, D. melanopogon, D. obscurus and D. taeniopterus are likely to be exclusively close to each other. The resultant phylogenetic tree contradicts the dichotomous relationships previously hypothesized on the basis of morphological characters.

The taxonomic status of the flying lizard, Draco cornutus Gunther, 1864, recently frequently regarded as a junior synonym of D. volans Linnaeus, 1758, is reassessed. Our field observations in Borneo confirmed sympatric occurrence of two morphotypes of D. volans sensu lato, one of which showed a diagnostic character of D. cornutus. The two morphotypes also differ from each other in live coloration, allozyme pattern and mitochondrial DNA sequence. From these results, it is concluded that D. cornutus is a valid species.

Variation in 28 quantitative characters and one qualitative character in the endemic Ryukyu skink Ateuchosaurus pellopleurus was analyzed. Multivariate analysis of the quantitative characters revealed extensive variation among the insular populations. Branching topology in the neighbor-joining phenogram deriving from Mahalanobis distances among island samples coincides well with their geographic arrangement, suggesting a great contribution of geohistory to the branching pattern. By contrast, branch length in the phenogram does not seem to reflect the paleogeography well, presumably due to noise from rapid morphological changes in small island populations. None of our analyses demonstrated distinct divergence between populations on islands northeast and southwest of the Tokara Tectonic Strait. Accepting the current paleogeographical hypothesis that this strait has consistently existed since its initial formation in the Pliocene, we interpret this result as indicative of recent oversea dispersal across the strait. Results of the analyses also suggested that in A. pellopleurus primary divergence occurred between populations of the Okinawa Group and the remainder. Nevertheless, because of the absence of even a single discriminant character between these two groups, we reject taxonomic subdivision of the species proposed by a few previous authors.

An electrophoretic survey was conducted for the Southeast and East Asian populations of Rana limnocharis. Results indicated that specimens from a single locality in Java derived from two genodemes showing complete allelic displacement at eight out of 25 presumptive loci examined. Within each of these genodemes, genotype frequencies at all polymorphic loci were well concordant with the Hardy-Weinberg expectation. These results strongly suggest that those specimens actually represent two biological species. Comprehensive distance analyses suggested that one of the two species from Java is genetically most divergent among all samples examined, whereas the other is most similar to the Laos sample and then to a group consisting of samples from Hongkong, western China, and the southern Ryukyus. Large values of genetic distances obtained for each combination of allopatric samples imply the presence of additional cryptic species in this nominal species.

A karyological survey was made on Eumeces quadrilineatus, for the first time, by the bone marrow-air dry method. This species has 2n=26 chromosomes, with six large and five small biarmed and two small uniarmed homologous pairs. Comparison of this karyotype with karyotypes of congeneric species strongly suggests that the Pariocela section of the genus Eumeces is karyologically considerably invariable.

単為生殖のヤモリであるオガサワラヤモリLepidodactylus lugubrisの雄型個体が,琉球列島の石垣島から発見された.この"雄"は,よく発達したヘミペニス,前肛大腿孔,外見的には正常な精巣をもっていた.しかし,生殖腺の組織切片を観察してみると,精巣内における精子形成は不完全で,成熟した精子は精巣上体中にほとんど観察されなかった.したがって,この"雄"は生殖能力がないと考えられる.石垣島や,隣接する島嶼には両性生殖する同属種が存在しないことから,この雄型個体が,南太平洋の島々の個体群で報告されているような,雌のオガサワラヤモリと同属の両性の雄の間での交雑や,後者の同定ミスに由来するとは考えられない.

The herpetological collection of the National Science Museum, Tokyo (NSMT), includes 65 type specimens representing 14 valid and nine currently invalid species and subspecies. A complete catalogue of these amphibian and reptilian types in NSMT is provided for the first time.

External characters, hemipenial morphology, karyotype, and reproductive mode were examined for the three subspecies of the endemic Ryukyu natricine, Amphiesma pryeri. Results revealed that populations of the Yaeyama Group, currently regarded as comprising a subspecies, A. P. ishigakiense, have several unique features such as the brownish ground colour of head, termination of sulcus spermaticus in the crotch between apical lobes of the hemipenis, terminal location of centromeres in the largest microchromosome pair, and the viviparous mode of reproduction. In the other populations, ground colour of head is black or dark greyish tan; sulcus spermaticus terminates near the tip of the left lobe of the hemipenis; the largest microchromosome pair is metacentric; and the reproductive mode is oviparous. Of these, however, the Miyakojima population, which currently consists solely of the subspecies, A. p. concelarum, differs from the nominotypical subspecies from the central Ryukyus in having only 94-102 subcaudal scales and telocentric W chromosome; A. P. pryeri has 112-130 subcaudal scales and submetacentric W chromosomes. These strongly suggest that the two subspecies have also substantially diverged from each other, constituting distinct evolutionary lineages. We thus accord full-species status to each of pryeri, concelarum and ishigakiense, and revise their definitions on the basis of the present results. A dichotomous key to the Japanese species and subspecies of Amphiesma is provided. (C) 1997 The Linnean Society of London.

An electrophoretic survey was conducted to examine genetic divergence among 34 East Asian populations of the Indian rice frog, Rana limnocharis, a species widely distributed over the Oriental region, as well as part of the Palearctic region. Only minor genetic differentiation was recognized among populations of the main islands of Japan, central Ryukyus, western Taiwan and eastern continental China. By contrast, populations of the southern Ryukyus are genetically distinct from those of surrounding areas with unique alleles at several presumptive loci. Less prominent genetic differentiation was revealed between the eastern and western populations of Taiwan. Considering the paleogeography of the East Asian islands, these results suggest overseas dispersal of Rana limnocharis across the East China Sea. Genetic distinctiveness of the southern Ryukyu populations indicates the absence of gene flow between these and other populations. Genetic divergence within Taiwan possibly resulted from the disruption of gene flow between the eastern and western populations by the central mountain range of the island. (C) 1997 Elsevier Science Ltd.