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PubMed2005

Phylogenetic relationships of the tribe Paini (Amphibia, Anura, Ranidae) based on partial sequences of mitochondrial 12s and 16s rRNA genes.

Partial sequences of mitochondrial 12S and 16S rRNA genes from 19 Asian frog species of the tribe Paini (Ranidae, Dicroglossinae) allowed a first molecular study of the phylogenetic relationships of this tribe. This analysis confirmed that this tribe is a monophyletic group, but suggested relationships did not agree with previous generic classification of this clade based on morphology. Two major clades were recognized within the Paini. For one of them, the generic name Quasipaa is available. Phylogenetic relationships within the other group are not yet fully clarified and need further study.

Animals↗
PubMed2005

Externally measured condition versus internal organ mass in the caecilian Gegeneophis ramaswamii (Amphibia: Gymnophiona: Caeciliidae).

The relationship between externally measured condition (mass x length(-3)) and the mass of internal major organs in the caecilian Gegeneophis ramaswamii is investigated, based on a collection of 67 specimens from three southern Indian localities in the early and mid-monsoon. Condition in juveniles (< 90 mm total length) is higher than in subadults (90-170 mm) and adults (> 170 mm). The relationship between condition and total length is consistent in subadults, but variable in adults, and these differences indicate that the delimitation of these ontogenetic stages has some biological meaning. Adult females have fat bodies which fluctuate in mass, but not in relation to their body size. On average, adult females have heavier fat bodies and lighter gut contents than adult males, but there are no significant differences between subadult males and females. Gravid females are predicted to have a notably greater condition. There is no consistent relationship between condition and any major internal organ, but there is some significant variation among samples grouped by sampling time and locality. More sampling throughout the year is required to clarify the complex relationships between condition and internal organs, and before externally measured condition from ecological studies of living animals can be readily interpreted. However, its utility in helping to differentiate between ontogenic classes may be of immediate use.

Amphibians↗
PubMed2005

Taxonomic relationships within the pan-oriental narrow-mouth toad Microhyla ornata as revealed by mtDNA analysis (Amphibia, Anura, Microhylidae).

A molecular phylogenetic survey was conducted using mtDNA sequences of 12S and 16S rRNA, and cyt-b genes to examine taxonomic relationships among populations of the Pan-Oriental microhylid, Microhyla ornata, from India, Bangladesh, Thailand, Laos, China, Taiwan, and the Ryukyu Archipelago of Japan. Two discrete clades are recognized within this species, one consisting of populations from India and Bangladesh, and the other encompassing the remaining populations. In the latter clade, populations from the Ryukyu Archipelago are clearly split from the rest (populations from Taiwan and the continent) with considerable degrees of genetic differentiations. Each of the three lineages is judged to represent a good species, and the name Microhyla ornata is restricted to the South Asian populations. For the populations from Taiwan and a wide region from China to Southeast Asia, the name Microhyla fissipes should be applied, whereas the Ryukyu populations are most appropriately referred to as Microhyla okinavensis, although further substantial genetic differentiations are recognized among some island group populations within this last species.

Animals↗
PubMed2005

Karyotype of a Japanese salamander Hynobius katoi and its implication on breeding ecology (Amphibia: Caudata).

Karyotype of a Japanese small salamander, Hynobius katoi, was first described. All individuals examined had 2n=58 chromosomes, consisting of nine pairs of biarmed macrochromosomes, four pairs of biarmed medium-sized chromosomes, six pairs of biarmed microchromosomes, and 10 pairs of uniarmed microchromosomes, although distinction of the second and the third groups of chromosome pairs was not clear. All pairs appeared homologous and no sexual dimorphism was found. Possession of 2n=58 chromosomes in H. katoi strongly suggests its lotic-breeding habits as was expected from the number and size of eggs and adult morphology. When compared morphology of chromosomes among lotic-breeders with 2n=58 chromosomes, metacentric nature of No. 10 seems to characterize the karyotype of H. katoi.

Animals↗
PubMed2005

A new Ansonia from the Isthmus of Kra, Thailand (Amphibia, Anura, Bufonidae).

A new species of torrent-dwelling bufonid frog of the genus Ansonia is described from the Isthmus of Kra, Thailand. Ansonia kraensis is morphologically similar to Malaysian A. malayana, but differs from it in ventral coloration and larval morphology. Occurrence of A. kraensis in this region suggests a heterogeneous nature of the anuran fauna between northern and southern regions of the Malay Peninsula.

Animals↗
PubMed2006

Distinct specific status of the Korean brown frog, Rana amurensis coreana (Amphibia: Ranidae).

We used morphological and genetic data to assess the taxonomic status of Rana amurensis coreana and R. a. amurensis. Morphological comparisons revealed these two subspecies to be different from each other in size of body, nature of tubercles on dorsal stripe, degree of development in toe webbing, and condition of lateral spots of trunk. They were also different in sequence of mitochondrial 16S rRNA gene, with genetic distance as large as those observed among different species of brown frogs. Therefore, Korean populations previously considered a subspecies of R. amurensis should be regarded as a distinct species (=R. coreana).

Animals↗
PubMed2006

A new species of Amolops from Thailand (Amphibia, Anura, Ranidae).

We describe a new species of torrent-dwelling ranid frog of the genus Amolops from western to peninsular Thailand. Amolops panhai, new species, differs from its congeners by the combination of: small body, males 31-34 mm, females 48-58 mm in snout-vent length; head narrower than long; tympanum distinct; vomerine teeth in short, oblique patches; first finger subequal to second; disc of first finger smaller than that of second, with circummarginal groove; no wide fringe of skin on third finger; toes fully webbed; outer metatarsal tubercle present; supratympanic fold present; dorsolateral fold indistinct; axillary gland present; horny spines on back, side of head and body, and chest absent; large tubercles on side of anus absent; glandular fold on ventral surface of tarsus absent; nuptial pad and paired gular pouches present in male; white band along the upper jaw extending to shoulder absent; larval dental formula 7(4-7)/3(1). This new species is the second anuran discovered which has a disjunct distribution around the Isthmus of Kra.

Animals↗
PubMed2006

Three new species of Leptolalax from Thailand (Amphibia, Anura, Megophryidae).

Three new megophryid species, Leptolalax melanoleucus, L. fuliginosus, and L. solus, are described from southwestern and southern Thailand on the bases of acoustic and morphological characteristics. Leptolalax melanoleucus and L. fuliginosus are similar to L. pelodytoides from northern Thailand, but differ from it completely in advertisement call characteristics and ventral color. Leptolalax solus is similar to L. heteropus from peninsular Malaysia, but differs from it by advertisement call, as well as by some body proportions. The distributional pattern of Leptolalax within Thailand is discussed.

Animals↗
PubMed1995

Variations in the numbers of phalangeal bones in the four-toed salamander, Hynobius tenuis (Amphibia: Hynobiidae), from two localities in Toyama Prefecture, Central Japan.

Variations in the numbers of phalangeal bones in the fingers (I to IV) and toes (I to V) of specimens of Hynobius tenuis collected from two localities (Ashikuraji and Arimine) in Toyama Prefecture, Central Japan, were recorded. In the case of fingers of fore limbs, eight phalangeal formulas were distinguished, and in the case of toes of hind limbs, ten phalangeal formulas were recognized. In the fingers of specimens from Ashikuraji, the predominant formulas were 2-2-3-2 (40%) and 2-2-3-1 (32%). In specimens from Arimine, 2-2-3-2 was predominant (75%). In toes, the predominant formula was 2-2-3-2-0- (96%) for Ashikuraji and 71% for Arimine. The maximal number of phalangeal bones, 2-2-3-3-2, found in the toes of specimens from Arimine seems to represent the fundamental formula in hynobiid salamanders. The predominant formula, 2-2-3-2-0-, observed in the two populations may have been derived from the fundamental formula by degeneration of the phalangeal bones in the fourth and the fifth toes. The reason why phalangeal bones were degenerated in this species is discussed from an ecological viewpoint of body growth.

Animals↗
PubMed1984

Common mechanisms in vertebrate axonal navigation: retinal transplants between distantly related amphibia.

Embryonic eye primordia were transplanted from the anuran, Xenopus laevis, to the urodele, Ambystoma mexicanum, in order to assess whether retinal axons of one species could grow to appropriate central targets in a distantly related species. To trace the early retinal projections, Xenopus primordia were removed, incubated for 20 min in a solution containing [3H]proline, washed, and then transplanted to host axolotl embryos. Genetically eyeless hosts were used in some of the experiments so that the Xenopus optic fibers would not be guided to their targets by the host's own optic nerve projections. Xenopus eyes were usually able to differentiate into small eyes in the axolotl host. Shortly after primary differentiation, the development of these eyes seemed to arrest. Autoradiography on paraffin sections of the central nervous system of the host revealed that in some cases Xenopus retinal ganglion cells were indeed able to send axons to the tectum of the axolotl host. This result suggests that the mechanisms of axonal navigation for this particular central projection are evolutionarily conserved.

Ambystoma↗
PubMed1988

Hydroperoxide metabolism of amphibia: tissue catalases of leopard frogs.

Catalase activities were measured and compared in liver, kidney, heart, and lung of American Leopard Frogs (Rana pipiens complex). The order of activities was found to be liver greater than kidney greater than heart approximately lung. The liver enzyme was found to be inhibited by aminotriazole, cyanide, and azide and appears to peroxidatively oxidize ethanol.

Animals↗