A new species of Odorrana (Anura, Ranidae) from Hunan Province, China

A new odorous frog species of Odorrana (Amphibia, Anura, Ranidae) from Guizhou Province, China

The frog genus Odorrana is distributed across east and southeastern Asia. Based on morphological differences and molecular phylogenetics, a new species of the genus occurring from Leigong Mountain in Guizhou Province, China is described. Phylogenetic analyses based on DNA sequences of the mitochondrial 12S rRNA, 16S rRNA, and ND2 genes supported the new species as an independent lineage. The uncorrected genetic distances between the 12S rRNA, 16S rRNA, and ND2 genes between the new species and its closest congener were 5.0%, 4.9%, and 16.3%, respectively. The new species is distinguished from its congeners by a combination of the following characters: body size moderate (SVL 39.1-49.4 mm in males, 49.7 mm in female); head width larger than head length; tympanum distinctly visible; small rounded granules scattered all over dorsal body and limbs; dorsolateral folds absent; heels overlapping when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level between eye to nostril when leg stretched forward; vocal sacs absent in male and nuptial pads present on the base of finger I.

Discovery of a new limestone karst-restricted odorous frog from northern Guangdong, China (Anura, Ranidae, Odorrana)

Karstic landscapes play an important role in biodiversity formation and often contain high levels of endemism. However, site-endemic taxa in karstic landscapes are being threatened by exploitation and weak legal protection. In this study, we describe Odorranaconcelata Wang, Zeng, & Lin, sp. nov., a limestone karst-restricted odorous frog from northern Guangdong, China. This new species shows distinctive genetic divergence and morphological differences from its congeners. Phylogenetic results suggest that the new species represents an independent lineage that is grouped with O.lipuensis and O.liboensis based on the mitochondrial 16S and 12S ribosomal RNA genes. We recommend the new species be listed as Vulnerable (VU) in the IUCN categorization as it is only known from the type locality with limited microhabitats and is threatened by habitat degradation.

Highly rapid and diverse sex chromosome evolution in the Odorrana frog species complex

Sex chromosomes in poikilothermal vertebrates are characterized by rapid and diverse evolution at the species or population level. Our previous study revealed that the Taiwanese frog Odorrana swinhoana (2n = 26) has a unique system of multiple sex chromosomes created by three sequential translocations among chromosomes 1, 3, and 7. To reveal the evolutionary history of sex chromosomes in the Odorrana species complex, we first identified the original, homomorphic sex chromosomes, prior to the occurrence of translocations, in the ancestral-type population of O. swinhoana. Then, we extended the investigation to a closely related Japanese species, Odorrana utsunomiyaorum, which is distributed on two small islands. We used a high-throughput nuclear genomic approach to analyze single-nucleotide polymorphisms and identify the sex-linked markers. Those isolated from the O. swinhoana ancestral-type population were found to be aligned to chromosome 1 and showed male heterogamety. In contrast, almost all the sex-linked markers isolated from O. utsunomiyaorum were heterozygous in females and homozygous in males and were aligned to chromosome 9. Morphologically, we confirmed chromosome 9 to be heteromorphic in females, showing a ZZ-ZW sex determination system, in which the W chromosomes were heterochromatinized in a stripe pattern along the chromosome axis. These results indicated that after divergence of the two species, the ancestral homomorphic sex chromosome 1 underwent highly rapid and diverse evolution, i.e., sequential translocations with two autosomes in O. swinhoana, and turnover to chromosome 9 in O. utsunomiyaorum, with a transition from XY to ZW heterogamety and change to heteromorphy.

Phylogenetic position of Odorrana macrotympana (Yang, 2008) (Anura, Ranidae) and extension of its geographical distribution

Based on a 16S rRNA gene fragment, a molecular phylogeny for the genus Odorrana Fei, Ye & Huang, 1990 was reconstructed, the validity of the poorly-known ranid species O. macrotympana (Yang, 2008) was confirmed and its phylogenetic position was evaluated. In addition, we report the first country record of O. macrotympana from Myanmar, based on our new records from Htamanthi Wildlife Sanctuary, Sagaing Division and present a supplementary description of this species. This report also constitutes the first record of O. macrotympana from outside of China.

The complete mitochondrial genome of Odorrana grahami (Anura: Ranidae)

The mitochondrial genome of the Disckless-fingered Odorous Frog, Odorrana grahami (Anura: Ranidae), was sequenced using high-throughput sequencing technology. The genome length was 17864 bp, including 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and 1 control region (D-loop). The AT content of the mitochondrial genome was 55.9%. The composition of mitochondrial genome of O. grahami is similar to that of other species of the genus Odorrana. Phylogenetic analysis of the mitochondrial genomes of six congeners shows that O. grahami is sister to O. margaretae, but the analysis using 16S rRNA gene of additional congeners do not resolve their relationships.