• The Korean Journal of Zoology
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• v.31 no.2
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• pp.104-110
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• 1988

The comparative karyological analysis of the Korean treefrog, Hyla japonica and Hyla suweonensis performed by conventional giemsa-staining and NOR-staining method. The karyotypes of both species were the same (2n=24). However, according to the Karyological analysis, the 6th chromosomes of the two species distinctly different. Eventhough the 6th chromosomes of the two species shown the same % length, construction of the 6th chromosome of H.japonica was subtelocentric chromosome while H. suweonensis was submetacentric chromosome. This phenomena could explain that the morphological differences in the 6th chromosomes might be caused by pericentric inversion. The two species have 1 pair of NOR site in the 6th chromosome.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.1-5
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• 1990

The comparative karyological analysis of the Korean treefrogs, Hyla japonica and Hyla suweonensis, were performed by C-banding method. Heteromorphic sex chromosomes, female heterogamety, has been identified in the 3rd chromosomes of H. suweonensis H. suweonensis seem to have sex chromosomes which are Zz/ZW type. The Z chromosomes contain large amount of constitutive heterochromatin, but little heterochromatin is located in the W chromosomes. This is in contrast to all previously known amphibian and most other vertebrate's W or Y chromosomes, except Gastrotheca oui'ern and G. walken (Schmid et al., 1988).

• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.71-74
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• 2017

Urbanization is a major driver of global amphibian declines. For the study on the effect of urbanization on amphibians, we compared the growth and the health status of Hyla japonica amphibians collected in the urban areas of Incheon and in the rural area of Gapyeong, Korea. The size and weight of Hyla japonica body in the urban area were smaller than those in the rural area. However, there was no significant difference in their condition factors as a health indicator between the two areas. Our study emphasizes the need for research into the specific mechanism of effects of urbanization on amphibian heath status for the further understanding of the relationship between urbanization and amphibians.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2007.10a
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• pp.82-86
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• 2007

• Animal cells and systems
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• v.2 no.4
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• pp.463-469
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• 1998

Hyla japonica males were observed to produce two distinctively different types of mating calls: advertisement call to attract conspecific females and encounter call to keep off potential competitor males. Whereas advertisement calls were organized in bouts of calls or notes, encounter calls were usually produced as separate calls. Encounter calls were much longer and had more pulses per call than advertisement calls. However dominant frequencies or pitches of the two calls did not differ significantly. Hyla Japonica males exhibited considerable plasticity in their calling behavior. They altered both qualitative and quantitative properties of their calls in response to other calling males. Sometimes, they even switched from producing advertisement calls to encounter calls. Advertisement calls produced by chorusing males were shorter in duration and thus move calls per bout than those produced by lone males. Males also produced much lower-pitched calls when calling together with other males. Considering that low pitch calls are often Highly correlated with body size, it is possible that H. japonica males may try to generate deceptive calls to indicate the size greater than the actual.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.675-681
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• 2012

In this experiment, I investigated toxicity evaluation of chemicals using domestic frog embryos, along FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol. I investigated $Cu^{2+}$ and Tebuconazole effect on the tree frog, Hyla japonica, embryos by probit analysis. Mortality and malformation rates increased and larval body length decreased depending on the concentrations of $Cu^{2+}$ and Tebuconazole. The teratogenic concentration ($EC_{50}$) of $Cu^{2+}$ and Tebuconazole were 0.05, 5.0mg/${\ell}$, respectively and the embryo lethal concentration ($LC_{50}$) of $Cu^{2+}$ and Tebuconazole were 0.16, 38.5, respectively. The teratogenic index (TI) appeared 3.0 in $Cu^{2+}$ and 7.7 in Tebuconazole, which showed teratogenicity in embryonic development of Hyla japonica. These results reveal that $Cu^{2+}$ and Tebuconazole in this experiment suppressed the development of embryos at relatively low concentration. Much of Hyla japonica embryos can be secured, and easy to incubate. In addition, mortality, malformation ratios, malformation patterns and growth rates are similar to the results from the other assay systems. Therefore, the Hyla japonica embryo teratogenesis assay system could be a useful tool to evaluate toxicity of pollutants in environment.

• Ecology and Resilient Infrastructure
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• v.4 no.4
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• pp.200-206
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• 2017

The damage and fragmentation of habitat due to urbanization pose a great threat to amphibians worldwide. To understand the effect of urbanization on the distribution and abundance of Hyla japonica, we measured their population sizes by listening frog calling and investigated the habitat their population sizes and land use in the 18 rice paddy fields located in Incheon and its surroundings. Abundance of H. japonica was 0 - 17 male adults / habitat or 0 - 41 male adults / ha in Incheon. The number of the frog was increased as the distance between the habitat and the road became longer or the ratio of circumstance / area of the habitat increased. Unlike the general prediction, the density of H. japonica showed a negative correlation with the size of the habitat and a positive correlation with the surrounding land use intensity. Our results suggested that H. japonica could be concentrated in a narrow habitat due to the habitat size decrease and the periphery development according to the urbanizaion.

• The Korean Journal of Zoology
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• v.31 no.1
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• pp.11-20
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• 1988

A comparison between two species of Hyla japonica and H. suweonesis in Korea was carried out to clarify their morphological, genetic and ecological differences, to estimate presumed divergent time between them, and to elucidate their probable process and mechanism of speciation. The results are as follows; 1.The breeding season of H. japonica was earlier than that of H. suweonensis about one and half months. 2.H.japonica was distributed all over the country, while H. suweonensis was restricted in Kyonggi plains. 3.On the extemal morphometric characters, differences were hardiy seen between two species. But on the discriminant function analysis, there was apparent differences between them. 4.Genic variation based on 24 loci showed that H. japonica populations were about two fold more variable than that of H. suweonensis populations. 5.Genetic relatedness between two species was rather remote (S =0.520, D=0.634) 6.Their presumed divergent time was estimated to be about three and a quarter mfllon years. It is presumed that H. suweonensis was originated from H. japonica during the period of late pleocene and early pleistocene. 7.Premating isolating mechanisrns (breeding season, mating call, and microhabitat segregation) may be operating to prevent gene ifow between them.

• Animal cells and systems
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• v.3 no.3
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• pp.295-301
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• 1999

The nucleotide sequence of a 447 base pair fragment in the mitochondrial cytochrome b gene and the complete sequence of the mitochondrial 12S ribosomal RNA gene, 938 bp, were analyzed to infer inter- and intraspecific genetic relationships of Hyla japonica and H. suweonensis from Korea and H, japonica from Japan. In the mitochondrial cytochrome b gene, genetic differentiation among H. japonica populations were 9.62% and 15.66% between H. japonica and H. suweonensis. Based on the Tamura-Nei distance, the level of sequence divergence ranged from 0.45% to 2.75% within Korean H. japonica, while 8.31%-8.87% between Korean and Japanese H. japonica and 11.51%-12.46% between H. japonica and H. suweonensis. In the neigh-bor-joining tree, Korean populations of H. japonica were clustered first at 2.22% and followed by Japanese H. japonica and H. suweonensis at 8.51% and 12.29%, respectively. In mitochondrial 12S rRNA gene, genetic differentiation between H. japonica and H. suweonensis nras 7.17% (68 bp) including 7 gaps. Based on Tamura-Nei distance, the level of sequence divergence ranged 3.53% between Korean and Japanese H. japonica and from 4.93% to 5.41% between H. japonica and H. suweonensis. Phenogram pattern of the 12S rRNA gene sequence corresponded with that of the mitochondrial cytochrome b gene.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.219-225
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• 1992

The genetic variation in mitochondrial DNA (mtDNA) was analysed within and between two species of tree frogs. Hyla japonica and H. suweonensis from South Korea. Purified mtDNAs were digested with each of 11 restriction enLvmes which cleave at six base recognition sequences. The genome size of H. iaponica revealed ho types (20.0 $\pm$ 0.3 and 19.6 $\pm$ 0.3 kb) and this difference is explained by either addition or deletion of about 0.4 kb fragment. On the other hand, the genome sire of H. suueonensis was about 19.0 $\pm$ 0.4 kb only. For the analysis, level of fragment homology (F) and nucleotide sequence divergence (p) were estimated from comparisons of digestion profiles. Among four populations of H. iaponica, substantial mean sequence divergence was 0.017 (range 0.001-0.026); between identical types, 0.001 IslilaRl type) and 0.004 (Large type) respectively; between different ones, 0.024 (range 0.023-0.026). The level of sequence divergence between he species was 0.142 (range 0.131-0.146). This result suggested that he species ㅂwere distinctly differentiated species. The divergence time between ko species was estimated 7.1 million years.