Il-Hun Kim

Northward dispersal of sea kraits (Laticauda semifasciata) beyond their typical range

Marine reptiles are declining globally, and recent climate change may be a contributing factor. The study of sea snakes collected beyond their typical distribution range provides valuable insight on how climate change affects marine reptile populations. Recently, we collected 12 Laticauda semifasciata (11 females, 1 male) from the waters around southern South Korea—an area located outside its typical distribution range (Japan, China including Taiwan, Philippines and Indonesia). We investigated the genetic origin of Korean specimens by analyzing mitochondrial cytochrome b gene (Cytb) sequences. Six individuals shared haplotypes with a group found in Taiwan-southern Ryukyu Islands, while the remaining six individuals shared haplotypes with a group encompassing the entire Ryukyu Archipelago. These results suggest L. semifasciata moved into Korean waters from the Taiwan-Ryukyu region via the Taiwan Warm Current and/or the Kuroshio Current, with extended survival facilitated by ocean warming. We highlight several contributing factors that increase the chances that L. semifasciata establishes new northern populations beyond the original distribution range.

Complete mitochondrial genome of Schlegel's Japanese gecko Gekko japonicus (Squamata: Gekkonidae)

Abstract We have determined the complete mitochondrial genome of Gekko japonicus, whose status as an endemic or invasive species is currently under debate in Korea. The total genome size is 16 544 bp and consists of 13 protein-coding genes, 2 rRNA (12S and 16S RNA) genes, 22 tRNAs and 2 non-coding regions. The A + T content of the genome is 55.8% (A, 31.2%; C, 29.4%; T, 24.6%; G, 14.9%). Phylogenetic analysis shows that G. japonicus has a close phylogenetic relationship with both G. swinhonis and G. chinensis. Our result will facilitate further genetic studies of this species to ascertain its species status.

First Record of Laticauda semifasciata (Reptilia: Squamata: Elapidae: Laticaudinae) from Korea

The Chinese sea snake Laticauda semifasciata (Reinwardt in Schlegel, 1837) is newly reported from Korean waters based on three specimens collected from Jeju Island, Korea, in August, September, and November 2015. This is the first time that the genus Laticauda and subfamily Laticaudinae has been reported from Korean waters. The subfamily Laticaudinae has ventrals that are four to five times wider than the adjacent dorsals, which are unlike the ventrals that are similar or up to two times wider than adjacent dorsals in the subfamily Hydrophiinae. Laticauda semifasciata is distinct from other species because it has three prefrontals and its rostrals are horizontally divided into two. As the result of this report, four species (L. semifasciata, Hydrophis (Pelamis) platurus, Hydrophis cyanocinctus, and H. melanocephalus) of sea snakes have been reported in Korean waters.

Complete mitochondrial genome of Lycodes tanakae (Perciformes: Zoarcidae)

Abstract The complete mitochondrial genome of Lycodes tanakae was sequenced for the first time from its muscle tissue using the next-generation sequencing method. Its mitochondrial genome was 16,594 base pairs in length, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one control region. Its overall A, C, G, and T contents were 25.6%, 30.6%, 18.7%, and 25.2%, respectively. Its, A + T content (50.8%) was slightly higher than its G + C content (49.2%). A phylogenetic tree was built using 10 belonging to the order Perciformes and two species belonging to the order Scorpaeniformes.

Complete mitochondrial genomes of Scincella vandenburghi and S. huanrenensis (Squamata: Scincidae)

Abstract Here, we report the complete mitochondrial genomes of the skink species Scincella vandenburghi and S. huanrenensis. The mitogenomes were determined to be 17103 bp for S. vandenburghi and 17212 bp for S. huanrenensis. The mitogenomes consist of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and two non-coding regions. We then used the mitogenome data to construct a phylogenetic tree for these two species and an additional 16 species within the suborder Lacertilia.

Phylogenetic relationships of three representative sea krait species (genus Laticauda; elapidae; serpentes) based on 13 mitochondrial genes

Abstract To investigate the phylogenetic relationships of the genus Laticauda to related higher taxa, we compared the sequences of four mitochondrial genes (12S rRNA, 16S rRNA, ND4, Cytb) from three Laticauda species (L. colubrina, L. laticaudata, and L. semifasciata) with those of 55 Asian and Australo-Melanesian elapid species. We also characterized the complete mitogenomes of the three Laticauda species and compared the sequences of 13 mitochondrial genes from Laticauda species with five terrestrial elapid and one viperid species to estimate phylogenetic relationships and divergence times. Our results showed that the genus Laticauda is paraphyletic to terrestrial elapids and diverged from the Asian elapids approximately 16.23 Mya. The mitogenomes of the three Laticauda species commonly encoded 13 proteins, 22 tRNAs, 12S and 16S rRNAs and two control regions and ranged from 17,170 and 17,450 bp in size. The L. colubrina mitogenome was more similar to that of L. laticaudata than that of L. semifasciata. The divergence time among the three Laticauda clades was estimated at 8–10 Mya, and a close phylogenetic relationship between L. colubrina and L. laticaudata was found. Our results contribute to our understanding of the evolutionary history of sea kraits.

Correction to: Development of 21 polymorphic microsatellite markers for the black-banded sea krait, Laticauda semifasciata (Elapidae: Laticaudinae), and cross-species amplification for two other congeneric species

The genus Laticauda (Reptilia: Elapidae), commonly known as sea kraits, is venomous marine amphibious snakes distributed throughout the south and southeast Asian islands and mostly found in coastal waters. To facilitate genetic studies, we have developed microsatellite loci for L. semifasciata using the 454 GS-FLX pyrosequencing technique. A total of 65,680 sequences containing a minimum of five repeat motifs were identified from 451,659 reads. Among 80 loci containing more than nine repeat units, 34 primer sets (42.5%) produced strong PCR products, of which 21 were polymorphic among 36 samples of L. semifasciata. All loci exhibited high genetic variability, with an average of 7.38 alleles per locus, and the mean observed and expected heterozygosities were 0.73 and 0.76, respectively. The cross-species amplification of these loci in two laticaudine species, L. colubrina and L. laticaudata, revealed a high transferability (78.6%) and polymorphism (59.5%) of the loci. Our work demonstrated the utility of next-generation 454 sequencing as the rapid and cost-effective method for development of microsatellite markers. The high level of polymorphism in these microsatellite loci will be useful for the detection of population subdivision and the study of migration, gene flow, relatedness and philopatry of L. semifasciata and other laticaudine species.

Complete mitochondrial genome of Hemilepidotus gilberti (Scorpaeniformes: Cottidae)

Abstract The complete mitochondrial genome of gilbert’s irish lord (Hemilepidotus gilberti), a fish belonging to family Cottidae, was sequenced for the first time. This complete mitochondrial genome was 16,907 nucleotides in length, consisting of 38 mitochondrial genes (13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region). The order of these genes was similar to that of other teleosts. The overall A, C, G, and T nucleotide contents in mitogenome were 26.8%, 30.4%, 17.0%, and 25.8%, respectively. The A + T content (52.6%) was higher than the G + C content (47.4%). NJ phylogenetic analysis was performed for 10 related species within the family of Cottidae along with, two fish species belonging to another family (Sebastidae).

The Relationship between the Time of Breeding Migration of the Gori Salamander (Hynobius yangi) and Climate Factors.

To elucidate which climate factors and what periods affect the time of breeding migration of Gori salamanders (Hynobius yangi), we have investigated relationships between the 5-years breeding monitoring data from 2006 to 2010 which had obtained in both natural and translocated breeding sites at Bongdae mountain, Gijang-gun, Busan-si and the matched climate data obtained from the weather station, approximately 25 km apart from the sites. Mean average and mean lowest temperatures during one month before the first breeding migration were related with the time of first female migration in the translocated site. Mean temperature variation and mean precipitation during 60~120 days before the first breeding migration affected the time of 30% male appearance at the natural site and the time of 30% female appearance at both natural and translocated sites. Climate factors were more closely related with female appearance than male and at the translocated site than at the natural site. Our results show that changes in mean temperature variation and mean precipitation rather than mean average temperature might more significantly affect the breeding migration of salamanders, female breeding migration is more closely related with climate factors, and the salamanders translocated could be more affected by climate changes than those in natural populations.