Background: In the Republic of Korea (ROK), six sibling species of theAnopheles sinensiscomplex are considered the vector species of malaria, but data on their susceptibilities to malaria and vector capacities have been controversial. The intensive use of insecticides has contributed to the rapid development and spread of insecticide resistance in theAn. sinensiscomplex. Knockdown resistance (kdr) to pyrethroids and DDT in theAn. sinensiscomplex is associated with a mutation in codon 1014 of the voltage-gated sodium channel (VGSC) gene. Because the degree of insecticide resistance varies among mosquito species and populations, the detection ofkdrmutations among the six sibling species of theAn. sinensiscomplex is a prerequisite for establishing effective long-term vector control strategies in the ROKMethods: In order to investigate species-specifickdrmutations,An. sinensiscomplex specimens have been collected from 22 sites in the ROK. Because of the difficulties with species identifications that are based only on morphological characteristics, molecular identification methods have been conducted on every specimen. Part of the IIS6 domain of the VGSC was polymerase chain reaction-amplified and directly sequenced.Results: The molecular analyses revealed that mutations existed at codon 1014 only inAn. sinensissensu stricto and no mutations were found in the other fiveAnophelesspecies. InAn. sinensiss.s., one wild type (TTG L1014) and three mutant types (TTT L1014F, TTC L1014F, and TGT L1014C) ofkdralleles were detected. The TTC L1014F mutation was observed for the first time in this species.Conclusions: The fact that the highly polymorphickdrgene is only observed inAn. sinensiss.s., out of the sixAnophelesspecies and their geographical distribution suggest the need for future studies of insecticide resistance monitoring and investigations of species-specific resistance mechanisms in order to build successful malaria vector control programmes in the ROK.

Hydrothermal vents are chemosynthetically driven ecosystems and one of the most extreme environments on Earth. Vent communities exhibit remarkable taxonomic novelty at the species and supra-species levels, and over 80% of vent species are endemic. Here, we used mitochondrial DNA to identify the biogeographic distribution of Munidopsis lauensis and the heme-binding regions of A1-type COX1 from six species (including M. lauensis) to investigate whether genetic variation in the protein structure affects oxygen-binding ability. We verified the identity of Indian Ocean specimens by comparing sequences from the barcoding gene mitochondrial cytochrome oxidase subunit 1 (COI) with known M. lauensis sequences from the NCBI database. The data show that these are the first recorded specimens of M. lauensis in the Indian Ocean; previously, this species had been reported only in the southwest Pacific. Our findings support the hypothesis that vent fauna in the Pacific and Indian Oceans can interact via active ridges. In the case of the mitochondrial DNA-binding site, the arrangement of heme-binding ligands and type A1 motif of M. lauensis was identical to that in other species. Moreover, our findings suggest that the mechanism of oxygen binding is well conserved among species from terrestrial organisms to hydrothermal extremophiles. Overall, dispersal of the same species to geologically separated hydrothermal vents and conserved heme-binding regions in mitochondrial proteins suggest that hydrothermal species might have evolved from shallow sea organisms and became distributed geographically using a dispersion corridor.

Organisms occupy diverse ecological niches worldwide, each with characteristics finely evolved for their environments. Crustaceans residing in deep-sea hydrothermal vents, recognized as one of Earth’s extreme environments, may have adapted to withstand severe conditions, including elevated temperatures and pressure. This study compares the exoskeletons of two vent crustaceans (bythograeid crab Austinograea sp. and squat lobster Munidopsis lauensis) with four coastal species (Asian paddle crabs, blue crab, hermit crab, and mantis shrimp) to identify traits influenced by vent environments. The goal was to identify distinctive exoskeletal characteristics commonly observed in vent crustaceans, resulting from their exposure to severe abiotic factors, including elevated temperatures and pressures, found in vent environments. Results show that the exoskeletons of vent crustaceans demonstrated significantly enhanced thermal stability compared to coastal species. These vent crustaceans consistently featured exoskeletons characterized by a reduced proportion of volatile components, such as water, and an increased proportion of CaCO₃, compared with coastal crustaceans. Furthermore, vent crustaceans lacked carotenoid pigments that had low heat resistance. However, no apparent differences were observed in the mechanical properties. Our findings suggest that the similar composition of exoskeletons in vent crustaceans evolved convergently to withstand high temperatures.

Biofouling has long been known as a major route for the invasion by non-indigenous species. The mantis shrimp, Gonodactylaceus randalli, is the first stomatopod species that has been identified in a biofouling community. In this study, we sequenced and analyzed the complete mitochondrial genome sequence of this species for the first time. Its mitochondrial genome is 15,907 bp in length and comprises 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a non-coding A + T-rich region. The overall base composition in the heavy strand is as follows: A: 37.3%, T: 31.3%, G: 11.9%, and C: 19.4%, with a G + C content of 31.3%. The phylogenetic analysis revealed that G. randalli belonged to the families Protosquillidae, Gonodactylidae, and Takuidae, in the same clade, within the superfamily Gonodactyloidea. This is the first record of the complete mitochondrial genome sequence of the genus Gonodactylaceus.