The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashoredwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashoredwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.
Many species of Oligochaeta occur in a variety of freshwater environments such as puddles, rice paddies, reservoirs, brooks, rivers, and streams. About 1,700 species are known (Caramelo and Martínez-Ansemil, 2012). Oligochaetes are small-sized worms, ranging from 1 mm to a few centimeters in length. Tubificids are a dominant group found in freshwater benthic habitats among aquatic oligochaetes, and consequently bear ecological importance. Their bodies are red, and their reproductive organs are well-developed during maturity. When alive, their head is in the bottom sediment, usually gregarious in habitat and most commonly found in soft sediments covered with organic matter (Schenková and Helešic, 2006). Oligochaetes serve as an important source of food for fish and other aquatic animals as well as decomposers. Some oligochaetes have been used to monitor water pollution in rivers and streams (Lin and Yo, 2008). As a result of recent faunistic studies (Park et al., 2013a, 2013b), nine species of tubificids have been described in Korea, including Branchiura
The complete mitochondrial genome of
Nais communis
was analyzed using the Illumina Hiseq 2000 platform. The length of the complete mitochondrial genome was 15,685 bp, and the data were submitted to NCBI (MW770354). The genome contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a putative control region. A phylogenetic tree was constructed based on the sequences of 13 PCGs identified by the maximum-likelihood method. Regardless of the lack of studies on the complete mitochondrial genome of other aquatic oligochaetes, the phylogenetic tree showed
N. communis
to cluster with
Tubifex tubifex
and
Limnodrilus hoffmeisteri
with high support value, and the freshwater oligochaete and earthworm groups to be sister groups.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.