Species diversity of epiphytic diatoms of Dokdo Island, Korea

Abstract

Dokdo is an island located in the easternmost of Korea, where has been concerned due to the economic and scientific merit. Recent compilations on biodiversity of Dokdo have showed the high level of biodiversity in the bird, fish, especially invertebrates such as Mollusca, Arthropoda, Annelida, Cnidarian, Echinodermata and Porifera. However, the biodiversity on microalgae is relatively little known, despite its ecological importance as a primary producer and bioindicators. In order to understand the biodiversity of epiphytic diatoms of Dokdo, we collected the macroalgae under 5 to 15m depth by SCUBA diving in 17 Oct. 2017. The epiphytic diatoms detached from the thalli of the macroalgae by vigorously shaking, and treated an acid to remove the organic matters. The acid cleaned materials were mounted in Pleurax and observed in light microscopy. The diatoms are documented 30 genera 70 species, and the highly diverse genera are Mastogloia, Navicula, Seminavis and Cocconeis. The diversity of epiphytic diatoms of Dokdo is similar to that of Chuuk, tropical Pacific, despite both regions are separated in the difference climate zone. In particular, Mastogloia, known to the tropical benthic diatom, shows the high number of species and it seems to be an indicator of Kuroshio Current across the temperate to tropical region. The biodiversity of epiphytic diatoms of Dokdo is fairly high and composed of sub- to tropical diatoms. The invertebrates such as Mollusca, Arthropoda, Annelida, Cnidarian, Echinodermata and Porifera. However, the biodiversity on microalgae is relatively little known, despite its ecological importance as a primary producer and bioindicators. In order to understand the biodiversity of epiphytic diatoms of Dokdo, we collected the macroalgae under 5 to 15m depth by SCUBA diving in 17 Oct. 2017. The epiphytic diatoms detached from the thalli of the macroalgae by vigorously shaking, and treated an acid to remove the organic matters. The acid cleaned materials were mounted in Pleurax and observed in light microscopy. The diatoms are documented 30 genera 70 species, and the highly diverse genera are Mastogloia, Navicula, Seminavis and Cocconeis. The diversity of epiphytic diatoms of Dokdo is similar to that of Chuuk, tropical Pacific, despite both regions are separated in the difference climate zone. In particular, Mastogloia, known to the tropical benthic diatom, shows the high number of species and it seems to be an indicator of Kuroshio Current across the temperate to tropical region. The biodiversity of epiphytic diatoms of Dokdo is fairly high and composed of sub- to tropical diatoms. The