Taxonomic reassessment of chaetognaths (Chaetognatha, Sagittoidea, Aphragmophora) from Korean waters

Abstract

Since the first record of chaetognaths (arrow worms) reported from Korean waters by Molchanov in 1907, three families, 12 genera and 21 species have been additionally described. Eighteen of the 21 recorded species have been reported under scientific names different from the latest taxonomic system. This study aimed to address this issue by conducting a taxonomic re-evaluation of chaetognaths collected from Korean waters. Furthermore, the taxonomic usefulness of morphological differences in corona ciliata and distribution of ciliary sense receptors were re-examined using specimens stained with 1% Chlorazol black E (CBE) solution. This study includes taxonomically-validated voucher specimens of 18 species from Korean waters. Based on the specimens, re-description including image data and CBE staining pattern, distribution, ecological information and improved key were provided for each species. However, Decipisagitta decipiens, Serratosagitta serratodentata and Sagitta pseudoserratodentata from Korean waters is still questioned because of the paucity of the voucher specimen and scientific literature.