A new species of the genus Paramesochra (Copepoda: Harpacticoida) from Korean waters

초록

We describe a new species of the genus Paramesochra that was found in sandy sediments off Taean on the west coast of Korea during a study of interstitial harpacticoid copepods. Paramesochra tacana, sp. nov. superficially resembles P. acutata hawaiiensis Kunz, 1981, in the structure of the antenna, shape of the caudal rami, and seta formulae of thoracopods P1-P4. However, the new species was clearly distinguishable from P. acutata hawaiiensis by a combination of characteristics. With the exception of the last two somites, the new species is the only species in the genus that has well-developed hyaline frills on all of the body segments. The female displays eight-segmented antennules, and the median incision between both plates of its baseoendopod reaches about to the proximal line of the exopod in P5. Lastly, in males the baseoendopodal plate has a deeper median incision in P5. An updated key for species of the genus Paramesochra is provided.