Emphasis Type="Italic"Thiriotia euchirellae/Emp

Authors: Masayoshi Sano Hiroomi Miyamoto Shuhei Nishida

Publish Date: 2015/12/21

Volume: 46, Issue: 4, Pages: 753-760

PDF Link

Abstract

A new gregarine species Thiriotia euchirellae n sp Apicomplexa Eugregarinorida is described from the gut lumen of a mesopelagic copepod Euchirella rostrata Calanoida Aetideidae collected in Sagami Bay Japan Thiriotia euchirellae n sp has an elongated and cylindrical body with an average length of 174 μm and is distinguished from its congeners by its shorter and thicker body the rounded anterior end with thicker folds than for the rest of the body and the posterior end covered by epicytic folds Molecular phylogenetic analysis based on nuclear 18S rDNA placed T euchirellae n sp in the clade of eugregarines infecting marine crustaceans and in the same subclade as T pugettiae Thiriotia euchirellae n sp infected 95  of the E rostrata population but was not detected in the other mesopelagic copepod species examined in the present study Euchirella rostrata has an elongated gut with a swollen and sigmoidal anterior part and a gradually narrowing posterior part connected through a narrow path Thiriotia euchirellae n sp were mostly observed in the posterior part of the gut The high infection rate of E rostrata by T euchirellae n sp and the characteristic gut morphology of the host suggest a specific host–parasite relationship between these speciesWe sincerely thank the captain and crewmembers of the R/V ‘TanseiMaru’ and the staff members of the Plankton Laboratory and the Center for International Collaboration of the Atmosphere and Ocean Research Institute We also thank Masako Hara for her support with SEM analyses This study has been partially supported by grants from the Japan Society for the Promotion of Science Multilateral Cooperative Research Program Coastal Oceanography and the Alfred P Sloan Foundation Census of Marine Zooplankton awarded to SN

Keywords: