A New Species of Coralliidae (Cnidaria: Octocorallia) Collected from Eastern Japan

Abstract

A new species of Hemicorallium Gray, 1867 (Coralliidae), Hemicorallium meraboshi sp. nov., is described here. The specimen was found at a depth of 1744–1755 m, approximately 340 km east of the Honshu (mainland Japan) coast. The colony was identified by visual and microscopic observation of standard morphological characteristics (colony size, diameters of colony base and branches, diameter and height of autozooid mound, thickness of coenenchyme, sclerite sizes, etc.) along with support from molecular evidence. The unique features of this specimen are the large (more than 2 mm in diameter) autozooid mounds and the sizable sclerites in the coenenchyme (over 0.1 mm long) that are 8-radiates and multi-radiates predominantly. This new species is the northernmost record of Pacific precious corals.