Hidden in the crowd: re-evaluation of the generic status of the Antarctic sea pen Kophobelemnon molanderi (Anthozoa: Octocorallia: Pennatuloidea), a molecular and morphological approach

Abstract

Our understanding of Antarctic octocoral diversity is still far from complete. Newly collected specimens of the Antarctic sea pen Kophobelemnon molanderi Pasternak, 1975 have allowed a detailed morphological and molecular description of the species. The results of this study, including the diversity and complete distribution of the sclerome, the distribution of autozooids and siphonozooids and the sequences of three mitochondrial markers (mtMutS, COI and ND2) and one nuclear marker (28S) contribute to knowledge of the complex relationships of the genera Kophobelemnon Asbjoørnsen, 1856 and Funiculina Lamarck, 1816, which were initially traced in some recent works on the taxonomy and phylogeny of this highly derived group of octocorals. The sequences attributed to the genus Kophobelemnon were divided into three different groups. Two of these groups are recognized here simply as Kophobelemnon I and Kophobelemnon II, pending further morphological and molecular review. The sister group of Kophobelemnon I was the genus Funiculina. The third group, corresponding to K. molanderi sequences, is here assigned to a new genus, Scotiabelemnon gen. nov. The family delimitation and the relationships of the families Kophobelemnidae Gray, 1860, Funiculinidae Gray 1860 and Gyrophyllidae López-González, Drewery and Williams, 2022 are discussed. Finally, it is proposed to merge Kophobelemnidae into Funiculinidae, leaving only two families within Clade III, Funiculinidae and Gyrophyllidae.

Keywords

• Southern Ocean
• biodiversity
• corals
• new genus
• Scotiabelemnon
• morphological and molecular approach