The Black Sea Pleurobrachia (Ctenophora): P. rhodopis or P. pileus?

Iu.S. Baiandina, O.N. Kuleshova & O.V. Krivenko

Abstract. Pleurobrachia Fleming, 1822 is the native taxon of ctenophores in the Black Sea. Until now, its species affiliation has not been resolved: the Black Sea Pleurobrachia is referred to either P. pileus (O.F. Müller, 1776) or P. rhodopis (Chun, 1879). In the taxonomic reviews, both species are recognised as occurring in the Black Sea. The experts on zooplankton identified the Black Sea Pleurobrachia based solely on its definitive body size, but size cannot be a sufficient diagnostic feature. To clarify the species identity of the Black Sea Pleurobrachia, we carried out a phylogenetic analysis using the nucleotide sequences of the mitochondrial COI and the nuclear 18S rRNA gene fragments. As a result, we have established that the Black Sea Pleurobrachia is P. pileus and its identification as P. rhodopis in the global taxonomic databases is erroneous.

Key words: phylogeny, taxonomy, Black Sea, distribution, Ctenophora, Tentaculata, Cydippida, Cydippidae, Pleurobrachia pileus, Pleurobrachia rhodopis

Zoosystematica Rossica, 2025, 34(1): 18-27 ▪ Published online 22 January 2025

https://doi.org/10.31610/zsr/2025.34.1.18 ▪ Open full article

Electronic supplementary materials

Electronic supplementary material 1

GenBank accession numbers of Ctenophora nucleotide sequences used in phylogenetic analysis. File format: PDF.

Electronic supplementary material 2

Video recording of free movement of the Black Sea Pleurobrachia in a laboratory aquarium. File format: MPG.

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