Description of a new and widely distributed species of Bathypathes (Cnidaria: Anthozoa: Antipatharia: Schizopathidae) previously misidentified as Bathypathes alternata Brook, 1889

Abstract

For many years an undescribed species of the genus Bathypathes has been misidentified as Bathypathes alternata Brook, 1889 (a species currently re-assigned to the genus Alternatipathes). This new species is rather common at mid- and lower bathyal depths of the Pacific, Atlantic and Indian oceans, often in areas with high concentrations of commercially valuable cobalt-rich ferromanganese crusts, where it was observed in underwater photo and video transects to occur in high densities. Under the name B. alternata this species is recorded in several inventories and databases. There is an urgent need for a formal description of this misidentified and widely distributed species to avoid further confusion. The new species is superficially similar to A. alternata in having a monopodial corallum and simple, bilateral and alternately arranged pinnules. However, it differs from the former in that it has an upright corallum with a straight pinnulated part (vs. a horizontally bent pinnulated part), pinnules of uniform length and density (vs. decreasing regularly distally), and a constant distal angle formed by the pinnules and the stem along different parts of the corallum (vs. a decreasing distal angle near the top). The new species can therefore be easily distinguished from A. alternata in underwater imagery. We formally describe this new species in the genus Bathypathes and assign it the new name B. pseudoalternata. An extensive synonymy list with previous misidentified records is provided. To evaluate the distributional patterns of the new species we review the geographic distribution of antipatharians reported below 800 m. The majority of the hitherto described lower bathyal and abyssal species have been recorded from one biogeographic province; however, 20 species are known from more than two provinces, and only three species are widely distributed (>5 provinces), including the newly described Bathypathes pseudoalternata. Members of the family Schizopathidae, to which the new species belongs, represent the majority of the lower bathyal (50.54%) and abyssal (82.35%) species.

A new species of Bathypathes (Cnidaria, Anthozoa, Antipatharia, Schizopathidae) from the Red Sea and its phylogenetic position

“…Within the genus Bathypathes, B. platycaulus Totton, 1923 andB. pseudoalternata Molodtsova, Opresko andWagner 2022 show alternate subpinnules. The former is characterised by a peculiar broadening of the stem in the middle region, to which the species name refers (Totton 1923), while B. thermophila sp.…”

“…Within the family Schizopathidae , the genus Bathypathes Brook, 1889 includes monopodial black corals and currently accounts for 14 valid species ( Molodtsova and Opresko 2021 ; Molodtsova et al 2022 ). It occurs in the Pacific, Indian, Atlantic, and Southern oceans, and has been recorded at depths ranging from 102 to 5393 m ( Brook 1889 ; Opresko 2002 ; Opresko and Molodtsova, 2021; Molodtsova et al 2022 ), although its shallowest record ( Thomson 1905 ) is currently considered doubtful. In fact, those of the genus Bathypathes are mostly deep-sea species, with few representatives in the mesophotic zone.…”