Corruptobranchus malakhovi (Ekimova, Mikhlina, Vorobyeva, Antokhina, Tambovtseva & Shepetov, 2021)

Description

A small aeolid up to about 8 mm in body length, narrow and elongate, with a translucent-white background colour and brilliant orange to reddish-orange digestive gland clearly visible through the cerata. Cerata are arranged in up to six rows with up to four cerata per row; the dorsal cerata are swollen, with the digestive gland filling about half of their volume, while the lateral cerata are tubular and almost entirely filled by the digestive gland. Oral tentacles and rhinophores are simple, elongate, up to about 0.8 mm long; rhinophores are stout and smooth, with minute white pigmentation. Each ceras carries a conspicuous white pigmented cap over the cnidosac at its tip. The anal opening is on the right side behind the third ceratal row, positioned lateral to the cerata.

Distribution

At the time of description known only from the type locality, Rudnaya Bay on the Russian coast of the Sea of Japan (44°28.55′N, 136°06.52′E), at 15–20 m depth. The original authors suggested that the species likely has a wider distribution along the Northwest Pacific.

Etymology

The specific epithet malakhovi honours Prof. Vladimir V. Malakhov, head of the Department of Invertebrate Zoology at Lomonosov Moscow State University and mentor of the original describers, in recognition of his long-standing contributions to marine invertebrate research in the Russian Far East.

Remarks

Found on and feeds upon sertulariid hydroid colonies. Morphologically and anatomically very similar to its North Pacific congeners Corruptobranchus odhneri and Corruptobranchus sanjuanensis, but distinguished by molecular data and fine-scale morphology.

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References

• Eubranchus malakhovi sp.n., Ekimova I.A., Mikhlina A.L., Vorobyeva O.A., Antokhina T.I. & Tambovtseva V.G. (2021). Young but distinct: description of Eubranchus malakhovi sp.n. a new, recently diverged nudibranch species (Gastropoda: Heterobranchia) from the Sea of Japan. Invertebrate Zoology. 18(3): 197-222. https://doi.org/10.15298/invertzool.18.3.02
• Corruptobranchus malakhovi, Martynov, A. & Korshunova, T. (2025). Hidden diversity of the North Pacific prompts reorganization of the taxonomic system. Moscow: Neptune. ISBN 978-5-9905149-3-5. 48 pp.