Bermudella polycerelloides

Bermudella polycerelloides Ortea & Bouchet, 1983

Bermudella polycerelloides by Enrico Ricchitelli

Taxonomic note: Paz-Sedano et al (2024) phylogenetic analyses and species delimitation tests showed that Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli & Crocetta, 2019 and Okenia polycerelloides (Ortea & Bouchet, 1983) as the same species, and thus, O. longiductis is synonym of O. polycerelloides. The genus Bermudella (type species Polycerella zoobotryon / Bermudella zoobotryon (Smallwood, 1910)) was erected by Odhner (1941) to separate the species Polycera zoobotryon based on the presence of a buccal bulb and the shape of the teeth, which was similar to Goniodorididae. Bermudella species have simple, short, and digitiform papillae, homogenously distributed along the sides of the body. Also, few dorsal papillae with similar shape to lateral ones are present, sparse lamellae in rhinophores, and digitiform oral tentacles. A previous morphological assessment also clustered B. brunneomaculata, B. angelensis, B. pellucida, and B. zoobotryon based on the similarities between the oral tentacles and the sparse rhinophoral lamellae (Gosliner, 2004). Rudman (2004) grouped the Bermudella species based on the feeding source: ctenostome bryozoans (i.e., species of Amathia Lamouroux, 1812). Thus, Paz-Sedano et al (2024) suggest transferring all these species to Bermudella until new material is sequenced.

Synonyms

• Bermudella longiductis (Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli & Crocetta, 2019)
• Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli & Crocetta, 2019
• Okenia polycerelloides (Ortea & Bouchet, 1983)
• Okenia zoobotryon (Smallwood, 1910)

Description
It can reach up to 10 mm in length. It has an elongated semi-transparent whitish body, so the grayish internal organs can be seen by transparency. The body is covered with small brown spots or scores, of different sizes and density depending on the specimen. Rhinophores are pigmented brown at the base, and are long and thick, with only 4-5 lamellae at the distal end. There are elongated papillae with brown and white spots in the center of the dorsum and around the entire mantle, even in front of the rhinophores and behind the gill. The gill is formed by 7-8 tripinnate leaves surrounding the anus, also with brown spots. The foot is pointed at the tail, of the same color and with the same spots as the rest of the body.

Biology
It lives associated with colonies of the gymnolemate bryozoan Amathia verticillata, on which it feeds and on which it lays the spawn, shaped like a cord with white eggs, arranged forming a circle. Until its recent description this species was reported in the Mediterranean as Okenia zoobotryon (Smallwood, 1910).

Etymology

• Bermudella. Related to the Bermuda archipelago. “-ella” Latin suffix is a diminutive because of the small size of these animals.
• Polycerelloides. Shape similar to Polycera, a genus of nudibranchs.

Distribution
So far it has only been found in the Adriatic Sea, along the Italian shores and in the Catalan coast, where it has been observed in the Coves of Cala Maset in Sant Feliu de Guíxols and in the bathing area of the Forum of Barcelona.

Videos

 

More pictures

Bibliography

1246567 Bermudella polycerelloides 1 eunomia-revista-en-cultura-de-la-legalidad 50 creator asc 1 29258 https://opistobranquis.info/wp-content/plugins/zotpress/
Bibliography based on the works by Steve Long, 2006. Bibliography of Opisthobranchia 1554-2000 and Gary McDonald, 2009. Bibliographia Nudibranchia, with later updates from other resources.

Further reading

• Salento Sommerso
• WoRMS

Cite this article as: