Rhodope roskoi

Rhodope roskoi Haszprunar & Hess, 2005

Rhodope roskoi @ Granada by David Ballesteros

Description
The body shape is worm-like. Size of living animals is about 1.5 mm. Body is coloured white with a distinct orange pattern consisting on a broad horizontal girdle after the head region surrounding the whole body and a separated, longitudinal stripe at the more posterior dorsal side. Head region is somewhat laterally depressed. Strong light allows to see the small eyes (deeply embedded in the cephalic brain), the paired statocysts, and densely arranged spicules. These spicules are slightly curved and verrucose, their length ranges from 90 to 120 μm, typically between 100-115 μm. There is no declined head and foot, and there is an adhesive gland at the ventral rear of the body.

Biology
Despite this species looks like a turbellarian at first, they can be distinguished because they move quite slowly, and because they can heavily contract when disturbed. It inhabits shallow subtidal areas with green algae and, unlike other true insterstitial species, it tends to climb to the light, instead of hiding from it. Specimens used for the original descrition were obtained by dredging on shelly gravel (“sable de amphioxus”) at about 25 m depth and carefully inspecting the samples.

Similar Species
Whereas the principal colour (white body with orange pattern) is shared with several other Rhodope species, Rh.roskoi differs from all other in the distinct orange pattern and the more densely arranged spicules, although the spicules themselves are similar to the type species of the genus. Haszprunar & Heß (2005) presented an overview of all named and some unnamed species of Rhodope, with a schematic drawing of the orange pattern in order to facilitate future identifications.

Etymology

• Rhodope. From ancient Greek “Ῥοδόπη” ‎(Rhodópē), one of the 3,000 Oceanids, water-nymphs daughters of the Titans Oceanus and his sister-wife Tethys.
• Roskoi. Named after the Bretonian name of Roscoff (Rosko).

Distribution
Rhodope species have been typically found in the North-East Atlantic during meiofaunal studies (Swedmark 1958; Karling 1966; Haszprunar & Heß, 2005). Original species was reported from Roscoff (Bretagne, France) in 2005. In 2024 there is also a report from Granada, Spain, in the Mediterranean Sea.

Videos

More pictures

Bibliography

1246567 Rhodope roskoi 1 eunomia-revista-en-cultura-de-la-legalidad 50 creator asc 1 46014 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

• Biodiversity Library
• Litoral de Granada
• Sea Slug Forum
• World Register of Marine Species

Cite this article as: