Favorinus ghanensis Edmunds, 1968
WoRMS Taxonomic Information
Current classification
| Superdomain | Biota |
|---|---|
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Gastropoda |
| Subclass | Heterobranchia |
| Infraclass | Euthyneura |
| Subterclass | Ringipleura |
| Superorder | Nudipleura |
| Order | Nudibranchia |
| Suborder | Cladobranchia |
| Superfamily | Aeolidioidea |
| Family | Facelinidae |
| Genus | Favorinus |
| Species | Favorinus ghanensis Edmunds, 1968 |
Description
Specimens range from 1.5 mm to 16 mm in length. The body is slender and gradually tapers to a pointed tail. It is translucent greyish-white, adorned with scattered iridescent white dots across the dorsum, head, oral tentacles, and tail. The oral tentacles and anterior foot corners share the same base coloration. The rhinophores are purple-brown or maroon, with a clear white-spotted tip, and exhibit three small swellings or “bulbs”. These swellings may appear indistinct when the animal is fully extended. Cerata are long, evenly thick, and arranged in arches anteriorly and rows posteriorly. Their walls are translucent, revealing the internal digestive gland, which is coloured cream to brown with purple-brown blotches, giving the cerata a generally dark purplish-brown appearance. The tips of the cerata are translucent white, often with minute white glands and scattered iridescent white dots. Cerata are readily autotomized when the animal is disturbed or mishandled. The anus is cleioproctic and lies within the second ceratal arch on the right side, while the genital opening is nestled among the foremost right ceratal group.
Biology
This species is primarily found in fouling communities, especially on boat hulls, fishing gear, and port structures. It feeds predominantly on the zooids of the bryozoan Amathia verticillata, a departure from the genus’ norm, which is more commonly associated with egg masses of other sea slugs. Feeding behavior includes sucking contents from broken bryozoan tubes, and occasional consumption of sessile ciliates such as Vorticella and Stentor. Despite lacking visible cnidosacs or nematocyst discharge, F. ghanensis is equipped with epidermal defensive glands in the cerata, and displays autotomy as a defensive response. Its small size and cryptic lifestyle may have led to underreporting, however, its affinity for artificial substrates and invasive bryozoans suggests a potential for further expansion via maritime traffic.
Etymology
- Ghanensis. From Ghana (West Africa).
Distribution
Its current known range includes eastern Atlantic and Mediterranean ports, often in habitats dominated by Amathia verticillata. Originally described from Ghana (Tema Harbour) in 1968, it has been subsequently recorded at the Canary Islands (Gran Canaria, 1995), Tunisia (Lac de Tunis, 2003) and in the Atlantic coast of Morocco (Agadir, 2012).
Abundance
Relative abundance of Favorinus ghanensis among the different marine basins, based on our own records
This chart displays the monthly observation probability for Favorinus ghanensis based on our own records.
This chart displays the number of annual observations of Favorinus ghanensis over the last 50 years, based on our own records. The trend should be interpreted with caution, as it may be biased by the growing popularity of this animal group.
More pictures
Bibliography
Further reading
Cite this article as:
Pontes, Miquel (2025) "Favorinus ghanensis" in OPK-Opistobranquis. Published: 01/05/2015. Accessed: 05/11/2026. Available at (https://opistobranquis.info/en/?p=19360)