Went snorkeling and saw a strange, large and colorful sea slug with what looked like a radar dish on its back? Congrats! You may just have met Felimare picta, also known as the regal sea goddess. Slugs don’t get much prettier than this one!
Below, you can find everything you need to know about this fascinating species, including what it looks like, where it’s from, what it eats, and more funky facts.
| Name (common, scientific) | Regal sea goddess, Felimare picta (formerly known as Hypselodoris picta) |
| Family | Chromodorididae |
| Spread | Mediterranean, parts of the Atlantic |
| Habitat | Rocky sea bottoms and tide pools |
Felimare picta appearance
The regal sea goddess is a type of sea slug known as a nudibranch. If you know anything about nudibranchs (and yes, that’s the correct spelling), you’ll be aware that they’re known for their bright colors and strange appearances. This one’s no exception!
The foremost thing to know about Felimare picta identification is that these slugs can have different colors and patterns. Some are almost entirely yellow, while others are almost completely midnight blue in color. There are pictures of both morphs in this post for reference.
Aside from their varied coloration, regal sea goddesses have all the bits a normal nudibranch does. The name “nudibranch” itself means “naked gill”, a reference to the fact that these slugs carry their gills out in the open, on their backs. In this case, the gill looks like a frilly star on the Felimare’s back.
The “eyestalks” or “bunny ears” you’ll spot on a Felimare picta are actually neither. They’re called rhinophores, and they’re meant for chemosensory reception: taste and smell. These slugs do have eyes, but they’re very rudimentary and difficult to spot. They find food and mates using their rhinophores.
In the world of nudibranchs, which can be incredibly tiny, the regal sea goddess is a veritable giant. It grows to a maximum size of up to 5″ (13 cm).
Did you know? Regal sea goddesses develop a more intricate pattern as they mature. That’s why larger specimens usually sport more dots and dashes than smaller ones.
Taxonomy
Sometimes scientists just don’t know what to do with a species, and this is one of those cases. Most importantly, the regal sea goddess used to be considered a type of Hypselodoris (usually Hypselodoris picta, but I’ve also seen loads of other names, like H. webbi)
This changed when several Hypselodoris species (including this one) were moved to Felimare following a paper published in 2012. The confusion didn’t end there, however: there used to be a bunch of subspecies, which were all eventually elevated to their own species, though not always without a fight.
Examples are the slugs now called Felimare lajensis and Felimare tema. The former started out as a subspecies, was then upgraded to a species, then downgraded again to a subspecies, and is now finally a full species again! Redemption at last.
Planning your next snorkel trip?
Felimare picta natural habitat
Range
Felimare picta, as it’s classified right now, can be found throughout the Mediterranean. It also occurs in the northeastern Atlantic (like around the Canary Islands, Madeira, and the Azores) and the Gulf of Mexico.
The fact that this species is present on both sides of the Atlantic is considered quite unusual, especially for a slug that can’t swim long distances.
The “mid-Atlantic barrier” is characterized by its deep waters, but it’s thought the regal sea goddess managed to cross it because it has a longer planktonic phase after hatching. This may allow the tiny larvae to be dispersed quite far by oceanic currents. Not so sluggish after all, as the authors of a 2016 study aptly note!
In its natural habitat, Felimare picta likes rocky seabeds. It can apparently occur as deep as 50m (165ft), but I’ve always had the best luck finding it in tide pools and shallow, sheltered areas.
Felimare picta facts
Diet
The regal sea goddess feeds exclusively on sponges, often those in the genus Dysidea, although the specific species can vary due to this slug’s wide natural range.
It consumes its meals using its radula, a tongue-like organ covered in hard “teeth” which is unique to mollusks and perfect for scraping off pieces of tough food.
Chemical defense
As its bright colors indicate, Felimare picta isn’t as defenseless as it looks. Like some other nudibranchs, these slugs thave glands along their bodies that excrete various foul-tasting substances. Examples include different alkaloids, diterpenes, and sesquiterpenes.
The Felimare doesn’t produce these defensive compounds itself. Instead, it gets them from the sponges it eats and stores them in its tissues to make itself unattractive to predators.
Reproduction
Nudibranch eggs comprise a significant percentage of the “what is this?!” questions I get from confused snorkelers. They’re orange-ish in color and laid in ribbon-like masses on rocks and other hard surfaces.
As mentioned, the slugs hatch in the form of tiny, planktonic larvae that drift freely in the ocean currents before settling down.
Did you know? Like other nudis, Felimare picta is a hermaphrodite. Two specimens are still needed to reproduce, but they can both act as male and female simultaneously.
If you have any more questions about Felimare picta or if you’d like to share your own experiences with this surprisingly beautiful sea slug, don’t hesitate to leave a comment below!
Sources & further reading
- Dacosta, S., Padula, V., & Schroedl, M. (2010). A new species of Hypselodoris and a redescription of Hypselodoris picta lajensis (Nudibranchia: Chromodorididae) from Brazil. Veliger, 51(1), 15.
- Domínguez, M., García, F. J., & Troncoso, J. S. (2006). Some aspects of the family Chromodorididae (Opisthobranchia: Nudibranchia) from Brazil, with description of a new species. Scientia Marina, 70(4), 621-634.
- Johnson, R. F., & Gosliner, T. M. (2012). Traditional taxonomic groupings mask evolutionary history: a molecular phylogeny and new classification of the chromodorid nudibranchs. Plos one, 7(4), e33479.
- Krings, W., Wägele, H., Neumann, C., & Gorb, S. N. (2023). Coping with abrasive food: diverging composition of radular teeth in two Porifera-consuming nudibranch species (Mollusca, Gastropoda). Journal of the Royal Society Interface, 20(202), 20220927.
- Troncoso, J. S., Garcia, F. J., & Urgorri, V. (1998). Anatomical data on a rare Hypselodoris picta (Schultz, 1836)(Gastropoda, Doridacea) from the coast of Brazil with description of a new subspecies. Bulletin of Marine Science, 63(1), 133-141.
- Winters, A. E. et al. (2018). Distribution of defensive metabolites in nudibranch molluscs. Journal of chemical ecology, 44, 384-396.