MARINE LIFE & BIODIVERSITY: the Violet Nudibranch
Flabellina Affinis; Violet Nudibranch
A beautiful snail. That sounds like a contradiction in terminis. That is‚ for those who don’t dive! Perhaps the most popular marine animals that are photographed by divers are snails. Small colorful snails‚ that vary in size‚ shapes and patterns and that populate the seas of the world: nudibranchs! The flabellina affinis is one of the most beautiful‚ gracious‚ elegant princesses of Mediterranean world of nudibranchs.
Description of the Flabellina Affinis Nudibranch
The flabellina affinis is an aeolid nudibranch. Nudibranchs are sea slugs with “naked gills” (nudi =naked; branch = gill)‚ usually a tuft that can be seen on their backs. The aeolid nudibranchs‚ are typical‚ because they don’t have gills‚ but instead have many dorsal protrusions (cerata) which they use for breathing. The flabellina affinis nudibranch has an elongated purplish or deep pink body of about 50mm long. They have two non-retractable rhinofores and tentacles at the level of the head.
Habitat of the Flabellina Affinis Nudibranch
The flabellina affinis is found in the Mediterranean Sea and West Africa (Ghana). While diving we can find this small nudibranch on a rocky seabed‚ where hydroids and photophilic algae are present‚ from just below the water surface to 40 meters of depth.
Feeding of the Flabellina Affinis Nudibranch
The flabellina affinis feeds on hydroid Eudendrium. It feed on the stinging polyps of these cnidarians. It keeps these stinging cells active and uses them on its own skin in his defense.
Reproduction of the Flabellina Affinis Nudibranch
The flabellina affinis is a simultaneous hermaphrodite. This means that both individuals try to be the male nudibranch‚ inducing their penis in the other‚ when they mate. The nudibranch that succeeds first in doing so is the one that will act as a male‚ the other will act as the female. Up to 1 million purplish eggs are deposited in a jelly-shaped spiral‚ usually on the Eudendrium branches to guarantee food for the larvae as they hatch.
Lifespan of the Flabellina Affinis Nudibranch
A nudibranchs lifespan is quite short‚ ranging from a few weeks up to 1 year.
Important & Curious Facts of the Flabellina Affinis Nudibranch
- The bright color of the flabellina affinis serves as a warning to other animals of its toxic stinging cells.
- The flabellina affinis‚ being and aeolid nudibranch‚ has no gills‚ but its body is covered with protrusions (cerata) with which it breathes. It practically breathes through its skin.
- It is a tiny nudibranch‚ but if you know how to spot the Eudendrium‚ you know how to spot the Flabellina Affinis.
- The eggs spirals contain chemical toxins to deter any predator.
On what dive sites can we spot the Flabellina Affinis?
In the Marine Protected Area of Ustica and Isola delle Femmine the flabellina affinis can be found numerously while diving at dive sites along the coast. There are dive sites where it is easier to spot this nudibranch‚ such as:
In the marine protected area of Ustica:
In the marine protected area of Isola della Femmine:
Dive site Parete dell';;;Ancora
Around the period of July to September‚ eggs can be found the branches of Eudendrium on these dive sites of the Marine Protected Area of Ustica and Isola delle Femmine and soon after very small flabellina affinis individuals can be spotted.
