14 August, 2023

By Gavin Gallagher

Pronounced “noo-di-branks,” they are a fascinating group of marine gastropod mollusks. One of the most remarkable features of nudibranchs is the presence of gills, which are protrusions on their backs or sides used for breathing. 

The name “nudibranch” originates from Latin, where “nudus” means naked, and “branchia” means gills. Naked Gills.

Colourful Nudibranchs. Photos by Anastasia Louhenapessy

Defense: Nudibranchs have evolved incredible defense mechanisms. Some species store stinging cells (nematocysts) from their prey, such as jellyfish or hydroids. When a predator attacks, they release these stinging cells for protection. 

Au-tot-o-my: Certain nudibranch species possess the ability to shed parts of their bodies when threatened. They can cast off their gills or even detach their entire body from their head if they feel endangered. The discarded body may continue to move, serving as a distraction for predators while the nudibranch escapes. 

Size & Lifespan: Ranging from a few millimeters to several centimeters and a few weeks to over a year. 

Hermaphroditic: Most nudibranchs are hermaphroditic. This enables them to mate with any other individual of their species they encounter. 

Nudibranchs species
Nudibranchs Species. Photos by Anastasia Louhenapessy

Amazing Adaptations: Nudibranchs exhibit diverse adaptations, such as mimicry. Some species imitate the appearance of toxic or dangerous animals to deter predators. This mimicry can include similarities to flatworms, fish, dragons! and other sea creatures

Scientists estimate that there may be thousands of nudibranch species, with many still waiting for you to discover and photograph.