There is more to coral reefs than the large charismatic animals like the turtles, dolphins and manta rays that we know and love. If you look closely the reef is teaming with an array of tiny but incredibly beautiful and fascinating creatures. One of Wings Whitsunday Adventure’s favourite little reef dwellers to find are the nudibranchs.
Nudibranchs are a very colourful and diverse group of marine molluscs made up of over 3000 different species. The name literally translates to naked gills, nudi= naked and branch= gills. This name is due to the fact that their gills are usually located on the exterior of their soft bodies. In Some types the gills appear to be a feather like plume on their backs while others have many tentacle-like appendages called cerata, covering their whole body which act as their gills.
Although most are quite small they have some pretty awesome abilities and features. Some species have the ability to take parts of their prey and utilize them in their own bodies. Some nudibranchs are vegetarians and feed on algae. Algae and other plants have specialised cells called chloroplasts which allow them to produce their own energy using sunlight. Once the nudibranch has eaten the algae it takes those special cells and uses them in its own body to produce more energy for itself.
Because they are so small, soft and lack the protective shell that many other molluscs have the nudibranchs have to use other ways to deter predators. Their bright colours and patterns, apart from looking fantastic, also aid in protection. In the animal world bright colours generally mean that the animal is toxic in some way and advertises to would be predators that the animal would not make a great snack.
There are also nudibranchs that feed on stinging hydrozoans. These hydrozoans do not harm the nudibranch and once it has eaten them it takes the hydroid stinging cells and moves them to the tips of its cerata (tentacle like appendages). These cells are then used in the nudibranchs own defence and when touched it is able to deliver a sting identical to that of its hydrozoan prey.
You can find nudibranchs across the world's oceans from the freezing waters of the arctic to the warm waters of tropical regions like the beautiful whitsundays. Finding these amazing little creatures never gets old and it's always a rush of excitement when you spot their colourful little bodies on the reef. So next time you join Wings Whitsunday Adventures for a snorkeling adventure keep a close eye out for some of our favourite little reef buddies.