Nudibranches are best described as marine underwater snails,
but instead of being protected by a hard shell like normal snails
they rely on bright colors to scare off potential attackers
( bright colors often indicate toxicity in nature). The colors
are also used as a disguise to blend the animal into the background.
Over 3000 species are known to science and they come in a huge
variety of spectacular bright colors.
The name nudibranch actually means naked gills, you can see
the gills on the back of the animal as the bits that flutter
around. They also have two feelerhorns (rhinophores) and one
row of teeth known (radula), their appearance varies of what
they feed on.
You may be lucky enough to encounter this graceful animal while
snorkelling or diving the Great Barrier Reef, while they enjoy
living on the ocean floor at depths up to 700 metres they are
also found near the surface. Do not be tempted to touch them,
they are extremely fragile and easily damaged!
They usually graze on sponges, barnacles, anemones etc. but
some feed on corals and store the photosynthetic algae known
as zooxanthallea in their bodies where they continue to photosynthesize,
thus producing an ongoing supply of energy for the nudibranch.
They are hermaphrodites and have both male and female sex organs,
making it much easier to find a mate. After mating eggs in a
huge variety of colors, shapes and sizes are laid around where
they feed and they take from 5 to 50 days to develop, depending
on water temperatures.