If nudibranchs weren't quite so small and didn't behave quite so inconspicuously, they would certainly be be the main attraction for scuba divers at coral reefs. Magnifa Nudibranch (Chromodoris magnifica).

Despite their small size, any scuba diver can find 5-10 different types of nudibranchs on an average dive at a nice coral reef.

Nudibranch, corals and sea squirt provide a colorful image.

The bright colouration seen in many species is believed to warn potential predators that the nudibranchs contain distasteful or even toxic compounds.

It's a big anemone for a small fish...

A see-though anemone shrimp sporting a brightly coloured tail. The little Nemo on the background.

Any better plans for a camouflage than being transparent?

Side view of a see-though anemone shrimp.

Hermit crabs lack the shell of 'true' crabs. They have solved their accommodation issues by carrying their home on their back. In most cases it is an empty sea shell.

Some hermit crabs attach anemones to the shell. The anemones provide the crab protection with their stinging tentacles and in turn receive leftover food from the crab's messy eating and free transportation. When the hermit crab grows, it changes shells, pries the anemones off the old one and coaxes them to attach to the new shell.

Thornback cowfish is a boxfish. The bodies of boxfish are covered in a toxic mucus which can be released when stressed.

Two commensal shrimps enjoying a flower coral's polyps...

...until something bigger appears.

Porcelain Crab amongst soft coral polyps.

Scuba divers' nemesis: trigger fish. Trigger fish fiercely defend their nest and cone shaped territory. If you get too close, they'll let you know...

Whitetip reef sharks are the most common sharks scuba divers see at reefs. If you don't bother them, they won't bother you.

Whitetip Reef Shark from a distance. Seeing sharks underwater is a good reason to get certified - while they are still around.

Humphead parrotfish, the largest parrotfish.

Leaf Scorpionfish

Nudibranch inspecting an egg ribbon.

Cone shell - a gastropod. Gastropods have one single solid shell that is usually coiled in some way.

The claws of a mantis shrimp are capable of inflicting serious damage on victims significantly greater than the shrimp. They are known to have broken aquarium glass with a single strike.