Blue-spotted spinefoot
Siganus corallinus
Rivulated Rabbitfish
Siganus rivulatus
About
The rivulated rabbitfish is a gregarious, mostly plant-eating fish that schools by the dozens over shallow reefs and seagrass. It grows to about 27 cm, though most divers see fish closer to 20 cm, moving in tight groups over algae-covered ground.
Also known as: little spinefoot
- Length
- 20 cm · max 27 cm
- Depth
- up to 30 m
Appearance
This is a flattened, oval-shaped fish with a slightly forked tail. Its colour is variable: the upper body is grey-green to brown, fading to a yellow or silvery-white belly, often marked with dark spots and wavy yellow lines along the sides. The fin spines are slender and venomous, a common warning feature of rabbitfish.
Habitat
It lives in shallow water over algae-covered rock, sand, and seagrass beds, usually less than 15 m deep, and sometimes enters brackish estuaries. It prefers sheltered areas and is found from the East African coast and Red Sea into the Mediterranean Sea.
Behaviour
It forms schools of 50 to several hundred fish and grazes mainly on algae. When startled, it can change colour to a mottled pattern with darker diagonal zones across the body. Its fin spines carry venom that causes painful stings if the fish is handled, though this is not fatal to people.
Did you know?
Though mostly a grazer of algae, in the northern Red Sea it has been seen attacking large comb jellies and even moon jellyfish, feeding on the jelly until the animal falls apart or sinks to the bottom.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
