Common Reef Creatures – Reef Fish Continued

Part 4—Reef Fish Continued

Triggerfish

Triggerfish are deep bodied, compressed fish with an almost diamond shaped body. Their eyes are set high on the head, and they have a small terminal mouth with large stout incisor teeth. They have a large spike like first spine and two smaller spines, all of which fit into a groove on the head. Triggerfish lay eggs under the sand and the nest is heavily guarded by the male. Some of the larger species will attack and bite divers during nesting. Smaller species can be shy and swim away or hide when approached, but often the larger fish are ill tempered.

Image: Picasso Triggerfish

Parrotfish

Parrotfish are prominent characters on coral reefs. They are medium to large elongate fish with teeth fused into strong beak like plates. All species have large cycloid scales and are herbivores. Parrotfish are important reef species because they graze on the algal film growing on coral rock, leaving room for coral species to settle and grow. Very few parrotfish eat leafy algae or living coral. Bits of rock eaten with the algae are crushed into sand and ground with the algae to aid digestion. This makes parrotfish among the most important producers of sand on coral reefs, with one fish producing up to 1 tonne of sand in a year. Many species occur in large mixed species schools, often with surgeonfish. Parrotfish also change colour with growth and sex and the colourful males charge around the reef protecting and bullying his harem of drab looking females.

image: Schlegel’s Parrotfish

Fiji Devil Damselfish

Fiji Devil Damselfish are small colourful fish with moderately compressed bodies. They like to live in shallow waters in lagoons and on offshore reefs. These fish have a stunning electric blue colour you can’t miss them! They can occur in small groups near shelter. The females lay eggs buried under sand, which are guarded by the males. The Fiji Devil is not usually shy and is happy to put on a show of its colours, by defending its territory.

Image: Fiji Devil Damselfish

Sweetlips

Sweetlips are medium to large fish with thickened lips, small conical jaw teeth and flat ended to rounded tails. The species found in Fiji are usually quite colourful and attractive fish such as the oriental sweetlips in the picture. Adult fish are typically inactive by day when they shelter near or under ledges, and disperse to feed on benthic invertebrates at night.

Image: Oriental Sweetlips

Angelfish

Angelfish are small to medium fish with deep compressed bodies and small mouths with brush like teeth. They are generally very colourful and beautiful to observe in the water. They can be confused with butterflyfish except that they have a distinctive spine on their gill cover. All species have a haremic social system with a dominant male typically defending a territory containing 2 to 5 females. They spawn in pairs usually at sunset. Their diet consists generally of sponges, soft bodied invertebrates, fish eggs, and algae. The Emperor Angelfish is shy and often seen around caves, ledges or large boulders. They make a ‘knocking’ sound when disturbed.

Image: Emperor Angelfish

Rays

Rays are elegant creatures that glide around the reef. The body is flattened into a round or angular shape. They have a small mouth, located on the underside of the body, with pavement-like teeth. They have one or more venomous barbs near base of tail. They often rest on sandy bottoms, or bury themselves under sand waiting for their unsuspecting prey. All species of rays are dangerous if stepped on and the larger ones can deliver a fatal sting. If you are getting into the water in a sandy area shuffle your way in. The rays will hear you and glide away before you even have a chance to see them. The blue spotted stingray is angular in shape with grey skin and blue and sometimes a few black spots.

Image: Bluespotted Stingray

This part completes the Common Reef Creatures series.