Fishes

Article | Updated 12 months ago

Fishes are among the most diverse and colourful marine animals. There are two major classes of fishes, the Cartilaginous Fishes (Class: Chondrichthyes) ie sharks and rays, and the Bony Fishes (Class: Osteichthyes). There are approximately 25 000 species of fish found worldwide and ~96% of these are bony fish.

Fish possess a range of body shapes and colour patterns depending on the ecosystem they inhabit. For example, some fish are able to achieve high speed in the open water, some camouflage in sand to ambush their prey and others blend into corals to avoid predators.

Fish are of great interest to humans: they are caught during recreational activities for food and for sport, are observed during SCUBA diving or snorkeling ventures, and are kept as aquarium pets.

Grey Reef Shark

The Grey Reef Shark inhabits coral reefs throughout the Indo-West Pacific Region at depths of up to 280 m.

This species is distinguished by the black margin on the tail. The upper body is dark grey to bronze-grey, while the underside is pale. The dark upper body makes it difficult for prey above it to see the shark against the darker deep waters below, while the light colouration of their underside blends in with the lighter coloured surface water when the shark is viewed from below.

Grey Reef Sharks can grow up to 2.5 m in length and weigh in excess of 30 kg.

Its diet consists mainly of reef fishes, but will also feed on squid, octopuses and crustaceans. Although this species may be active during the day, they are most active and feed at night.

Grey Reef Sharks were recorded in relatively low numbers during a visual survey throughout the Dampier Archipelago.

Image of a Grey Reef Shark (Carcharhinus amblyrhynchos).

Grey Reef Shark (Carcharhinus amblyrhynchos).
Image copyright Barry Hutchins, WA Museum. 

Blue-spotted Fantail Ray

This ray can be found living in areas with sandy bottoms, near coral reefs. When the tide is low or falling they take shelter under ledges or in caves, while during a rising or high tide they emerge into the shallows to feed on molluscs, worms and crustaceans.

This ray is distinguished by its orange colour and the vivid blue spots on its upper surface. The Blue-spotted fantail ray may possess one or two venomous spines on its tail. Members of this species can grow to a length of 70 cm and a width of 30 cm.

Blue-spotted fantail rays are found through out the Indo-West Pacific Region. During a recent visual survey of fishes in the Dampier Archipelago observations of this species were relatively low.

Image of a Blue-spotted fantail ray (Taeniura lymma).

Blue-spotted fantail ray (Taeniura lymma).
Image copyright Clay Bryce, WA Museum. 

Image of a Blue-spotted fantail ray (Taeniura lymma).

Blue-spotted fantail ray (Taeniura lymma).
Image copyright Barry Hutchins, WA Museum. 

Yellow-edged Moray

Yellow-edged Moray Eels can be found among crevices of coral reefs along the northern coast of Australia and throughout south-east Asia.

Yellow-edged Morays are generally yellow-brown in colour with the dark spotting along the body and head. They also possess a black patch on the gill opening.

Their diet comprises of fishes, crustaceans, octopuses and squid. Like other moray eels the Yellow-edged Moray possess sharp needle like teeth. However, they are not considered dangerous to humans unless provoked.

This species was observed to be present in the Dampier Archipelago in relatively low numbers during a visual survey.

Image of a Yellow-edged Moray (Gymnothorax flavimarginatus).

Yellow-edged Moray (Gymnothorax flavimarginatus).
Image copyright Barry Hutchins, WA Museum. 

Western Australian Seahorse

The Western Australian Seahorse can be found living among sheltered reefs or seagrasses at depths of up to 10 m along the northern and western coasts of Australia.

The colouration of Western Australian Seahorses includes a combination of white, yellow, orange or brown with distinctive brown lines across their snout. Seahorses are poor swimmers and, therefore, rely on camouflage to avoid predators. They are able to change colour or grow skin filaments to blend in with their surroundings.

An unusual behaviour exhibited by seahorses is that the male carries the eggs while they develop. During reproduction, female seahorses transfer their eggs to the brood pouch of a male. The males then carries the eggs until they are fully developed.

Image of a Western Australian Seahorse (Hippocampus angustus).

Western Australian Seahorse (Hippocampus angustus).
Image copyright Barry Hutchins, WA Museum. 

Scribbled Angelfish

The Scribbled Angelfish lives in coastal waters around reefs or in areas with open flat sea beds among coral, sponges and sea-whips. They are generally found in pairs or small groups, and feed on sponges or sea squirts.

Growing up to 28 cm in length, these angelfish have a dark bar running through the eye, a yellow band along their back, and a yellow tail. Males have blue wavy lines along their sides, while the females possess yellow or blue spots.

The Scribbled Angelfish can be found across northern Australia and up into Papua New Guinea, but has also been reported as for north as Taiwan.

This species is relatively abundant around the reefs of the Dampier Archipelago.

Image of a Scibbled angelfish (Chaetodontoplus duboulayi).

Scibbled angelfish (Chaetodontoplus duboulayi).
Image copyright Sue Morrison, WA Museum. 

Image of a Scribbled angelfish (Chaetodontoplus duboulayi).

Scribbled angelfish (Chaetodontoplus duboulayi).
Image copyright Clay Bryce, WA Museum. 

Margined Coralfish

Margined Coralfish have a predominately white body, with a broad vertical yellow band towards the tail. They also have two narrow vertical orange bars near the head. The lack of several more orange bars along its body distinguishes it from other similar species.

This fish is found in the waters of northern Australia and, as the name implies, inhabits coral reefs. Margined Coralfish are relatively abundant around reefs of the Dampier Archipelago.

Image of a Margined coralfish (Chelmon marginalis).

Clay Bryce, WA Museum
Image copyright Clay Bryce, WA Museum. 

Image of a Margined coralfish (Chelmon marginalis).

Margined coralfish (Chelmon marginalis).
Image copyright Clay Bryce, WA Museum. 

Moon Wrasse

Moon Wrasse have an elongated body that is dark green to blue with fine pink vertical lines, and with bright yellow markings on the tail. The head is also dark green to blue with a pattern of pink markings. This species can grow up to 30 cm in length.

Moon Wrasse are found in lagoons and coastal reefs throughout the Indo-Pacific Region.

Moon Wrasse occur in large numbers on reefs throughout the Dampier Archipelago.

Image of a Moon Wrasse (Thalasoma lunare).

Moon Wrasse (Thalasoma lunare).
Image copyright Barry Hutchins, WA Museum.