Meet some of the locals
Spotted wobbegong
Spotted wobbegong(Orectolobus maculatus) lay motionless on the sand or nestled in the reef ready to ambush their prey. These predators feed mainly at night, snatching fishes, crustaceans and octopuses that come within reach with their needle-sharp teeth. Spotted wobbegong are differentiated from other wobbegong species by the well-defined pale markings within the dark saddles along their back.
Image Ecological Service Professsionals
Giant Queensland groper
Giant Queensland groper (Epinephelus lanceolatus) is a protected fish in NSW. It is one of the largest reef-dwelling fish in the world reaching up to 3 m and 600 kg. Usually solitary and commonly seen in caves on coral reefs, it is a large-mouthed ambush hunter feeding on a variety of fishes, as well as small sharks, juvenile sea turtles, crustaceans and molluscs—all are swallowed whole.
Image Leigh Edwards
Blue groper
The eastern blue groper (Achoerodus viridis) is the fish emblem for NSW. It is actually a species of wrasse. They hunt crustaceans, urchins, and shellfish among rocky and coral habitats. Eastern blue gropers are all born females, but can change sex at roughly 50 cm length if few males are present. Juveniles are green-brown, adult females are reddish-brown, and males are vivid blue. Males can grow to over a metre and weigh up to 18 kg.
Image Leigh Edwards
Black edged nudibranch
Nudibranchs are sea slugs named for their exposed or naked gills. The black-edged nudibranch (Doriprismatica atromarginata) is a carnivore, feeding on sea sponges. They can store sponge toxins in their body and use them for self-defence. Often displaying bright colours and markings to warn-off potential predators.
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Humpback whale
The humpback whale (Megaptera novaeangliae) can be found playing, resting, or cruising through the aquatic reserve from May to November during their annual migration. The song of male humpback whales evolves each year to impress the females, and can sometimes be heard by snorkellers and divers as they explore the aquatic reserve.
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Spanish dancer
The Spanish dancer (Hexabranchus sanguineus) ) is one of the largest nudibranchs, reaching up to 60cm. It feeds on sponges and can be found among rocky or coral habitats. Like other nudibranchs, the Spanish dancer generally moves using its muscular foot; however, when threatened, it will undulate through the water, with its rippling display and vibrant red hues resembling the skirt of a flamenco dancer.
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Banded sea urchin
The banded sea urchin (Echinothrix calamaris) is typically active at night, hiding in crevices of the reef during the day. They have two types of spines: the longer, paler banded spines usually have blunt ends, while the shorter, darker spines are fine and sharp, and capable of delivering a sting to predators. Like most other urchins, the banded sea urchin is a herbivore that grazes on algae.
Image Rudi Vir
Indo-Pacific bottlenose dolphin
A resident pod of Indo-Pacific bottlenose dolphins (Tursiops aduncus) ) spends most of their time in the open water of the reserve, surfing, hunting for fish and squid, resting and mating. They will also forage for crustaceans among the rocky and coral reef habitats.
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Blue sea star
The blue sea star (Linckia laevigata) has five cylindrical arms and is usually light to bright blue in colour, although some individuals have different colouration due to different pigment ratios. It is found in seagrass beds or among coral or rocky reef. Their varied diet includes decaying animals and plants, small invertebrates, and algae. Sea stars project their stomach out through their mouth to start digesting large meals externally.
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Grey nurse shark
The grey nurse shark (Carcharias taurus) is critically endangered. Their diet consists of fish, rays, and squid. While Cook Island is not a key aggregation site, these sharks cruise through the aquatic reserve during their migration along the NSW and Queensland coasts. The grey nurse shark is slow to reproduce, and is threatened by some human activities.
Image David Harasti
Goldspotted sweetlips
Goldspotted sweetlip (Plectorhinchus flavomaculatus) ) is a carnivore that scours sand and reef habitats for small fish, worms and crustaceans. They swim solo, in pairs or in small groups, including with other species of sweetlips. The adults are dusky silver-blue with yellow-orange lines on their face and spots over their body. Juveniles have thick brown lines running from head to tail over a silver-white body.
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Noble feather star
Feather stars are related to sea stars and sea urchins. While most can walk short distances using small, leg-like structures, or swim using their feathery arms, the noble feather star (Comaster nobilis) usually stays in one place. It feeds mainly at night, using its arms to filter plankton and detritus from the water and bring food to its mouth.
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White's seahorse
White’s seahorse (Hippocampus whitei) is named after John White, Surgeon General to the First Fleet, rather than for its colour. White’s seahorse can change colour to reflect its mood or for camouflage. It is an endangered species due to habitat loss and pollution, and was recorded in the Cook Island Aquatic Reserve for the first time in 2024. White’s seahorse feeds on zooplankton and small crustaceans.
Image Leigh Edwards
Persian carpet flatworm
Persian carpet flatworm (Pseudoceros bedfordi) ) is aptly named for its bold colours and ability to ‘fly’ through the water by undulating its body. It grows to 8–10 cm in length and is a hermaphrodite, having ovaries and testes. It has two penises used to engage in penis fencing, attempting to inject sperm into its opponent to fertilise it, while trying to avoid being fertilised by its opponent.
Image Professor Stephen Smith
Bulb-tentacle sea anemone
Bubble-tip or Bulb-tentacle sea anemone (Entacmaea quadricolor) is a host for anemone fish, commonly attached deeply in a crevice or hole so that only tentacles are visible. It is a carnivorous, opportunistic feeder on small invertebrates but also receives nutrients via a symbiotic zooxanthellae, which produces food through photosynthesis. Anemone fish and shrimp will also incidentally provide their host with food.
Image Hamish Malcom
Green turtle
The green turtle (Chelonia mydas) is a threatened species. They are common within the aquatic reserve, grazing on seagrass and algae, resting on the sand, or nestled under ledges in coral and rocky reef habitats. They are named for the greenish colour of their internal tissues (cartilage and fat), rather than their external colouration.
Image Gary Shuttleworth
Hawksbill turtle
The hawksbill turtle (Eretmochelys imbricata) ) is a threatened species. It has a narrow head and jaws shaped like a beak so it can reach into crevices in coral reefs. Sponges are its most important food although it also eats seagrass, sea anemones, squid, algae, and soft corals. Colouration is olive grey with black and mottled brown spreading to the sides. The carapace has serrated edges.
Image Tommy Byrnes
Loggerhead turtle
The loggerhead turtle (Caretta caretta) ) is a threatened species. It has a large head and its thick, powerful jaws are used crush shellfish and crustaceans.This species is mainly carnivorous, eating a varied diet including sponges, corals, molluscs, crustaceans, sea urchins, sea cucumbers, sea stars, fish and jellyfish.
Image Rudi Vir
