Australian ghostshark

What it is

This creature is a cartilaginous fish belonging to the subclass Holocephali, known as chimaeras. It is not a true shark, though it shares the broader group Chondrichthyes with sharks and rays. The body is smooth, torpedo-shaped, and silvery with iridescent reflections and dark markings. Two triangular dorsal fins sit widely apart on its back. A distinctive hoe-shaped snout helps it probe the sea floor. Adults can reach lengths of up to 1.5 metres, with males maturing at half that size and females at roughly 70 centimetres.

Where it lives

The species inhabits waters off southern Australia, including Tasmania, and extends to New Zealand south of East Cape and Kaipara Harbour. It lives at depths ranging from the surface down to 200 metres. During spring and autumn, adults migrate inshore towards estuaries and bays. There is some scientific hypothesis that the populations in Australia and New Zealand might represent separate species, though they are currently classified as one.

How it lives

These fish use their specialized snouts to search for invertebrates and small fish on the ocean bottom. They possess three cone pigments, granting them colour vision similar to humans. A sharp spine on the dorsal fin has a reputation for being venomous, although no serious injuries have been recorded. The maximum lifespan is estimated at fifteen years. They are active in coastal zones and move into shallower waters seasonally.

Breeding and life cycle

Spawning occurs from spring through autumn when adults move into sheltered bays. Females deposit large yellowish egg capsules onto sandy or muddy seabeds. Seawater enters the case after a few months as it partially opens. Juveniles hatch after six to eight months, emerging at approximately 12 centimetres in length. This extended development period protects the young during their most vulnerable stage.

Fish and people

In New Zealand, the white flesh is popular in fish-and-chips shops. In Australia, it is sold as flake or whitefish, though often discarded by gillnet fisheries targeting gummy sharks due to lower market value. Recreational anglers catch them in Victoria and Tasmania. The species is vital for science; its small genome helps researchers understand vertebrate evolution, sharing a common ancestor with humans from 450 million years ago.

Status and threats

The New Zealand Department of Conservation classifies the species as Not Threatened, noting it is conservation dependent but increasing. Commercial exploitation occurs in New Zealand during spring and summer. In Australia, it is caught incidentally or by recreational fishers. No major global conservation alerts are currently raised for this population.

Relatives and look-alikes

It belongs to the chimaera group, distinct from true sharks and rays which form the subclass Elasmobranchii. Genetic studies show its genome sequence is more similar to humans than to teleost fish like zebrafish, despite humans being more closely related to teleosts. It is sometimes confused with other chimaeras but is identified by its specific snout shape and regional distribution.

Questions people ask about Australian ghostshark

Good reading and sources

• Client ChallengeNature, Article
• Transcriptional Activation of Elephant Shark Mineralocorticoid Receptor by Corticosteroids, Progesterone and SpironolactonearXiv, Article

• Australian ghostshark on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data