Blue cod
A temperate marine fish endemic to New Zealand known for its blue-green colour and territorial behaviour.
The blue cod (Parapercis colias) is a ray-finned fish found only in New Zealand. It lives on rocky coasts and is managed under a quota system due to fishing pressure.
- Endemic to New Zealand coastal waters
- Can live up to 32 years
- Changes sex from female to male
- Lacks a swimming bladder
- Annual catch reaches 2,500 tonnes
What it is
The blue cod is a marine fish belonging to the family Pinguipedidae. It has a plump body covered with firm scales and a rounded head. Adults display bluish-green or blue-black colouring on their backs, fading to white on the belly. Smaller individuals often show brown blotches. The fish possesses prominent eyes that can rotate independently. It lacks a swimming bladder, which keeps it close to the seabed. Its fins include a short anterior dorsal section and a long posterior one. Males typically grow larger than females.
Where it lives
This species is endemic to New Zealand. It inhabits coastal waters around the entire coastline, excluding the Kermadec and Snares Islands. Populations are most abundant south of Cook Strait, particularly near Southland and the Chatham Islands. It occupies depths up to 150 metres, preferring rocky outcrops, gravel, or sandy seabeds with sponges or algae.
How it lives
Blue cod are bottom-dwellers that use their pectoral fins for movement. They are territorial, with males holding large home ranges containing small groups of females. They feed on an omnivorous diet including small fish, crabs, polychaetes, and molluscs. Natural predators include sharks, dolphins, and sea birds. The fish can change sex from female to male as they mature. They are sensitive to noise, with thunder causing them to leap from water.
Breeding and life cycle
Spawning occurs during the southern spring and winter months. Females release eggs continuously over time rather than in a single event. Eggs may drift significant distances before hatching. Juveniles initially inhabit deeper sponge gardens before moving to shallower waters in summer. Sexual maturity varies by region, with males maturing at different sizes depending on location.
Fish and people
The blue cod is a valued food source for Māori communities in the South Island. It is also important for recreational fishing and commercial harvest. Annual catches range between 2,000 and 2,500 tonnes. Management occurs under New Zealand's quota system. Some local populations have declined due to fishing pressure. Traditional practices included offering fish heads to deities after harvest.
Status and threats
Populations are managed through a quota system to prevent overfishing. Some areas show signs of scarcity due to high fishing pressure. The species is considered near threatened in certain contexts. Conservation efforts focus on maintaining sustainable catch levels. Habitat degradation from activities like oyster dredging may negatively impact prey diversity and fish size.
Questions people ask about Blue cod
Where does the blue cod live?
It is found exclusively in New Zealand. It inhabits shallow coastal waters up to 150 metres deep. It prefers rocky areas with sponges or algae. Populations are densest south of Cook Strait.
What does the blue cod eat?
It is an omnivore that eats small fish, crabs, and crustaceans. Adults also consume molluscs and algae. They stalk prey and swallow it whole. Their diet varies by region and availability.
How big can a blue cod get?
Adults can reach 60 centimetres in length. They typically weigh between 1 and 3 kilograms. Males generally grow larger than females. Maximum recorded weight is around 3 kilograms.
Is the blue cod endangered?
Some local populations are scarce due to fishing. Management uses a quota system to protect stocks. The species is not globally extinct but faces regional pressure. Conservation aims to maintain sustainable numbers.
Good reading and sources
The facts on this page come from the Wikipedia article "Blue cod", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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