Gemfish

How to identify gemfish

A long, slender, compressed fish with an iridescent bluish back that turns silver below. The front of the first dorsal fin carries a large black blotch. The best feature is the forked lateral line: one branch runs high along the back to below the second dorsal fin, and the other drops below the first dorsal fin and runs in a wavy line along the middle of the side to the tail. Two small finlets follow the second dorsal and anal fins. The jaws hold strong, knife-like fangs.

Where it lives in New Zealand

Found around New Zealand on the continental shelf and upper slope, mostly in 50 to 550 m and sometimes to 800 m. Gemfish school near the bottom; juveniles live in open water. There are two stocks. The northern stock lives mainly off the east coast of the North Island and migrates north to spawn north of the North Island in May and June. The southern stock is found around the South Island.

How to catch it

Gemfish are mainly a commercial trawl catch, usually taken in 150 to 400 m. Recreational fishers do catch some, mostly in the north while bottom fishing in deep water, and the recreational take there has grown in recent years. Handle gemfish with care, alive or dead, as the teeth are very sharp.

Eating

White, delicate flesh that flakes easily. Gemfish suits most methods, including baking, frying, poaching, grilling and steaming, and the fillets are excellent smoked. Gemfish is richer than many white fish, with about 7 g of fat per 100 g. Steaks can be blackened in a hot pan.

Recipes

• Zak and Tamar's blackened gemfish steaks (Seafood New Zealand)
• Smoked fish salad with lemon and herbs (Seafood New Zealand)

Good to know

Recreational harvest in SKI 1 (north-east North Island) was estimated at 2752 fish in 2012 and 7140 fish in 2018. Gemfish stocks rely on occasional strong years of young fish, and the northern stock grew between 2019 and 2023 after strong recruitment. They are managed under the Quota Management System.

Questions

What does a gemfish look like?

Gemfish are long, slender and compressed, with an iridescent bluish back fading to silver below. The front of the first dorsal fin has a large black blotch. The key feature is a forked lateral line, with a lower branch that runs in a wavy line along the middle of the side to the tail.

Is gemfish good to eat?

Yes. Gemfish has white, delicate flesh that flakes easily and is richer than many white fish, with about 7 g of fat per 100 g. It suits baking, frying, poaching, grilling and steaming, and the fillets are excellent smoked. Steaks can be blackened in a hot pan.

Where are gemfish caught in New Zealand?

Mostly by commercial trawlers in 150 to 400 m. There are two stocks: a northern stock off the east coast of the North Island and a southern stock around the South Island. Recreational fishers catch some while bottom fishing in deep water, mostly in the north.