Koi fish

Anabas · climbing perch

The small fish that can walk — and is worth the trouble.

What it is

Koi is the climbing perch — a small, hardy freshwater fish, remarkable for its ability to breathe air and even move short distances over land. In the kitchen it is prized for firm, flavourful flesh and comparatively few, manageable bones, cooked in dishes built to honour it.

Where it comes from

It belongs to the ponds and wetlands of Bengal and the wider east, a fish of the River Delta's rich freshwater tradition. Wild koi has grown scarcer, and much on sale is now farmed.

What it's called

Koi · koi maach (Bengali) · climbing perch. Botanically Anabas testudineus. Not the ornamental Japanese koi.

In the kitchen

Classically fried and finished in a spiced mustard-oil gravy as tel koi (koi in oil), or in a light jhol — preparations that let its firm flesh and distinct flavour show. A prized fish for a good meal rather than an everyday filler. Tilapia is a common stand-in where koi can't be had.

What we know about the claims

A wholesome freshwater fish, good protein; the usual bone caution applies, though koi has fewer than many. No other note.

Choosing and buying

Fresh or frozen in South Asian grocers serving Bengali communities (UK and US); tilapia substitutes for its firm flesh in tel koi. Sourcing wild koi is increasingly hard.