Carp Species Explained: Mirror, Common, Leather, Ghost, Koi and F1 Carp

Table of Contents

Updated September 2026.

Every carp you catch in the UK is the same species, Cyprinus carpio, with one exception covered at the end. Commons, mirrors, leathers, ghosts and koi are not different species but different scale patterns and colour forms of the same fish, produced by selective breeding over centuries. That said, anglers talk about them as if they were separate, and there are real differences in how they look, how they grow and how often you will meet them. This guide explains each type, how to tell them apart on the mat, and a little of the history behind them.

Key points

Common, mirror and leather carp are the same species with different scaling genes.
Ghost and koi carp are colour variants, usually from ornamental stock, and are common in day-ticket lakes.
F1 carp are a crucian and common carp hybrid, bred for commercial fisheries, and rarely exceed a few pounds.
Wild carp are the original slim, fully scaled form and are now very rare in Britain.

Type	Scales	How to recognise it	Typical UK size
Common	Full, even	Neat rows of scales over the whole body, torpedo shape	10 to 30 lb, 40 lb plus in a few waters
Mirror	Irregular, large	Scattered, linear or fully scaled patterns of oversized scales	10 to 40 lb, holds most UK records
Leather	Almost none	Smooth skin, at most a few scales along the back or wrist	Usually smaller, slower growing
Ghost	Common or mirror pattern	Pale, silvery or gold body with a dark metallic head	10 to 30 lb
Koi	Any	Ornamental colours: white, orange, red, black patches	Rarely large in the wild
F1	Small, even	Crucian-like shape, no barbules or very small ones	1 to 5 lb, occasionally larger

Common carp

The common carp is the fully scaled form, with neat, regular rows of scales covering the whole body. It is the closest to the original wild fish in appearance, and in most waters it is the type you will catch most often. Commons tend to be long and powerful, fight hard, and in many lakes are the fastest-growing fish. A big common is a beautiful thing, usually a deep bronze or gold with a paler belly, and the largest commons in the UK now run well past 50 lb in a small number of waters.

Mirror carp

Mirror carp carry a gene that reduces the number of scales and enlarges the ones that remain, giving the scattered, mirror-like plates that give the fish its name. No two mirrors are the same, which is why individual fish in a lake are given names and recognised year after year. Anglers distinguish several patterns: a scattered mirror with a few random scales, a linear with a single row along the lateral line, a fully scaled mirror covered in irregular oversized scales, and the rare plated fish with a handful of enormous scales. Mirrors are the form most associated with big carp fishing, partly because the fast-growing strains stocked in the twentieth century, such as the Leney and Galician fish, were mostly mirrors.

Leather carp

A true leather carp has almost no scales at all, at most a few along the dorsal and near the tail, and its skin has a smooth, leathery look. Leathers also have fewer fin rays and tend to grow more slowly than commons and mirrors because the gene that removes the scales also affects development. They are uncommon, and a big leather is a genuine rarity. Many fish called leathers are actually mirrors with very few scales, so check the back and wrist of the tail: a true leather has no line of scales along the dorsal.

Ghost carp

Ghost carp, sometimes called ghosties, are a cross between a common or mirror carp and a metallic koi. They have the pale, silvery or gold body of the koi parent with a dark head and dark scale edges, and in clear water they show up from a long way off, which is how they got the name. Ghosts are hardy, grow reasonably well and are stocked widely in commercial and day-ticket lakes. Some anglers look down on them, but a 20 lb ghost fights as well as anything, and on some lakes they are the biggest fish present.

Koi carp

Koi are the ornamental form bred in Japan for colour, and they turn up in fishing lakes either through deliberate stocking or through escapees and garden pond fish being released. In the wild their bright colours make them easy prey, and they rarely grow large or live long in a lake with predators, but you will occasionally catch a bright orange or white fish in a commercial pool. Under the skin they are exactly the same fish as a common carp.

F1 carp

The F1 is the one true exception. It is a hybrid between a common carp and a crucian carp, bred for commercial match fisheries because it feeds through the winter, fights well for its size and does not grow large enough to wreck light tackle. F1s have a deep, crucian-like body, small even scales, and either no barbules or very short ones, which is the easiest way to separate them from a small common. They are usually 1 to 4 lb, although fish over 6 lb exist. If you are fishing a commercial for pleasure they are a good day out on light gear, but they are not a target for specimen carp anglers.

Wild carp

The wild carp is what the species looked like before centuries of selective breeding: long, slim, fully scaled, with a small head and a big paddle of a tail. Genetically pure wild carp are now extremely rare in Britain, though a few old estate lakes and river stretches hold fish that look and fight like them. They rarely exceed low double figures but are among the hardest-fighting carp you will hook.

Telling them apart on the mat

Scales tell you most of what you need. Even scales over the whole body means a common. Large irregular scales, or a row down the middle, means a mirror. No scales at all along the back means a leather. A pale body with a dark head is a ghost, and unnatural colour is a koi influence. If the fish is small, deep bodied and has no proper barbules, it is an F1. Whatever you are holding, treat it well: our carp care guide covers unhooking, weighing and returning fish safely.

Carp Species Explained: Mirror, Common, Leather, Ghost, Koi and F1