One species, many coats
The common, mirror and leather are all Cyprinus carpio. The Wildlife Trusts describe the mirror and the leather as varieties of the common carp that show different scale patterns. Everything else, from the shape of the fish to the barbels at its mouth, is the same.
So the types are coats. Same fish underneath. The fish underneath is one fish.
Where carp came from
Carp aren't native to Britain. The Wildlife Trusts say they were introduced in the Middle Ages, for food. The British record committee includes them on its coarse list because they've been here for over 1,000 years. That long history is why the common, the mirror and the leather all share one record. The crucian, a separate species, has its own.
Common carp
Fully scaled, in neat and even rows from head to tail. The Wildlife Trusts describe the colour as greyish-bronze, and a big common can look gold in low sun. Because every common looks much like the next, anglers often tell them apart by size and by marks on the fins. On a print, the rows have to run straight, or it looks wrong at once.
Mirror carp
A mirror has a scatter of large, shiny scales, often in patches along the back, the lateral line and the tail root. The rest of the body is bare. No two mirrors share a pattern, which is why carp anglers can recognise an individual fish years after they first caught it. Some well-known mirrors carry names, and their regulars can pick them out from a single photo. That's a high bar for any print.
Linear and fully scaled mirrors
A linear is a mirror whose scales run in a neat line along the lateral line. A fully scaled mirror is covered in big, irregular scales, quite unlike the even rows of a common. A linear's scales follow the lateral line from the gill plate towards the tail, and any gap in that line belongs to the fish. Both are prized by carp anglers. Both are hard to get right on a print, because every scale is a different size and sits in its own place.
Leather carp
A leather has few scales or none. Some are almost bare. Striking. Often there's a handful along the back by the dorsal fin, and the bare skin gives the whole fish a smooth, dark look. Where a leather does carry scales, they're as individual as a mirror's pattern. Check them on any print. A leather photographed in low sun shows every fold of skin, which suits the pencil study.
How big carp grow
Size isn't a type. Commons, mirrors and leathers all grow big, and the British record happens to be a mirror of 68lb 1oz, caught in 2016. Our biggest carp guide covers typical sizes, the record and how to weigh a big fish.
Crucian carp
Crucian carp are a different species, Carassius carassius. The Canal & River Trust describes a hump-backed fish with a deep bronze or golden body and a long, convex dorsal fin. Unlike the common carp, it has no barbels.
The Trust lists the crucian as rare and protected, and notes it's on the IUCN Red List. Its record on the committee's list is 4lb 14oz.
Other fish called carp
Grass carp are a different species again: long and grey-green, and they feed mainly on plants. They don't share the common carp's record. Koi are ornamental carp, bred for colour. Catch either and it won't count towards a carp PB. Most carp anglers wouldn't want it to. If you're not sure what you've caught, a clear side-on photo settles it.
How to tell them apart on the bank
Look at the flank first, in good light, with the fish lying flat on a wet mat or held low in the water. Even rows mean a common. Scattered big scales mean a mirror, and a single line means a linear. Bare skin means a leather. Then check the mouth: a common or mirror has barbels at the corners, and a crucian has none. A crucian is also much smaller and rounder, so if you're still in doubt, photograph it side on and ask someone who knows crucians. Easy, once you've seen a few.
Photographing the scales
If the scales are what make your fish, make sure the camera sees them. Shoot side on and keep fingers off the flank. Glare hides a mirror's pattern, so tilt the fish a touch until the shine goes. Take several frames. One will be sharp. Our catch photo guide has the camera settings, with advice from Angling Times and Carpology.
Carp through the year
Carp fishing isn't tied to the river season. Under the GOV.UK rod fishing rules, rivers are closed to coarse fishing from 15 March to 15 June. Most enclosed stillwaters and canals stay open all year. Private waters can set their own close seasons. Check before you go, especially in spring, when some private waters close for a few weeks. If you're buying a day ticket as a present, ring the fishery first and ask whether it closes at any point in spring.
A print of your carp
On a mirror, the scale pattern is the fish, so any print of it has to keep every scale where it was. Count them if you like. Print your catch photo as it is, or see it in a house style and check the scales in the preview. Our carp prints show each type. Get the photo right first with our catch photo guide.
Craig Fearn runs Scale & Fin, a UK studio that prints anglers' catch photos and fish art to order. He writes the guides here, and every fact in them links to the body that published it.