Angler's Mail fishery boffin, Dr Ian Welch turns his scientific spotlight on common carp, Cyprinus carpio.
How things have changed for carp in the UK. Just a generation ago, this introduced species was relatively limited in its distribution.
It was only fished for by a handful of dedicated anglers, indeed some deemed it virtually uncatchable.
Now it drives a multi-million pound industry, is widely distributed, regularly stocked and is THE target species for a huge number of anglers.
They are so widespread now… on all types of venues, including commercial pools, gravel pits, lakes and slow-moving rivers.
All common carp are defined as genus Cyprinus and species carpio. Breeding programmes have accentuated different physical attributes.
You might be forgiven for thinking that commons, mirrors, leathers, koi and ghosties are all different species. They are, in fact, genetically identical.
Common carp origins
Originally from the Caspian Sea basin of southern Russia, commons were widely spread throughout Europe during Roman times.
Firstly they were in Italy and then more widely to feed monastic communities.
The establishment of monastic ponds brought the first selective breeding programmes.
These were designed to enhance growth rates and biological features, and it is from these early experiments that the different characteristics emerged.
It is impossible to be 100 per cent certain, but evidence suggests that commons probably reached the UK from the Low Countries sometime during the late 14th and early 15th century.
The introduction of so-called ‘king carp’ – the term used to define carp with scale patterning other than the ‘common’ scaling – was established during the 19th century.
Let’s take a closer look at the common carp variants that you are most likely to encounter.
With an even spread of usually uniform-sized scales, the common variant most resembles the original wild fish.
It has a deeper frame and higher shoulders, resulting from early selective breeding experiments to produce fish that carried more meat for eating.
As described above, the genetic selection of scale characteristics to produce king carp was a later breeding development.
Mirror scaling varies enormously indeed and, like a fingerprint, the patterning is a useful aid to identification of individual fish.
Notable variants prized by anglers include fully scaled mirrors, which are, as the name suggests, fully scaled just like common carp, but with large, oversized scales.
Linear mirrors have scales that follow the lateral line along their flanks.
Leather, or nude, carp are totally scaleless, although some exhibit a few scales around the tail wrist or along the dorsal line.
Contrary to popular belief, leather carp are not just mirror carp without scales, but a distinct variant resulting from an historic genetic mutation.
Leather patternation is relatively rare. The gene combination required to produce a true leather also produces eggs and fry that are less viable than those of mirror and common variants.
This inherent genetic weakness means that fewer leather carp reach maturity than commons or mirrors, and those that do are usually smaller than their common and mirror siblings.
Carp were originally introduced into Japan as a food source, where fish farmers identified small numbers of fry exhibiting slightly different colour variations to their siblings.
These fish, which were originally blue, grey and dull orange, were selectively bred to produce the distinctively coloured and patterned specimens now seen in the ornamental trade.
Although not usually regarded as an angler’s fish, some commercial fisheries have chosen to introduce koi.
The threat of transferring diseases, such as Koi Herpes Virus (KHV), with imported ornamental fish makes the practice a risky one.
‘Ghosties’ are a cross between a common or mirror carp and a koi carp, the resulting offspring tending to have a much lighter colouration than the parent fish.
Ghost carp were selectively bred for the UK ornamental market back in the 1980s, and have subsequently found their way into a number of fisheries.
Common carp tend to spawn when the water temperature reaches 18 to 20 Celsius, usually in late-May to July.
They hybridise readily with crucians to produce offspring, which are known commercially as F1s.
They also hybridise with goldfish, but are usually easy to identify. The key anatomical determinants are two pairs of barbules, 35-40 lateral line scales, 17-22 soft dorsal fin rays and five soft anal fin rays.
Carp mat and weighing set
CAUGHT A FINE FISH, GOT A STORY OR VIEWS TO SHARE WITH US? Email us, with or without photos, to: email@example.com YOU could get into print with us.
For the best exclusive content, read Angler’s Mail magazine every week. It’s in shops but also available via easy home-delivery methods, as you can find out here.
Watch brilliant Mail columnist Steve Collett explain more…
There has never been a better time get AM print magazine delivered to you by subscription… each and every week.
You may also like to read these Angler’s Mail stories…
The nation’s passion for angling has rarely been greater than it is now in the summer of 2020. Anglers of…
‘Where are the best carp lakes near me?’ is one question that our Where To Fish team often hear. We…
FLOATER FISHING time is well and truly here. I always look forward to the balmy days of summer… visions of…
THE Nunnery is a six-lake complex run by Paul (Tinker) Taylor and Jason Davies of the Norfolk and Suffolk Fisheries.…