Fish
Roach
Rutilus rutilus · also called common roach
The roach is the fish that taught most of Europe to fish. It is small, silvery, red-finned, and almost everywhere, shoaling in canals, ponds, gravel pits, and slow rivers, and willing enough to take a bait that a child with a jam jar and a bent pin has a fair chance of catching one.
Overview
Rutilus rutilus is a member of the carp family, a deep, flat-sided silvery fish with reddish-orange lower fins and, usually, a red eye. Most are 10 to 20 cm long. It lives across most of Europe and northern Asia in lakes, canals, and the slower parts of rivers, and it eats a broad omnivore’s diet of plants, algae, plankton, and small invertebrates.
Roach or rudd
The two look alike and share the same waters. The reliable difference is the dorsal fin, which sits directly over the pelvic fins in the roach and further back in the rudd. Roach also hybridise freely with rudd, bream, and bleak, producing in-between fish that fit no species neatly.
The keystone prey
Roach are a central prey fish of European fresh water, eaten in quantity by pike, perch, zander, eels, herons, grebes, cormorants, and otters. They are also tough, tolerating warm, murky, low-oxygen water, which is why they dominate canals and city rivers.
Status
The roach is Least Concern, one of the most numerous freshwater fish across its huge native range. Where it has been introduced — to Ireland, Italy, Australia, and elsewhere — its spread is a concern for native fish.
Roach: common questions
What is the difference between a roach and a rudd?
They are close relatives that share the same waters and are often confused. The clearest structural difference is the position of the front of the dorsal fin relative to the pelvic fins, since in the roach it sits directly above them, while in the rudd it is set further back, behind them. The rudd also has a more sharply upturned mouth for surface feeding, a brassier, more golden body, and blood-red fins including the dorsal, and a yellow to orange eye. The roach has a level or slightly downturned mouth, a more silvery body, orange-red lower fins, and a red eye. Hybrids between the two are common and blur all of these features.
How big does a roach get, and how long does it live?
Most roach an angler catches are small, 10 to 20 cm and well under 200 grams, because roach are slow-growing and populations are usually dominated by young fish. A roach of 30 cm and around half a kilogram is a good specimen, and the best waters produce fish approaching 1 kg, which are old, deep-bodied individuals. Roach can live 10 to 15 years or more in favourable conditions. Growth and maximum size depend heavily on food supply and on how crowded the population is, with stunted roach common in small, overpopulated ponds.
Why are roach so common in canals and city rivers?
Because they are unusually tolerant of the conditions those waters offer. Roach cope well with warm, still, turbid, nutrient-rich water and periods of low oxygen that would stress or kill trout, grayling, and many other fish. They feed on a wide range of foods, breed prolifically by scattering sticky eggs over any available weed or structure, and shoal for safety in open, featureless water. In canals, urban rivers, and enriched lowland lakes these traits let roach build very large populations and often become the single most abundant fish, supporting the pike, perch, and fish-eating birds of those same waters.
Is roach good to eat?
It is edible but rarely eaten in Britain, where it is valued purely as a sport and match-fishing fish and almost always returned alive. The flesh is white and reasonably flavoured but soft and, like other members of the carp family, threaded with many fine intra-muscular bones that make small roach fiddly to prepare. In parts of continental and eastern Europe roach are eaten more, usually pan-fried whole when small, or salted, dried, or smoked, and dried roach is a traditional snack served with beer in some countries. Fish from clean water taste far better than those from muddy, weedy ponds.