Common Roach

Common Roach
Conservation status
Least Concern (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Rutilus
Species:	R. rutilus
Binomial name
Rutilus rutilus (Linnaeus, 1758)

The Common Roach (Rutilus rutilus, family Cyprinidae, plural also "common roach") is a freshwater and brackish water fish native to most of Europe and western Asia. It is locally simply known as "the roach", but actually the fishes called "roach" can be any species of the genera Rutilus and Hesperoleucus depending on locality.

Description

large female roach before spawning season

The roach is typically a small fish, often reaching no more than about 35 cm (14 inches). Maximum length is 45 cm. The body has a blueish silvery color and becomes white at the belly. The fins are red. The number of scales along the lateral line is 39-48. The dorsal and anal fin has 12-14 rays. Young specimen have a slender build, older specimen get a higher and broader body shape. The roach can often be recognized by the big red spot in the iris above and beside the pupil. Colours of the eye and fins can be very pale however in some environments.

Differences from common rudd

The roach can most easily be confused with the common rudd, the dace and the ide.

• The common rudd has a more yellow/greenish or golden color. The backfin is placed more backwards and between the tip of the ventral scales and the first ray of the anal fin there are only one or two scales. The roach will have 4 or 5 scales there. The mouth of the rudd is more upturned and the head appears sharper.
• The dace has a greenish body , colorless eyes and fins and a distinct 'nose'.
• The ide has a higher number of scales along the lateral line (55-61), a rounder body and a bigger mouth and head.

On exhibition Subaqueous Vltava in Prague

Distribution

The common roach is found throughout Europe except for the area around the Mediterranean and its distribution reaches eastward into Siberia. In Eastern Europe and Asia there are several subspecies, some with an anadromous lifecycle living around the Caspian and Black Sea. Around the Mediterranean and in northwestern part of Spain and Portugal several closely related species occur with no overlap in their distribution.

Ecology

The common roach prefers to feed in the deeper parts of water bodies but can be found in any water body deeper than 20 cm and wider than 1.5 m and will adapt to local circumstances. It has a great tolerance for organic pollution and is one of the last species to disappear but is on the other hand also often the most numerous cyprinid in nutrient poor water bodies. It also has a tolerance for brackish water. The lethal temperature is around 31 °C.

In most parts of its distribution it is also the most numerous fish, but it can be surpassed by the carp bream in terms of biomass in water bodies with high turbidity and sparse vegetation. The roach is a shoaling fish and is not very migratory with the exception of the anadromous subspecies. In the cold season they migrate to deep waters where they form large and dense shoals (places like small inland harbours are a favourite).

The roach will prefer waters that are somewhat vegetated, because larval and young fish are protected by the vegetation and the mature fish can use it for food.

The common roach will eat plant material, bottom dwelling (benthic) invertebrates and plankton. Young fish feed mainly on plankton, the mature fish will feed mainly on benthos. It can adapt to environments where invertebrates are scarce by slow growth, maintaining a slender body shape and early maturation.

On exhibition Subaqueous Vltava in Prague

Reproduction

The spawning season for common roach is in April and May. Most often spawning occurs on sunny days. Roach will generally use the same spawning location as the previous year. It has been observed that big males form schools where the females enter and have their eggs fertilized by males trailing the female. The behavior is rough and the fish will often jump out of the water. The females can lay up to 100,000 eggs. When the pH of the water is below 5.5 the roach will not be able to reproduce successfully.

Fishing

Fishing for roach in Britain is relatively easy because the species is found in most rivers, lakes and ponds throughout the country. Larger specimens tend to be particularly elusive, but smaller individuals are easy to catch on relatively light line and with a bait such as maggot or worm. They also take particle baits such as sweetcorn and can be caught on a variety of different types. The only limit in type is regarding the size of the bait, because the mouth of the roach is relatively small and the pharyngeal teeth are not particularly strong. A popular bait particularly in France and Belgium is germinated cooked hemp seed.

Essential for good catches is regular feeding to keep the shoal active and feeding around the bait. For roach mostly fixed rods and floats are used for a controlled presentation of the bait, and for larger distances and roach also match rods and swim feeders are being used. The line doesn't need to be thicker than 0.12 mm and the hook not more than a size 12. Thinner lines and smaller hooks will produce more fish especially when the roach are of small size. The best catches with fixed float fishing are often made when the bait is presented just a few cm above the bottom.

Boilies and luncheon meat are generally avoided by roach because they are too large for them to swallow. Because it is a schooling species, it is not unusual for an individual fish to be caught many times during a single session, and sometimes a larger, specimen individual could be waiting outside the shoal. Roach are infamous for their ability to throw the hook during retrieval, which further perpetuates the idea that larger roach are notoriously difficult to bank. The maximum recorded weight for the species in Britain is 4 lb 3 oz (1.90 kg) and any fish over a pound is regarded as a specimen individual.

It is possible to make large catches in harbours where large shoals are concentrated in the winter season. Flyfishing in such places with sinking artificial flies with a gold colored bead for a head on long leaders can produce good catches and often specimen roach are caught that way.

See also

• Vobla, salted Caspian roach.

External links

• Fishbase on roach
• The Common Roach
• Roach fact sheet, about subspecies Rutilus rutilus caspicus
• "Rutilus rutilus." ITIS Standard Report. (Integrated Taxonomic Information System: National Museum of Natural History, Washington, D.C., 2004-06-03). ITIS 163761
• Brief guide to fishing for Roach