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Bitterling

Introduced from central and eastern Europe, the bitterling is now naturalised in several parts of the UK and has established itself in ponds, small lakes and canals.

Bitterling, courtesy of Jack Perks Bitterling are a small non-native species that has little impact on native fish in our canals.

Bitterling facts

Scientific nameRhodeus sericeus
FamilyCyprinidae (Carp)
DietVegetable matter
PredatorsPike, zander and fish-eating birds
Size5-6cm
Weight3-20gm
Lifespan2-3 years
British record catch21gm

Bitterling and our canals

Bitterling are a non-native fish species. In the UK, they live in small lakes, ponds and slower-flowing rivers, where they feed on algae, plant matter and tiny invertebrates.

How to identify a bitterling

Bitterling have a narrow and flattened body with bright silver and iridescent light purple sides. They have long bright orange dorsal and anal fins, with white pectoral and pelvic fins. Their eyes are large and golden red in colour, and they have slightly upturned mouths. Bitterling have an incomplete lateral line, extending to only 5-6 scales.

Lifecycle of a bitterling

This small fish, typically 6cm in length, has a remarkable breeding system and unusual life cycle.

The female lays her eggs in April and May through an ovipositor into freshwater mussels, which protect the eggs from predators. Ovipositors are tube-like organs, typical among insects, that lay eggs.

The fertilised eggs hatch in two or three weeks, staying within the mussel for about a month. Males adopt and defend a well-defined territory.

Where to find bitterling

The bitterling has been found in the Llangollen Canal and Shropshire Union Canal for decades, and appears to have little impact on native fish stocks.

How to catch a bitterling

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Location is more of a key than tactics when it comes to catching bitterling.
Carl Nicholls, fisheries & angling manager

Bitterling are small fish that require light float tackle and small hooks and baits. If you catch one of these non-native fish and have the fishery owner's permission to humanely kill it, please do so. You must not take it home live.

Read the story behind the bitterling record fish holder.

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Other fish species to look out for

Last Edited: 24 April 2025

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