The ballan wrasse (Labrus bergylta) is the largest wrasse species found around the coasts of the United Kingdom. Its name “ballan” comes from an old word meaning strong or sturdy — a fitting description for this thick-set, burly fish. Adults typically grow to around 30cm in length, though they can reach up to 50cm.
Ballan wrasse are powerful feeders, preying on hard-shelled molluscs and crustaceans. They have strong jaws and specialised crushing teeth in their throat (pharyngeal teeth) that help them pulverise shells. Unusually, they are agastric, meaning they do not have a true stomach — instead, digestion takes place entirely within the gut.
Like many wrasse species, ballan wrasse begin life as females. Between roughly 4–14 years of age (most commonly around 5–6 years), some individuals will change sex and become males, usually in response to social or environmental cues.
