As its name suggests, the lumpsucker is among the least graceful of fish and has even been described as grotesque. It has a broad head and a large rounded body covered in bumps. These are formed by the bony plates with which it is covered. Overall colour is generally blue-green, but breeding males become reddish in colour.

Lumpsuckers are usually classified as an incidental fishing catch. The flesh is watery but the roe is treated with salt and black dye to produce caviar substitute. Who said caviar was just like salty, black, fishy jelly Lumpsuckers can reach 60cm in length and weigh 5kg, with the female larger than the male.

Lumpsuckers spend most of their time in deep water. In the spring, they come into shallow water to spawn. While the female immediately returns to the relative safety of the depths, the male will stay and zealously protect the clump of up to 200,000 eggs until they hatch two months later. It is during this tour of duty that divers usually encounter them (see picture).

The pelvic fins are adapted to form a powerful sucker on the belly. This is useful for clinging to rocks, particularly in wave-bashed shallow water. Eighteenth century scientists noted that a bucket full of water could be lifted by the tail of a lumpsucker clinging to its base. The experiments showed little regard for the poor

Lumpsuckers lay their eggs attached to rocks in very shallow water, often above low-water mark. Not only does this expose on-guard males to surging waves, it makes them vulnerable to attack from the air by marauding gulls or crows when the tide is out.

Males will attempt to stop creatures such as crabs and starfish devouring the eggs they guard, but their chief task is probably to aerate the clump by fanning it with their fins and pushing their head into it (look out for the hollows in the clump where this has happened). Despite all this effort, lumpsuckers go on a fast for several months during the breeding season.