Giant goby  (Gobius cobitis)

Britain's largest native species of goby, the giant goby is greyish to olive brown (4) with 'pepper and salt' freckling, which is particularly marked in smaller fish (5). The deep body is covered in small scales, the eyes are small and the tail stalk is short. Males in breeding condition are darker in colour than females (4).

In the UK, the giant goby is known only from the coasts of south-west England between Wembury and the Isles of Scilly (4). Outside of the UK it is found from the western English Channel to Morocco, in the Mediterranean, the Black Sea and the Gulf of Suez, (4) probably via the Suez Canal (5).

Inhabits rock pools high up in the intertidal zone of sheltered shores. Occupied pools typically contain boulders under which this fish species takes shelter, and have inputs of freshwater, so the water in the pools is usually brackish (4).

This species can often be observed basking on sunny days in pools (4). It has a broad diet, which includes large quantities of green algae, polychaete worms, crustaceans, small fishes, and insects (4). The range of food taken varies depending on the age of the fish. Younger giant gobies mainly take small items such as small amphipods and ostracods while older individuals take larger items, until a large proportion of the food intake consists of green algae (4).

Both sexes live for about ten years, sexual maturity is reached at 2-3 years of age, and breeding occurs between March and May. Up to 12,000 eggs are laid per clutch (5); the eggs are attached to the underside of stones and fertilised by the male who then guards them (4). Females produce two clutches of eggs each year for about eight years (4).

In 1992, giant gobies were absent from one site in south Devon and one from south Cornwall, which are parts of the historic range. It was assumed that the species was in decline, but the species was recorded again in the south Cornwall site in 1998. Although there is no evidence that the species is endangered in the UK, it seems likely that it is vulnerable to human disturbance due to the recreational pressures on the shore habitat (4).

In 1998 the species was added to Schedule 5 of the Wildlife and Countryside Act, 1981 (6). Under this Act it is an offence to kill, injure, take or sell giant gobies, or to damage or destroy any structure or place used by an individual for shelter or protection (3). Furthermore, it is included in English Nature's Species Recovery Programme.

For more on the giant goby see the Marine Life Information Network (Marlin) species information, available on-line at:
http://www.marlin.ac.uk
For more on English Nature's Species Recovery Programme see:
http://www.english-nature.org.uk/science/srp/default.asp

Information authenticated by Dr Keith Hiscock of the Marine Biological Association of the UK:
http://www.mba.ac.uk/