There are two species of weever fish found in UK waters: the lesser weever and greater weever. Weever fish are a rare example of a venomous fish which inhabits British waters – both species have spines on their backs and gill covers which secrete a potent venom. Lesser weever fish come into shallow water and are the species most likely to be encountered by both anglers and bathers in the summer months, while the greater weever is a species which is found offshore in deeper water.

Lesser Weever

Scientific name: Echiichthys vipera
Also known as: Sting Fish
Size: Up to 8ins/20cm, but commonly 8 – 12cm
UK minimum size: N/a
UK shore caught record: 95 grams
IUCN Status: NE (Not Evaluated)
Distribution: Found all around the UK and Ireland over sandy and muddy seabeds.
Feeds on: Small and immature fish, fish fry, crustaceans and prawns.
Description: Small fish with a thickset body. Colour is silver to white with a brown/yellowy mottled pattern. The upturned mouth is relatively large in comparison to body size, and eyes are located at top of the head. The first dorsal fin is black in colour and made up of five spines which contain venom, as do additional spines located on the gill covers. A second dorsal fin runs the length of the rest of the body, as does the anal fin. The tail is small and usually has a black tip.

Despite the fact that the lesser weever is a small fish – the UK shore caught record is 95 grams (3oz 4dr) – it is one of the most dangerous fish found in UK waters due to the potent venom it can deliver. Lesser weever fish are a constant hazard for anglers, bathers and tourists and commercial fishermen in the summer when this species comes closest to the shore.

Weever Fish Size — The small size of a lesser weever fish can be seen in this picture. The tape measure is in centimetres.

Lesser weever fish are common all around the UK and Ireland over sandy, muddy and light shingle seabeds. They are also present in European waters mostly in the Mediterranean, and along the north coast of Africa. In winter lesser weever fish are found in slightly deeper water away from the shore. However, in the warmer summer months lesser weever fish come inshore and can be found in very shallow water. Lesser weever fish bury themselves under the sand with just their eyes and spines protruding. They are aggressive predators and will snap at any small fish, crustaceans or prawns which pass them. Once the sun has started to set lesser weever fish will emerge from the sand, sometimes forming in small loose shoals and swim freely, hunting for small fish. Weever fish are poor swimmers but have a surprising burst of speed over a short distance and use this to catch their prey.

Weever Fish Distribution — Lesser weever fish are found in European waters and along the north coastline of Africa.

It is during warm weather that weever fish are most likely to come into contact with humans. Commercial fishermen are stung by weever fish that are caught in nets which are being hauled on board, and bathers sometimes step on weevers which have buried themselves in sand near to the shore. Anglers are most likely to come across the lesser weever when fishing for mackerel with daylights or feathers as weevers often go for these lures when they are hunting, although they will also take small baits such as ragworm, prawn and mackerel strip. Anglers who are unaware of the lesser weever and mistake it for a sprat or other small fish may swing the fish into their hands to unhook it and receive a deeply unpleasant surprise if the spines of the lesser weever pierce their skin.

Effects of Weever Fish Venom

Once the spines of the weever fish have pierced skin the venom is discharged. The effect of weever fish venom varies from person to person with some only suffering from relatively mild pain. However, in others, the pain can be excruciating and the part of the body which has been stung can become red, inflamed and swell up. There may also be numbness and in extreme cases there can even be localised paralysis for a short period of time.

Bilingual warning sign for weever fish (incorrectly identified as a ‘weaver’ fish) at Tywyn Promenade, Wales.

Usually, the pain begins to subside after a few hours and should be gone within 12 to 24 hours. Further complications will emerge if the spines have broken off into the wound, as they may need to be removed before the pain will subside. If a healthy adult is stung by a lesser weever fish it is not usually necessary to see medical attention. The best course of action is to place the injured body part into very hot water (as hot as the victim can stand without scalding) as the venom is protein-based it is destroyed by heat.

If children, elderly people or those with underlying health issues are stung by a weever fish, or someone is having a particularly bad reaction to a sting, it can be wise to seek further medical advice, and going to hospital can be necessary if pain and symptoms such as swelling persist. On a busy beach lifeguards will be trained to deal with weever fish stings or refer the victim on to more advanced medical care if this is necessary. The NHS website has further information on what to do in the event of a weever fish sting – read it here.

Greater Weever

The other species of weever fish found around the UK is the greater weever (Trachinus draco). This fish is much larger than the lesser weever, weighing up to four pounds, although typically it is half of this weight. It has the same venomous dorsal fin spines as its smaller relative. It is not as common as the lesser weever and inhabits much deeper water, meaning it is rarely encountered by anglers or bathers. There is a British shore caught record for this species, a specimen of 1lb 9oz caught by P. Robinson Porthtowan in Cornwall in 2014. The boat caught record is a greater weever of 2lb 2oz caught by R. Pope off Porthcurno which is also in Cornwall in 1999. The International Game Fish Association list the all-tackle world record as a greater weever weighing 3lb 13oz caught by John H. Williams off the Canary Islands in Spain in 2005.

Commercial Value and Origin of Name

Despite its venomous nature the greater weever fish is edible and is of minor commercial importance, with a limited market for the greater weever as a food fish existing in Scandinavia and Southern European countries. The weever fish is often mistakenly referred to as the ‘weaver fish’. The spelling weever comes from the Old French word ‘wivre’ which means snake or viper.