Watch out for weevers on the beach!

Watch out for weevers on the beach!

No sea angler deliberately sets out to catch either the lesser weever or its bigger relative, the greater weever. But, since they are sometimes accidentally caught by anglers, it’s important to know what they look like – they are two of the few dangerous fishes found in British seas.

The lesser weever – which reaches up to 15cm (6in) long – is fairly common around the coasts of Britain and Ireland, although distribution is patchy. It lives in shallow water from the tide line down to about 50m (160ft).

During the day the weever burrows in the sand so that its eyes, the top of the head and the back are exposed. Much of its food, particularly crustaceans and small bottom-living fish such as sand gobies and sandeels, is captured as they pass over the buried weever. With a rapid lunging movement the weever attacks from underneath, catching its prey with its upward-pointing mouth.

Going with the flow

At night the weever actively forages for food, moving up the shore as the tide advances to feed on dislodged animals. The weever also retreats with the tide, but occasionally becomes trapped in shallow tide pools on the shore.

The burrowing habit is the clue to their local distribution since weevers may be common on one beach and absent on the next. The size of the grains of sand is all-important: burrowing is easier in fairly coarse sand than on a shore where the sand is fine-grained or mixed with mud. Unfortunately, clean sandy shores also attract bathers and shrimpers — and this brings the weever into conflict with man.

Lying in wait

Both species of weever have two dorsal fins – the first, short-based one is armed with four strong spines. There is also a stout spine on each gill cover. All these spines have venom glands at the base. The weever lies buried in the sand and raises its dorsal spine if disturbed. Somebody stepping on the fish is instantly stabbed by the spines, which then inject venom into the wounds.

Anglers and shrimpers are also at risk -when picking up their catch they can be stabbed by the gill cover spines as well as by those on the dorsal fin. Holding the fish by its tail is no solution either, since it swings itself from side to side and stabs the back of your hand.

The protein-based venom is incredibly painful and the affected area rapidly swells up. The pain usually subsides within 12 hours, giving credence to the old fisherman’s tale that the effects last until the tide returns to the height it was when the injury occurred! Although the sting is not directly fatal, it is serious – due in large part to shock and to secondary infections that may occur (keep the wound clean).

Big brother

The greater weever, at 40cm (16in) long, is up to three times the size of the lesser weever. Fortunately it lives offshore over sandy ground in depths of 10-100m (30-330ft) and is not frequently caught by anglers.

Apart from size and habitat, you can distinguish the two species by looking at the first dorsal fin – this is entirely black in the lesser weever but only partly so in the greater. Similarly, the lesser weever has smoothly rounded pectoral fins, while those of the greater are more squarely cut. The greater weever is often caught in trawls, particularly over known sole fishing grounds, and is turned into fishmeal. On the Continent it is reckoned to be excellent for eating.

Little is known about the life-cycle of either species, other than that they spawn inshore between June and August. The eggs are free-floating.