Greater Weever

• It is the commonest cause of fish envenomation on European beaches: a bather treading on a buried individual suffers excruciating pain that can last for hours.
• The standard treatment is to immerse the area in water as hot as can be borne, because the venom is heat-labile and breaks down with warmth.
• It keeps the ability to envenomate for hours after death, so accidents also happen while handling the catch at the fish market.
• It causes most fish stings on European beaches, and almost always through being trodden on: it lies buried in the sand of the shore with only its eyes and spines showing.
• The venom is injected through the spines of the first dorsal fin and through a spine on each gill cover. Its own specific toxin is called dracotoxin.
• The pain is excruciating and can last for hours. The recognised first aid is to immerse the area in hot water, up to about 45 °C, for 30 to 90 minutes: the venom is heat-labile and the heat denatures it.
• At night it abandons its camouflage and comes out to hunt invertebrates and small fish.
• Its venom apparatus is a case of evolutionary convergence with that of the stonefish: two families with no close kinship arrived at the same design of grooved spine and gland.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat and environment

Sandy and muddy bottoms, from the intertidal down to about 150 m

Sexual maturity

At one year old, between 12 and 16 cm

Gestation / incubation

Pelagic spawning; the eggs measure 1 mm

Sources consulted: https://es.wikipedia.org/wiki/Trachinus_draco

Best time: Summer, when it moves into shallow sandy bottoms