The carnivorous whelk

Herewith, as promised a couple of days ago and with little adornment, is the life cycle of the common whelk (Buccinum undatum).

Whelks reproduce annually, with spawning occurring between October and May. The process begins when water temperatures drop below 12°C. Females attract males by releasing pheromones, and fertilisation occurs internally. After mating, females move to hard substrates like rocks, shells, or stones to lay their eggs. The eggs are deposited in small, spherical protective capsules, which are stuck together in a sponge-like mass. Each capsule can contain up to 2,700 eggs, and a single female may produce 80-150 capsules.

The embryos develop within the egg capsules for 2-5 months. During this time, many of the eggs serve as food for the developing embryos, with only about 1% successfully developing into juveniles. After 4-5 months, fully formed juvenile whelks hatch from the capsules in winter. Newly hatched whelks measure about 3 mm in shell length. They then grow slowly, reaching 10-15 mm after one year and 21-26 mm at two years. They typically reach sexual maturity between 4.7 and 7.5 years of age, at a shell height of 45-70 mm.

Adult whelks are carnivorous predators and active scavengers. They use chemosensors to detect food in the water, extending a tube called a siphon to funnel water into their sensory organs. Their diet includes polychaete worms, small bivalve molluscs, and carrion. Common whelks typically live for about 10 years.

Unless, of course, they are caught for eating by carnivorous humans.

Brighton & Newhaven Fish Sales operate several boats that catch whelk (among other fish). The Evie Mae, an under-10m multipurpose catamaran, engages in whelk fishing during the warm summer months. One of its fishermen, Kier Foster, was quoted recently as saying: ‘There’s not much of a market here for these [local catches]. It’s best to cook the whelks, slice them up and send them to China where they go for £30 a kilo.” 

Nevertheless, you can buy fresh whelks on Brighton’s pebbles in the summer thanks to Frazer Leigh Smith’s Brighton Shellfish & Oyster Bar where they are served with vinegar and pepper. Delicious - if you like the sort of thing!