Waved whelk

Breeding in the waved whelk takes place mainly during the colder months, from late fall to early spring. Water temperatures of 0 to 6 degrees Celsius are favourable for embryo development.

To mate, the male positions himself beside the female and transfers a spermatophore, a gelatinous mass containing sperm, by internal fertilization. The female can store the sperm for several weeks before using it to fertilize her eggs, allowing her to wait until conditions are right to spawn. She then produces sturdy egg capsules, protective cases containing the eggs, which she attaches to hard substrates on the seafloor.

The egg masses often form spongy clusters made up of several hundred capsules. Each capsule contains several eggs, but only a few develop. This stage lasts five to seven months, depending on temperature.

At hatching, young waved whelks resemble miniature adults. They reach sexual maturity at about five to seven years of age, a relatively late stage that contributes to the vulnerability of populations.