This is a Spindle Shell (Colus jeffreysianus), a species of predatory sea snail belonging to the family Colidae. Historically, it was sometimes referred to as Fusus berniciensis, but this name is now obsolete. Recognised for its elegant, elongated spiral form (fusiform), the shell features prominent whorls and typically displays a pale or off-white colour, occasionally with faint darker bands.

Location:
Northeastern Atlantic Ocean, including waters around the British Isles and North Sea. Found on sandy or muddy seabeds from depths of approximately 50 to over 200 metres.

Average Size:
Shell length commonly ranges between 6 and 10 cm.

Family:
Colidae (Spindle Snails)

Species:
Colus jeffreysianus (formerly referred to as Fusus berniciensis)

Ecological Role:
A slow-moving, predatory gastropod, this species feeds on small invertebrates such as marine worms and bivalves, playing a role in the benthic food web by helping regulate prey populations.

Reproduction:
Separate sexes; fertilisation is internal. Females lay distinctive egg capsules, often deposited on hard substrates or shells on the seabed.

Conservation Status:
Not currently listed as threatened. It is relatively common in suitable habitats, although sensitive to significant changes in seabed conditions.