This is the Large Harp (Harpa major), a distinctive predatory sea snail in the family Harpidae. Known for its ornate but robust shell and powerful hunting anatomy, it is a prominent species among harp snails.

Location:
Indo-Pacific region—recorded off East Africa (including Tanzania and Mozambique), the Mascarene Basin, and as far afield as Hawaii. It inhabits sandy substrates, often associated with coral reefs, from sublittoral zones down to depths of around 200 metres.

Average Size:
Shells range from approximately 60 mm to 130 mm (about 6–13 cm), with average adults around 90 mm.

Family:
Harpidae (Harp Snails)

Species:
Harpa major

Shell Description:
The shell is ovate in shape with a heavily calloused spire. The columella typically displays a dark brown hue. The snail possesses a long siphon, a large mouth aperture, and a disproportionately large muscular foot, adaptations that support its predatory lifestyle.

Ecological Role:
A nocturnal, voracious predator focused on benthic crustaceans—most notably crabs, including individuals nearly as large as the snail itself.

Reproduction:
Specific reproductive data for *H. major* is sparse. Like other harp snails, it likely has separate sexes and employs internal fertilisation, with females producing egg capsules or egg masses on sandy substrates.

Conservation Status:
Not formally assessed at international level. Known threats include habitat degradation and collection for the shell trade. In some localities (e.g., Singapore), it may be considered endangered due to collection pressure.