Description: This topshell has a straight-sided conical shell, usually with markings in pink and red. A white form lyonsii is common at some localities, especially in strong tidal streams.

Habitat: Predominantly a sublittoral species, almost ubiquitous on rocky substrata where it feeds on a variety of sessile invertebrates, especially hydroids.

Distribution: Widely distributed all round the British Isles.

Similar Species: Juveniles could be confused with other topshells such as Clelandella clelandi.

Key Identification Features:

• Straight-sided conical shell.
• Pink markings on shell.

Distribution Map from NBN: Calliostoma zizyphinum at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Calliostoma zizyphinum at iNaturalist World Species Observations database.

WoRMS: Calliostoma zizyphinum at World Register of Marine Species. Accepted name: Calliostoma zizyphinum (Linnaeus, 1758). AphiaID: 141767.

Classification: Biota; Animalia; Mollusca; Gastropoda; Vetigastropoda; Trochida; Trochoidea; Calliostomatidae; Calliostomatinae; Calliostoma