Marine Biology (2+1)

Trochus radiatus

Species: Trochus radiate

Family : Trochidae

Common Name : Top shell

Habitat : Intertidal rock boulders

 

Description: Thick, solid, trochoidal shell with moderately elevated spire; the body whorl with sharply angled periphery. Shell surface is circled by irregularly beaded bands. The beads in each whorl is larger on the upper row than those at lower rows. Columella with blunt teeth. Aperture grooved within. Umbilicus wide and deep.

Colour of the shell yellowish white with broad uninterrupted, axial, reddish streaks. Aperture, columella and umbilical area pearl white.

Normally adult and large shells are encrusted with algae. Shells washed on beaches are usually clean, exposing the underlying pearly layer below the surface. Feed on encrusting algae.

Size: 25mm.