Planaxis sulcatus, common name the tropical periwinkle, is a species of sea snail, a marine gastropod mollusc in the family Planaxidae.

[1] This marine species occurs in the Red Sea and in the Indian Ocean off Mozambique, Kenya, Madagascar, Tanzania and off Mauritius, Chagos, Aldabra and the Mascarene Basin.

[1] It is also found off the Pakistani coast, specially Sonmiani Bay (Miani hor).

Parasites of Planaxis sulcatus include trematode Lobatostoma manteri.

This Planaxidae-related article is a stub.