The area of distribution of T. ciliatum consists of two separate parts. The first part comprises the Red Sea and the western part of the Indian Ocean. Along the eastern coast of Africa it is extremely common, and extends as far south as Zululand Further it has been recorded from Madagascar and many island groups (Comores, Mascarenes, Seychelles, Aldabra, Maldives, Chagos Archipelago). The second part of the area comprises the eastern part of Malesia, the Solomon Islands and the eastern coast of Queensland; the species is apparently rather rare in this part of the area. In Malesia it has been found in Java, Philippines, Celebes, Lesser Sunda Islands, Moluccas and New Guinea.