* Aliculastrum cylindricum (Helbling, 1779) Figure 6E

Material examined.

Two specimens 25-30 mm, LB.

Ecology.

In soft sediment habitats outside the coral reef where it is found associated with cyanobacterial mats on the benthos. May also be found near the reef edge when cyanobacteria abundances increase, indicating a possible seasonal influence in abundance. Often found together with other Haminoeidae species from Koh Tao, apart from Atys sp. It may be a probable prey species for the mantis shrimp Haptosquilla cf. nefanda (Kemp, 1911) (see ecology of Aliculastrum debilis below). Depth 8-18 m.

Distribution.

Widespread across the Indo-Pacific including Mozambique (Macnae and Kalk 1958), Tanzania, Madagascar, the Philippines, Papua New Guinea, New Caledonia (Gosliner et al. 2008), South Africa, Seychelles, Mauritius, India, Japan, China, Fiji, and Tahiti (Too et al. 2014). Known from the Gulf waters of Thailand (Nabhitabhata 2009).