The Klong U-Tapao Basin in southern Thailand
has many canals, with U-Tapao and Waad Canals
being the two most important ones in Songkhla
Province. Both of them collect natural and
discharged water from rural areas and from Hat Yai
City and drain into Songkhla Lake. U-Tapao Canal
originates from the Sankarakiri Mountain Range
and Ton Nga Chang Canal while Waad Canal starts
in the Khao Ban Thad Mountain Range at Ton
Nga Chang Wildlife Sanctuary. U-Tapao Canal is
90 km long, while Waad Canal is only 37 km in
length (Royal Thai Survey Department 1997a, b,
c). The flora and fauna are very rich in the
watershed area of Ton Nga Change Wildlife
Sanctuary, but there are few reports on species
diversity, aside from studies of ant diversity
(Watanasit et al. 2000; Watanasit & Noon-anant
2005; Watanasit et al. 2005b)