INTRODUCTION
Surat Thani is the largest of the southern provinces
of Thailand, and is popular for both Thai and foreign
tourists for its beautiful islands, beaches, and submarine
fauna and flora. This includes Samui Island, a large
island in the Gulf of Thailand, which is 84 km east of
Surat Thani Province. Land development can be found
at many areas around the island.
Brandt (1974) reported that 43 common species
of brackish-water mollusks inhabit Thailand. Another
11 snail species can be found in Surat Thani Province,
of which 2 species of Cerithidea (Cerithidea)
charbonnieri and Morrisonietta bandonensis, are
present only in Surat Thani Province.
The major intent of this study was to investigate the
distribution of species of brackish-water mollusks
(hereafter referred to as snails) in Surat Thani Province,
southern Thailand. The secondary purpose was to
determine the common trematode infections in snails and
the abundance of snail species in the localities. Surat
Thani Province was chosen because land development is
continuously expanding for residences, agriculture,
fisheries, water resource development, recreation, and
tourism. Hence, some of the brackish-water snails