Determination of gut contents of Thai abalone Haliotis asinina Linnaeus

Samples of the abalone Haliotis asinina were collected from Samed Island, R aayong Province, Thailand, by SCUBA diving every 3 mo for a period of 1 y f or determination of gut contents. The average shell length, shell width, an d total body weight for these samples were 68.3 +/- 9.1 mm, 32.1 +/- 3.5 mm , and 48.2 +/- 11.4 g, respectively. The percentages by weight of visceral mass, foot, and shell were 23.8, 61.6, and 14.5%, respectively. The average volume of microcontents (<120 mu m) in gut contents was 80.3%, and that of macrocontents (>120 mu m) was 19.7%. Most microorganisms were benthic diat oms (99.3%), and the dominant genera were Nitzschia, Amphora, Cocconeis, Na vicula, and Diploneis. Macrocontents consisted mainly of sand grannies and foraminiferans. Therefore, the main food of H. asinina along Samed Island a ppears to be composed of benthic diatoms, which were the predominant floral elements in the local environment.