The diversity of acorn barnacles (Cirripedia, Balanomorpha) across Thailand's coasts: The Andaman Sea and the Gulf of Thailand Author Pochai, Ashitapol Department of Biology, Faculty of Science, Burapha University, Chon Buri, Thailand Author Kingtong, Sutin Department of Biology, Faculty of Science, Burapha University, Chon Buri, Thailand Author Sukparangsi, Woranop Department of Biology, Faculty of Science, Burapha University, Chon Buri, Thailand Author Khachonpisitsak, Salinee Department of Biology, Faculty of Science, Burapha University, Chon Buri, Thailand salineek@buu.ac.th text Zoosystematics and Evolution 2017 2017-01-11 93 1 13 34 http://dx.doi.org/10.3897/zse.93.10769 journal article http://dx.doi.org/10.3897/zse.93.10769 1860-0743-1-13 9FF0B30AA53548DEB756BD1C0DFE2B92 0A7C24F9688C57469A1E32EA5B0ADFA4 238998 Tetraclita singaporensis Chan, Tsang & Chu, 2007 Figure 7 ; Suppl. material 2; Tables 2 , 3 Tetraclita singaporensis Chan, Tsang & Chu, 2007: 52-53, figs 1-3. Non-type material examined. Andaman Sea : 2 specimens , Phang-nga province , Takua Thung district , Na Tai beach, 16.V.2015 , A. Pochai (BUU16.TS.TSG01-02) . Description. Peduncle absent; base membranous; shell purplish-dusky green with 4 plates (1 carina, 2 latus, 1 rostrum), parietes conical, plates inseparable, 5-6 rows of parietal tubes (parietes multiple tubiferous), external surface with deep and irregular longitudinal striations from apex to base and small radiating lines, internal surface of parietes smooth and white with greyish-green horizontal striations around aperture. External surface of operculum yellowish brown mixed with dusky green, internal surface of operculum dusky green-purplish and white around spur of the tergum. Scutum bigger than tergum, scutum triangular, short articular ridge-basal margin, external surface of scutum with horizontal striations, occludent margin of scutum with rough teeth. Tergum higher than wide, tergum with broad spur and not beaked, spur angle 30-35°, basi-scutal margin 148-150°. Mandible with 4 big teeth, 2nd and 3rd teeth consisting double teeth, 1st tooth with small spines, lower margin pectinate with 8 small teeth and obvious double bigger teeth at the edge; maxillule notched, two large setae above notch, 13-17 setae below notch; labrum with 4-5 large teeth on each side; cirri I possessing bidenate serrulate setae. Figure 7. Tetraclita singaporensis collected from (BUU16.TC.TSG02) from Na Tai beach, Phang-nga. A. Dorsal and ventral view of external shell, B. External (left panel) and internal (right panel) view of tergum (upper panel) and scutum (lower panel), C. Lateral side showing external surface of shell, D. Close up on the external surface of shell, E-H. Light microscopy on mouthparts, E. Labrum, E. Close up on the teeth of the labrum, G. Mandible, G. Close up on the pectinated lower margin of mandible. E-H. Scale bars in µm . Distribution. Tetracliata singaporensis has been reassigned the name from previously known as Tetraclita squamosa , which were collected from Singapore. Hence, the distribution of this species is firstly marked at Singapore, Indo-West Pacific region ( Chan et al. 2007a ). In this present work, the specimens were collected from Na Tai, Andaman Sea and it distributes in the mid shore. Remarks. Tetraclita singaporensis differs from Tetraclita squamosa in that it has tergum without beak and broader spur, and scutum with short articular ridge-basal margin.