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 Euraphia hembeli Conrad, 1837 Figure 4 ; Tables 2 , 3 Euraphia hembeli Conrad, 1837: 261. Non-type material examined. Andaman Sea : 2 specimens , Phang-nga province , Takua Thung district , Na Tai beach, 16.V.2015 , A. Pochai (BUU16. CH .EH01-02) . Description. Peduncle absent; base membranous; body length larger than Chthamalus and range from 10-30 mm. Shell brownish grey with 6 plates (1 carina, 2 carinal latus, 2 latus and 1 rostrum), carina bigger than rostrum, carinal latus bigger than latus. External surface of shell irregularly ribbed around basal margin, inner surface of parietes smooth and white with dark brown and pale violet horizontal striations around aperture. Parietes symmetrical, calcareous and solid, parietes separable, sutures coarsely serrate or with interlocking toothed structure. Orifice rhomboidal. Operculum plates symmetrical, tergum smaller than scutum, tergum and scutum separable. Scutum triangular, occludent margin of scutum with strong teeth. Tergum strongly marked with 10-12 lateral depressor crests, scutal margin strongly articulated. Figure 4. Euraphia hembeli collected from Na Tai beach, Phang-nga (BUU16.CH.CH01). 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. External (upper panel) and internal (lower panel) view of shell plates. Abbreviations: c, carina; cl, carinal latus; l, latus; r, rostrum. Distribution. Barnacles in the genus Euraphia were recorded in several regions including West Africa, the Mediterranean, Hawaii and Southern Japan ( Newman and Ross 1976 ). Euraphia hembeli was previously recorded in California around San Diego ( Barrett and Freeman 2016 ). In this study, we report the presence of Euraphia hembeli distributing along low and middle shore of the intertidal zone, which was only found at Na Tai station, the Andaman Sea (Table 2 and 3 ). In addition, this is the first report of its presence in Thailand. Table 3. Distribution of acorn barnacles on different habitat types of intertidal zone (vertical zonation): low shores/sublittoral zone (LS), middle shores/littoral zone (MS), and high shores/supralittoral zone (HS).
Scientific name Habitat type Settlement pattern on habitats
LS MS HS
Family Chthamalidae
Chthamalus malayensis - - + Attached to rock platform, shell of Tetraclita spp. and other substrates
Euraphia depressa - - + Attached to sheltered sites of rock
Euraphia hembeli + + - Attached to rocky shore exposed to heavy wave action
Family Tetraclitidae
Newmanella spinosus + - - Attached to rocks on a wave exposed shore
Tetraclita kuroshioensis - + - Attached to rock platform and sheltered sites of rock
Tetraclita singaporensis - + - Attached to rock platform and sheltered sites of rock
Tetraclita squamosa - + - Attached to rock platform and sheltered sites of rock
Family Balanidae
Amphibalanus amphitrite + + + Attached to rocks on a wave exposed shore, shell of oyster and Asian green mussel, offshore vessel and various substrates
Amphibalanus reticulatus + + - Attached to shell of Asian green mussel, oyster, ridged Venus clam and other substrates
Megabalanus tintinnabulum + - - Attached to rocky shore exposed to heavy wave action
Remarks. Based on the shell and opercular valve morphology ( Newman and Ross 1976 ; Kim and Yamaguchi 1996 ), two candidates: Euraphia hembeli Conrad, 1837 and Euraphia pilsbryi Hiro, 1936 (reassigned as Hexechamaesipho pilsbryi (Hiro, 1936)) show similar patterns of opercular plates to our collected specimens. Based on Newman and Ross (1976) , description of Euraphia hembeli in Barrett and Freeman (2016) and Chan et al. (2008) , our specimens fit more into Euraphia hembeli and differ from other Euraphia in its gigantic appearance (up to 30 mm) and the presence of strong marked lateral depressor crests (10-12 in number, less in Hexechamaesipho pilsbryi ).