Euraphia hembeli Conrad, 1837

Pochai, Ashitapol, Kingtong, Sutin, Sukparangsi, Woranop & Khachonpisitsak, Salinee, 2017, The diversity of acorn barnacles (Cirripedia, Balanomorpha) across Thailand's coasts: The Andaman Sea and the Gulf of Thailand, Zoosystematics and Evolution 93 (1), pp. 13-34 : 16

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.

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.

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 ).

Figures

Figure 4. Euraphia hembeli collected from Na Tai beach, Phang-nga (BUU 16. CH. CH 01). 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.