Amphibalanus reticulatus (Utinomi, 1967)

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 : 21

Amphibalanus reticulatus (Utinomi, 1967) Figure 10 ; Tables 2, 3

Balanus amphitrite var. communis Darwin, 1854: 240, pl. 5, figs. 2e, h, l [type locality: Tachitgatani, Tanabe Bay, Japan].

Balanus amphitrite communis : Hiro 1938: 301, figs. 1a, b; Utinomi 1956: 52, pl. 26, fig. 11.; 1960: 44, figs. 1c, d, 2c, d.

Balanus reticulatus : Utinomi 1967: 216, figs. 9a, b, 10a, b, 11a-e, pl. 6, figs. 7-8; Henry and McLaughlin 1975: 88, text figs. 11, 18, pl. 7, fig. d, pl. 8, pl. 9, figs. a, d, e.

Non-type material examined.

Andaman Sea: 2 specimens, Phang-nga province , Takua Thung district, Na Tai beach, 16.V.2015, A. Pochai (BUU16.BN.AR01-02) .

Gulf of Thailand: 3 specimens, Chon Buri province, Si Racha district, Si Racha beach, 04.VII.2015, A. Pochai (BUU16.BN.AR03-05) . 3 specimens, Chon Buri province, Mueang Chon Buri district, Khao Sam Muk beach, 05.VII.2015, A. Pochai (BUU16.BN.AR06-08) . 3 specimens, Chon Buri province, Ko Si Chang district, Ko Kham Yai beach, 05.VII.2015, S. Khachonpisitsak (BUU16.BN.AR09-11) .

Description.

Peduncle absent; base calcareous. Shell white-pale pink and orange with 6 plates (1 carina, 2 carinal latus, 2 latus, 1 rostrum); single rows of parietal tubes (parietes single tubiferous) with transverse septa; radii solid. External surface with longitudinal and horizontal striations, transverse teeth on suture edges with denticles on lower regions, internal surface of parietes white. External surface of operculum white-pale pink and orange with striations in both tergum and scutum, internal surface of operculum white. Scutum bigger than tergum, scutum triangular; tergum spur sharp with growth lines.

Distribution.

Amphibalanus reticulatus is widely distributed from Japan, the Indo-West Pacific to Australia, of which the latter is considered as an introduced species carried by ship transport ( Jones 2004). In this study, Amphibalanus reticulatus occurred in the intertidal zone along the Andaman Sea and the Gulf of Thailand. These specimens were found at Si Racha, Khao Sam Muk, Ko Kham Yai (Chon Buri) and Na Tai (Phang-nga).

Remark.

Amphibalanus reticulatus exhibits clear vertical and horizontal striations while Amphibalanus amphitrite shows only vertical purple striation in all shell plates. In addition, the shapes of shell of Amphibalanus reticulatus is more columnar than that of Amphibalanus amphitrite , which might be due to elongation of parietes in response to crowding when growing as colonies. On all examined stations, distinct distribution and settlement between Amphibalanus amphitrite and Amphibalanus reticulatus can be noticed, in that Amphibalanus amphitrite were found in almost all kinds of substrates but Amphibalanus reticulatus preferred its attachment on shells which obviously did not live along the rocky shores and it might probably inhabit the deeper areas of the sea and were occasionally carried away into the shores by wave action.

Figures

Figure 10. Amphibalanus reticulatus collected from Si Racha beach, Chon Buri (BUU 16. BN. AR 01, A; BUU 16. BN. AR 03, B & C). 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.