Trianguloscalpellum regium (W. Thomson, 1873)

Shalaeva, Kate & Boxshall, Geoff, 2014, An illustrated catalogue of the scalpellid barnacles (Crustacea: Cirripedia: Scalpellidae) collected during the HMS “ Challenger ” expedition and deposited in the Natural History Museum, London, Zootaxa 3804 (1), pp. 1-63 : 45-49

Trianguloscalpellum regium (W. Thomson, 1873)

Fig. 33 A, B

Scalpellum regium Wyville-Thomson, 1873: 347–348 [description only, not figs 1–2 which refer to Trianguloscalpellum ovale ( Hoek, 1883) ].

Scalpellum regium: Wyville-Thomson, 1877: 4 , figs 2–3; Hoek, 1883: 106, pl. IV, figs 3–5, pl. IX, fig.12, pl. X, figs 1–2; 1884: 10; Pilsbry, 1907a: 28, pl. III, fig. 5 [not pl. III, fig. 4 = T. ovale ( Hoek, 1883) ]; Gruvel, 1912: 2; 1920: 30, pl. 1, fig. 7; Zevina, 1970: 263, figs 10–11; 1973c: 136 [(not S. regium , probably T. gigas ( Hoek, 1883) ]; 1976: 1155.

Scalpellum molle Aurivillius, 1898: 191 ; Gruvel, 1905: 77; 1920: 29, pl. V, figs 10–12; Nilsson-Cantell, 1955: 218; Belloc, 1959: 3; Zevina, 1976: 1155.

non T. regium: Zevina, 1981b: 86 ; Foster & Buckeridge, 1995a: 355, fig. 6K [( Trianguloscalpellum moluccanum? ( Hoek,

1883)]. Scalpellum regium latidorsum Pilsbry, 1907a: 29 . Arcoscalpellum regium: Weisbord, 1977: 271 , pl. 31, fig. 1–5. Trianguloscalpellum regium: Zevina, 1978b: 1350 ; Shreider, 1994: 159; Foster & Buckeridge, 1995b: 167, figs 2A–D, 3;

Young, 1998b: 28–30, figs 20a–h, 22; 1999b: 617, fig. 5B,C; 2001a: 741; 2001b: 464, fig. 7; 2004: 26; 2007: 62–63, fig.

72; Poltarukha & Zevina, 2006a: 158; Poltarukha & Zevina, 2006b: 167, fig. 5; Poltarukha, 2007: 20, fig. 4; Chan et al.,

2009: 125–127, figs 106–108; Chan et al., 2010: 13–14, figs 1G, 10; Poltarukha, 2012: 37–38, fig.11. Trianguloscalpellum regium regium: Zevina, 1981a: 309–310 , fig. 234; Zevina & Shreider, 1992: 40. Trianguloscalpellum regium latidorsum: Rosell, 1991: 22 , fig. 1h–i; Jones et al., 2000: 253.

Material examined. Two syntypes (both partially disintegrated) NHM UK 2013.1127–1128, Stn 61: Atlantic, Western Central (North Western Atlantic Basin); 5210 m.

Supplementary descriptions. Young (1998b) showed plates only; Chan et al. (2009) and Poltarukha (2012) described hard and soft parts.

Distribution. Worldwide excluding polar region (see remarks). Known depth range 1507 to 6135 m.

Remarks. This species may be attributed to the Arcoscalpellum michelottianum group. Numerous specimens have been described from the Atlantic, Pacific and Indian Oceans and this species may represent a complex of cryptic species. Some authors such as Zevina (1981a) and Poltarukha (2012) consider that T. regium is widely distributed across all regions, with the Pacific T. moluccanum treated as a synonym, whereas others retain them as separate species, e.g. Young (1998b, 2007).

According to Hoek (1883), “numerous” specimens of the species were found at two “Challenger” stations: 61 and 63. However, only two specimens (both from Stn 61) are now in the NHM collection. The two specimens, figured and referred as types by Young (1998b), are treated here as syntypes, because it can be demonstrated that these were the specimens observed by Wyville-Thomson in his brief description in 1873.

Both specimens are now in different stages of disintegration. One specimen (syntype A) ( Fig. 33A ) has the tergum and the apical part of the carina separated ( Fig. 33B (b)). The other two fragments (tergum and scutum with the upper latus and upper fragment of the rostral latus joined) appear to belong to the second syntype (syntype B) ( Fig. 33B (a, c, d)).

Figures

FIGURE 33A. Trianguloscalpellum regium (W. Thomson, 1873). “Challenger” Stn 61: syntype A (left and right lateral view). Scale bar 10 cm.