Arcoscalpellum dubium ( Hoek, 1883 )

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 : 21-22

Arcoscalpellum dubium ( Hoek, 1883)

Fig. 14

Scalpellum dubium Hoek, 1883: 125 , pl. IV, figs 14–15.

Arcoscalpellum dubium: Zevina, 1981a: 348 ; Jones et al., 1990:5; Jones, 2012: 369, tables 1–2.

Material examined. Holotype NHM UK 2013.1085, Stn 184: Pacific, Western Central (Coral Sea); 2560 m.

Diagnosis. The original diagnosis of Hoek (1883) contained no appendage descriptions. The diagnosis should be amended to take into account the presence of a rostrum (See Remarks). A total of 14 capitular plates is present, not 13 as stated by Hoek (1883)

Distribution. Pacific, Western Central. Known depth 2560 m.

Remarks. This species is known from the holotype only. Hoek (1883) noted similarities between the carinal latus of A. dubium and that of Trianguloscalpellum regium (W. Thomson, 1873) and Arcoscalpellum michelottianum ( Seguenza, 1876) . Newman & Ross (1971) noted similarities with Arcoscalpellum acicularum Newman & Ross, 1971 from off the Falkland Islands taken at a depth of 4008 m, although they also pointed to the absence of a rostral plate in A. dubium as a major diagnostic feature separating these two species. We report here the presence of a small, transparent rostrum in the “Challenger” holotype. More detailed comparative study is required in order to confirm the validity of these species.

Figures

FIGURE 14. Arcoscalpellum dubium (Hoek, 1883). “Challenger” Stn 184: holotype, right lateral view. Scale bar 10 mm.