17. Altenaeum charcoti (E. Lamy, 1906) [Figs 9A–E]

Montaguia charcoti E. Lamy, 1906: 46, fig. 2

Material examined. • 7 spms, Stn. 2; • 2 spms, Stn. 3; • 5 spms, Stn. 6; • 61 spms, Stn. 7; • 200 spms, Stn. 8; • 22 spms, Stn. 10; • 126 spms, Stn. 11; • 32 spms, Stn. 12; • 25 spms, Stn. 13; • 8 spms, Stn. 14; • 34 spms, Stn. 15.

Type locality. Anvers Island (Antarctic Peninsula).

Bathymetric distribution. 5–113 m.

Substrate. Soft bottom.

Geographical distribution. ANTARCTICA:Antarctic Peninsula, Bellingshausen Sea. SUBANTARCTICA: Kerguelen Islands, Macquarie Islands. SCOTIA ARC: South Georgia, South Orkney Islands, South Shetland Islands. SOUTH AMERICA: -.

Remarks. In contrast to the following species, A. charcoti was never found in the intertidal, but occupied depths between 15 and 100 m. This common species was regularly colonised by polyps of the hydrozoan Monobrachium Mereschkowsky, 1877 . Altenaeum charcoti is easily confused with A. narchii, with which it often occurs sympatrically. The somewhat more bulbous shape, the shorter main teeth of the left valve, and the absence of the ligament plate clearly distinguish this species from the following species. The species is already known from the Maxwell and Admiralty Bays. The species is a free-living, shallow-burrower, with a predominantly deposit-feeding habit (Passos et al. 2005).

References. Arnaud et al. (1986), Dell (1990), Rauschert (1991), Absher & Feijó (1998), Narchi et al. (2002), Passos et al. (2005), Passos & Domaneschi (2006), Engl (2012), Aldea et al. (2016).