XENOPHYOPHORES (PROTISTA, RHIZOPODA) IN BOX-CORE SAMPLES FROM THE ABYSSAL NORTHEAST ATLANTIC-OCEAN (BIOTRANS AREA) - THEIR TAXONOMY, MORPHOLOGY, AND ECOLOGY

Forty-nine xenophyophores were collected in 16 box-core and 3 multiple-core samples taken at six closely spaced stations in the northeast Atlantic (3,800-4,550 m). Densities ranged from 0 to 9 specimens per box-core (0-36 per m2, xBAR = 10.5 +/- 10.7 per m2). The 11 morphologically distinct forms recognized from this material are believed to represent at least seven species: Reticulammina labyrinthica Tendal, 1972, sensu Gooday and Tendal, 1988; Psammina aff. delicata Gooday and Tendal, 1988; Homogammina crassa sp. nov.; Galatheammina irregularis sp. nov.; Galatheammina erecta sp. nov.; Galatheammina sp. A, and Occultammina sp. A. Some of these species, particularly H. crassa, G. erecta, and R. labyrinthica, are highly variable. All seven species are present at one station, a greater species diversity than in any previous northeast Atlantic samples. Study of complete specimens soon after recovery shows that individuals of Homogammina, Galatheammina, and Reticulammina have morphologically different upper (exposed) and lower (buried) parts. The lower part usually takes the form of root-like bars. These bars commonly are branched and are extensively developed in some specimens of Reticulammina. The genus Occultammina is reported here for the first time from outside the Pacific Ocean.