Deep-sea parasitic nematodes of the genus Trophomera Rubtsov et Platonova, 1974 (Benthimermithidae) from the Equatorial Atlantic, with the descriptions of two new species

Nematode females of the genus Trophomera (Benthimermithidae) from the collection of the Smithsonian's National Museum of Natural History (Washington, DC, USA) were examined. Nematodes were collected in different parts of the Western Atlantic (Hatteras Abyssal Plain, Brazil Basin, and Argentina Basin) from depths of 467-5,223 m. Two new species are described. Body length of T. americana sp. n. is 3,250-4,470 mu m; posterior end conical with rounded tip; cephalic setae about 3-4 mu m long; trophosome consisting of several longitudinal rows of large cells; ovaries reflected; mature eggs 35 mu m in diameter. Body length of T. longiovaris sp. n. is 7,870-15,400 mu m; posterior end conical with rounded tip; cephalic sensilla 7 mu m long; mouth opening vestigial, present as very narrow apical pore; pharynx devoid of internal lumen and muscular envelope; midgut represents a trophosome without internal lumen; trophosomal cells arranged in 3-4 longitudinal rows; rectum and anus vestigial; female reproductive system didelphic, amphidelphic, very long, occupying about 0.8 total body length; ovaries telogonic, outstretched; oviducts very long, repeatedly folded across body axis; proximal parts of oviducts being than distal ones, uterus distinctly formed. New finds of two known species, T. arnauidi and T. marionensis, are also recorded and described.