Lohmannella Trouessart 1901

Lohmannella sp.

Material examined. One protonymph, Sula Ridge, 64°05’N, 8°02’E, 285 m, 31 July 1999, POSEIDON Cruise 254; coll. W. Michaelis and T. Pape.

Description. Length of idiosoma 232 µm. Gnathosoma short, length 120 µm, length of rostrum and palps 51 and 67 µm, respectively. Basal pair of maxillary setae in middle of rostrum. Leg segments short. Tibia IV hardly longer than telofemur. Tarsus IV with three dorsal setae. Claws with minute accessory process.

Remarks. The shape of the idiosoma, gnathosoma and legs is most similar to that of L. norvegica of which the adults have a length of about 425 µm. Lohmannella, as most other halacarids, have three juvenile stages, namely one larval and two nymphal ones (proto- and deutonymph) (Bartsch 2015). In general, the size of the dorsal and ventral plates, the gnathosoma and legs increases from one stage to the other, allometric growth is common, the shape of the plates changes, also the number of setae on the legs (cf Bartsch 2007a). Since only a protonymph is available for study and the description of L. norvegica is not detailed, a reliable identification is not possible.