Scaptognathus magnus Abé, 1990

Abé, Hiroshi, 2021, Taxonomic review of the subfamily Lohmannellinae (Acari: Trombidiformes Halacaridae) with morphological comparisons among genera, Zootaxa 4980 (2), pp. 201-255 : 231

Scaptognathus magnus Abé, 1990

Diagnosis. Glp-1 same level as Ds-1. Ds-2 on membranous cuticle. PE with 1 dorsal seta. GA bipartite in female. Female with 6 Pgs and 2 Sgs. Tr I–IV with 1-1-1-1 setae; Bf I–IV with 2-2-2-2 setae; Tf I–IV with 4-3-2- 2 setae, 2-1-0-0 Bp setae; Gn I–IV with 4-5-3-3 setae, 2-1-0-0 Bp setae; Tb I–IV with 8-6-6-6 setae, 5-3-3-3 Bp setae; Ta I–IV with 3-3-3-3 dorsal setae, 1-1-0-0 Bp setae. Lc I with unidentate accessory process. Idiosoma length 384–484 in female. Idiosoma width 247–324 in female. Gnathosoma length 328–368 in female. Gnathosoma width 154–169 in female. Ratio of gnathosoma to idiosoma 0.74–0.85 in female. Ratio of P-2 to P-1 3.50.

Remarks. This species resembles S. tridens and S. trouessarti , however, differs from the latter two species in having a trapezoidal AD and a unique leg chaetotaxy. S. magnus is the largest species in the genus. Female is known.

Habitat. Sublittoral zone: Coarse sands at 10 m depth.

Distribution. North Pacific Ocean:Teuri Is. (Hokkaido) [ Japan]. Simnibawi Rock (37°48’43’’N, 128°54’38’’E), Gangneung [ South Korea].

References. Abé (1990c), Abé & Green (1994), Lee et al. (2020).

Depository. NHMIC.