Diamphidaxona (Diamphidaxonella) platysoma, Smith, Ian M. & Cook, David R., 2006

Smith, Ian M. & Cook, David R., 2006, North American species of Diamphidaxona (Acari: Hydrachnida: Hygrobatidae), Zootaxa 1279, pp. 1-44 : 20-21

Diamphidaxona (Diamphidaxonella) platysoma sp. nov.

( Figs. 75–80 )

Description. Character states of Diamphidaxonella. Dorsal edge of camerostome acutely rounded anteriorly ( Fig. 76 ). Pedipalps with tibia bearing one ventral seta ( Fig. 77 ). Dorsal shield with anterior plate wider than posterior plate and weakly pointed anteriorly ( Fig. 75 ). Ventral shield with suture lines between third and fourth coxal plates with medial loops deeply arched and lateral loops U­shaped and open anteriorly ( Fig. 76 ). Projections covering insertions of fourth pair of legs with anterior extensions moderately long, sinuous and directed anterolaterally ( Fig. 76 ). Genital field of males separated from ventral shield by distinct band of membranous integument ( Fig. 76 ). Measurements: Male (n=2): Length/width anterior dorsal plate 144–150/276–288 (150/276), length/width posterior dorsal plate 276–282/276–282 (282/282), length/width ventral shield 390–402/324–330 (402/330), length/width genital field 64–67/114 (64/114). Lengths pedipalp segments: Tr 13–16 (16), Fe 40–43 (40), Ge 22–25 (25), Ti 27–31 (27), Ta 23–25 (23). Lengths leg segments: ITr 37–39 (37), IBFe 46–49 (46), ITFe 44–49 (49), IGe 56 (56), ITi 62 (62), ITa 74–75 (74); IITr 39 (39), IIBFe 46 (46), IITFe 46 (46), IIGe 53–56 (53), IITi 62–65 (65), IITa 78–81 (78); IIITr 39 (39), IIIBFe 46–52 (46), IIITFe 47 (47), IIIGe 60 (60), IIITi 65–70 (65), IIITa 81 (81); IVTr 85 (85), IVBFe 65 (65), IVTFe 70–72 (72), IVGe 78–79 (79), IVTi 81–85 (85), IVTa 82–83 (83). Female (n=2): Length/width anterior dorsal plate 144–150/272–288, length/width posterior dorsal plate 287–300/267–282, length/width ventral shield 406–426/312–330, width genital field 99. Lengths pedipalp segments: Tr 13–14, Fe 40, Ge 23–26, Ti 35–39, Ta 23–25. Lengths leg segments: ITr 43, IBFe 36–40, ITFe 48–50, IGe 55–61, ITi 58–63, ITa 65–73; IITr 38–39, IIBFe 43–45, IITFe 48, IIGe 55–59, IITi 60–65, IITa 75–80; IIITr 41–45, IIIBFe 43–45, IIITFe 48–49, IIIGe 58–61, IIITi 68–70, IIITa 79–82; IVTr 75–78, IVBFe 65–68, IVTFe 68–72, IVGe 80–83, IVTi 83–85, IVTa 79–85.

Types. Holotype: Male from Turkey Creek at Sycamore Campground, Chiricahua Mountains east of Sunizona, Cochise Co. , Arizona on 15 July 1987 by IMS (slide, CNC). Paratypes: Arizona: Cochise Co. : Same locality as holotype — 1 male, 15 May 1991, IMS (slide, CNC); 1 female, 5 May 1998, IMS (slide, CNC). Cave Creek below dam at Herb Martyr Campground, Chiricahua Mountains west of Portal — 1 female, 1 May 2001, IMS (slide, CNC).

Etymology. From the Greek platys meaning “wide” and soma meaning “body”.

Distribution. Streams in the Chiricahua Mountains of southeastern Arizona.

Remarks. Adults of Diamphidaxona platysoma differ from those of all other known North American species of the subgenus Diamphidaxonella in that the dorsal shield is very wide with the anterior plate wider than the posterior plate.

Figures

FIGURES 75 – 80. Diamphidaxona (Diamphidaxonella) platysoma sp. nov., adult male. 75, dorsal shield; 76, ventral shield and genital field; 77, pedipalp; 78, gnathosoma, lateral view; 79, leg I; 80, distal segments of leg IV.