Xystonotus (Xystonotus) phytotelmaticola Pešić, 2015

Pešić, Vladimir, Piccoli, Gustavo Cauê De Oliveira, Araújo, Marcel Santos De, Rezende, José Marcos & Gonçalves, Ana Zangirolame, 2015, A new species of Xystonotus Wolcott, 1900 (Acari, Hydrachnidia, Mideopsidae) from bromeliad phytotelmata in Brazilian Atlantic rainforest, Zootaxa 3981 (1), pp. 147-150 : 149-150

Xystonotus (Xystonotus) phytotelmaticola Pešić n. sp.

( Figs. 1A–H , 2A–B )

Type series. Holotype male, dissected and slide mounted in Hoyer's fluid, Brazil, São Paulo, Cananéia, Ilha do Cardoso, 25°04′ 16′′ S, 47°55′23′′ W, in Vrisea procera (Martius ex Schultes f.), xii.2011 col. Ana Zangirolame. Paratype: one male, same data as holotype.

Diagnosis. Male (Female unknown). Dorsal shield with U-shaped area of smaller pores only slightly raised laterally, not reaching caudal margin of dorsal shield, more close to each other in the middle part; gnathosomal bay V-shaped; a short ridge extending anterolaterally from suture line between Cx-III and Cx-IV; Cxgl–2 anterior to gonopore, the gland portion absent; three pairs of acetabula; swimming setae absent; I–L-6 slender (L/H ratio 3.0); P-4 stout (L/H ratio 2.1) with an enlarged, forward-directed tubercle bearing two small setae.

Description. Male (holotype, in parentheses some measurements of paratype): Idiosoma (ventral view: Fig. 1B ) L/ W 506 (494)/451 (459). Dorsal shield ( Figs. 1A , 2A ) L/W 453/400, ratio 1.13; gnathosomal bay L 81; gonopore L/W 55/ 28, ratio 1.96; ejaculatory complex ( Fig. 1H ) L 166. Palp ( Figs. 1C–D ): total L 169; L/H, L/H ratio: P-1, 22/23, 0.94; P- 2, 42/39, 1.08; P-3, 32/33, 0.98; P-4, 52/25, 2.09; P-5, 21/9, 2.4; gnathosoma vL 75; chelicera total L 89, maximum H 39, L/H ratio 2.25, basal segment L 54, claw L 41, L basal segment/claw ratio 1.3. Legs: dL of I–L-3–6 ( Fig. 1F ): 57, 54, 74, 90; I–L-6 H 30, I–L-6 dL/H ratio 3.0; dL of IV–L-1–6 ( Fig. 1G ): 68, 63, 64, 85, 119, 114.

Female: Unknown.

Etymology. Named for its occurrence in bromeliad phytotelmata (singular phytotelm = “ plant that holds water ”).

Remarks. The only Xystonotus species known fom the Neotropical region, X. mexicana ( Cook, 1980) from Mexico differs from the new species in the V-shaped area on the dorsal shield opening in a wider angle, more distanced to each other in the middle part, leaving a broader medial, and narrower lateral area; P-4 comparatively slender, with a small dorsal hump and I–L-6 being more stout (L/H ratio 2.2, calculated from figure, see Cook 1980: fig. 1595).

Distribution. Brazil; only known from the type locality.

Habitat. The mites were found in the water-filled leaf axils of the epiphytic bromeliad Vriesea procera (Martius ex Schultes f.). A diverse aquatic arthropod fauna is associated with this bromeliad species, composed mainly of aquatic insect larvae of several groups such as dipterans ( Chironomidae , Ceratopogonidae , Psychodidae , Culicidae , Corethrellidae , Tabanidae and others), beetles ( Scirtidae , Hydrophillidae and Dytiscidae ) and damselflies ( Coenagrionidae ), but also small non-insect invertebrates, such as Crustacea (ostracods), Annelida (oligochaetes) and mites (Mideopsidae—described in this study).

Figures

FIGURE 1 A – H. Xystonotus phytotelmaticola n. sp., male holotype: A = dorsal shield; B = idiosoma, ventral view; C = palp, lateral view; D = palp, medial view (P- 1 lacking); E = gnathosoma and chelicera; F = I – L- 3 – 6; G = IV – L; H = ejaculatory complex. Scale bars = 100 µm.

FIGURE 2 A – C. A – B Photographs of Xystonotus phytotelmaticola n. sp., male holotype: A = dorsal shield; B = ventral shield. C Photograph of Vriesea procera (Martius ex Schultes f.) Wittmack from the State Park of Ilha do Cardoso, São Paulo, Brazil.