Setogalumna minisetosa, Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2016

Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2016, New species and records of Galumnidae (Acari, Oribatida) from the Philippines, Zootaxa 4171 (1), pp. 77-100 : 84-87

Setogalumna minisetosa sp. nov.

( Figs 13–18 )

Diagnosis. Body size: 332–365 × 265–282. Rostrum rounded. Rostral setae long, barbed. Lamellar setae of medium size, thin, indistinctly barbed. Bothridial setae long, clavate, slightly barbed. Sejugal and postanal porose areas and median pore present. Anterior notogastral margin not developed medially. Three pairs of porose areas, Aa and A3 elongate, A1 rounded. Setal alveoli la located posterior to Aa. Subcapitular setae a longer and thicker than m and h. Epimeral formula: 1–0–2–1. Circumpedal carinae directed to pedotecta I.

Description. Measurements. Species with small body size. Female larger than male. Body length: 332 (holotype: male), 365 (1 paratype: female); notogaster width: 265 (holotype), 282 (1 paratype).

Integument. Body color brown. Surface punctate. Genital plates each with one longitudinal strium in medial part.

Prodorsum ( Figs 13–16 ). Rostrum broadly rounded. Lamellar and sublamellar lines thin, parallel, curving backwards, S poorly visible. Rostral (32–36) and lamellar (18–22) setae setiform, directed antero-medially; ro thicker and more strongly barbed than le. Interlamellar setae minute (4). Bothridial setae (65–73) clavate, directed antero-upwards, with long, smooth stalks and shorter, slightly barbed heads. Exobothridial setae and their alveoli absent. Sejugal porose areas oval (10–12 × 6–8), transversely oriented.

Notogaster ( Figs 13–15, 17 ). Anterior notogastral margin not developed medially. Dorsophragmata elongated longitudinally. Ten pairs of notogastral setae minute (4). Three pairs of porose areas with indistinct borders: Aa elongate (length 45–49), dilated near pteromorphal hinges, transversely oriented, A1 rounded (10–12), A3 elongate oval (length 32–36), transversely oriented. Setae la inserted posterior to Aa. Median pore present in males and females, small, inserted posterior to the virtual line connected porose areas A1. All lyrifissures distinct, im located between Aa and A1. Opisthonotal gland openings located laterally to A1 and distanced from them.

Gnathosoma ( Fig. 18 ). Morphology of subcapitulum, palps and chelicerae as described in Galumna Heyden, 1826 and Pergalumna Grandjean, 1936 (e.g. Engelbrecht 1969; Ermilov & Anichkin 2011; Ermilov et al. 2011, 2014 c; Bayartogtokh & Akrami 2014). Subcapitulum size: 73–82 × 69–73. Subcapitular setae setiform, indistinctly barbed, a (12–36) longer and thicker than m and h (both pairs 8). Two pairs of adoral setae (8) setiform, barbed. Palp length: 57–61. Palp formula is typical (0–2–1–3–9+1ω). Axillary saccules distinct, slightly elongated. Chelicera length: 73–77. Cheliceral setae setiform, barbed, cha (28–32) longer than chb (18–20). Trägårdh’s organ elongate triangular, rounded distally.

Epimeral and lateral podosomal regions ( Figs 14 , 15 ). Anterior margin of epimere I smooth. Setal formula: 1– 0–2–1. Setae similar in length (4–6), thin, smooth. Pedotecta II rounded distally in ventral view. Discidia triangular. Circumpedal carinae (cp) directed to pedotecta I.

Anogenital region ( Fig. 14 ). Six pairs of genital, one pair of aggenital, two pairs of anal and three pairs of adanal setae similar in length (4–6), thin, smooth. Genital plates with two genital setae on anterior edges. Aggenital setae inserted between genital and anal apertures, equal distanced from them. Adanal lyrifissures located close and parallel to anal plates. Setae ad 3 inserted laterally to iad. Distance ad 1– ad 2 slightly shorter than ad 2– ad 3. Postanal porose area present, oval (10–12 × 6–8), transversely oriented.

Legs. Morphology of leg segments, setae and solenidia as described in Galumna Heyden, 1826 and Pergalumna Grandjean, 1936 (e.g. Engelbrecht 1969; Ermilov & Anichkin 2011; Ermilov et al. 2011, 2014 c; Bayartogtokh & Akrami 2014). Claws of medium size, indistinctly serrate on dorsal sides, median claw distinctly thicker than laterals. Formulas of leg setation and solenidia: I (1–4–3–4–20) [1–2–2], II (1–4–3–4–15) [1–1–2], III (1–2–1–3–15) [1–1–0], IV (1–2–2–3–12) [0–1–0]; homology of setae and solenidia indicated in Table 1 . Solenidia φ of tibiae IV inserted dorsally in distal part of segments.

Material examined. Holotype (male) and 1 paratype (female): Binaloan municipality, Western Samar Province, Samar Island, Philippines, 6 July 2003, collected by William Sm. Gruezo, sample of litter from unknown forest type (not provided by collector).

Type deposition. The holotype (alcohol) is deposited in the collection of the Senckenberg Institute , Görlitz, Germany; 1 paratype (alcohol) is in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia .

Etymology. The specific name minisetosa refers to the very small notogastral setae.

Remarks. Setogalumna minisetosa sp. nov. is morphologically most similar to S. luzonica Ermilov & Corpuz- Raros, 2015 c from the Philippines in having elongated notogastral porose areas Aa. However, the new species differs from the latter by its smaller body size (332–365 × 265–282 vs. 813–1045 × 697–830), the presence of minute interlamellar and notogastral setae (vs. well developed) and, median pore (vs. absent), elongated notogastral porose areas A3 (vs. rounded), and the absence of notogastral porose areas A2 (vs. present).

Figures

FIGURE 13. Setogalumna minisetosa sp. nov., adult: dorsal view. Scale bar 100 µm.

FIGURE 14. Setogalumna minisetosa sp. nov., adult: ventral view (subcapitulum and legs not shown). Scale bar 100 µm.

FIGURES 15 – 18. Setogalumna minisetosa sp. nov., adult: 15 — anterior part of body, lateral view (subcapitulum and legs not shown); 16 — rostrum, frontal view; 17 — posterior view; 18 — anterior part of subcapitulum, ventral view. Scale bars 100 µm (15 – 17), 50 µm (18).