Pergalumna (Pergalumna) crassipora Mahunka, 1995

Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2016, New species and records of Galumnidae (Acari, Oribatida) from the Philippines, Zootaxa 4171 (1), pp. 77-100 : 92-97

Pergalumna (Pergalumna) crassipora Mahunka, 1995

( Figs 32–43 )

Description. Measurements. Species with small body size. Females slightly larger than males. Body length: 265– 282 (24 specimens: all females), 249 (13 specimens: all males); notogaster width: 199–215 (24 specimens: all females), 190–199 (13 specimens: all males).

Integument ( Figs 32–34 , 40, 41 ). Body color light brown. Surface densely microgranulate (diameter of granules up to 1). Notogaster and ano-genital regions foveolate (diameter of foveoles up to 4). Pteromorphs striate in some specimens ( Fig. 40 ). Ventral side with two lateral, transverse striate bands between genital and anal plates.

Prodorsum ( Figs 32–35 , 38, 39 ). Rostrum broadly rounded. Lamellar and sublamellar lines thin, parallel, curving backwards. Rostral (8–12) and interlamellar (16–22) setae setiform, thin, smooth, ro directed anteromedially, in— medially or medio-upwards. Lamellar setae (41–53) setiform, barbed, directed antero-medially. Bothridial setae (57–65) clavate, directed antero-laterad, with long, smooth stalks and shorter, barbed heads. Exobothridial setae and their alveoli absent. Sejugal porose areas absent.

Notogaster ( Figs 32 , 34, 36 , 40, 41 ). Anterior notogastral margin not developed. Dorsophragmata slightly elongated longitudinally. Notogastral setae represented by 10 pairs of alveoli, however, minute setae c (4) present in some specimens ( Fig. 40 ). Three pairs of porose areas rounded, with indistinct borders: A3 (10–12) shorter than Aa and A1 (both pairs 14–16) rounded. Porose areas Aa located between setal alveoli la and lm, very near to the former. Median pore present in males and females, very small, often poorly visible, inserted posterior to the virtual line connected porose areas A1. All lyrifissures distinct, im located antero-laterally to A1 and distanced from them. Opisthonotal gland openings located postero-laterally to A1.

Gnathosoma ( Fig. 37 ). 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 × 65–73. Subcapitular setae setiform, a (14–16) barbed, longer and thicker than smooth m and h (both pairs 8–10). Two pairs of adoral setae (8–10) setiform, barbed. Palp length: 53–57. Palp formula is typical (0–2–1–3–9+1ω). Axillary saccules distinct, slightly elongated. Chelicera length: 69–73. Cheliceral setae setiform, barbed, cha (24–26) longer than chb (16). Trägårdh’s organ elongate triangular, rounded distally.

Epimeral and lateral podosomal regions ( Figs 33 , 34 , 42 ). Anterior margin of epimere I smooth. Setal formula: 1–0–1–3. Setae setiform, thin, smooth, 3b and 4c (10–14) longer than others (6). Pedotecta II rounded distally in ventral view. Discidia triangular. Circumpedal carinae (cp) directed to pedotecta I.

Anogenital region ( Fig. 33 ). Six pairs of genital (g 1, 6–8; g 2– g 6, 4), one pair of aggenital (4), two pairs of anal (4) and three pairs of adanal (4) setae setiform, thin, smooth. Genital plates with two genital setae on anterior edges. Aggenital setae inserted between genital and anal apertures, nearer to the former. 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 absent.

Legs ( Fig. 43 ). 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, slightly 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 anterior part of segments.

Material examined. 26 specimens (15 females and 11 males): Mt. Huraw , San Jose de Buan municipality , Western Samar Province , Samar Island, Philippines, 25 October 2002, collected by William Sm . Gruezo, sample of secondary forest litter; 11 specimens (9 females and 2 males): Sibulan watershed , Polillo municipality, Polillo Island , Quezon Province, Philippines, 27 September 2003, collected by Ireneo L. Lit, Jr. and Orlando L. Eusebio, sample of decaying log.

Remarks. The specimens of Pergalumna (Pergalumna) crassipora Mahunka, 1995 from the Philippines are almost identical in general appearance to those from East Malaysia according to the original description ( Mahunka 1995). However, they are distinguishable from the latter by the longer interlamellar setae (in distinctly longer than ro vs. ro and in slightly different in length). We believe these differences represent intraspecific (perhaps geographical) variability.

Also, some specimens from the Philippines have striate pteromorphs and the presence of minute notogastral setae c on pteromorphs. Since these differences registered in both populations in the Philippines, we believe that it is intrapopulation variability. Hence, new data should be considered in any future identification of P. (P.) crassipora .

Figures

FIGURE 32. Pergalumna (Pergalumna) crassipora Mahunka, 1995, adult: dorsal view. Scale bar 100 µm.

FIGURE 33. Pergalumna (Pergalumna) crassipora Mahunka, 1995, adult: ventral view (subcapitulum and legs not shown). Scale bar 100 µm.

FIGURES 34 – 37. Pergalumna (Pergalumna) crassipora Mahunka, 1995, adult: 34 — anterior part of body, lateral view (subcapitulum and legs not shown); 35 — rostrum, frontal view; 36 — posterior view; 37 — anterior part of subcapitulum, ventral view. Scale bars 100 µm (34 – 36), 20 µm (37).

FIGURES 38 – 43. Pergalumna (Pergalumna) crassipora Mahunka, 1995, adult, microscope images: 38 — part of prodorsum, ventral view; 39 — bothridial seta; 40 — part of pteromorph; 41 — notogastral porose area Aa and setae la and lm; 42 — podosomal region, left half; 43 — leg claws on tarsus IV, left, antiaxial view. Scale bars 20 µm.