Galumna (Galumna) reunionensis, Ermilov & Mary, 2025

Ermilov, Sergey G. & Mary, Nathalie J., 2025, Oribatid mites (Acari, Oribatida) of La Réunion Island, Zootaxa 5673 (1), pp. 119-131 : 121-125

Galumna (Galumna) reunionensis sp. nov.

( Figs 2 , 3 )

Type material. Holotype (male) and 11 paratypes (five males and six females): La Réunion, Ravine Sèche source Lesquelin amont, site RSS LAM/NA, forest stream, 770 m a.s.l., 21°13'10.5434" S, 55°21'46.1606" E, 08.ii.2019, collected by OCEA Consult'.

Three paratypes (one male and two females): La Réunion, Ravine des Trois Cascades , forest stream ( Fig. 1C ), 967 m a.s.l., 21°04'10.0333" S, 55°30'49.0057" E, 07.x.2021, collected by OCEA Consult' .

The holotype is deposited in the collection of the Senckenberg Museum of Natural History , Görlitz, Germany ; six paratypes are deposited in the collection of the University of Tyumen, Museum of Zoology, Tyumen, Russia ; eight paratypes are in the personal collection of the first author. All specimens are preserved in 70% solution of ethanol with a drop of glycerol .

Diagnosis. Body length: 840–900. Body surface densely and slightly microgranulate.Rostrum rounded.Lamellar and sublamellar lines long, parallel, curving backwards at ventral end. Rostral, lamellar, and bothridial setae long,

setiform, barbed; interlamellar seta vestigial. Dorsosejugal porose area present. Dorsosejugal suture complete. Four pairs of notogastral porose areas: Aa elongate boomerang-like (transverse part longer than longitudinal part); A1

circular or oval; A2 and A3 elongate oval. Median pore present, comparatively large. Opisthonotal gland opening lateral to A1 and anterolateral to A2; im between lm and A1, closer to A1. Subcapitular setae a and m slightly longer than h, all similar in thickness. Epimeral setal formula: 1-0-1-2. All anogenital setae comparatively short, setiform,

roughened. Circumpedal carina medium-sized.Adanal lyrifissure close and slightly oblique to posterior half of anal plate. Postanal porose area elongate oval. Leg famulus inserted anterior to solenidia ω 1 and ω 2; solenidion of tibia IV inserted in anterior part of dorsal side of segment.

Description of adult. Measurements. Body length: 870 (holotype), 840–900 (paratypes); notogaster width: 660 (holotype), 660–735 (paratypes). No difference between males and females in body size.

Integument. Body color brown. Body surface densely microgranulate (visible under high magnification, ×1000); basal part of prodorsum and antiaxial side of leg trochanters III, IV partially with short, longitudinal, dense, slightly developed ridges; antiaxial side of leg femora I–IV and trochanters III, IV partially microtuberculate.

Prodorsum. Rostrum rounded. Lamellar and sublamellar lines long, thin, parallel, curving backwards at ventral end. Rostral and lamellar setae (86–94) setiform, barbed; insertion of le distinctly lateral to L; interlamellar seta vestigial; bothridial seta (123–131) setiform, roughened; exobothridial seta not observed. Dorsosejugal porose area elongate oval (52–60 × 15–19), located posterolateral to in. Dorsophragma medium-sized, elongated.

Notogaster. Dorsosejugal suture complete, distinct. All notogastral setae represented by setal alveoli. Four pairs of porose areas (Aa, A1, A2, A3): Aa elongate boomerang-like, with long transverse part (length: 90–116) and shorter, longitudinal part (length: 64–75), located close to pteromorphal hinge, anterior to la and anterolateral to lm; A1 circular (30–34) or oval (34–41 × 22–26); A2 (77–105 × 15–19) and A3 (67–82 × 19–30) elongate oval. Median pore comparatively large, circular (15), present in posterior half of notogaster in both genders. Opisthonotal gland opening and all lyrifissures distinct: gla lateral to A1 and anterolateral to A2; im between lm and A1, closer to the latter; ip close and lateral to p 1; ih and ips close to each other, lateral to gla and anterior to p 3.

Gnathosoma . Size of subcapitulum: 229–240 × 187–199; subcapitular (a, m: 41–49; h: 34–41) and adoral (19) setae setiform, roughened; a, m, h similar in thickness. Length of palp: 157–161; setation: 0-2-1-3-9(+ω); postpalpal seta (7) spiniform, smooth. Length of chelicera: 262–266; setae (cha: 90–94; chb: 52–60) setiform, barbed.

Epimeral and lateral podosomal regions. Epimeral setal formula: 1-0-1-2; all setae (3b: 60–64; 1b: 45–49; 4a, 4b: 26–34) setiform, roughened. Circumpedal carina directed to insertion of 3b, but not reaching it.

Anogenital region. Anogenital setal formula: 6-1-2-3; genital, aggenital, anal, and adanal setae (26–34) setiform, roughened; anterior edge of genital plate with three setae; aggenital seta located between genital and anal apertures, closer to former; ad 1 and ad 2 posterior, ad 3 lateral to anal plate and iad; distance ad 1 – ad 2 equal to ad 2 – ad 3. Adanal lyrifissure located close and slightly oblique to posterior half of anal plate. Postanal porose area well defined, elongate oval (142–157 × 26–37).

Legs. Median claw slightly thicker than lateral claws; all claws slightly barbed on dorsal side. Porose area on femora I–IV and on trochanters III, IV distinct; proximoventral porose area of tarsi I–IV and distoventral porose area of tibiae I–IV not observed. 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; famulus straight, inserted anterior to solenidia ω 1 and ω 2; seta s on tarsus I eupathidial; solenidion of tibia IV inserted in anterior part of dorsal side of segment.

Remarks. Galumna (Galumna) reunionensis sp. nov. is similar to G. (G.) capensis Engelbrecht, 1969 from South Africa and Congo, G. (G.) paracapensis Ermilov, 2020 (in Ermilov & Rybalov 2020) from Ethiopia, and G. (G.) szentivanyorum Balogh & Balogh, 1983 from Australia in its main morphological traits: body size large; rostrum rounded; lamellar and sublamellar long, parallel, curving backwards at ventral end; interlamellar seta short; bothridial seta setiform; dorsosejugal suture complete; four pairs of notogastral porose areas (Aa, A1, A2, A3), with Aa boomerang-like; all anogenital setae comparatively short; postanal porose area elongate oval. The new species differs from G. (G.) capensis and G. (G.) paracapensis by the body size (length: 840–900 versus 630 in G. (G.) capensis , 1195–1310 in G. (G.) paracapensis), the size of a median pore (comparatively large versus small), the morphology of the notogastral porose area Aa (transverse part longer than longitudinal part versus similar in length in G. (G.) capensis , shorter in G. (G.) paracapensis), and the morphology of the notogastral porose areas A2 and A3 (elongate oval versus oval); the new species differs from G. (G.) szentivanyorum by the body size (length: 840–900 versus 694), the absence (versus presence of dense longitudinal ridges on the prodorsum, the length of the rostral and lamellar setae (long versus ro represented by alveolus, le short), the morphology of the bothridial seta (roughened versus densely barbed), the presence (versus absence) of a median pore, and the location of the adanal lyrifissure (lateral to posterior part of anal plate versus lateral to median part of anal plate).

Etymology. The species name reunionensis refers to the place of origin of the new species, La Réunion Island.

Figures

FIGURE 1. Maps of locations: A—La Réunion Island in the Afrotropical region; B—Locations within La Réunion; C— Location 10.

FIGURE 2. Galumna (Galumna) reunionensis sp. nov., adult (sculpturing shown partially): A—dorsal view; B—ventral view (gnathosoma, legs and right pteromorph omitted); C—anterior part of prodorsum, anterior view; D—right lateral view (legs and pteromorph omitted); E—posterior view. Scale bars 200 μm.

FIGURE 3. Galumna (Galumna) reunionensis sp. nov., adult (sculpturing shown partially): A—subcapitulum, ventral view; B—palp, right, antiaxial view; C—chelicera, left, paraxial view; D—leg I, right, antiaxial view; E—leg II, right, antiaxial view; F—leg III, left, antiaxial view; G—leg IV, left, antiaxial view. Scale bars 50 μm (A, C–G), 20 μm (B).