Galumnella mikhailovi Ermilov, 2021

Ermilov, Sergey G. & Bąkowski, Marek, 2021, A new species of Galumnella (Acari, Oribatida, Galumnellidae) from Mozambique, Zootaxa 5006 (1), pp. 37-44 : 40-43

Galumnella mikhailovi Ermilov sp. nov.

Figs 1–13

Material examined. Holotype (male) and 4 paratypes (2 males and 2 females): Mozambique, Sofala Province, Gorongosa District, Gorongosa National Park , 18°29’00.1”S; 34°02’34.6”E, 842 m a.s.l., soil-litter in riverine forest near Murombodzi Waterfall, 14.05.2019 (M. Bąkowski).

FIGURES –2. Gathering place of Galumnella mikhailovi Ermilov sp. nov.: riverine forest near Murombodzi Waterfall, Gorongosa National Park, Mozambique.

Type deposition. The holotype is deposited in the SMNH; four paratypes are deposited in the TSUMZ. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.

Etymology. The species name is dedicated to the well-known Russian arachnologist, Kirill G. Mikhailov (the Zoological Museum of M.V. Lomonosov State University, Moscow, Russia), who was one of the founders of Acarina , the Russian Journal of Acarology.

Diagnosis. Body size: 232–265 × 182–215. Body surface with small, sparse foveolae; in addition, notogaster rugose. Rostrum narrowly rounded. Lamellar line present, sublamellar line absent. Rostral seta of medium length, lamellar seta short, interlamellar seta minute; all setiform, thin, smooth. Bothridial seta long, setiform, unilaterally spinose. Notogastral, epimeral and anogenital setae short, setiform, smooth. Median pore and postanal porose area absent. Posterior part of notogaster with median longitudinal furrow. Circumpedal carina long, reaching of the middle part of epimere I. All leg tarsi with one claw.

Description of adult. Measurements. Body length: 232 (holotype: male), 232–265 (4 paratypes, 2 males and 2 females); notogaster width: 182 (holotype), 182–215 (4 paratypes).

Integument. Body color dark brown. Body surface (including subcapitular mentum and genital and anal plates) sparsely foveolate (diameter of foveola small, up to 4). In addition, notogaster rugose.

FIGURES 0– 3. Galumnella mikhailovi Ermilov sp. nov., adult: 10—leg I (trochanter omitted), right, antiaxial view; 11—leg II (trochanter omitted), right, antiaxial view; 12—leg III, left, antiaxial view; 13—leg IV, left, antiaxial view. Scale bar 20 μm.

Prodorsum (Figs 1, 3). Rostrum protruding, narrowly rounded. Lamellar line thin, curving backwards at ventral end. Sublamellar line absent. Prodorsal leg niche and lateral ridges of prodorsum well developed. Rostral (24) and lamellar (8) setae setiform, thin, smooth; ro thicker than le. Insertion of lamellar seta located close and lateral to L. Interlamellar setae minute (2) setae setiform, thin, smooth. Bothridial seta (69–77) setiform, unilaterally spinose. Exobothridial seta and dorsosejugal porose area absent.

Notogaster (Figs 1, 3, 4). Dorsosejugal suture present, simple. With 10 pairs of short (4–6), setiform, thin, smooth setae. Median pore absent. Posterior part of notogaster with median longitudinal furrow. Dorsolateral pore, opisthonotal gland opening and all lyrifissures distinct.

Gnathosoma ( Figs 7–9 ). Subcapitulum size: 65–69 × 49–53. Subcapitular setae (a: 14; m: 6; h: 4) setiform, smooth; a thickest, h thinnest. Adoral setae not observed. Length of palp: 49–53. Postpalpal seta (4) spiniform, smooth. Length of chelicera: 90–94. Cheliceral seta cha represented by alveolus; chb and Trägårdh’s organ not observed.

TABLE. Leg setation and solenidia of Galumnella mikhailovi Ermilov sp. nov.

Note: Roman letters refer to normal setae, Greek letters – to solenidia (except ɛ = famulus). Single quote (’) marks seta on the anterior and double quote (”) – seta on the posterior side of a given leg segment. Parentheses refer to a pair of setae.

Epimeral and lateral podosomal regions (Figs 2, 5). Epimeral setal formula: 1-0-2-3. Setae (4–6) setiform, thin, smooth. Pedotecta I and II rounded in ventral aspect. Discidium triangular. Circumpedal carina long, reaching of the middle part of epimere I.

Anogenital region (Figs 2, 5, 6). Genital, aggenital, anal, and adanal setae (4–6) setiform, thin, smooth.Anterior edge of genital plate with three setae. Aggenital seta located posterolateral to genital aperture. Adanal lyrifissure not observed. Distance of adanal setae ad 1 – ad 2 equal to ad 2 – ad 3. Postanal porose area absent.

Legs (Figs 10–13). Monodactylous. Claw strong, smooth, with ventrobasal tubercle. Porose area on all femora and on trochanters III, IV slightly visible. 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 of tarsus I mini-stickform, slightly swollen and blunt-ended apically, inserted anterior to solenidion ω 1. Seta s of tarsus I eupathidial, located before setae a. Seta l’ on genu IV thick, thorn-like, spinose. Solenidia ω 1 and ω 2 on tarsi I, II and σ on genu III bacilliform, other solenidia setiform. Solenidion on tibia IV inserted in the middle part of the segment.

Remarks. Galumnella mikhailovi Ermilov sp. nov. is morphologically most similar to G. csavasorum ( Mahunka, 1994) , known from the Oriental region, in the presence of setiform, unilaterally spinose bothridial setae and rugose notogaster. However, G. mikhailovi sp. nov. differs from G. csavasorum in smaller body size (232–265 × 182–215 vs. 294–316 × 223–240), monodactylous (vs. bidactylous) legs, rounded (vs. pointed) rostrum, and the absence (vs. presence) of sublamellar line and rugose sculpturing in the anogenital region.

Figures

FIGURES 5–9. Galumnella mikhailovi Ermilov sp. nov., adult: 5—lateral view (gnathosoma, legs and pteromorph omitted); 6—posterior view; 7—subcapitulum, ventral view; 8—palp, right, antiaxial view; 9—chelicera, right, antiaxial view. Scale bar 50 μm (5, 6), 10 μm (7–9).