Indoribates hauseri ( Mahunka, 1997 ) Ermilov & Sandmann & Scheu, 2019

Ermilov, Sergey G., Sandmann, Dorothee & Scheu, Stefan, 2019, New and interesting species of sacculonotic Haplozetidae (Acari, Oribatida, Haplozetidae) from Indonesia, Zootaxa 4656 (3), pp. 459-474 : 468-471

Indoribates hauseri ( Mahunka, 1997) comb. nov.

( Figs 7–9 )

Material examined. Seven specimens. Four specimens (two females and two males): Indonesia, Sumatra, Bukit Duabelas landscape, secondary tropical rainforest, research site BF3a, 01°56’33.9’’S, 102°34’52.7’’E, litter, November 2013 (B. Klarner). One specimen (one male): Indonesia, Sumatra, Harapan landscape, secondary tropical rainforest, research site HF2b, 02°09’29.4’’S, 103°20’01.5’’E, soil, November 2013 (B. Klarner). One specimen (one female): Indonesia, Sumatra, Harapan landscape, secondary tropical rainforest, research site HF1b, 02°09’09.9’’S, 103°21’43.2’’E, litter, November 2013 (B. Klarner). One specimen (one female): Indonesia, Sumatra, Harapan landscape, secondary tropical rainforest, research site HF3a, 02°10’30.1’’S, 103°19’57.8’’E, litter, November 2013 (B. Klarner).

Description. Measurements. Body length: 398–498 (seven specimens: four females and three males); notogaster width: 249–315 (seven specimens). Females larger than males: 481–498 × 298–315 versus 398–415 × 249–265.

Integument ( Figs 7A, 7B, 7C , 8A, 8C , 9A, 9B, 9D ). Body color brown to dark brown. Body (mostly prodorsum, lateral and posterior parts of notogaster) partially covered by cerotegument of blocky structure. Body surface (including subcapitular mentum and genae, genital and anal plates, leg trochanters III, IV and all femora) foveolate (diameter of foveoles up to 6) and partially microfoveolate and microgranulate.

Prodorsum ( Figs 7A, 7C ). Rostrum rounded. Lamellae well-developed, located dorsolaterally, as long as half of prodorsum (measured in lateral view). Sublamellae short, poorly visible. Sublamellar porose areas oval (10–14 × 6–8). Prolamellae absent. Tutoria of medium size, ridge-like. Lateral carinae of prodorsum removed from to prodorsal margins, directed to tutoria. Rostral (77–86) and lamellar (98–102) setae thick, pointed distally, heavily barbed, curved inside and directed medially; ro inserted at the tutorial ends, le on the lamellar ends. Interlamellar setae (82–86) thick, obtuse or slightly pointed distally, heavily barbed. Exobothridial setae (28–32) setiform, slightly barbed. Bothridial setae (98–102) setiform, shortly ciliate unilaterally. Dorsosejugal porose areas not observed. Dorsophragmata slightly elongate.

Notogaster ( Figs 7 A–7C, 8B). Anterior notogastral margin convex medially. Ten or 11 (if one pair of centrodorsal setae dp present) pairs of notogastral setae very long (118–123), setiform, smooth. One pair of sacculi (S3) observed, with small openings and drop-like channels. All lyrifissures and opisthonotal gland openings distinct. Circumgastric scissure and circumgastric sigillar band poorly visible, often indistinct.

Gnathosoma ( Figs 8 C–8E). Subcapitulum longer than wide (114–123 × 90–94). Subcapitular setae (a, 24–28; m, 16–20; h, 12–16) setiform, barbed; a thickest. Adoral setae (16–20) setiform, heavily barbed. Palps (length 73–77) with setation 0-2-1-3-9(+ω). Solenidion and seta acm of tarsi connected, arch-like mediodistally. Postpalpal setae (6) spiniform, smooth. Chelicerae (length 135–143) with two setiform, barbed setae (cha, 45–49; chb, 26–28). Trägårdh’s organ of chelicerae elongate triangular.

Epimeral and lateral podosomal regions ( Figs 7C , 8A ). Epimeral setal formula: 3-1-3-3. Epimeral setae 1a, 1c, 2a (6–8) setiform, slightly barbed, 3a, 3c, 4a, 4b, 4c (10–14) and 1b (16–20) setiform, heavily barbed, 3b (32–36) thickened, pointed distally, heavily barbed. Pedotecta II rounded in ventral view. Discidia roundly triangular. Humeral porose areas (Am, Ah) not observed. Circumpedal carinae long, directed to pedotecta II.

Anogenital region ( Figs 7B, 7C , 8A, 8B ). Five pairs of genital setae present; one pair of them longer (g 1, 14–16), setiform, heavily barbed, others shorter (g 2 – g 5, 8–10), setiform, barbed. One pair of aggenital setae (12–16) setiform, heavily barbed. Two pairs of anal (32–36) and two pairs of adanal (ad 1, ad 2, 45–49) setae thick, obtuse distally, heavily barbed. One pair of adanal setae (ad 3, 82–86) thick, pointed distally, heavily barbed, located on short, longitudinal thickenings. Adanal lyrifissures located close and lateral to anal aperture. Adanal setae ad 1 posterior, ad 2 posterolateral, ad 3 anterior to anal aperture. Anal plates with longitudinal carina. Marginal porose area not observed. Preanal organ goblet-like. Ovipositor elongated (143 × 36), blades (61) shorter than length of distal section (beyond middle fold; 82). Each of the three blades with four smooth setae, ψ 1 ≈ τ 1 (20) setiform, ψ 2 ≈ τ a ≈ τ b ≈ τ c (12) thornlike. Coronal setae (4) spiniform.

Legs ( Figs 9 A–9D). All legs monodactylous. Claw thick, with small tooth ventrobasally. Femora I-IV and trochanters III, IV with distinctly developed dorsoparaxial porose area. Ventroproximal porose area on tarsi slightly developed. Ventrodistal porose area on tibiae not observed. Tibiae I, II with ventroproximal tubercle. Formulas of leg setation and solenidia: I (1-5-3-4-19) [1-2-2], II (1-5-3-4-15) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia as indicated in Table 1 . Famulus of tarsi I located posterior to solenidion ω 2. Solenidion φ 2 of tibiae I located paraxial to φ 1; dorsodistal apophysis absent. Seta pl’ located laterally on tarsi I. Setae pl” on tarsi I and l” on tarsi I and tibiae I, II thick.

Remarks. (1) The monotypic genus Bolkiah was described by Mahunka (1997) with Bolkiah hauseri Mahunka, 1997 as type species. According to the catalogue of Subías (2019), it is regarded as subgenus of the genus Indoribates . Bolkiah differs from the similar haplozetid genera by three main traits ( Mahunka 1997): a) lamellae poorly developed; b) 11 pairs of notogastral setae; c) two pairs of minute sacculi. In our opinion, these listed traits cannot serve as distinctive traits of the genus for the following reasons: the degree of development of lamellae can vary among specimens (e.g., lamellae are well-developed in specimens of B. hauseri from Indonesia); the number of notogastral setae is variable in this species (specimens of B. hauseri from Indonesia have either 10 or 11 pairs of setae); the related genus Indoribates includes species with different number of notogastral sacculi. Thus, the generic/subgeneric status of Bolkiah appears unjustified. Based on the above morphological argument and in accordance with the principle of priority, we propose that Bolkiah is a junior subjective synonym of Indoribates , and the species Bolkiah hauseri Mahunka, 1997 must be recombined as Indoribates hauseri ( Mahunka, 1997) comb. nov.

(2) The specimens of I. hauseri from Indonesia (data in this paper) are similar in general appearance to those from Borneo according to the original description ( Mahunka 1997). However, some differences are present:

a) interlamellar setae obtuse or slightly pointed distally; they are heavily barbed, similar to rostral and lamellar setae (versus in distally setiform, less barbed than ro and le in specimens from Borneo);

b) lamellae well-developed (versus poorly developed in specimens from Borneo);

c) one pair of notogastral sacculi observed (versus two pairs in specimens from Borneo);

d) setae pl” on tarsi I and l” on tibiae I, II thick (versus slightly thickened in specimens from Borneo).

We believe these differences represent intraspecific variability. Hence, all listed additions to the original description ( Mahunka 1997) and supplementary description of I. hauseri should be considered in any future identification of this species.

Based on the supplementary description of I. hauseri from Indonesia and literature data ( Mahunka 1997), we propose the following diagnostic morphological traits for this species.

Body size: 398–594 × 249–420. Body partially covered by cerotegument of blocky structure. Body surface foveolate. Rostrum rounded. Prolamellae absent. Rostral and lamellar setae long, thick, pointed distally, heavily barbed, directed medially. Interlamellar setae long, thick, obtuse or pointed distally, heavily barbed. Bothridial setae long, setiform, shortly ciliate unilaterally. Ten or 11 pairs of notogastral setae very long, setiform, smooth. One or two pairs of small sacculi. Epimeral setae 3b of medium size, thickened, heavily barbed, other epimeral, genital and aggenital setae setiform, slightly or heavily barbed. Five pairs of genital setae. Anal and adanal setae ad 1, ad 2 thick, obtuse distally, heavily barbed, adanal setae ad 3 longer, thick, pointed distally, heavily barbed. Anal plates with longitudinal carina. Leg tarsi with one claw.

Figures

FIGURE 7. Indoribates hauseri (Mahunka, 1997), adult: A—dorsal view (legs not shown); B—posterior part of body, lateral view; C—anterior part of body, lateral view (gnathosoma and legs not shown). Scale bar 100 μm.

FIGURE 8. Indoribates hauseri (Mahunka, 1997), adult: A—ventral view (gnathosoma and legs not shown); B—posterior view; C—subcapitulum, ventral view; D—palp, left, paraxial view; E—chelicera, left, paraxial view. Scale bar 100 μm (A, B), 20 μm (C–E).

FIGURES 9. Indoribates hauseri (Mahunka, 1997), adult: A—leg I, without trochanter, right, antiaxial view; B—femur, genu and tibia of leg II, right, antiaxial view; C—trochanter, femur and genu of leg III, left, antiaxial view; D—leg IV, left, antiaxial view. Scale bar 20 μm.