Cultroribula berolina Weigmann, 2006

Bayartogtokh, Badamdorj, 2012, The genus Cultroribula (Acari: Oribatida: Astegistidae) in Mongolia, with new findings from Altai Mountains and remarks on known species of the world, Zootaxa 3302, pp. 44-60 : 53-56

Cultroribula berolina Weigmann, 2006

( Figs. 6 & 7 )

Cultroribula berolina Weigmann, 2006 , p. 234, fig. 125d.

Cultroribula berolina: Subías, 2006 , p. 139; Weigmann, 2008, p. 146, figs. 1 & 2.

Diagnosis. Small species, covered with thin cerotegument; males relatively smaller than females; rostrum with three large central teeth of equal size, deeply incised in-between, and further two small teeth situated laterally; lamella relatively narrow, fused medially; lamellar cusp slightly shorter, but wider than basal part of lamella, with large rounded distal end bearing long lamellar seta; rostral and lamellar setae moderately long, with conspicuous barbs, interlamellar seta short, thin, smooth; sensillus with short stalk and club-shaped head smooth or with minute barbs; tutorium wide at base, with relatively short, but sharply pointed cusp distally not reaching alveolus of rostral seta; humeral process of notogaster well developed, with distinct protruding blades; ten pairs of notogastral setae medium long; five or six pairs of genital setae, legs monodactylous.

Measurements. Body length: 278–291 (285) μm; width of notogaster 131–157 (145) μm; length of notogaster 198–205 (202) μm. In total eight specimens were measured.

Integument. Body yellowish to light yellowish in color. Surface of body and leg segments with very thin, nearly smooth cerotegument. Integument finely microtuberculate on lateral part of prodorsum and around leg acetabula.

Prodorsum. Rostrum with three large central teeth of equal size, deeply incised in-between; further two small teeth situated laterally ( Fig. 6 ). Rostral seta moderately long, with fine barbs. Lamella relatively narrow, fused medially; lamellar cusp slightly shorter, but wider than basal part of lamella, with large rounded distal end bearing long lamellar seta. Interlamellar seta short, thin, smooth; bothridium large, with wide opening directed anterolaterad, partly concealed under anterior margin of notogaster ( Figs. 6 & 7 B). Exobothridial seta short, but longer than in, smooth. Sensillus with short stalk and club-shaped head minutely barbed. Tutorium wide at base, with relatively short, but sharply pointed cusp distally not reaching alveolus of rostral seta ( Figs. 6 C & 7B).

Notogaster. Oval, longer than wide, anterior margin almost straight, slightly rounded; humeral process well developed, with distinct protruding blades ( Fig. 6 A & B). Ten pairs of medium long notogastral setae thin, smooth, all setae subequal in length. Lyrifissures im, ih, ips, ip and opisthonotal gland opening (gla) well developed; lyrifissure ia not evident.

Gnathosoma . Subcapitular mentum nearly as long as wide, with minute microtubercles. Hypostomal setae a, m and h medium long, thin, smooth ( Fig. 7 A). Chelicera typical for genus as shown in C. altaica sp. nov., with few slightly sclerotized blunt teeth; seta cha barbed, about 1.4 times as long as smooth chb; Trägårdh’s organ well developed, large. Palp typical for genus as in C. altaica sp. nov., palpal setation: 0-2-1-3-8, including solenidion ω of tarsus.

Epimeral region. Apodemes apo.2, apo. sj and apo.3 well developed, slightly obliquely oriented. Epimeral setae medium long, smooth; setal formula: 3-1-3-3. Discidium well developed, projecting distally; circumpedal carina well developed, its anterior tectum not reaching level of pedotectum II ( Fig. 7 A).

Ano-genital region. Anal and genital apertures medium in size, situated far from each other. Genital aperture nearly rounded, genital plates with five or six pairs of short, smooth setae. Aggenital seta as long as genital setae, thin, smooth. Anal aperture widened posteriorly, slightly longer than wide; anal and adanal setae short, equal in size. Adanal lyrifissure (iad) well developed, situated adjacent to anterolateral corner of anal plate ( Fig. 7 A).

Legs. Tarsi monodactylous, trochanter and femora of all legs with large porose areas. Setation of legs similar to that of C. altaica sp. nov. Most of tarsal and tibial setae barbed, but those of genua, femora and trochanters mostly smooth. Formula of leg setation (including famulus): I (1-5-3-4-18), II (1-5-2-4-15), III (1-3-1-3-15); IV (1-3-2-3- 12); formula of solenidia: I (1-2-2); II (1-1-2); III (1-1-0); IV (0-1-0).

Material examined. Eight specimens (five females and three males): Mts. Mongol Altai, close to Lake Dayan, District Sagsai, Province Bayan-Ulgii, foliose or subfruticose lichens growing on bare rocks ( Xantoria candelaria , Melanelixia exasperatula , Parmelia sulcata ), N48o14’, E88o57’, elevation 2375 m a.s.l., 0 3 July 2010, Col. B. Bayartogtokh. Additional material: eleven specimens (five females and six males): Sevsuul valley, Eastern shore of the Lake Hövsgöl, District Khankh, Province Hövsgöl, fruticose lichens ( Usnea sp.) growing on larch trees ( Larix sibiricus Ledebour, 1833 ), 51o16’N, 100o74’E, elevation 1680 m, 0 8 July 2007, Col. B. Bayartogtokh.

Remarks. The features of the Mongolian specimens correspond well with those of the European materials as described by Weigmann (2006, 2008). The only differences are the presence of six pairs of genital setae in the Mongolian specimens in contrast to five pairs in the European specimens, tutorium without long free tip in the present specimens (only some specimens have relatively short free tip of tutorium) as opposed long acute tip in the type specimens. Except for these points, all other characters of the Mongolian specimens match well with those of the European specimens. Therefore, I consider the above-mentioned differences as intraspecific variations of different populations of this Palaearctic species. It is worth to mention that I found distinct difference in body size between the female and male, as the latter was relatively smaller and slender than the former.

This is the first record of C. berolina in Asia. Among the monodactylous species of Cultroribula , C. elongata Fujikawa, 1972 known from Japan resembles C. berolina in general appearance of body, indentation of rostrum and club-shaped sensillus. However, the Japanese species has four pairs of genital setae in contrast to five or six pairs in C. berolina . On the other hand, C. elongata is poorly known in terms of morphological characters and the original description is not adequate for further detailed comparison (see Fujikawa 1972).

Figures

FIGURE 6. Cultroribula berolina Weigmann, 2006. (A) Dorsal view of idiosoma, female; (B) Dorsal view of idiosoma, male; (C) Lateral view of prodorsum and anterior part of notogaster, female. A & B to same scale.

FIGURE 7. Cultroribula berolina Weigmann, 2006. (A) Ventral view of idiosoma, female; (B) Lateral view of prodorsum and anterior part of notogaster, male.