Galumna triangulata, Bayartogtokh & Akrami, 2014

Bayartogtokh, Badamdorj & Akrami, Mohammad Ali, 2014, The soil mite family Galumnidae of Iran (Acari: Oribatida), Journal of Natural History 48 (15), pp. 881-917 : 893-897

Galumna triangulata sp. nov.

( Figures 4K–N and 7 )

Diagnosis

With typical characters of Galumna (lamellar and sublamellar lines present; alveolus of lamellar seta inserted between lines L and S; anterior margin of notogaster distinctly developed, rarely interrupted; notogastral median pore present or absent); rostrum with small triangular central carina and larger subtriangular lateral carina; rostral and lamellar setae thin, finely barbed; interlamellar seta long, thin, finely barbed; sensillus medium long, with finely barbed slightly dilated head; porose area Aa large, irregular oval, A 1 smallest, nearly round or slightly oval, A 2 and A 3 elongate oval, subequal in size; median pore absent; postanal porose area large, elongate oval.

Measurements

Holotype: body length 512 µm, width of notogaster 381 µm; length of notogaster 414 µm; paratypes (n = 5): body length 475–540 (515) µm, width of notogaster 375– 405 (393) µm.

Description

Integument. Body colour yellowish brown. Cuticle of body and legs with minute granules; prodorsum with faint striations and minute granules; notogaster nearly smooth, with very minute granules; gnathosomal and epimeral regions with small granules, sejugal area with faint longitudinal striations; pteromorph with radiated ridges and faint striations; marginal part of notogaster with radiating ridges.

Prodorsum. Rostrum with small triangular central carina and larger lateral carina of subtriangular shape, clearly seen in dorsofrontal view ( Figures 4M and 7B ). Rostral seta thin, 57–65 µm long, finely barbed, inserted ventrally and visible in dorsofrontal view. Lamellar seta thin, 69–78 µm long, finely barbed. Interlamellar seta thin, 74– 80 µm long, finely barbed ( Figure 7B ). Sensillus 90–102 µm long, with thin stalk and slightly dilated finely barbed head ( Figures 4N and 7B ). Lamellar and sublamellar lines well developed ( Figures 4K and 7A and B ). Dorsosejugal porose area large, elongate oval, located posterolaterad to seta in ( Figure 7B ).

Notogaster. Notogaster slightly widened posteriorly, dorsosejugal furrow well developed, nearly straight. Pteromorph with radiated ridges and faint striations ( Figures 4L and 7A ). Notogastral setae vestigial, their alveoli clearly discernable. All porose areas poorly visible; Aa large, irregular oval; A 1 smallest, nearly round or slightly oval; A 2 and A 3 elongate oval, subequal in size; median pore absent. Lyrifissures ia, im, ih, ip, ips and opisthonotal gland opening (gla) well developed ( Figure 7A and C ). Posterior and lateral margins with radiating ridges ( Figures 4L and 7D ).

Gnathosoma . Subcapitulum longer than wide, with few microtubercles; hypostomal setae a, m and h 9–12 µm long, smooth ( Figure 7D ). Palp typical for family as shown in Pergalumna iunctiporosa sp. nov., all setae except on tarsus finely barbed, formula of setation: 0-2-1-3-10 including solenidion ω on tarsus. Chelicera same as in Allogalumna dentirostrata sp. nov., with few heavily sclerotized blunt teeth on fixed and movable digits; setae cha and chb long, barbed; Trägårdh’ s organ well developed, its proximal part clearly discernable.

Epimeral region. With small granules and faint striations in sejugal area; apodemes apo.1, apo.2, apo.sj, apo.3, circumpedal carina and discidium well developed. Five pairs of epimeral setae of 8–12 µm length observed, setal formula: 2-0-2-1 ( Figure 7D ).

Ano-genital region. Anal aperture 102 µm long, 118 µm wide; genital aperture 70 µm long, 78 µm wide. Genital, aggenital and anal setae well developed, thin, smooth; genital setae 12–20 µm long, aggenital seta 10–12 µm long; anal setae 6–9 µm long; adanal setae vestigial; adanal lyrifissure (iad) situated in paranal position, at level anterior to alveolus of seta ad 3 ( Figure 7D ). Postanal porose area large, elongate oval ( Figure 7C ).

Legs. Structure and setation of legs typical for family as shown in the description of Allogalumna dentirostrata sp. nov. Formula of setation, including famulus: I (1-4-3-4- 20), II (1-4-3-4-15), III (1-2-1-3-15), IV (1-2-2-3-12), formula of solenidia I (1-2-2), II (1-1-2), III (1-1-0), IV (0-1-0).

Material examined

Holotype (female): Poloor, Amol, Mazandaran province, Northern Iran, 35°57 ʹ N, 52°07 ʹ E, 2100 m a.s.l., 5 August 2004, Coll. M. A. Akrami; five paratypes (females): same data as holotype. The holotype and paratypes are deposited in the collection of the Department of Plant Protection , College of Agriculture, Shiraz University, Iran.

Remarks

Galumna triangulata sp. nov. is clearly differentiated from the other species of Galumna by the combination of following characters, namely: triangular carina of rostrum; very slightly dilated sensillus; large, irregular oval shape of porose area Aa; presence of radiating ridges or grooves on pteromorph and marginal part of notogaster, and elongate-oval shape and subequal size of porose areas A 2 and A 3.

Among the known species of Galumna , the following species, Galumna elimata (C. L. Koch, 1841) , Galumna lanceata Oudmans, 1900 , Galumna obvia (Berlese, 1915) and Galumna rossica Sellnick, 1926 resemble the new species in the structure of very narrow and slightly dilated sensillus. However, the first two species, G. elimata and G. lanceata are easily differentiated from the new species by the presence of notogastral median pore (absent in the new species), consisting of single or several small pores; smooth pteromorph and marginal part of notogaster (ridges present in new species), and absence of rostral carina (present in new species).

Another species, G. obvia is easily distinguished from the new species by the minute interlamellar seta as opposed to long seta in the new species; elongate-oval porose area Aa, and much larger body size. The Palaearctic species, G. rossica clearly differs from the new species in the different shape and size of porose areas Aa, A 2 and A 3; absence of rostral carina; smooth pteromorph and marginal part of notogaster and much larger body size.

Two Iranian species, Galumna iranensis Mahunka et Akrami, 2001 and Galumna karajica Mahunka et Akrami, 2001 can be differentiated from the new species by the characters given in the identification keys hereunder (see Discussion).

Etymology

The specific epithet “ triangulata ” refers to the triangular shape of rostral carina.

Ecology

This species is an inhabitant of the highland pasture soil.

Figures

Figure 4. Morphological characters of different species. (A–F) Allogalumna dentirostrata sp. nov. (A) Anterior part of prodorsum; (B) gnathosomal, epimeral and genital regions; (C) pteromorph showing ridges on its cuticle; (D) left side of humeral region; (E) porose area Aa; (F) transversal ridges on notogastral margin. (G–J) Acrogalumna lanceolata sp. nov. (G) Rorstrum (arrow indicates central carina); (H) humeral region; (I) pteromorph; (J) porose areas, lyrifussure and opisthonotal gland opening. (K–N) Galumna triangulata sp. nov. (K) Lateral view of prodorsum; (L) lateral view of pteromorph and part of notogaster, showing transversal ridges; (M) rostrum (arrow indicates central carina); (N) lateral view of sensillus.

Figure 7. Galumna triangulata sp. nov. (A) Dorsal view of idiosoma; (B) dorsofrontal view of prodorsum, partial; (C) posterior view of opisthonotum, partial; (D) ventral view of idiosoma.