Cheiroseius ovalis Bhattacharyya & Bhattacharyya 2004, sp. nov.
Creators: name: Bhattacharyya, Asit K.
name: Bhattacharyya, Sisir K.
Publisher: name: Zenodo
Year: 2004
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Ascidae
Cheiroseius
Cheiroseius ovalis

description: Cheiroseius ovalis sp. nov. (Figs. 1–8)
Diagnosis: Dorsal shield with 36 pairs of thick, spinelike setae; all dorsal setae on prominent tubercles; setae J5 simple, setae Z4 longest; sternal shield with conspicuous marking; ventri­anal shield broadly oval, with seven setae; six rows of deutosternal denticles, each row with 7–14 denticles.
Female: Holodorsal shield (448µ long along midline, 264µ wide) highly sclerotized, with dense reticulation, and with 36 pairs of thick, spinelike setae; anterior region with 21 pairs of setae, remaining setae on posterior region of the shield; setae J4–J5, Z5 and S5 are 32µ, 12µ, 36µ and 39µ long respectively; setae Z4 longest (41µ) of all dorsal setae; lateral membrane lineated, with 7 pairs of setae; all setae on dorsal shield borne on prominent tubercles (Fig. 1); peritreme visible dorsally, extending upto beyond setae j1 (16µ); dorsal shield complement of poroids and gland pores difficult to discern amidst ornamentation.
Tritosternum with elongate base, lacinae paired, sparsely plumose (Fig. 2). Sternal shield (88µ long along midline, 166µ wide at level of anterolateral corners) extended anterolaterally, with three subequal (22µ – 24µ) sternal setae; reticulation and conspicuous marking on sternal shield as depicted in fig. 3; metasternal shields large, with metasternal setae (18µ); genital shield finely granulated along posterior margin, truncate posteriorly, widened behind genital setae forming slightly convex lateral margin; hyaline anterior margin of genital shield extending over the region posterior to sternal shield to level of metasternal setae; remnants of endopodal shield present between coxae II–IV; posterior extremities of exopodal­peritrematal shield broad, finely granulated, with several components, curving behind coxae IV; ventral membrane between genital and ventri­anal shield folded, with 5 pairs of setae, including the two pairs posterior to the level of para­anal setae. Peritreme wide, stigmatal opening large, placed at level of anterior half of coxae IV. Ventri­anal shield broadly oval, slightly wider (134µ) than long (120µ), coarsely granulated posteriorly, with 7 simple, subequal (31µ – 32µ) ventral setae; anal opening large; cribrum present in the form of a broad strip behind the post­anal seta.
Epistome trispinate, each spine denticulate, with 2–3 spines each (Fig. 4); hypognathum with short, peglike corniculi; paired corniculi almost parallel to each other; internal malae finely fringed extending upto midlevel of corniculi; six rows of deutosternal denticles, with 7–14 denticles in each row; sixth row widest, discontinuous (Fig. 5); four pairs of simple, subcapitular setae; posterior hypostomatic (26µ) and palpcoxal setae subequal (28µ) but almost half length of anterior hypostomatic setae (52µ); besides simple setae, thornlike and club­shaped setae present on palpal genu and tibia respectively (Fig. 6). Chelicerae damaged, not examined.
All legs with well­developed ambulacra and claws; tibia I slightly shorter (150µ) than tarsus I (160µ); excluding ambulacra, length of legs I–IV as follows: 720µ, 460µ, 420µ and 530µ; tarsus of legs I and II depicted in figs. 7 and 8 respectively; all leg setae smooth; setation of legs I­II­III­IV, respectively: femora 11­10­6­6 and genua 13­10­8­9.
Male: Unknown.
Type: Holotype female, Zoological Survey of India compound, Jodhpur, Rajasthan; ex. decomposed grass litter collected from semi­dried drainage system; 23 March 2003; A.K. Bhattacharyya coll.
Distribution: INDIA: Rajasthan.
Differential diagnosis: The new species, Cheiroseius ovalis differs from all the known species of Cheiroseius in having 7 setae on its ventri­anal shield. The only known other Cheiroseius species which possesses 7 setae on ventri­anal shield is Cheiroseius dromadis (Evans and Hyatt, 1960). Besides the above similarity, the new species shows affinities with C. dromadis in having a three­pronged tectum, which is common for most of the Cheiroseius species. C. dromadis shows a number of dissimilarities with the new species, on both dorsal and ventral aspects such as: presence of 37 pairs of pilose dorsal setae; presence of dorsal hump; absence of anterolateral marking on sternal shield; weakly developed tritosternum; shape of metasternal, genital and ventri­anal shield; comparatively longer length of ventral setae; structure of periitrematal shield; longer internal malae (several times longer than that of C. ovalis); strongly developed ambulacra and presence of club­shaped setae on tarsus II. The new species also shows affinities with C. parbatensis (Evans and Hyatt, 1960) in having following similarities: number, nature and almost same relative length of dorsal setae, similar shape of tectum, sternal and metasternal shield. However, the new species differs from C. parbatensis in the following aspects: shorter length of setae J4, prominent, characteristic marking on anterolateral edge of sternal shield, shape of genital and ventri­anal shield, number of setae on ventri­anal shield and setation of tarsus II.
Etymology: The species name ovalis has been derived from the broadly oval shape of the ventri­anal shield.
description: Published as part of Bhattacharyya, Asit K. & Bhattacharyya, Sisir K., 2004, Two new species of the genus Cheiroseius Berlese, 1916 (Ascidae: Mesostigmata) from the Indian Thar Desert, pp. 1-11 in Zootaxa 403 (1) on pages 3-6, DOI: 10.11646/zootaxa.403.1.1, http://zenodo.org/record/5027758