Compactozetes crenellatus, Colloff, 2023

Colloff, Matthew J., 2023, The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families, Zootaxa 5365 (1), pp. 1-93 : 63-64

Compactozetes crenellatus sp. nov.

( Fig. 33 )

Dimensions. Holotype male length 837 μm, breadth 672 μm. Paratype females (n = 5) mean length: 927 μm (range 916–971 μm); mean breadth 781 μm (range 758–822 μm). Paratype males (n = 3) mean length: 833 μm (range 818–845 μm); mean breadth 677 μm (range 664–695 μm). Ratio of prodorsum to total length: 0.37.

Description of adult. Prodorsum: rostrum entirely covered by lamellae; rostral setae (ro) relatively long, smooth, curved, only visible in ventral aspect. Lamellae very broad, anterior margin truncated, forming convex apex with two short lateral lobes ( Fig. 33a ). Lamellae curving ventrally, fused with each other and with prodorsum, with large paired lateral foramina between lamellae and rostrum, visible in ventral view ( Fig. 33b ), corresponding with lighter, ovoid areas of cuticle on dorsal surface. Lamellar seta (le) short, thin, smooth. Interlamellar setae (in) minute, on lamellae close to median margins, connected by faint transverse line. Bothridia fused with lamellae. Bothridial seta shorter than distance between setae in, with sparse apical spines.

Notogaster: ratio of length to breadth: 0.85; notogaster rounded, convex, smooth. Humeral process with reticulate microsculpture and rounded anterior lobe with three ridges and crenellated margin, extending anteriorly to level with opening of bothridium; lateral margin of humeral process indented posterior of anterior lobe, with one short lobe and one longer posterior one; humeral process terminating posteriorly at point level with seta lm ( Fig. 33a ). Lyrifissure ia not visible. With nine pairs of notogastral setae in marginal position; l and h series short, curved, smooth, slightly longer than p series.

Ventral aspect: subcapitulum acute, elongated; subcapitular setae thin, short, sub-equal in length. Epimeral plates I-III well-defined, plates IV lacking posterior margins, plates III longer (in transverse plane) but much narrower than plates II; epimeral setation 3-1-3-3; setae relatively short, sub-equal in length ( Fig. 33b ). Pedotectum I (pd I) with very large spine, extending to point level with tutorium, projecting laterally well beyond margin of prodorsum; pd II broad, trapezoid in lateral outline with slight median indentation; discidium lobed, rounded; perigenital carina and enantiophysis E4 absent. Ventral plate ovoid, markedly broader than long. Genital and anal plates separated by distance of two-thirds length of genital plates; genital plates 90 µm long, with indentations on anterolateral margins and six pairs of short setae, aligned longitudinally, g 1 same length as others; three pairs of short adanal setae; lyrifissure iad in para-anal position, close to margin of anal plate. Anal plates lozenge-shaped, 135 µm long. Pre-anal organ (po) oval.

Etymology. The specific name refers to the crenellated margin of the anterior lobe of the humeral process.

Type designation, material examined and locality data. Holotype male, ANIC accession no. 53-1081, paratype: female, ANIC accession no. 53-1082, ANIC 299 , wet sclerophyll forest, Mount Donna Buang, Yarra Ranges National Park , Victoria, 1,060 m, coll. R. W. Taylor and R. J. Bartell, 5.xi.1970 . Paratypes: four females, three males, ANIC accession no. 53-1083, ANIC 592 , leaf litter and decaying log, Cement Creek, 5 km west of Warburton , Victoria, 37°3’3S 145°42’E, coll. J. Lawrence and T. Weir, 18.i.1977 .

Diagnosis. Compactozetes crenellatus can be distinguished from other species in the genus by the following combination of characters: (1) the lamellar apex consisting of two short trapezoid lateral lobes; (2) the relatively short bothridial seta with apical spines; (3) pedotectum I with a very large anterior spine extending to a point level with the tutorium; (4) the crenellated anterior lobes of the humeral processes; (5) the broad pedotectum II, trapezoid in lateral outline; (6) the absence of perigenital carinae and enantiophyses E4; (7) the indentations on the anterolateral margins of the genital plates.

Remarks. Compactozetes crenellatus belongs to the ‘zeugus’ species group. It is morphologically most similar to C. goongerah , though in the former species the anterolateral margin of pedotectum II is trapezoid, not lobed and rounded. The anterior margin of the fused lamellae is similar in both species, as is the lateral margin of the humeral process, though lacking the crenelations in C. goongerah .

Figures

FIGURE 33. Compactozetes crenellatus sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.