Tenuiala hubeiensis, Zhang & Jin, 2016

Zhang, Yan & Jin, Daochao, 2016, Two new species and two newly recorded species of Tenuialidae in China, with an updated key to the family (Acari: Oribatida: Gustavioidea), Zoological Systematics 41 (3), pp. 243-252 : 248-251

Tenuiala hubeiensis sp. nov. ( Figs 20–26 )

Diagnosis. Rostrum notched, the medial tooth tiny or rounded, two lateral teeth sharply pointed and strongly bent ventrally, causing blunt shape in dorsal view ( Fig. 23 ). Lamellae broad and large, overhung lateral contour of prodorsum in dorsal aspect and separated from each other; notched at the cusp of lamellae, the inner projection markedly developed ( Fig. 20 ). Tutorium distally broad ( Fig. 23 ). Humeral process extended beyond to anteromedial border of notogaster, with marginal serrations ( Fig. 25 ). Notogaster with 13 pairs of setal alveoli ( Fig. 20 ).

Description. General color a very dark brown. Integument shiny. Large, body length 1160–1360, width 860–990.

Prodorsum ( Figs 20, 23–24 ). Anterior part of prodorsum steepened. Notched at rostrum, two lateral teeth sharply pointed and the medial one tiny or rounded in lateral view. Rostral setae (108) inserted behind rostral notches. Lamellae broad and large, overhung lateral contour of prodorsum in dorsal aspect, and separated from each other; cusp of lamellae not reached to the rostral margin, notched to produce two projections, the inner one markedly developed. Lamellar setae (113) inserted at the bottom of notch of lamellar cusp. Rostral setae<lamellar setae<interlamellar setae (135), setiform, sparsely barbed. Sensillus (123) spindlelike, narrow and glabrous. Tutorium distally broad with tooth, didn’t extend anteriad of insertion of rostral seta.

Notogaster ( Figs 20, 22 ). Polished, obviously convex. Without visible setae and porosae areae, but with 13 pairs of alveoli (da, dm and dp present) and five pairs of lyrifissures (ia, im, ih, ips, ip). Humeral process moderately large, extending anteriad beyond to anteromedial border of notogaster, with marginal serrations.

Gnathosoma. Subcapitulum diarthric ( Fig. 26 ), longer than wide. Subcapitulum setae setiform, h, m and a 63, 60, and 38 in length respectively. Chelicerae chelate-dentate.

Ventral region ( Fig. 21 ). Epimeral borders distinctly. Third pair of epimeral borders incomplete and the fourth epimeral borders united with anterior border of genital opening. Epimeral setal formula: 3-1-3-3. Genital plate with 6 pairs of setae, anterior two setae longest. 1 pair of aggenital setae present. Anal plates much larger than genital plates, with 2 pairs of setae. 3 pair of adanal setae present. Lyrifissure iad located posteriad of level of seta ad 3, and adjacent to margin of anal aperture.

Legs. Tridactyle. Chaetotaxy of leg Tr-Fe-Ge-Ti-Ta (famulus included, solenidia in parentheses): leg I 1-5-3(1)-4(2)- 20(2); leg II 1-4-3(1)-4(1)-16(2); leg III 2-3-2(1)-3(1)-15; leg IV 1-2-3-3(1)-12. Femur of leg IV with a narrow ventral blade throughout its length.

Material examined. Holotype China, Hubei, Houhe National Nature Reserve (30°04 ′ N, 110°37 ′ E), 28 July 2010, Wenqin Liang. Paratypes. 1 adult, same data as holotype ; 1 adult, China, Shanxi, Taibaishan National Forest Park, 22 July 2012, Wenqin Liang, Qiouxiao Tang ; 1 adult, China, Sichuan, Luding County, Hailuogou National Forest Park (29°34 ′ N, 101°59 ′ E; elev. 3382 m), 29 July 2012, Wenqin Liang, Qiouxiao Tang .

Etymology. The specific name “ hubeiensis ” is derived from holotype locality

Remarks. Tenuiala hubeiensis sp. nov. has 13 pairs of notogastral alveoli present clearly (da, dm and dp present), which is quite different from other known species with 10 pairs of notogastral alveoli in Tenuiala .

Key to species of Tenuialidae .

1. Nine pairs of prominent large setae present on notogaster ( Peltenuiala )............................................................................................. 2

Only setal alveoli, or one pair of setae (p 1) present on notogaster.......................................................................................................3

2. Lamellae cusps short, subtriangle; Humeral process of notogaster long, reaching anteriad approximately to origin of cusps .............. ................................................................................................................................. Peltenuiala orbiculata (Aoki & Ohnishi, 1974)

Lamellae cusps elongated and mostly parallel-side; Humeral process of notogaster short, not reaching anteriad as far as origin of cusps .............................................................................................................................................. Peltenuiala pacifica Norton, 1983

3. Lamellae close together, fused basally, cusps bifid at tip, similar in shape to that of Oribatella (Ceratotenuiala) ............................... ....................................................................................................................... Ceratotenuiala echigoensis Aoki & Maruyama, 1983

Lamellae close together or separated from each other, not similar like Oribatella ..............................................................................4

4. Lamellae close enough to each other so lateral contour of prodorsum visibale in dorsal aspect; Tutorium usually gradually narrowing distally ................................................................................................................................................................................5

Lamellae overhanging lateral contour of prodorsum in dorsal aspect; Tutorium distally broad with corner or tooth ............................ ............................................................................................................................................................................................................9

5. With a translamella ( Tenuialoides )......................................................................................................................................................6

Lamellae tuched together at level of cusp origin, without a translamella ( Hafenrefferia )...................................................................7

6. Sensillus with narrow, uniform width except at pointed tip .................................. Tenuialoides medialis Woolley & Higgins, 1966

Sensillus baciliform, the apical portion being slightly swollen .................................................... Tenuialoides fusiformis Aoki, 1969

7. Lamellar cusps broad, notched at antero-later margins, lamellar setae inserted close to the outer projection of lamellar cusps............ ....................................................................................................................................................... Hafenrefferia eurycuspis sp. nov.

Lamellar cusps narrow, gradually tapering distally............................................................................................................................ 8

8. Sensillus setiform with sparsely ciliate .............................................................................................. Hafenrefferia acuta Aoki, 1966

Sensillus somewhat clavate, with the distal half slightly thicked, but pointed at distal end......... Hafenrefferia gilvipes (Koch, 1839)

9. Humeral process of notogaster without marginal serrations; Without translamella ( Hafenferrefia ) .................................................10

Humeral process of notogaster usually with marginal serrations, if without serrations, translamella present ( Tenuiala ).................. 11

10. Lamellar cusps short, subtriangle; Sensillus short, fusiform ...................................................... Hafenferrefia nitidula (Banks, 1906)

Lamellar cusps prolonged anteriorly, with a small notch; Sensillus long, somewhat clavate, with the distal half slightly thicked, but pointed at distal end .................................................................................................................. Hafenferrefia nevesi (Sellnick, 1952)

11. Notogaster with 10 pairs of setal alveoli ............................................................................................................................................ 12

Notogaster with 13 pairs of setal alveoli, da, dm and dp present ........................................................... Tenuiala hubeiensis sp. nov.

12. With translamella ......................................................................................................... Tenuiala crenulata Woolley & Higgins, 1966

. Without translamella .......................................................................................................................................................................... 13

13. Lamellae separated from each other......................................................................................................... Tenuiala nuda Ewing, 1913

. Lamellae appeared to touched together at base of lamellae cusps........................................ Tenuiala kurti Woolley & Higgins, 1955

Figures

Figures 20–26. Tenuiala hubeiensis sp. nov. 20. Dorsal view. 21. Ventral view. 22. Lateral view of notogaster. 23. Prodorsum, dorsal-later view. 24. Sensillus. 25. Humeral process. 26. Subcapitulum, ventral view, right half. Scale bars=100µm.