Crotonia eungella, Colloff, Matthew J., 2010

Colloff, Matthew J., 2010, The Gondwanan relict oribatid genus Crotonia (Acari: Oribatida: Crotoniidae) from rainforests in Queensland and Northern New South Wales: new species show a mixed pattern of short-range and long-range endemism, Zootaxa 2649, pp. 1-51 : 32-34

Crotonia eungella sp. nov.

( Figs. 12 , 18 l, 21)

Dimensions: holotype male length 1098, breadth 466. Ratio of length of prodorsum to total body length: 0.34.

Description of female. Prodorsum: ratio of length to breadth 1.08. Rostrum with squat naso, barely projecting beyond rostrum; lateral edges slightly concave; rostral seta short, 24, straight, spiniform, smooth ( Fig. 12 a). Lamellar seta 260, recurved, smooth. Lamellar apophyses 107, curved, inflexed, uniformly narrow except slightly broader basally, almost three quarters as long as their mutual distance; extending anteriorly beyond apices of rostral setae. Interlamellar apophyses cylindrical (28 long, 13 broad); interlamellar seta 335, flagelliform, smooth; extending anteriorly as far as apex of curve of lamellar setae. Prodorsal short, extending a third of the distance between bases of interlamellar and lamellar apophyses. Diameter of bothridium 50; anteriolateral auriculate ridge of bothridium a blunt projection with curved pattern; hexagonal reticulations of operculum with crenellated ridges and with point of origin near lateral margin ( Fig. 18 l). Inter-bothridial ridge and median field of muscle sigilla very faint. Prodorsal microsculpture smooth, porose.

Notogaster: ratio of length of notogaster to breadth of notogastral shield 1.62; notogastral shield broadest at bases of setae e 2 ( Fig. 12 a); ratio of width of shield to entire notogastral width 0.83; margins of notogastral shield between c 3 and f 2 undulating, slightly convex, narrowing caudally. Dorsosejugal suture simple, with faint, single discrete ridge. Lyrifissure ia short (20) positioned in concavity immediately lateral of seta c 3. Posterior of concavity a short, narrow ridge extends posteriolaterally onto cuticle dorsal of acetabulum III. With 13 pairs of smooth notogastral setae (c 2 absent). Pre-notogastral shield and transverse hyaline strip broad, well-developed. Long flagelliform seta c 1 (207) and c 3 (144) on short, squat tubercles; c 1 extending as far as bases of apophyses of interlamellar setae, c 3 extending as far as bothridia. Notogastral shield with diffuse lateral strips of small tubercles extending from anteriolateral margin and broadening in caudal region posterior of setae f 2. Lateral hyaline strip (suprapleural scissure) broad, well-developed. Seta cp short, stout, spiniform (38); e 2 and f 2 short (52–64), curved, flagelliform apically, on small tubercles. Seta d 2 thin, 35, setiform; mutual distance (136) the same as between setae c 1. Opisthosomal gland opening (gla) medial of setae f 2. Caudal apophyses bifurcating diagonally from short, broad caudal stalk. Apophyses of h 2 long (104) expanded basally, converging apically; caudal margin between them an inverted V-shape. Apophysis of h 1 (46) emerging dorsally from base of that of h 2; apophysis of f 1 (35) projecting dorsolaterally, adjacent to, and anterior of, that of h 1. Apophysis of seta h 3 positioned ventral of f 1. Caudal setae smooth, short, flagelliform apically, f 1, h 1 and h 2 subequal in length (72–92) h 2 38.

Ve nt er: epimera smooth, porose ( Fig. 12 b); epimeral setae short (17–25), smooth, spinose, formula 3-1-3- 3; 3c on well-developed tubercle. With lcs broad, curved, forming broad obtuse angle (ca. 150°) with pcs. Anteriolateral margin of adanal plate with slight indentation. Genital plates sub-circular; posterior margin straight, transverse. Perigenital region smooth. Each genital plate 170 long, 104 broad, with eight short (20– 28) setiform setae (20–30); two pairs of short (11) aggenital setae. Anal plate 40 broad, 260 long, with three minute (10) thin setae on central region of plate; adanal setae ad 2-3 setiform (20), ad 1 spiniform (28); distance between ad 3 and ad 2 two-thirds of that between ad 1 and ad 3. Ventral margin of notogaster surrounding anal plates U-shaped. Setae of p series short (25–34), flagelliform apically; mutual distance between p 1 about twice width of tubercle. Tubercles of setae h 3 broad, sub-conical, emerging from ventral surface of apophyses of setae h 2.

Lateral view: Caudal margin curved, contiguous with notogastral shield ( Fig. 12 d); dorsal and ventral surfaces slightly convex, not parallel, distance between them 426 perpendicular of seta f 2, narrowing anteriorly. Apophysis of seta f 1 pointing anteriodorsally, h 1 dorsally and h 2 horizontal, pointing posteriorly, twice length of that of h 1. Apophysis of h 3 positioned ventral of f 1, pointing ventrally. Apophysis of seta p 1 on ventral region, the most dorsal of the p series, then p 2, then p 3, spaced equidistantly. Pleuraspis with sparse tubercles in posteriodorsal part.

Material examined. Holotype male, QM S26046 , moss on trees and rocks, rainforest, Sky Window Lookout, Eungella National Park, Queensland, 21°8'43"S 148°29'57"E, 771 m., coll. G.B. Monteith, 18.iv.1979. Holotype deposited in Queensland Museum, Brisbane.

Etymology. Crotonia eungella is named for its type locality, Eungella National Park, Queensland.

Remarks. Crotonia eungella differs from all other Crotonia spp. by the following combination of characters: 1) with setae c 1 and c 3 long, extending as far as bothridium; on cylindrical apophyses; 2) setae cp short and spiniform; 3) setae e 2 and f 2 short, subequal to cp, but flagelliform apically; 4) all caudal setae are borne on apophyses extending from the short, thick caudal stalk; those of h 2 curved, twice the length of those of h 1, converging apically; 5) the faint interbothridial ridge; 6) the smooth prodorsum, epimeres and perigenital region, sparingly tuberculate pleuraspis and notogastral shield; 7) the setae of the p series are all short and flagelliform apically; 8) the lozenge-shaped outline of opisthosoma; 9) ridge of bothridium a blunt projection bearing a curved pattern.

Crotonia eungella is morphologically most similar to C. cameroni , as discussed above under the remarks section for this species.

Figures

FIGURE 12. Crotonia eungella sp. nov. holotype female a) dorsal; b) ventral; c) lateral.

FIGURE 18. Details of bothridia of a) Crotonia sterigma sp. nov.; b) Crotonia borbora Luxton, 1987; c) Crotonia brisbanensis sp. nov.; d) Crotonia maculata sp. nov.; e) Crotonia capistrata Luxton, 1987; f) Crotonia ardala Luxton, 1987; g) Crotonia monteithi sp. nov.; h) Crotonia daviesae sp. nov.; i) Crotonia weiri sp. nov.; j) Crotonia yeatesi sp. nov.; k) Crotonia cameroni sp. nov.; l) Crotonia eungella sp. nov. m) Crotonia queenslandiae sp. nov.; n) Crotonia seemani sp. nov.; o) Crotonia raveni sp. nov.