Crotonia cameroni, 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 : 30-32

Crotonia cameroni sp. nov.

( Figs. 11 , 18 k, 21)

Dimensions: holotype female length 1067, breadth 348; paratype male length 853, breadth 292. Ratio of length of prodorsum to total body length: 0.35 (holotype).

Description of female. Prodorsum: ratio of length to breadth 1.26. Rostrum well-developed, with prominent naso, lateral edges markedly incised; rostral seta 28, straight, spiniform, smooth ( Fig. 11 a). Lamellar seta 185, recurved, smooth, flagelliform. Lamellar apophyses 73, straight, parallel, half as long as their mutual distance; extending anteriorly almost as far as apices of rostral setae. Interlamellar apophysis twice as long as broad; interlamellar seta slender, 205, flagelliform, smooth; extending anteriorly almost as far as apices of lamellar apophyses. Prodorsal ridges absent. Diameter of bothridium 49; anteriolateral auriculate ridge of bothridium in the form of a blunt-tipped conical projection with concentric ridges; hexagonal reticulations of operculum each with single circumferential ridge and with point of origin near lateral margin ( Fig. 18 k). Inter-bothridial ridge a shallow, uniform curve with a median invagination. Median field of muscle sigilla present. Prodorsal microsculpture smooth, porose.

Notogaster: ratio of length of notogaster to breadth of notogastral shield 2.08; notogastral shield broadest at level of bases of setae e 2 ( Fig. 11 a); ratio of width of shield to entire notogastral width 0.57; lateral margins of notogastral shield lozenge-shaped. Dorsosejugal suture diffuse series of ridges. With 13 pairs of smooth notogastral setae. Pre-notogastral shield bearing long, stout, flagelliform seta c 1 (338) on long, well-developed cylindrical apophyses (55 long, 15 broad), and separated from notogastral shield by transverse hyaline strip. Apophysis of seta c 3 subequal in length and shape to that of seta c 1. Region posterior of apophyses of setae c 3 strongly concave, waisted; lyrifissure ia located in concavity immediately posterior of apophyses of setae c 3. Seta c 3 stout, flagelliform, 335, extending posteriorly at least as far as bases of setae e 2. Notogastral shield smooth, sides parallel. Lateral hyaline strip (suprapleural scissure) well developed, with small tubercles of setae cp, e 2 and f 2 on medial margin. Seta cp long, flagelliform (198), d 2 short, setiform (34), mutual distance about two-thirds (56) of that between setae c 1; seta e 2 short, setiform (79). Opisthosomal gland opening gla positioned medial of short (62), setiform f 2. Caudal apophyses on stalk projecting dorsally and posteriorly from caudal margin; caudal apophyses bi-lobed; those of h 2 parallel, 170 long, with those of f 1 and h 1 projecting posteriolaterally from anterior dorsal surface. Flagelliform setae f 1 and h 1 118 and 125. Seta h 2 60, spiniform, smooth. Seta h 3 and its apophyses positioned ventral of f 1 when viewed dorsally.

Ve nt er: epimeral microsculpture smooth, porose ( Fig. 11 b); epimeral setae smooth, spiniform, formula 3- 1-3-3; subequal (ca. 20–33); 3c on well-developed tubercle. Lateroventral circumgastric scissure (lcs; the aggeno-gastronotic band of Woas, 2002, his Fig. 10) broad, curved, forming a broadly obtuse angle (ca. 150°) with perianal circumgastric scissure (pcs; the ano-adanal band Woas, 2002) with ( Fig. 1 b). Anteriolateral margin of adanal plate at junction of lcs and pcs broadly and deeply indented. Genital plates sub-circular; posterior margin transverse; posteriolateral margins straight, diverging. Perigenital region sparsely tuberculate. Each genital plate 186 long, 118 broad with eight setiform setae, subequal in length (25); two pairs of aggenital setae, subequal in length to genital setae. Anal plate 60 broad, 222 long with three very short (17) setiform setae on posterior half of plate; three pairs of spiniform adanal setae, ad 2-3 slightly shorter and thinner than spiniform stout ad 1 (42). Ventral margin of notogaster surrounding anal plates V-shaped. Setae p 1 curved, short (20) on short tubercles, their mutual distance twice their length; p 2 70, setiform; p 3 34.

Lateral view: Caudal margin slightly inflated, curved, contiguous with notogastral shield ( Fig. 11 c); dorsal and ventral surfaces more-or-less parallel, distance between them ca. 365 perpendicular of seta f 2. Apophyses of setae on well-developed caudal stalk projecting above level of notogastral plate; f 1 and h 1 pointing posteriodorsally, those of h 2 three times length of h1, extending horizontally; those of h 3 positioned anterioventral of h 2, pointing ventrolaterally. Apophyses of setae of p 1 and p 2 much closer together than p 2 and p 3. Pleuraspis smooth.

Material examined. Holotype female, paratype male, QM S26064 . sieved litter, rainforest, Mount Dryander, Queensland, 20°15'S 148°33'E, 590 m., coll. G.B. Monteith, 24.iv.1979. Holotype and paratypes deposited in Queensland Museum, Brisbane.

Etymology. Crotonia cameroni sp. nov. is named in honour of my colleague, Dr Stephen Cameron (Australian National Insect Collection, CSIRO Ecosystem Sciences), in recognition of his contribution to phylogenetic systematics of Australian invertebrates.

Remarks. Crotonia cameroni differs from all other Crotonia spp. by the following combination of characters: 1) setae c 1, c 3 and cp are long, flagelliform; the former two setae with large, well-developed apophyses; 2) all caudal setae are borne on apophyses extending from the caudal stalk; those of h 2 very long, close together; 3) the narrow notogastral shield with parallel margins; 4) the smooth prodorsum, notogastral shield, pleuraspis and epimeres, but sparse tubercles in perigenital region; 5) the apophyses of setae of p 1 and p 2 much closer together than p 2 and p 3; 6) the lozenge-shaped outline of opisthosoma; 7) the elongate, narrow prodorsum.

Crotonia cameroni shows some morphological similarity to C. eungella sp. nov. in that they share long, flagelliform setae c 1 and c 2, well-developed caudal apophyses arising from a diagonally-angled bifurcation of the caudal stalk, and a lozenge-shaped outline of the opisthosoma. However, C. cameroni has a smooth notogastral shield (it is tuberculate laterally and caudally in C. eungella ), longer c setae (and their apophyses) e 2 and f 2 as well as apophyses of setae h 2.

Figures

FIGURE 1. Crotonia sterigma sp. nov. holotype female a) dorsal; b) ventral; lcs = lateroventral circumgastric scissure; pcs = perianal circumgastric scissure; c) posteriolateral.

FIGURE 11. Crotonia cameroni 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.