Crotonia carioca, Colloff, Matthew J., 2009

Colloff, Matthew J., 2009, Species-group concepts and biogeography of the genus Crotonia (Acari: Oribatida: Crotoniidae), with new species from South and Central America, Zootaxa 2081, pp. 1-30 : 8-10

Crotonia carioca sp. nov.

( Fig. 5 )

Dimensions: holotype: a damaged male with several dorsal setae broken off; length 1102, breadth (estimate) 488; ratio of length of prodorsum to total length: 0.32. Transverse measurements are only estimates because the specimen is tilted to its left on the permanent slide mount.

Male. Prodorsum: rostrum prominent, 28 long, 71 broad; rostral setae broken off ( Fig. 5 a). Lamellar setae strongly recurved, 283, smooth. Lamellar apophyses extremely long (152), divergent, over three quarters of their length extending beyond rostrum. Interlamellar setae broken off. Interlamellar apophyses more than four times as long as broad. Short straight convergent prodorsal ridges, extending half the distance between interlamellar and lamellar apophyses. Posterior interbothridial ridge absent. Sensillus globular, enclosed in bothridium, with veined microsculptural covering. Prodorsum smooth.

Notogaster: ratio of length to breadth ca. 2.1; slightly broader at level of setae e 2 ( Fig. 5 a). Dorsosejugal suture discrete, waisted, concave lateral margins adjacent to setae c 3. Notogastral shield discrete, smooth, narrow, with parallel marginal hyaline strips, lateral of which is a strip with underlying transverse musculature visible. With 13 pairs of notogastral setae; all smooth. Tubercles of setae of c, e 2 and f 2 very long, prominent; setae c 1 long (311), stout, flagelliform, smooth; c 3 broken off; cp smooth, very long (202), flagelliform.

Distance between tubercles c 3 and c 1 not measurable accurately as the specimen is tilted to its left on the permanent slide mount. Setae d 2 minute, emerging from alveoli. With gla positioned immediately anterior of f 2. Setae f 1 and the h series on short, clustered apophyses positioned on a caudal extension, 61 long, 122 broad, comprising a clearly constricted zone of cuticle between the posterior notogaster and the apophyseal cluster. Holotype with apophyses of caudal cluster asymmetric, ca. 40 long, with left f 1 directed laterally, right one directed anteriolaterally and slightly dorsally; h 1 directed posteriolaterally, 40; apophyses of h 2 ventral of h 1, 25, left one directed posteriorly, right one anteriolaterally. Apophyses of h 3 anterior of f 1 and ventral of h 2. Only right seta f 1 and left h 2 present, ca. 30, setiform, the former curved, the latter straight.

Ve n t e r: epimera smooth ( Fig. 5 b); epimeral setae smooth, spiniform, minute, formula 3-1-3-3; seta 3c slightly removed from anterior margin of epimere. Ventral margin of notogaster surrounding anal plates Ushaped; genital plates sub-circular. Each genital plate 170 long, 100 broad with 8 spiniform setae. Aggenital setae subequal to epimeral setae. Anal plate 49 broad, 235 long; anal and adanal setae plus p 2 and p 3 subequal, spiniform; p 1 broken off, but their tubercles markedly larger than those of p 2 and p 3. Irregular, inverted Ushaped testes containing sperm mass visible in perigenital region.

Material examined and locality data. Type material: holotype male only; on slide labelled ‘ACARINA ORIBATID [printed] Nothrus N. sp. Rio de Janeiro [in A.D. Michael’s hand]. E. BOSTOCK [printed] Acronothrus [in J.A. Wallwork’s hand] A.D. MICHAEL COLL [printed]. 1930. 8 .25.1230 [NHM acquision number]. Orchids. Dec 1888 C Balsam [in A.D. Michael’s hand].’ Holotype in Natural History Museum, London.

Etymology. The specific name, carioca , is a Portuguese adjective that refers to Rio de Janeiro and is the demonym for the inhabitants of that city. It is derived from the indigenous Tupi word, kara'i oca, meaning ‘White Man's House’.

Remarks. The holotype was originally in the collection of Edwin Bostock, which was bequeathed to A.D. Michael after Bostock’s death in 1901. Michael, retired by that time, only described a small portion of the collection from New Zealand ( Michael, 1908). Edwin Bostock, a shoe manufacturer, amateur microscopist and avid collector of mites, was a friend and naturalist colleague of Michael ( Baker & Colloff, 2006). He is known to have recruited people to collect mites on his behalf in New Zealand (Colloff & Cameron, in press), and it is likely that he had similar connections in South America, via business ties with the leather and hide trade.

This species can be distinguished from other members of the genus by the following combination of characters: 1) very long flagelliform setae cp; 2) the very long apophyses of all the marginal notogastral setae; those of e 2 and f 2 especially are much larger than known hitherto; 3) the extremely long, slender lamellar apophyses, with two-thirds of their length extending beyond the rostrum; 4) a caudal stalk; 5) with f 1 the longest caudal apophyses, directed laterally.

Crotonia carioca sp. nov. has clear affinities with the Unguifera group. The arrangement of apophyses in the caudal cluster is very similar to that of C. nukuhivae Jacot, 1935 , as redescribed by Ramsay (1969; his Fig. 3 ), and C. cervicorna Luxton, 1982 .

Figures

FIGURE 3. Crotonia macfadyeni sp. nov. deutonymph a) dorsal; b) ventral

FIGURE 5. Crotonia carioca sp. nov. holotype male a) dorsal; b) ventral; c) caudal apophyses