Australonura gili, Queiroz & Deharveng, 2014

Queiroz, G. C. & Deharveng, L., 2014, New Australonura Cassagnau 1980 (Neanuridae: Neanurinae) from Brazil, Journal of Natural History 48 (37 - 38), pp. 2293-2305 : 2299-2303

Australonura gili sp. nov.

( Figures 3 , 4 ; Tables 3, 4)

Type material

Holotype: female (#2193 CM / MNRJ), 26 October 2011, Queiroz G.C. leg. Paratypes: one juvenile (#1989 CM / MNRJ), 15 March 2011, Queiroz G.C. leg.; one male in moult (#2183 CM / MNRJ), 25 October 2011, Queiroz G.C. leg. Deposited at MNRJ, Rio de Janeiro, Brazil . Two paratypes, one female and one juvenile, 15 March 2011, Queiroz G.C. leg., in slides MNHN-EA011508 and MNHN-EA011509 deposited at MNHN in Paris , France .

Type locality

Parque Nacional de Itatiaia (ICMBio), Itatiaia municipality, Rio de Janeiro State, Brazil. 2400 m asl. Coordinates: 22°22 ʹ 58.26 ʺ S, 44°40 ʹ 0.49 ʺ W. Leaf litter and soil of ‘campos de altitude’ .

Description. Length 0.7–1.1 mm (adults, n = 4); juvenile = 0.6 mm. Colour white in ethanol. No pigment. Eyes 2 + 2, ellipsoids, their longer axis 2.7–3 times as long as Ocm socket diameter. Habitus typical of the genus ( Figure 3 ). Weak cryptopygy. Head and tergite tubercles well developed, with tertiary granulation differentiated in bosses rising from the integument, more visible on the lateral side of head and body segments. No reticulations. No plurichaetosis. No buttonhole structures on tergites.

Dorsal chaetotaxy constituted of ordinary chaetae and S-chaetae. Ordinary chaetae differentiated in dorsal macrochaetae of similar length and morphology, rather long, with strong serrations covering more than two-thirds of their length (from the base and almost till the apex), distally sheathed, rounded apically; lateral macrochaetae longer, less serrated and thinner apically; mesochaetae similar in shape, but smaller than dorsal macrochaetae (details of Figure 3 ); one mesochaeta of CL, four mesochaetae of L + So, one mesochaeta of each lateral tubercle from Abd. I to III, several on tubercle L of Abd. IV and all three of Abd. V smooth and acuminate; microchaetae, thinner, shorter, bent, acuminate, smooth. S-chaetae thinner, less than half the length of closest macrochaetae.

Antennae shorter than head, about two times as long as basis length. Ant. I with seven chaetae, Ant. II with 11 chaetae; dorsally the chaetae are serrated and some tertiary granulation can be seen on Ant. I and II. Ant. III with 17 ordinary chaetae (d4 absent) and the five S-chaetae of Ant. III organ, whose guard chaetae Sgd and Sgv are slender than S-chaetae of Ant. IV. Ant. IV organite as a very small rod, almost entirely buried in the integument; apical bulb trilobed, fused to Ant. IV tip ( Figure 4A, B ). Eight subequal S-chaetae (S1–S8) on Ant. IV ( Figure 4A ). Ventral chaetotaxy of Ant. III–IV complete ( Figure 4B ).

Buccal cone moderately elongated. Maxilla styliform, mandible thin, probably tridentate. Labrum rounded apically, elongate, labral formula?/?2,4. Labium with four basal, three distal and three lateral chaetae; x-papillae not seen ( Figure 4C ).

Head chaetotaxy as in Table 3, with 11 chaetal groups: CL, Af; 2 (Oc), (Di + Di), 2 (De), 2 ( DL), 2 (L + So). Tubercles well developed, Af not fused to Oc. Central area with A, B, D, G, H, Oca, Ocm and Ocp (C, E, F and O absent). Tubercles Di fused, constituted of six elementary tubercles (four anterior and two posterior), with 1 + 1 chaetae Di1.

Tergite chaetotaxy illustrated on Figure 3 . Tubercles well developed, more visible laterally from head to Abd. VI. Chaeta Di present on Th. I as a me. Tubercle Di of Th. II and Th. III with two chaetae (Di1 M and Di 2 mi, on the border of the tubercle) and Di 3 mi, outside the tubercle. Tubercle De of Th. II and Th. III with three chaetae (De1–2 M and De 3 mi) and one S-chaeta. Tubercles De and DL well separated on Abd. IV; Abd. V with tubercles Di fused or at least adjacent on the axis, separated from De, and tubercles De and DL fused, with four chaetae (3 M and 1 mi) and one S-chaetae. Tubercle Di of Abd. V with Di1 M, Di 2 mi, and Di3 absent. Abd. VI bilobed. S-chaetotaxic formula: 2 + ms, 2/11111.

Tita without chaeta M, B4–B5 slightly longer than other chaetae of the Tita ( Figure 4D ). Claw untoothed, not striated in its basal part, and devoid of secondary granulation.

Ventral chaetotaxy of Abd. II– VI and VT as in Figure 4E . Furcal rest with four chaetae, apparently devoid of mi. Chaetae Ag 3 + 3. Female genital plate as in Figure 4F . Postcephalic chaetotaxy summarised in Table 4.

Derivatio nominis. A tribute to Gilberto Gil, Brazilian songwriter and singer.

Discussion. As for A. neotropica sp. nov., the new species A. gili sp. nov. is also well characterised in the genus. The chaetal arrangement of Di tubercles on Th. II and Th. III are of the grossi type sensu Greenslade and Deharveng 1990, with chaetae Di2 on the border of the tubercle and Di3 outside the tubercle. Moreover, the new species also presents other similarities to A. grossi ( Yosii, 1966) , as for the dorsal chaetotaxy of tubercles Di and De on all segments of Th. and Abd., especially the five chaetae on tubercle De + DL of Abd. V. For the DL tubercles, however, the number of chaetae are different. The ventral chaetotaxy is also very similar to that of A. grossi . Nevertheless, A. gili sp. nov. does not have chaeta C on Af tubercle of the head, which is present in A. grossi .

The recently described species Australonura paraguayensis Palacios-Vargas and Deharveng, 2014 is also similar to A. grossi for most of body chaetotaxy, but it is even more similar to A. gili sp. nov., not only because of body chaetotaxy, but especially due to the adjacency of Di tubercles on Abd. V. The main difference between them is the type of chaetae Di of Th. II–III – one M and two mi in A. gili sp. nov. and one M, one me and one mi in A. paraguayensis – and Abd. I–IV – one M and one mi in A. gili sp. nov. and one M and one me in A. paraguayensis . In addition to that, the ciliation of M and me of A. paraguayensis is much more distinct than of A. gili .

Together with A. neotropica sp. nov. and A. gili sp nov., A. paraguayensis may form a group of South American Australonura with adjacent Di tubercles of Abd. V. Differential characters between the species are summarised in Table 5.

Figures

Figure 3. Australonura gili sp. nov. Dorsal chaetaotaxy with detail of dorsal macrochaeta, lateral macrochaeta and mesochaeta. Scale bars: 80 µm (body); 20 µm (chaetae).

Figure 4. Australonura gili sp. nov. (A) dorsal view of Ant. III–IV; (B) ventral view of Ant. III– IV; (C) labium; (D) tibiotarsus of leg II; (E) VT and ventral chaetotaxy of Abd. II–VI; (F) female genital plate. Scale bars: 20 µm (A–D, F); 80 µm (E).