Austrogastrura marambaia, Fernandes, Liliane Henriques, Bellini, Bruno Cavalcante & Mendonça, Maria Cleide De, 2010

Fernandes, Liliane Henriques, Bellini, Bruno Cavalcante & Mendonça, Maria Cleide De, 2010, Revision of the genus Austrogastrura Thibaud & Palacios-Vargas, 1999 (Collembola: Poduromorpha: Hypogastruridae), Zootaxa 2542, pp. 61-68 : 64-67

Austrogastrura marambaia sp. nov.

Figs 12–20 , Tab. 1

Syn. A. travassosi ( Arlé 1939) sensu: Thibaud & Palácios-Vargas (1999) Type material. Holotype male, Brazil, Rio de Janeiro, Mangaratiba, Restinga da Marambaia , 30.vii.2007. Abrantes & Fernandes coll, on slide Nº1753 CM/MNRJ. Paratypes: two specimens on slides Nº 1752 CM/ MNRJ; one specimen on slide Nº1754 CM/MNRJ; one specimen on slide Nº1755 CM/MNRJ; one specimen on slide Nº1759 CM/MNRJ; 30.x.2007. Abrantes & Fernandes coll., two specimens on slide Nº1815 CM/ MNRJ; three specimens on slide Nº1817 CM/MNRJ.

Other examined material. Brazil, Rio de Janeiro, Mangaratiba, Ilha da Marambaia , 29.vii.2005. Anjos- Santos coll., 14 specimens on slide and 68 specimens in alcohol Nº1590 CM/ MNRJ.

Description. Total length of the holotype 0.90 mm. Alive specimens orange, specimens preserved in ethanol pale, only eye patches pigmented..Body elongated, subcylindrical. Cuticular granulation moderate.

Antennae shorter than head diagonal, measuring 120Μm and 160Μm, respectively; antennal segment IV with bi- or trilobed apical vesicle, eight subcylindrical sensilla, subapical organite, and lateral microsensillum present. Sensory organ of antennal segment III consist of two globular microsensilla hidden under a cuticular fold, two guard sensilla and ventral microsensillum. Antennal segments I and II bear 7 and 11–12 setae, respectively ( Figs 12, 13 ).

5+5 eyes on strongly pigmented patch, eye measuring 8 Μm; postantennal organ, measuring 12Μm, with a strong tendency to division into four peripheral lobes and a central one ( Fig. 14 ). Chewing mouthparts typical of the family Hypogastruridae ; maxilla with 3 teeth and 6 fringed lamellae; maxillary outer lobe with 2 sulobal hairs; labium with 5 papillae (A–E); labral chaetotaxy: 2/2344.

Leg setae from I to III as follow: precoxae 0,3,3; coxae 4,6,6; trochanters 6,6,5; femora 12,11,11; tibiotarsi 19,19,18, all acuminate, M seta present; pretarsi with 2 setae. Ungues simple (18Μm) toothless; unguiculi absent ( Fig. 15 ). Ventral tube with 4+4 setae ( Fig. 16 ). Tenaculum with 3+3 teeth. Furca complete; dens short, measuring 30Μm, with 6 dorsal setae, one internal longer than others; mucro slender, about 1/3 of dens length, with notch in apical part ( Fig. 17 ). Anal valves with 14+14 setae and 3+3 hr setae ( Fig. 18 ). Female plate with 2 eugenital setae and 4–6 pregenital setae ( Fig. 18 ); male plate with 4 pairs of eugenital setae and 10 circumgenital setae ( Fig. 19 ). No anal spines.

Dorsal setae on head and body smooth; sensory setae thicker and longer than ordinary setae; setae on abdominal segments V and VI much longer than others ( Fig. 20 ). Head sd2 seta present; a0 and c1 setae absent; three Oc setae present. Thoracic segment I bears 2+2 dorsal setae and 1+1 lateral; thoracic segments II and III with two sensillae (m6/7 and p4); no lateral microsensilla. Abdominal segments I–IV with one pair of sensilla in position p4, on abdominal segment V in position p3; p2 seta absent. Ventral setae smooth and thin.

Remarks. Austrogastrura marambaia sp. nov. is closely related to A. travassosi having the same color pattern, number of ocelli and dental setae, shapes of PAO and mucro, and very similar chaetotaxy. However the species can be easily distinguished by the different number of sensilla on antennal segment IV (8 in A. marambaia sp. nov. ver. 5 in A. travassosi ), structure of antennal organ III (inner sensilla are hidden under tegumental fold in the new species), number of tibiotarsal setae (19,19,18 in A. marambaia sp. nov. ver. 18,18, 17 in A. travassosi ), differentiation of tenent hairs (short and acuminate in A. marambaia sp. nov. ver. long and spatulate in A. travassosi ), shape of unguis (toothless in A. marambaia sp. nov. ver. clear inner tooth in A. travassosi ), and setal shape (smooth in A. marambaia sp. nov. ver. serrate in A.travassosi ).

Other characteristics of the known species of Austrogastrura are compared in Table 1 .

The examination of material collected in the same locality as material of Thibaud & Palacios-Vargas (1999) let us add some corrections to their description. The main of them are as follows: bright orange coloration in alive specimens rapidly lost in alcohol, remaining only pigmentation of eye patches; apical organ of the fourth antennal segment can be bi- or trilobed; tibiotarsi with 19, 19 and 18 setae (19,18,17 in Thibaud & Palacios-Vargas 1999) and anal valves with 14+14 setae (not 13+13).

In the following papers: Fernandes & Mendonça (2007) and Fernandes et al. (2009ab), with data of the Poduromorpha fauna of Restinga de Maricá, Autrogastrura specimens were also incorrectly identified as A. travassosi , since the identifications were based on Thibaud & Palacios-Vargas (1999).

Etymology. The species was named after its type locality.

Distribution. Good’s biogeographic zone 27: South Brazilian ( Good 1974).

Habitat. A. marambaia was found in Mangaratiba municipality, in Rio de Janeiro State, southeastern Brazil, during dry season on soil and litter of halophyte-psammophyte vegetation. The climate of Mangaratiba is ‘Aw’ according to Koeppen’s system ( Mattos 2005). The area is located in a littoral biome named Restinga, which flora is xeromorphic, basically composed of creeping and herbal plants capable to survive in high salinity, direct exposure to the solar radiation and winds.

Figures

FIGURES 12 – 20. Austrogastrura marambaia sp. nov.: 12, antenna; 13, sensory organ of the antennal segment III; 14, right eye patch and postantennal organ; 15, tibiotarsus and pretarsus with unguis of leg III; 16, ventral tube; 17, dens and mucro; 18, anal valves and female plate; 19, male plate, 20, dorsal chaetotaxy.