Pseudonannolene ambuatinga Iniesta & Ferreira, 2013

Iniesta, Luiz Felipe Moretti & Ferreira, Rodrigo Lopes, 2013, Two new species of Pseudonannolene Silvestri, 1895 from Brazilian limestone caves (Spirostreptida: Pseudonannolenidae): synotopy of a troglophilic and a troglobiotic species, Zootaxa 3702 (4), pp. 357-369 : 358-362

Pseudonannolene ambuatinga Iniesta & Ferreira, 2013

( Figs. 2–6 )

Material examined: Holotype: 1 Male ( ISLA 2267) from Gruta Loca d’água de baixo, Pains/MG, Brazil, 28/I/ 2009.

Paratypes: 1 Male (fragmented, ISLA 2272) from Gruta Loca d’água de baixo, Pains/MG, Brazil, 28/I/2009; 2 Males (fragmented, ISLA 2273, ISLA 2275) from Gruta do Éden, Pains/MG, Brazil, 15/III/2012; 1 Female ( ISLA 2274) from Gruta do Éden, Pains/MG, Brazil, 15/III/2012; 4 Female (fragmented, ISLA 2268, ISLA 2269, ISLA 2270, ISLA 2271) from Gruta Loca d’água de baixo, Pains/MG, Brazil, 28/I/2009; 4 females ( ISLA 2276, ISLA 2277, ISLA 2278, ISLA 2279) from Gruta do Éden, Pains/MG, Brazil, 15/III/2012.

Etimology. Ambuatinga is formed by a combination of words: ‘‘ Ambua,’’ means ‘‘millipede’’ and ‘‘ tinga’’ means ‘‘white’’, both words coming from the Tupi-Grarani (Brazilian Indian languages). Therefore, ambuatinga means ‘‘white millipede.” It is to be treated as a noun in apposition.

Diagnosis. Body and eyes depigmented. Eyes with 27-33 ocelli. Basal section of gonopod 0.75 times longer than width and distal section 0.5 times longer than width. Solenomere rhomboid, spine directed laterally.

Measurements: Length from 40 up to 44 mm; maximum midbody diameter between 2.40 to 3.36 mm; body rings ranging between 61 to 66; length of antennae ranging from 2.5 to 2.89 mm (relation to diameter ranging 0.86 to 1.04); length of legs 1.60 to 2.11 mm (relation to diameter ranging 0.67 to 0.63); length of tarsal claw 0.1 to 0.14 mm (relation to diameter of 0.04).

Color: Whitish.

Description of Adults. Head ( Fig. 2 ): Head glabrous and depigmented. Three small labral teeth, a row of 15 labral setae and above a row of 6 supralabral setae. Mandibles depigmented, glabrous and with 2 external teeth, 4 internal teeth and 10 pectinate lamellae (difficult to see). Eyes depigmented with 27 to 33 ocelli, arranged in 4-5 rows. Antennae depigmented and densely setose. First antennomere small, with setae exclusively positioned on the distal edge. Second and third antennomeres of similar sizes. Fourth and fifth antennomeres shorter than third ( Fig. 3 A), the width in the fifth being longer than the fourth. Sixth antennomere longer and wider than the fourth and fifth and with four terminal sensory cones ( Fig. 5 C). Groups of basiconic sensilla on the edge of the fifth and sixth antennomeres ( Fig. 5 B).

Gnathochilarium ( Fig. 4 A; B): Gula (Gu) with short setae. Mentum (Me) rounded with few setae visible. Males with a concavity deeper in Me than the female and Stipes (St) more rounded in distal region. St with basally and distally rounded lateral borders. Promentum (Pme) divided into two triangular parts separated by a midline suture. Laminae linguaies (Ll) triangular, entirely separated by Pme.

Trunk: Tergites and collum depigmented. Lateral region of rings with transverse striae present (striae variable in individuals). Anal shield and anal valve slightly pigmented.

First male pair of legs ( Fig. 5 A): The first leg pair is modified and densely setose. Sternum (St) small and rounded. Coxae (Cx) larger than those of remaining legs and densely setose. Prefemur (Prf) with thin oral process parallel (P) to the coxa ( Fig. 5 B). Postfemur (Psf) and tibia (Tb) reduced ( Fig. 5 C). Femur (F) longer and wider than other podomeres. Terminal claw (Tc) not modified ( Fig. 5 D).

Gonopod ( Fig. 6 A): Coxae (Cx) reduced, glabrous and joined with basal section of telopodite. The basal section (Bs) of telopodite with surface more membranous than Cx. Shoulder absent. Length is about 0.75 times longer than width. Bs beset with basiconic sensilla (B) extending toward the internal margin of section ( Fig. 6 D).

Distal section (Ds) ( Fig. 6 B) sturdier and with length about 0.5 times longer than width. Ds divided into solenomere (S) ( Fig. 6 C) and an internal branch (Ib), separated by a seminal groove (Sg). Ib (coxosternal branch) like a shield of solenomere, densely setose. S rhomboid, with two different regions of squamous surface, a lateral surface more rounded and another spiniform in anteromedian region. Presence of a spine (Sp) in apex directed laterally.

Remarks. Individuals of P.ambuatinga were observed in seven caves in the Pains region (Minas Gerais, Brazil), totaling 327 individuals, although few were collected for the study. In all caves, the organisms were always found in aphotic areas, far from entrances, also showing a clear preference for extremely humid locations. The largest populations were found in caves with underground rivers, such as the Gruta do Éden ( Fig. 1 B, C, D, E) and the Loca d´água de baixo. Hundreds of individuals were observed in these caves. The organisms showed clear preference for plant remains that accumulated on the banks of rivers and for underground deposits of bat guano (especially that of the bat Desmodus rotundus , a hematophagous species). Furthermore, we observed completely submerged organisms, walking along the bottom of streams ( Fig. 1 F), in the Gruta do Éden and Loca d´água de baixo. Some individuals were collected alive and reared in the laboratory. The terrarium was modified to contain two regions, one photic and the other aphotic (covered with aluminum foil and black plastic). Under these conditions, individuals exhibited clear preference for the aphotic area of the terrarium as expected, with some specimens burying themselves in sediments and remaining there.

Figures

FIGURE 1. Distribution map of P. ambuatinga n. sp. and P. saguassu n. sp. A) Map of Brazil and Minas Gerais state, indicating the location of the Pains municipality; B) Map of the Gruta do Éden. The arrows show the cave entrances (blue arrow—natural entrance; red arrow—artificial entrance, opened by mining activities). The blue star indicates the area where P. saguassu was found and the yellow area shows the population distribution of P. ambuatinga inside the cave; C) Artificial entrance of the Gruta do Éden (red arrow); D) Upper conduits of the cave; E) Stream conduit, in which the population of P. ambuatinga lives; F) P. ambuatinga n. sp. found walking under the water; G) P. ambuatinga n. sp. on a rock.

FIGURE 2. P. ambuatinga n. sp., paratype female (ISLA 2269), stereoscope images. Detail of anterior region;

FIGURE 3. P. ambuatinga n. sp., paratype male (ISLA 2272), SEM, antenna view. A) 5 ° and 6 ° antennomeres; B) Fifth antennomere with detail of aesthetascs; C) Last antennomere with detail of sensory cones. Abbreviations: Ae = aesthetascs; Sc = Sensory cones. Scales bars: A = 200 µm; B = 20 µm; C = 10 µm.

FIGURE 4. P. ambuatinga n. sp., paratype female (ISLA 2268) and paratype male (ISLA 2272), SEM, gnatochilarium view. A) Female; B) Male. Abbreviations: Gu = gula; St = stipes; Me = mentum; Pme = pro-mentum; Ll = laminae linguaies; L = labrum; Lt = labrum teeth; Op = outer palpus; Ip = inner palpus. Scales bars: 200 µm.

FIGURE 5. P. ambuatinga n. sp., paratype male (ISLA 2272), SEM of the first pair of legs. A) First pair of legs; B) Detail of process on the pre-femur; C) Detail of the left leg; D) Detail of tarsus and claw. Abbreviations: St = sternum; Cx = coxae; P = process; Pf = pre-femur; F = femur; Psf = post-femur; Tb = tibia; T = tarsus; Tc = tarsal claw. Scale bars: A = 200 µm; B = 20 µm; C = 100 µm; D = 100 µm.

FIGURE 6. P. ambuatinga n. sp., paratype male (ISLA 2272), SEM of the gonopod. A) Gonopod; B) Detail of distal segment of the telopodite; C) Detail of the solenomere; D) Basiconics bristles. Abbreviations: Cx = coxae; B = basiconic bistles; Bs = basal segment; Ds = distal segment; Sg = seminal groove; Ib = internal branch; S = solenomere; Sp = spine. Scale bars: A = 100 µm; B = 20 µm; C = 10 µm; D = 10 µm.