Ribautia donatellae, Pereira, Luis A., Uliana, Marco & Minelli, Alessandro, 2006

Pereira, Luis A., Uliana, Marco & Minelli, Alessandro, 2006, New species and new records of the genus Ribautia Brölemann, 1909 (Chilopoda: Geophilomorpha: Geophilidae) from South America, Zootaxa 1106, pp. 45-68 : 55-66

publication ID	https://doi.org/ 10.5281/zenodo.171440
DOI	https://doi.org/10.5281/zenodo.6255017
persistent identifier	https://treatment.plazi.org/id/1D5687B5-6666-FFC7-3A5C-BA17FBC4FE04
treatment provided by	Plazi
scientific name	Ribautia donatellae
status	sp. nov.

Treatment

Ribautia donatellae n. sp.

( Figs. 30–71 View FIGURES 30 – 34 View FIGURES 35 – 40 View FIGURES 41 – 48 View FIGURES 49 – 56 View FIGURES 57 – 60 View FIGURES 61 – 64 View FIGURES 65 – 69 View FIGURES 70 – 71 )

Diagnosis: A species of Ribautia with coxal organs opening independently on the coxopleura of last legbearing segment and last legs with tuberclelike praetarsus. Of the Neotropical species in the same genus, R. donatellae n. sp. shares most traits with R. ducalis Pereira, Minelli & Barbieri, 1995 , R. onycophaena Pereira, Foddai & Minelli, 2000 ; R. rossi Chamberlin, 1957 and R. tropica (Brölemann, 1898) . Characters in table 3 differentiate these five species.

For diagnostic characters of Neotropical species of Ribautia with coxal organs opening independently on the coxopleura, see also Pereira, Minelli & Barbieri (1995) and Pereira, Minelli & Foddai (1997, 2000).

Type material: Holotype ɗ (with 4+3 coxal organs), 49 pairs of legs, body length 19 mm, from Brazil: Amazonas: at Km 45, BR174 near Manaus, sandy soil of primary whitesand shrubs (Campina) [K 11 CPA], 10.06.1987, J. Adis et al. leg. ( INPA).

Other material examined: same locality, 10.06.1987, J. Adis et al. leg.: 1 ɗ, adult, 47 pairs of legs, body length 22 mm, 3+3 coxal organs; 1 ɗ, subadult, 49 pairs of legs, body length 14 mm, 3+3 coxal organs ( INPA); 1 Ψ, subadult, 53 pairs of legs, body length 13 mm, 3+3 coxal organs ( INPA); 1 Ψ, juvenile, 51 pairs of legs, body length 9 mm, 2+2 coxal organs ( INPA).

Etymology: The species is dedicated to dr. Donatella Foddai, who was a very kind and active partner in our previous studies on Neotropical centipedes.

Description of ɗ holotype. 49 pairs of legs, body length 19 mm, maximum body width 0.5 mm. Colour (of preserved specimen in alcohol) pale ochre.

Antennae ca. 3.0 times as long as the cephalic plate, distally very slightly attenuate. Setae on a.a. I to VI of various length, few in number; those of remaining articles progressively shorter and more numerous towards the tip of the appendage ( Fig. 30 View FIGURES 30 – 34 ). Terminal a.a. with ca. 11 claviform sensilla on the external border and ca. 12 on the internal border ( Fig. 31 View FIGURES 30 – 34 ). Distal end of this a.a. with ca. five very small sensilla, apparently not split apically ( Fig. 31 View FIGURES 30 – 34 ). Ventral and dorsal surface of a.a. II, V, IX and XIII ( Figs. 32– 33 View FIGURES 30 – 34 ) with very small specialised sensilla. On the ventral side these sensilla are restricted to an internal lateroapical area and are represented by two different types: a and b. Type a sensilla are very thin and not divided apically, type b sensilla are thicker than type a, have two diminutive apical branches and are pale in colour (a, b, Fig. 32 View FIGURES 30 – 34 ). Specialised sensilla on dorsal side restricted to a lateroapical area and of two types: a and b similar to those of ventral side (a, b, Fig. 33 View FIGURES 30 – 34 ). Distribution of sensilla as in table 4.

Ribautia donatellae n. sp.

Cephalic plate subrectangular with curved sides, distinctly longer than wide (ratio 1.50:1). Shape and chaetotaxy as in Fig 34 View FIGURES 30 – 34 .

Clypeus: anterior part with two pairs of setae on the clypeal area, two setae on the middle and a seta on each side, remaining clypeal surface without setae ( Fig. 35 View FIGURES 35 – 40 ). Clypeal area very small, surface very densely reticulate ( Fig. 36 View FIGURES 35 – 40 ).

Labrum: midpiece well developed and sclerotized, with four relatively short and sharply pointed teeth in the middle and 5+5 hyaline filaments at the sides. Sidepieces with 7+6 long hyaline filaments on the internal half and 3+3 very small sharply pointed hyaline teeth on the external half ( Fig. 37 View FIGURES 35 – 40 ).

Mandible: pectinate lamella with ca. 12 hyaline teeth ( Fig. 38 View FIGURES 35 – 40 ).

First maxillae without coxosternal lappets ( Fig. 39 View FIGURES 35 – 40 ); telopodites with rudimentary lappets ( Fig. 40 View FIGURES 35 – 40 ). Coxosternum without setae; median projections of coxosternum subtriangular, welldeveloped, with 3+4 large setae. Article II of telopodite with 2+2 ventral setae and 2+2 lateral sensilla ( Fig. 39 View FIGURES 35 – 40 ), dorsal surface apparently without sensilla.

Second maxillae: coxites with 5+5 setae near the internal margin and 3+4 sensilla near the external margin, medially joined through a narrow, hyaline and nonareolate membranous isthmus only ( Fig. 39 View FIGURES 35 – 40 ). Process of anterointernal corners of coxosternum inconspicuous ( Fig. 41 View FIGURES 41 – 48 ). Apical claw of telopodite welldeveloped, tip slightly curved inward ( Fig. 42 View FIGURES 41 – 48 ). Chaetotaxy of coxosternum and telopodites as in Figs. 39 View FIGURES 35 – 40 and 42 View FIGURES 41 – 48 .

Forcipular segment: when closed, the telopodites reach the level of the anterior margin of the head or slightly project beyond. Forcipular tergum trapeziform; an irregular transverse row of ca. six setae on the middle, very few additional smaller setae dispersed on the remaining surface. Coxosternum with incomplete chitinous lines ( Fig. 43 View FIGURES 41 – 48 ). Telopodites: trochanteropraefemur apically with a conspicuous, subtriangular, deeply pigmented tooth; proximally and next to it there is a smaller, unpigmented, roundtipped projection. Femur and tibia without denticles. Tarsungulum basally with a well developed, deeply pigmented, subtriangular denticle; dorsal and ventral edges of the ungular blade inconspicuously serrulate ( Fig. 44 View FIGURES 41 – 48 ). Calyx of poison gland as in Figs. 44–45 View FIGURES 41 – 48 . Chaetotaxy of coxosternum and telopodites as in Fig. 43 View FIGURES 41 – 48 .

Walking legs: chaetotaxy uniform throughout the body length ( Figs. 46–50 View FIGURES 41 – 48 View FIGURES 49 – 56 ). Claws with an anterior and a posterior ventrobasal spine ( Fig. 51 View FIGURES 49 – 56 ).

Sterna: pore fields on the second to the penultimate sternum. Fields undivided on sterna II–XVIII and XLIV–XLVIII, divided in two subsymmetrical areas on sterna XIX– XLIII. Form of fields changing along the trunk as in Figs. 52–59 View FIGURES 49 – 56 View FIGURES 57 – 60 . Number of pores on selected sterna: on sternum II, 17 pores; on IX, 36; on XVIII, 25; on XIX, 9+8; on XLIII, 12+10; on XLIV, 21; on XLV, 27; on XLVIII, 12.

Last legbearing segment without pleurites at the sides of praetergum. Praesternum not divided along the sagittal plane; form and chaetotaxy of tergum and sternum as in Figs. 60–61 View FIGURES 57 – 60 View FIGURES 61 – 64 . Coxopleura sligthly protruding at the distal ventral end, setae numerous on the distal internal edge, the remaining surface with few setae. Right coxopleuron with four single ('homogeneous') coxal organs ( Figs. 61–63 View FIGURES 61 – 64 ), left coxopleuron with three coxal organs ( Fig. 61 View FIGURES 61 – 64 ), opening near the membrane between coxopleuron and sternum ( Figs. 61, 63 View FIGURES 61 – 64 ). Last legs with seven podomeres, form and chaetotaxy as in Figs. 60–61 View FIGURES 57 – 60 View FIGURES 61 – 64 . Praetarsus as a very small tubercle with a diminutive apical spine ( Fig. 64 View FIGURES 61 – 64 ).

Terminal segments: intermediate tergum with posterior margin convex, intermediate sternum and first genital sternum with posterior margin concave. Gonopods biarticulate, basal article with 6 setae, apical article with 6–7 setae ( Figs. 65–66 View FIGURES 65 – 69 ); penis with 3+2 dorsal apical setae ( Fig. 67 View FIGURES 65 – 69 ). Anal organs present ( Figs. 61 View FIGURES 61 – 64 , 68 View FIGURES 65 – 69 ).

Ψ (subadult specimen): 53 pairs of legs, body length 13 mm. All features similar to those in the ɗ except for the shape and hairiness of the last legbearing segment and terminal segments.

Last legbearing segment: form and chaetotaxy of tergum and sternum as in Figs. 69– 70 View FIGURES 65 – 69 View FIGURES 70 – 71 . Coxopleura slightly protruding at the distal ventral end, setae small and numerous on the distal ventral edge, the remaining surface with few larger setae. Three single coxal organs on each coxopleuron ( Figs. 69–70 View FIGURES 65 – 69 View FIGURES 70 – 71 ). Shape and chaetotaxy of the podomeres of last legs as in Figs. 69–71 View FIGURES 65 – 69 View FIGURES 70 – 71 .

Terminal segments: shape and chaetotaxy as in Figs. 69–70 View FIGURES 65 – 69 View FIGURES 70 – 71 .

Individual variation. In our small series, the ɗɗ have 47 or 49 pairs of legs, the ΨΨ 51 or 53. Adult and subadult ɗɗ have 4+3 or 3+3 coxal organs, the only subadult Ψ 3+3 coxal organs. No significant variation was detected in other characters.