Sandalodesmus fandango Figueiredo & Bouzan, 2025

Sandalodesmus fandango Figueiredo & Bouzan , sp. nov.

Figs 1 View FIGURE 1 , 11–12 View FIGURE 11 View FIGURE 12

Diagnosis. Males of S. fandango sp. nov. differ from other Sandalodesmus by the following combination of gonopodal characters: prefemoral process ( pfp) with a serrated medial apical margin ( Fig. 12D View FIGURE 12 ) vs. smooth in the other species, and with a small acute projection on the ectal apical margin. Mesal projection of prefemoral process ( mpfp) folds posteriorly, positioning the frontal face of the pfp dorsally ( Figs 12B, D View FIGURE 12 ). Acropodite spiniform process ( asp) present ( Figs 12B, D View FIGURE 12 ) vs. absent, except in S. peruibe sp. nov. Presence of an incision in the median-basal portion of the acropodite region, in mesal view ( Fig. 12 B, D View FIGURE 12 ), similar to the condition observed in S. peruibe , S. avilectus and S. librellus .

Etymology. The specific epithet “ fandango ” refers to the “Fandango Caiçara”, a traditional cultural dance of the coastal inhabitants of the southern Atlantic Forest in São Paulo state, where the species was collected. Noun in apposition.

Material examined.

Type material: Holotype: BRAZIL ● ♂; Estação Ecológica Juréia-Itatins ( -24.3571, -47.0136), Peruíbe, São Paulo, Brazil; iii.1997; A. D. Brescovit leg.; IBSP 320 View Materials . GoogleMaps

Description. Male ( Holotype, IBSP 320). Coloration (preserved in 70% ethanol): clypeus reddish; labrum region yellowish; vertex reddish; head, antennae, and body rings uniformly brownish red ( Fig. 11A–C View FIGURE 11 ). Paranota tip yellowish ( Fig. 11B View FIGURE 11 ). Sternites reddish ( Fig. 11E–F View FIGURE 11 ). Legs reddish orange, lighter than sternites ( Fig. 11D–E View FIGURE 11 ). Telson reddish, lighter at tip ( Fig. 11C View FIGURE 11 ). Antennae: thin setae; 5th, 6th and 7th antennomeres with small clusters of basiconic sensilla on distal external margin. Gnathochilarium: all plates with uniform coverage of small setae. Body rings: cuticle smooth, flat. Paranota well projected laterally and slightly downward, forming lowered arch; anterior margin rounded; posterior margin subtriangular. Ozopore ( oz) arrangement typical for Polydesmida (5, 7, 9, 10, 12, 13, 15–19); surrounded by peritremata; located dorsally in posterior region ( Fig. 11B View FIGURE 11 ). Sternites: body ring 4 with a pair of flat projections; body ring 5 with one pair of subpyramidal bumps; symmetrical; anterior face flat and transversely elongated; between anterior legs; body ring 6 with V-shaped posterior-ventral depression; reduced; body ring 7 without projections. Gonopod aperture extending into prozonite; anterior margin oval; body rings 8–19 with two pairs of small projections near each coxae ( Fig. 11E View FIGURE 11 ). Legs: gonopores opening as longitudinal slits, on concave area at apex of subrectangular gonapophyses. Coxae of walking legs with one long ventral seta; Leg modification patterns (ring numbers): prefemoral knob (2 <3–15> 16–18); tibial sole (2 <3–12> 13–14> 15–16; absent on 17–18); presence and degree of development of lateral projections dorsal to the stigma are as follows: 2–7 <8–13 <nearly absent from 14–20. Telson : without modifications ( Fig. 11F View FIGURE 11 ); hypoproct with a posterior marginal projection and two (1+1) lateral marginal setae.

Gonopods ( Fig. 12 View FIGURE 12 ): Gonocoxite ( gcx) approximately as long as telopodite; broad at mid-length, narrowing toward ectal margin ( Fig. 12A View FIGURE 12 );Anterior margin with transverse striations, in ectal view ( Fig. 12C View FIGURE 12 ); spiniform process small ( gsp) ( Fig. 12C View FIGURE 12 ). Cannula ( c) without prominent projections. Prefemoral region ( pfr) short, approximately one-third telopodite length ( Fig. 12D View FIGURE 12 ). Prefemoral process ( pfp) with serrated medial apical margin ( Fig. 12D View FIGURE 12 ); small acute projection on ectal apical margin; mesal prefemoral process ( mpfp) folded posteriorly, positioning frontal face of pfp dorsally ( Fig. 12B, D View FIGURE 12 ). Acropodite spiniform process ( asp) present ( Fig. 12B, D View FIGURE 12 ). Acropodite process ( ap) with longitudinal striations on ventral margin ( Fig. 12D View FIGURE 12 ); without apical curvature, perpendicular to gonocoxite ( gcx). Median-basal incision present in mesal view; creates fold along spermatic groove path ( Fig. 12B, D View FIGURE 12 ). Solenomere ( s) shorter than acropodite.

Measurements (in mm): Body: total length 49.9, width of 10 th body ring 7.0. Antennomere lengths (1−7): 0.5; 1.5; 1.2; 1.2; 1.2; 1.0; 0.2. Podomere lengths of 6 th leg (1−7): 0.8; 1.0; 2.0; 1.0; 1.0; 1.0; 1.0; tarsal claw 0.2. Telson length 1.5. Gonopod aperture: length 1.5, width 2.6. Gonopod: length 2.6, width 2.6. Gonocoxite: length 2.0, width 1.2. Telopodite: length 2.0, width 1.0.

Female. Unknown.

Species group. Sandalodesmus fandango sp. nov. is assigned to the iguazuensis species group based on the following shared characters: prefemoral region short, not significantly extended mesally ( Fig. 12D View FIGURE 12 ); prefemoral process shorter than the acropodite region and non torsate ( Fig. 12B View FIGURE 12 ); acropodite process broad, forming a hood-like structure ( Fig. 12 View FIGURE 12 ); and solenomere being small and short, not extending beyond the acropodite process ( Fig. 12D View FIGURE 12 ).