Nyctaster sidereus, Carvalho & Kury, 2025

Nyctaster sidereus sp. nov.

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( Figs. 5–7 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Type data. Holotype ♂ paratype ♂ ( MNRJ 3690 View Materials ), BRAZIL, Paraná state, Rio Branco do Sul, trail near Gruta da Lancinha, -25,16017, -49,2795, 875 m, 20–21.i.2024, Carvalho , R. N. & Kury, A. B. leg. ♂ paratype 2 ♀ paratypes ( MNRJ 3887 View Materials ), ♂ paratype ( MNRJ 3888 View Materials ), BRAZIL, Paraná state, Adrianópolis, Parque Estadual das Lauráceas, Trilha das Antas, -24.8594, -48.71691, 929 m, 24–25.i.2025, Carvalho, R. N. & Kury, A. B. leg. 3 ♂ paratype 2 ♀ paratypes 1 juv paratype ( MNRJ 3903 View Materials ), BRAZIL, Paraná state, Adrianópolis, Parque Estadual das Lauráceas, Trilha dos Cedros, -24.8543, -48.6982, 913 m, 26.i.2025, Carvalho, R. N. & Kury, A. B. leg. GoogleMaps

Type locality. Brazil, Paraná State, Rio Branco do Sul, trail near Gruta da Lancinha .

Etymology. The specific name is an adjective derived from the Latin sīdĕrĕus (starry or celestial). It refers to the star-like arrangement of pale tubercles on the dorsal scutum, evoking the appearance of a starry sky and highlighting a distinctive morphological feature of the species.

Diagnosis. Nyctaster sidereus sp. nov. can be distinguished from N. lanceatus sp. nov. by the following characteristics: a) ventral process of the glans measuring half the diameter of the stylus ( Fig. 7B View FIGURE 7 ); b) cheliceral bulla with two ectal spines on the proximal margin ( Figs. 6A–B View FIGURE 6 ); c) mesotergum with scutal area II laterally extending into scutal area I ( Figs. 5A, D–E View FIGURE 5 , 6A–B View FIGURE 6 ); d) scutal area IV undivided ( Figs. 5D–E View FIGURE 5 , 6A View FIGURE 6 ); e) Cx IV prodorsal apophysis with distal portion forming an obtuse angle relative to the body ( Figs. 5A, D–E View FIGURE 5 , 6A View FIGURE 6 ); f) Fe IV retrolateral face with an outstanding spine on the distal half ( Figs. 5A–B, D–E View FIGURE 5 , 6J, L–M View FIGURE 6 ); g) Pa IV retro ventral face with two-three tiny and equal-sized spines ( Fig. 6O View FIGURE 6 ).

Description of male. DS measurements of ♂ holotype (MNRJ 3690): CW 3.3, CL 2.2, AW 6.7, AL 3.6; Pp and legs I–IV measurements in Table 4; tarsal counts: 6(3) / 6(3) - 10(3) / 12(3) - 7 / 7 - 7 / 7.

Dorsum. DS gamma-pyriform type, wider than long, with AS lateral margins strongly convex, widest at area II and highest at area III ( Figs. 5A, C–D View FIGURE 5 , 6A–B View FIGURE 6 ). AS posterior margin sinuous ( Figs. 5A, C View FIGURE 5 , 6A View FIGURE 6 ). DS anterior portion with two rows of five or six acuminated tubercles ( Figs. 6A–B View FIGURE 6 ). Carapace covered by many tubercles, with a pair of paramedian higher tubercles on the posterior portion ( Figs. 5A, C–E View FIGURE 5 , 6A–B View FIGURE 6 ). Cheliceral sockets shallow, with a small apophysis in between ( Fig. 6A View FIGURE 6 ). Ocularium elliptical, high (ca. 3× the diameter of the eyes), almost perpendicular to the anterior portion of DS, placed in the middle of the carapace ( Figs. 5A, C–E View FIGURE 5 , 6A–C View FIGURE 6 ). Ocularium with a pair of divergent blunt apophyses (ca. 2x the diameter of the eyes) fused at baseline and almost perpendicular in relation to DS ( Fig. 6A–C View FIGURE 6 ). Mesotergum divided into four clearly defined scutal areas ( Figs. 5A, D–E View FIGURE 5 , 6A View FIGURE 6 ). Scutal area I divided into left and right halves by median groove ( Figs. 5A, D–E View FIGURE 5 , 6A View FIGURE 6 ). Scutal area II anterior lateral groove slightly invading the space of the scutal area I and posterior lateral groove invading the space of area III to a half its length ( Figs. 5A, D–E View FIGURE 5 , 6A View FIGURE 6 ). Scutal area III posterior paramedian grooves invading the space of scutal area IV ( Figs. 5A, D–E View FIGURE 5 , 6A View FIGURE 6 ). DS posterior border central groove invading the space of scutal area IV ( Fig. 6A View FIGURE 6 ). AS lateral borders with two rows of tubercles, the innermost row (composed only by ordinary tubercles) originates in the anterior region of the carapace, while the outermost row (with five or six prominent tubercles at the scutal areas II–IV height, increasing in size backwards) arises from its central portion; both rows end at the level of scutal area IV ( Figs. 5A, C–E View FIGURE 5 , 6A–B View FIGURE 6 ). All scutal areas bear numerous tubercles, most of which are lighter in color than the darker background ( Figs. 5A, C–E View FIGURE 5 , 6A View FIGURE 6 ). Scutal area I with a pair of paramedian tubercles ca. 2.5× taller than the surrounding ones. ( Figs. 5A, C–E View FIGURE 5 , 6A–B, C View FIGURE 6 ). Scutal area III with a pair of paramedian, elevated sub-conical blunt apophyses ( Figs. 5A, C–E View FIGURE 5 , 6A–B, E–F View FIGURE 6 ). Scutal area III with two pairs of prominent tubercles, ca. 2× taller than the surrounding ones, positioned laterally to the paramedian armature ( Figs. 5A, C–D View FIGURE 5 , 6A–B View FIGURE 6 ). Scutal area IV with two paramedian pairs of prominent subconical tubercles, ca. 1.5× taller than the surrounding ones ( Figs. 6A–B View FIGURE 6 ). DS posterior border with two transverse rows: inner row discontinuous with ordinary tubercles; outer row continuous, bearing three pairs of prominent tubercles (ca. 2× taller than the surrounding ones) in central and paramedian regions ( Fig. 6A View FIGURE 6 ). Free tergites with a transverse row of mixed prominent and ordinary tubercles ( Figs. 5A, D View FIGURE 5 , 6A View FIGURE 6 ).

Venter . Cx I–III parallel to each other, with Cx I and III compressing centrally both sides of Cx II ( Fig. 5B View FIGURE 5 ); each one bears ventral transverse rows of 7–15 setiferous tubercles (Cx I anterior row taller than the others). Cx II posterior face with a row of four acuminated tubercles. Cx III posterior face with a row of eight acuminated tubercles. Cx IV much larger than the others, obliquely oriented ( Fig. 5B View FIGURE 5 ). Stigmatic area Y-shaped, distinctly sunken relative to Cx IV distal region ( Fig. 5B View FIGURE 5 ). Intercoxal bridges well-marked. Stigmata clearly visible ( Fig. 5B View FIGURE 5 ). Free sternites with a transverse row of minute tubercles ( Fig. 5B View FIGURE 5 ). Anal operculum covered by ordinary tubercles.

Chelicerae. Basichelicerite elongate; bulla distinct, bearing marginal setiferous tubercles—two ectal, three posterior, one mesal; hand not swollen ( Figs. 6A–B View FIGURE 6 ).

Pedipalps. Tr ventrally with one regular and one geminate subconical tubercle on distal half. Fe with two setiferous tubercles: one prolateral apical, one proventral basal. Pa unarmed. Ti with ventro-mesal and ventro-ectal rows of four (IiIi) setiferous tubercles. Ta with ventro-mesal and ventro-ectal rows of three (III and IIi, respectively) setiferous tubercles. Claw smooth, slightly ventrally arched.

Legs. Tr I–III dorsally and ventrally covered with minute tubercles; ventral face with a central prominent tubercle. Fe I–II straight, Fe III sub-straight ( Fig. 6G View FIGURE 6 ). Fe–Mt I–III with rows of minute tubercles on all faces (except ventral) ( Fig. 6G View FIGURE 6 ). Fe II–III retro dorsal face with an apical spur nearly equal to segment diameter ( Fig. 6G View FIGURE 6 ).

Cx IV: large, surpassing DS in dorsal view and distally reaching posterior DS margin ( Figs. 5A, D View FIGURE 5 , 6A View FIGURE 6 ). It is covered with rows of tubercles on prodorsal, prolateral, proventral and ventral faces; pro dorsal tubercles more developed than others ( Figs. 8A–D View FIGURE 8 , 6A View FIGURE 6 ). A long prolateral distal apophysis, basal half perpendicular to DS, and bifurcated distally into a main posteriorly curved claw-shaped branch and a reduced secondary branch aligned with basal axis ( Figs. 5A View FIGURE 5 , 6A–B, H, J–L View FIGURE 6 ); pro dorsal apophysis with a reduced basal secondary branch ( Figs. 5A View FIGURE 5 , 6A, I–J View FIGURE 6 ); a short retrolateral apophysis bearing a minute secondary branch ( Figs. 5A–B View FIGURE 5 , 6A, I–J, L–M View FIGURE 6 ).

Tr IV: rectangular ( Fig. 5A–E View FIGURE 5 , 6A, I, J–M View FIGURE 6 ), dorsally and ventrally tuberculate ( Figs. 5B View FIGURE 5 , 6I–M View FIGURE 6 ), with a pair of prominent tubercles on pro ventral and retroventral distal portions ( Fig. 6L View FIGURE 6 ). Proximal portion with conical apophyses on prolateral and retrolateral faces—the latter well-developed and slightly anteriorly curved ( Figs. 5A View FIGURE 5 , 6A, I–J, L–M View FIGURE 6 ); distal portion with claw-shaped apophyses on pro dorsal and retrolateral faces; pro dorsal with an anterior subconical secondary process, retrolateral smaller and dorsally tuberculate ( Figs. 5D View FIGURE 5 , 6A, I–K, M View FIGURE 6 ). Tr IV central portion with two prominent tubercles on pro lateral and retrolateral faces, distal ones larger ( Figs. 6A, I–K, M View FIGURE 6 ); a prominent tubercle on the prolateral face near the distal border, adjacent to the prodorsal apophysis ( Figs. 6A, I–L View FIGURE 6 ); retrolateral face with one prominent subconical tubercle next to the distal margin ( Figs. 6I–J, L–M View FIGURE 6 ).

Fe IV: sub-straight, centrally oriented to retroventral ( Figs. 5C–E View FIGURE 5 , 6J–M View FIGURE 6 ). Dorsal face with one spine and two prominent subconical tubercles on the proximal half, and one prominent tubercle, one spine, and a reduced apical spine on the distal half ( Figs. 6J–K, M View FIGURE 6 ); prodorsal face with a row of 13–15 prominent tubercles ( Figs. 6J–K View FIGURE 6 ); prolateral face with a row of 15–17 tubercles ( Figs. 6J–L View FIGURE 6 ); proventral face with five prominent subconical tubercles on the proximal half, and three spines (iII) on the distal half ( Figs. 6K–L View FIGURE 6 ). Fe IV ventral face with one prominent tubercle and two well-developed spines (iI) curved retro laterally on the proximal half ( Figs. 6K–M View FIGURE 6 ); retro ventral face with a prominent subconical tubercle near to the basal margin, and two well-developed spines (II) on the distal third ( Figs. 6L–M View FIGURE 6 ); retrolateral face with three prominent tubercles, one large conical tubercle and a dorsally curved spine on the proximal half, and two spines—the proximal one highly developed (ca. 2.5× segment diameter)—on the distal half ( Figs. 6J, L–M View FIGURE 6 ); retro dorsal face with a row of ordinary tubercles, ending with a spine and an apical spur on the distal quarter ( Figs. 6J, M View FIGURE 6 ).

Pa IV: dorsally and laterally covered by ordinary and prominent subconical tubercles, increasing size towards to retrolateral face ( Figs. 6N–O View FIGURE 6 ); proventral face with four spines (iIiI) ( Fig. 6O View FIGURE 6 ); ventral face with five–six subconical tubercles ( Fig. 6O View FIGURE 6 ); retroventral face with two spines (Ii) ( Fig. 6O View FIGURE 6 ).

Ti IV: dorsally covered by conical tubercles, taller on the proximal–central thirds ( Figs. 6N View FIGURE 6 ). Prolateral face with a row of subconical tubercles ( Figs. 6N–O View FIGURE 6 ); proventral face with a row of nine prominent subconical tubercles on the proximal half, and three–four spines on the distal half ( Fig. 6O View FIGURE 6 ); retro ventral face with a row of seven spines, the two proximal smallest ( Fig. 6O View FIGURE 6 ); retrolateral face with a row of nine tubercles, two proximal most conical and taller, others subconical ( Figs. 6N–O View FIGURE 6 ).

Mt IV: with rows of minute tubercles on all faces (except ventral); proventral and retro ventral apical portions with spurs.

Color (in vivo) (MNRJ 3690, ♂ holotype) ( Figs 5A–E View FIGURE 5 ). Ocularium, DS background and its lateral portions, free tergites I–III, anal operculum, Cx–Tr IV apophyses and Fe–Pa IV spines Brownish Black (65), with apophyses and spines’ apices Vivid Orange (48). DS with anterior and lateral margins Strong Orange (50). DS and free tergite I posterior margins Moderate Orange Yellow (71). DS scutal grooves Olive Gray (113). Pair of spines from ocularium Dark Grayish Olive (111) with tips Brownish Gray (64). DS, free tergites I–III and Cx IV bear numerous Vivid Greenish Yellow (97) tubercles contrasting with the background. Pair of spines from DS scutal area III Blackish Purple (230) with tips Grayish Olive Green (127). Chelicerae and pedipalps with Dark Greenish Yellow (103) background and a honeycombed Dark Olive (108) reticulation. Cx I–IV and Tr–Pa IV with Very Dark Red (17) background. Tr–Mt I–III and Ti–Mt IV with Dark Orange Yellow (72) and Olive Gray (113) background. Tr I–III distal third with a Brilliant Orange Yellow (67) and Moderate Olive (107). Fe II–III retro dorsal spur and Ti IV proventral and retro ventral distalmost spines Deep Yellow (85). Articular membranes White (263).

Color ( in ethanol) (MNRJ 3690, ♂ holotype). Ocularium, DS background and its borders, free tergites I–III, and anal operculum Dark Olive Green (126). DS scutal grooves Light Olive (106). DS and free tergites I–III bear numerous Moderate Yellow Green (120) tubercles contrasting with the background. Pair of spines from DS scutal area III Olive Black (114) with tips Grayish Green (150). Chelicerae, pedipalps, Tr–Mt I–II, Fe–Mt III and Ta–Mt IV with Light Yellow Green (119) background and a honeycombed Dark Grayish Olive Green (128) reticulation. Cx I–II and Cx–Tr III background Dark Greenish Yellow (103), with honeycombed Grayish Olive Green (127) reticulation. Cx–Tr IV background Olive Gray (113), with a longitudinal comb of Dark Yellow (88) transverse stripes. Cx–Tr IV apophyses Dark Grayish Olive Green (128) with apices Moderate Orange Yellow (71). Tr IV distal quarter and Fe IV background Dark Grayish Olive (111). Fe IV spines Deep Olive Green (124) with tips Moderate Greenish Yellow (102) or Light Olive (106). Pa IV background Light Olive Brown (94), with honeycombed Grayish Olive (110) reticulation. Articular membranes White (263).

Male genitalia. VP is divided into two regions, a distal trapezoidal part and a proximal elliptical part ( Fig. 7A View FIGURE 7 ). VP ventral surface entirely covered with type 1 microsetae. All MS are laterally inserted on the VP: A1–A3 cylindrical, thick and acuminate, forming a diagonal row on the basal third of VP (MS A3 ventral most) ( Figs. 7A–B View FIGURE 7 ); B1 conical and very reduced, inserted ventrally, at height of A1 ( Figs. 7B View FIGURE 7 ); C1–C3 similar in shape to MS A, forming a longitudinal row on the distal third of the VP ( Figs. 7A–B View FIGURE 7 ); D1 small, positioned closer to C3 than A1 ( Figs. 7A–B View FIGURE 7 ); E1–E2 similar in shape to B macrosetae, located on the distal lateral border of the VP, E1 between the height of C1–C2 and E2 at the height of C3 ( Fig. 7B View FIGURE 7 ). Glans sac short, arising from middle bulge on podium, not extended as a dorsal process ( Figs. 7A–C View FIGURE 7 ). Stylus and ventral process basally fused, forming a long pedestal at an acute (almost V-shaped) angle ( Figs. 7B–C View FIGURE 7 ). Apex of the stylus sub-straight, bent 45° dorsad, without clearly defined head and ventrally covered by small subdistal spines (some of them reaching the central part of the stylus) ( Figs. 7A–C View FIGURE 7 ). The ventral process of the stylus is S-shaped, thinner and as long as the stylus, and nearly reaches the distal VP border in situ ( Figs. 7A–C View FIGURE 7 ). The flabellum of the ventral process is “hand-shaped”, with lateral spines ( Figs. 7A–C View FIGURE 7 ).

Description of female. DS measurements of ♀ paratype (MNRJ 3903) ( Fig. 5G View FIGURE 5 ): CW 2.7, CL 2.1, AW 5.6, AL 3.6; Pp and legs I–IV measurements in Table 5; tarsal counts: 6(3) / 6(3) - 9(3) / 9(3) - 7 / 7 - 7 / 7.

Characters differing from the male: DS gamma-pyriform type, as wide as long ( Figs. 5G View FIGURE 5 ). Ocularium slightly lower than in males. Scutal area III with a paramedian pair of spines bearing pointed apices ( Figs. 5G View FIGURE 5 ). Cx IV narrower than in males, with prodorsal apophysis reduced to a conical spine ( Figs. 5G View FIGURE 5 ). Tr IV square-shaped, with short conical apophyses on the proximal third of both prolateral and retrolateral faces; prodorsal face with a distal conical apophysis; retrolateral face with a reduced subconical apophysis on the distal third (Fis. 5G). Fe IV sub-straight, slightly arched retro ventrally on the distal third, shorter and thinner than in males ( Figs. 5G View FIGURE 5 ); it bears four–five spines on the dorsal face; pro dorsal and retroventral faces each with a row of eight–nine spines ( Figs. 5G View FIGURE 5 ); retrolateral face with a large spine (longer than the segment diameter) on the central third; pro dorsal and retro dorsal faces each with a spur on the apical portion, retro dorsal larger ( Figs. 5G View FIGURE 5 ).

Intraspecific variation. Among major morph males: the Cx IV prodorsal apophysis forms an angle ranging from 90° to obtuse relative to the DS.

In the minor morph male (n=1) ( Fig. 5F View FIGURE 5 ) (compared to major morphs, n=5): (1) narrower DS; (2) reduced Cx IV prodorsal distal apophysis, with the secondary branch visible dorsally; (3) reduced Tr IV retrolateral proximal apophysis; (4) Tr IV retrodorsal apophysis reduced to a monticule with minute tubercles; (5) Fe IV thinner and nearly straight, with reduced but similarly patterned armature; (6) Pa IV bearing blunt spines dorsally and laterally; (7) Ti IV with similarly patterned but reduced armature.

No significant intraspecific variation was observed among females.

Geographic distribution. BRAZIL, state of Paraná: Adrianópolis, Rio Branco do Sul ( Fig. 4 View FIGURE 4 ).