Cylindroniscus seurati Arcangeli, 1929 by monotypy (see Schmidt and Leistikow 2004).

Brazil●1♀, Gruta da Tapagem (Caverna do Diabo), Eldorado, Parque Estadual Caverna do Diabo, Açungui geomorphological group, state of São Paulo, 24°38'17.00"S, 48°24'4.00"W, leg. ME Bichuette, T Zepon, JE Gallão, 24.III.2021, LES 27755●1♀, same locality and collectors as for preceding, 24.III.2021, LES 27756●1♂, 1♀, same locality and collectors as for preceding, 24.III.2021, LES 27757●1♀, same locality and collectors as for preceding, 24.III.2021, LES 27758●2♀♀, same locality and collectors as for preceding, 24.III.2021, LES 27759●1♂, same locality and collectors as for preceding, 25.III.2021, LES 27760.

Cylindroniscus flaviae shows preference for organic matter deposits and highly humid areas in the aphotic zone (Fig. 2B). The organic matter was observed in several conduits of the Gruta da Tapagem, always far from the touristic stretches, and it was composed of particulate vegetal debris or small tree branches. The environmental variables along the cave ranged from 19.9 °C to 20.4 °C and the relative air humidity from 95% to 99.1%. The individuals demonstrated sensitivity to the flash lights of the lanterns, always moving in opposite direction.

This species is recorded from several caves in the Açungui geomorphological group (see Campos-Filho et al. 2017).

Pectenoniscus angulatus Andersson, 1960 by monotypy (see Schmidt and Leistikow 2004).

After Andersson (1960) and Campos-Filho et al. (2019). Animals of reduced size, ≤ 3.5 mm. Body unpigmented and eyes absent. Body slender with lateral sides almost parallel. Dorsal surface of cephalon and pereon bearing small transverse tubercles, conferring granulated appearance, pleon smooth or slightly tuberculate. Cephalon with 4–6 rows of tubercles, gradually reducing in number from posterior to distal portion, pereonite 1 with two or three rows of tubercles, pereonites 2–7 with two rows of tubercles. Dorsal scale-setae triangular. Cephalon with antennary lobes and suprantennal line. Pleonites 3–5 epimera not developed (only developed in P. angulatus). Telson triangular with lateral sides concave and rounded apex. Antennula of three articles, distal article with aesthetascs arranged in one longitudinal row. Antennal flagellum of 3–5 articles. Mandibles with strong molar process, left mandible with two penicils, right mandible with one penicil (sometimes one penicil on molar process). Maxillula inner endite with three penicils, proximal one longest; outer endite composed of eight or nine teeth plus slender stalks. Maxilla of two lobes covered with thick and fine setae, inner lobe wider. Maxilliped basis with lateral sides almost parallel, endite rectangular bearing one stout penicil. Uropod protopod subquadrangular, exopod longer than endopod, protopod and exopod sometimes bearing glandular pores, endopod inserted proximally. Male pleopod 1 endopod of two articles, distal article flagelliform. Male pleopod 2 endopod consisting of two articles, distal portion stout bearing complex apparatus.

The genus Pectenoniscus was created by Andersson (1960) to allocate the new species P. angulatus from Itá, Nova Teutônia, state of Santa Catarina, Brazil. The author defined the genus by having the cephalon of “Trichoniscus-type”, dorsal surface of the cephalon and pereon with rounded tubercles, pleonites epimera large, left mandible with two penicils near lacinia mobilis, right mandible with one penicil near lacinia mobilis plus one in the molar process, maxillula outer endite composed of nine teeth and two slender stalks, inner endite of three penicils and proximal one longer than distal ones, genital papilla pear-shaped with tubelike termination, male pleopod 1 of “Styloniscus-type”, male pleopod 2 endopod with distal portion broad and bearing a comb-like formation, and male pleopod 5 exopods with a dorsal lobe to fit the pleopod 2 endopod. Campos-Filho et al. (2019) described P. liliae Campos-Filho, Bichuette & Taiti, 2019 from Caverna Chico Pernambuco, Coribe, Serra do Ramalho karst area, state of Bahia, and added some characters in the diagnosis of the genus. Recently, Cardoso et al. (2020b) described six new species from karst areas of the states of Bahia and Minas Gerais, increasing the knowledge on the diversity of the genus, that now comprises eight species, i.e., P. angulatus, P. carinhanhensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. iuiuensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. juveniliensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. liliae, P. montalvaniensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. morrensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, and P. santanensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020.

Brazil●1♂, holotype, Gruna do Govi, Feira da Mata, Serra do Ramalho karst area, Bambuí geomorphological group, state of Bahia, 13°56'43.30"S, 44°14'25.94"W, 12.X.2020, leg. ME Bichuette, DF Torres, JS Gallo, LS Horta and JE Gallão, LES 27761●1♂ (parts in micropreparations), paratype, same data as for holotype, LES 27762●2 ♀♀, paratypes, same data as for holotype, LES 27763.

Maximum length: ♂ 2.2 mm, ♀ 3.5 mm. Dorsal surface slightly granulated, granules on pereonites 1–7 in two transverse rows, pleon smooth (Fig. 4A, B). Dorsal scale-setae tricorn-shaped (Fig. 5A). Cephalon (Figs 4C, 5B) with well-developed quadrangular antennary lobes, slightly directed outwards; profrons with suprantennal line bent downwards medially. Pereonite 1–3 epimera with postero-lateral corners right-angled, 4–7 progressively more acute and directed backwards; pleonite 5 epimera with glandular pores at sides near distal margins (Figs 4A, B, 5C). Telson (Fig. 5C) almost three times as wide as long, with concave sides and rounded apex. Antennula (Fig. 5D) with distal article longer than second and first, and bearing at least 12 aesthetascs. Antenna (Fig. 5E) with fifth article of peduncle as long as flagellum, bearing one distal strong seta; flagellum of four articles, first article longest, apical organ as long as distal article of flagellum. Mandibles as in Fig. 5F, G, right mandible with leaf-like lacinia mobilis. Maxillula (Fig. 5H) with two robust penicils; outer endite with 4+5 teeth, apically simple, one subapical slender stalk near medial margin. Maxilla as in Fig. 5I. Maxilliped (Fig. 5J) basis with lateral sides fringed with fine setae; palp with first article bearing two setae, distal articles fused and bearing many setae on lateral margins; endite much longer than wide, lateral margins covered with fine setae, distal margin bearing two strong setae and one elongated penicil. Grooves and scales for water conducting system on ischium, merus, carpus and propodus of pereopod 6 and basis of pereopod 7 (Fig. 6C). Dactylus with ungual seta simple and dactylar seta bifid and setose. Uropod (Fig. 6A) protopod and exopod grooved on outer margins bearing glandular pores; exopod longer than endopod, endopod inserted proximally.

Male. Pereopods 1–6 (Fig. 6B) without any sexual modifications. Pereopod 7 (Fig. 6C) propodus with brush of setae on rostral margin. Genital papilla (Fig. 6D) enlarged on median portion, apical part narrow and elongated. Pleopod 1 (Fig. 6D) protopod subrectangular, distal margin sinuous; exopod subtriangular, outer margin almost straight, proximal and outer margins convex; endopod longer than exopod, basal article short, distal article three times longer than basal one. Pleopod 2 (Fig. 6E) exopod ovoid, more than three times as wide as long; endopod of two articles, thickset, second article more than twice as long as first, distally bearing round shaped lobe directed outwards. Pleopod 5 exopod (Fig. 6F) subquadrangular, slightly wider than long, bearing three setae, distal margin rounded.

Figure 4. 

Pectenoniscus pankaru Campos-Filho, Torres & Bichuette, sp. nov. (♀, LES 27763) A habitus, dorsal view B habitus, lateral view C cephalon, dorsal view. Pectenoniscus fervens Campos-Filho, Taiti & Bichuette, sp. nov. (♀, LES 27764) D habitus, dorsal view E habitus, lateral view F cephalon, dorsal view.

Figure 5. 

Pectenoniscus pankaru Campos-Filho, Torres & Bichuette, sp. nov. (♂, LES 27762) A dorsal scale-seta B cephalon, frontal view C pleonites 4, 5 and telson D antennula E antenna F left mandible G right mandible H maxillula I maxilla J maxilliped.

Figure 6. 

Pectenoniscus pankaru Campos-Filho, Torres & Bichuette, sp. nov. (♂, LES 27762) A uropod B pereopod 1 C pereopod 7 D genital papila and pleopod 1 E pleopod 2 F pleopod 5 exopod.

The new species is named for the indigenous people Pankaru, who inhabited the northern portion of Serra do Ramalho region.

Pectenoniscus pankaru sp. nov. differs from all other species of the genus in the shape of the male pleopod 2 endopod. Moreover, it differs in having the antennal flagellum composed of four articles (vs. five in P. angulatus, three in P. carinhanhensis, P. iuiuensis, P. juveniliensis, P. lilae, P. montalvaniensis, P. morrensis and P. santanensis), antennula bearing 12 aesthetascs (vs. six in P. morrensis and P. santanensis, eight in P. angulatus and P. montalvaniensis, nine in P. juveniliensis and P. lilae, ten in P. iuiuensis, and 11 in P. carinhanhensis) (see also Andersson 1960; Campos-Filho et al. 2019; Cardoso et al. 2020b).

Specimens of Pectenoniscus pankaru sp. nov. were found only in the aphotic zone associated to the sediment banks close to a small subterranean stream (Fig. 2B) and characterised by high humidity levels, which are more suitable for terrestrial isopods. The specimens were collected near vegetable debris.

Brazil●1♂ (parts in micropreparations), holotype, Gruta Toca Coroa do Frade, Coronel José Dias, Barra Bonita karst region, Casa Nova geomorphological group, state of Piauí, 8°47'51.58"S, 42°25'1.47"W, 8.I.2018, leg. DM Schimonsky, DF Torres and JE Gallão, LES 22421●6♀♀ (one with parts in micropreparations), paratypes, same data as for holotype, LES 27764.

Maximum length: ♂ and ♀ 3 mm. Dorsal surface granulated, granules on pereonites 1–7 in two transverse rows, on pleonites 3–5 in one row (Fig. 4D, E). Dorsal scale-setae tricorn-shaped in middle segments (Fig. 7A). Cephalon (Figs 4F, 7B) with antennary lobes small, triangular and slightly directed outwards; profrons with suprantennal line bent downwards medially. Pereonites 1 and 2 epimera with postero-lateral corners rounded, 4–7 progressively directed backwards and more acute (Fig. 4D, E). Pleonites 3–5 epimera without glandular pores (Fig. 7C). Telson (Fig. 7C) twice as wide as long, with concave sides and rounded apex. Antennula (Fig. 7D) with distal article longer than second and first, and bearing at least six aesthetascs plus distal tip. Antenna (Fig. 7E) with fifth article of peduncle slightly longer than flagellum, bearing one distal strong seta; flagellum of four articles, first and second articles subequal in length, third and fourth articles shorter; apical organ longer than distal article of flagellum. Mandibles as in Fig. 7F, G; right mandible with leaf-like lacinia mobilis. Maxillula (Fig. 7H) inner endite with apical penicil robust; outer endite of 4+5 teeth, apically simple, one subapical slender stalk near medial margin. Maxilla as in Fig. 7I. Maxilliped (Fig. 7J) basis with lateral sides fringed with fine setae; palp with first article bearing two setae, distal articles fused and bearing distal fringe of fine setae; endite much longer than wide, lateral margins covered with fine setae, distal margin bearing two strong setae and one elongated penicil. Grooves and scales for water conducting system on ischium, merus, carpus and propodus of pereopod 6 and basis of pereopod 7 (Fig. 8B). Dactylus with ungual seta simple and dactylar seta simple and apically setose. Uropod (Fig. 8A) protopod and exopod not grooved on sternal margin; exopod longer than endopod and inserted almost at same level.

Male. Pereopods 1–7 (Fig. 8B, C) without any sexual modifications. Genital papilla as in previous species. Pleopod 1 (Fig. 8D) protopod subrectangular, distal margin concave; exopod ovoidal, outer margin almost straight, proximal, inner and distal margins rounded; endopod longer than exopod, basal article short, distal article ca. twice longer than basal one. Pleopod 2 (Fig. 8E) exopod ovoidal, twice as wide as long, one seta on inner margin; endopod of two articles, thickset, second article more than three times longer than first, distal portion subquadrangular, distal outer margin with round shaped lobe directed outwards bearing one triangular process on ventral margin. Pleopod 3–5 exopods as in Fig. 8F–H.

Figure 7. 

Pectenoniscus fervens Campos-Filho, Taiti & Bichuette, sp. nov. (♀, LES 27764) A dorsal scale-seta B cephalon, frontal view C pleonites 4, 5 and telson D antennula E antenna F left mandible G right mandible H maxillula I maxilla J maxilliped.

Figure 8. 

Pectenoniscus fervens Campos-Filho, Taiti & Bichuette, sp. nov. (♀, LES 27764) A uropod (♂, LES 22421) B pereopod 1 C pereopod 7 D pleopod 1 E pleopod 2 F pleopod 3 exopod G pleopod 4 exopod H pleopod 5 exopod.

Latin. fervens for very hot, boiling hot. The new species name refers to the very hot temperatures of the Brazilian state of Piauí.

Pectenoniscus fervens sp. nov. differs from all other species of the genus in the shape of the male pleopod 2 endopod. Moreover, it differs from P. pankaru sp. nov. in having the antennula bearing six aesthetascs, the dactylar seta stout and in the different shape of the male pleopod 1 and pleopod 3–5 exopods. The new species shows the same number of aesthetascs of the antennula as in P. morrensis and P. santanensis, from which it differs in the antennal flagellum composed of four articles (three in P. morrensis and P. santanensis), male pleopod 1 protopod with the distal margin concave (vs. straight in P. morrensis, almost straight in P. santanensis), male pleopod 4 exopod triangular (vs. subrectangular in P. morrensis, subquadrangualar in P. santanensis), and male pleopod 5 exopod rhomboid and longer than wide (vs. triangular and as long as wide in P. morrensis, subquadrangular in P. santanensis).

The specimens of Pectenoniscus fervens sp. nov. were found only in the aphotic zone (Fig. 2J), in vegetable debris with clay and under rocks, where the humidity was higher than at the cave entrance.