A new species of Spelunconiscus (Isopoda: Oniscidea: Styloniscidae) for Brazilian caves: new record for the type species and an emended diagnosis for the genus Author Ferreira, Rafaela Bastos-Pereira Leila A. Souza Beatriz de S. Sandi Rodrigo L. text Nauplius 2022 e 2022018 2022-07-15 30 1 16 https://doi.org/10.1590/2358-2936e2022018 journal article 10.1590/2358-2936e2022018 2358-2936 14667362 Spelunconiscus septemlacuum sp. nov. ( Figs. 6–8 ) Zoobank: urn:lsid:zoobank.org:act: D665B2ED-60DF-480C-B716-E32FEDE0BE98 Etymology. The specific epithet means septem (seven) + lacuum (lakes) in Latin, in reference to the name of the municipality where the cave is located (Sete Lagoas, in Portuguese, meaning “seven lakes”). Figure 4. Ventral view of the holotype of Spelunconiscus castroi (MZUSP27521) highlighting the presence of a spur-like structure proximally on the pereopod 7 ischium inner face (red arrow). Scale bar: 1 mm. Material examined. Holotype : male (ISLA 79134), June 2018 , Taboa Cave, Sete Lagoas , Minas Gerais , Brazil ( 19°28’30.00”S 44°19’41.70”W ); coll. R . Ferreira . Paratypes : 3 males ( ISLA 62791, ISLA 62792, ISLA 62793) and 1 female ( ISLA 62794) mounted on slides, July and December 2015 ; 3 males ( ISLA 79133) , 5females ( ISLA 62797), same data as holotype ; 1 male mounted on slide (ISLA 62790), Tatuzinhos cave , Sete Lagoas , Minas Gerais , Brazil ( 19°28’26.28”S 44°20’1.60”W ), July 2015 , coll. F. Bondezanll. Diagnosis. Antennula distal article with 5 long aesthetascs. Antenna fifth article of peduncle longer than flagellum; flagellum with 4 or 5 articles proximal article longer (subequal in length to the distal ones). Pleopod II exopod sub-rectangular, distal margin straight; endopod three to fourfold longer than exopod, distal article about twofold longer than proximal, about fourfold longer than wide, robust, cylindrical, with beak-like distal portion, proximally with lateral lobe, distally with digitiform structure and several small projections. Description. Maximum body length: 10.6 mm . Body unpigmented, slender, flexible, able to bend, surface smooth, with pointed scale setae ( Fig. 6A ). Eyes absent. Cephalon trapezoidal in dorsal view; posterior margin straight; less than half of its length, inserted in pereonite 1; small quadrangular antennal lobes; vertex with 2 shallow transverse antero-lateral grooves; profrons with supra-antennal line medially truncated, directed to projected clypeus. Antennula distal article longer than second and first; second article shorter than first, distal article with 5apical aesthetascs ( Fig.6B ).Antenna fifth article of peduncle article longer than flagellum; flagellum with4 to 5 articles, proximal article longer (subequal in length to distal ones) ( Fig. 6C ). Right mandible with 1 penicil; distal leaf-shaped (serrate) lacinia; molar process with 1 short penicil ( Fig. 6D ). Left mandible with 2 penicils ( Fig. 6E ). Maxillula outer branch with 5 + 5 teeth apically entire and 1 slender stalk; inner branch with 3 penicils, inner penicil longest ( Fig. 6F ). Maxilla setose, inner lobe larger than outer lobe ( Fig. 6G ). Maxilliped basis triangular enlarged on distal portion, outer, inner, and distal margins with fringe of thin setae; palp with 3 projections, each of them with 1 tuft of setae; endite narrow, densely setose, narrowing towards apex with large conical penicil not attaining palp first tuft of setae, 1 proximal spine at each side ( Fig. 6H ). Pereopod I carpus with antennal grooming brush ( Fig. 7A ). Pereopod VII basis with water-conducting scale-rows on caudal face, dactyli with glabrous and unbranched dactylar setae. Uropod endopod slightly shorter than exopod, both inserted at same level; exopod more than twice the protopod length ( Fig. 6I ). Figure 5. Spelunconiscus castroi Campos-Filho, Araujo and Taiti 2014 . A : Pereopod 7 and detail of the spur-like structure on the ischium. B : pleopod 1; C – E : pleopod 2; F : pleopod 3; G : pleopod 4; H : pleopod 5. Scale bar: 0.2 mm. Figure 6. Spelunconiscus septemlacuum sp. nov. A : Habitus; B : antennule, C : antenna; D : right mandible; E : left mandible; F : maxillule; G : maxilla; H : maxilliped; I : pleotelson and uropod. Scale bar: 0.2 mm. Male. Pereopod VII ischium rostral face with spur-like structure ( Fig. 8A ). Genital papilla lanceolate. Pleopod I exopod triangular; endopod 2-jointed; protopod external half enlarged projecting laterodistally, with simple setae on lateral and distal margins ( Fig. 8B ). Pleopod II exopod sub-rectangular, with rounded vertices, distal margin straight; endopod 2-jointed, three- to fourfold longer than exopod, distal article about twofold longer than proximal, about fourfold longer than wide, robust, cylindrical, with beak-like distal portion, proximally with lateral lobe, distally with digitiform structure and several small projections( Fig.8C–E ). Pleopod exopods III to V subtrapezoidal with short setae at margins ( Fig. 8F–H ).