Xangoniscus chaimowiczi Lopez-Orozco, Borja-Arrieta & Campos-Filho 2024, sp. nov.
Creators: name: López-Orozco, Carlos Mario
name: Borja-Arrieta, Ricardo
name: Carpio-Díaz, Yesenia Margarita
name: Gallão, Jonas Eduardo
name: Campos-Filho, Ivanklin Soares
name: Bichuette, Maria Elina
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Styloniscidae
Xangoniscus
Xangoniscus chaimowiczi

description: Xangoniscus chaimowiczi López-Orozco, Borja-Arrieta & Campos-Filho sp. nov.
Figs 1, 3, 4, 5, 6
Type material.
Holotype • 1 male (MZUSP 29529), Bahia, Santana, Gruta do Padre cave, - 13.216325, - 44.065194, Sala dos Anfipodes, July 1987, leg. F. Chaimowicz. Paratypes • 1 male (parts in slides), 1 male (MZUSP 29529), same data as holotype • 2 males (MZUSP 29429), same data as holotype • 1 male (MZUSP 29565), sedimentos do conduto das plaquetas (no rio), same data as holotype • 4 males (MZUSP 29540), rio dos Travertinos, same data as holotype • 2 males, 1 female (MZUSP 29421), Conduto Biógeo, same data as holotype.
Description.
Maximum body length: male 10.2 mm, female 6.5 mm. Body outline as in Figs 3 A, B, 4 A. Colourless (Fig. 3). Dorsal surface smooth, with scattered fringed scale setae (Figs 3 A, B, 4 A, B). Cephalon (Figs 3 C, 4 C) with large quadrangular antennary lobes; vertex with slightly lateral depression to fit antennae when extended backward, profrons with V-shaped suprantennal line, not surpassing antennule insertion; eyes absent. Pereonite 1 epimera with distal corners developed frontwards, posterior corners right-angled; pereonites 2–7 epimera gradually directed backward posterior corners progressively more acute (Figs 3 A, B, 4 A); pleon narrower than pereon; pleonites 3–5 epimera posterior point not developed (Figs 3 D, 4 A). Telson with concave sides and rounded apex (Fig. 4 D). Antennula (Fig. 4 E) composed of three articles, proximal and distal articles subequal in length, second article shortest, and distal article with 12 long aesthetascs. Antenna (Fig. 4 F) short, not surpassing pereonite 2 when extended backward; flagellum shorter than fifth article of peduncle, with three articles subequal in length. Left mandible (Fig. 4 G) with two penicils; right mandible (Fig. 4 H) with one penicil. Maxillula (Fig. 4 I) inner endite with three penicils; outer endite with 5 + 5 teeth, apically simple, and two plumose stalks. Maxilla (Fig. 4 J) with setose and bilobate apex, outer lobe smaller. Maxilliped (Fig. 4 K) basis enlarged on distal portion bearing fringe of fine setae; first article of palp with two tiny setae, distal articles with three tufts of setae; endite rectangular, outer and medial margins setose, apically with two triangular teeth and large rounded penicil. Uropod (Fig. 4 D) branches short and inserted at same level, exopod slightly longer than endopod. Pereopods 1–7 (Fig. 5 A – G) gradually elongated, with merus, carpus, and propodus bearing sparse setae; dactylus of one claw bearing many setae on outer margin.
Male. Pereopods 1–6 (Fig. 5 A – F) merus with proximal portion bearing fringed scales and thin setae on sternal margin. Pereopod 1 (Fig. 5 A) carpus with large antennal grooming brush. Pereopod 5 (Fig. 5 E) carpus with slightly lobe on proximal sternal margin. Pereopod 6 (Fig. 5 F) ischium enlarged with flattened sternal part; carpus enlarged, rostral portion bearing dense field of tiny lobules; propodus with central part enlarged, with longitudinal furrow in ventral view, and very tiny setae in dorsal. Pereopod 7 (Fig. 5 G) without distinct modifications. Genital papilla (Fig. 6 A) lanceolate. Pleopod 1 (Fig. 6 A) exopod subtriangular, longer than wide, inner and outer margins bearing fringe of fine setae; endopod longer than exopod, with narrow basal article and flagelliform distal article; basipod distal margin elongate and acute apex, longer than exopod, with fine and long setae. Pleopod 2 (Fig. 6 B) exopod trapezoidal, distal margin slightly convex; endopod of two articles, distal article about three times as long as proximal, with distal margin subquadrangular and apex rounded, with transversal process in V-like on apex in ventral view. Pleopod 3 (Fig. 6 C) exopod triangular, longer than wide, covering pleopods 1 and 2, fringed with short setae. Pleopod 4 and 5 (Fig. 6 D, E) exopods trapezoidal, wider than long, with margins bearing several short setae.
Etymology.
The new species is named after Dr. Flavio Chaimowicz, for his important contributions to the knowledge of the Brazilian speleology, who collected the specimens.
Distribution.
Presently known only from Gruta do Padre cave in the state of Bahia, northeastern Brazil (Fig. 1).
Remarks.
The genus Xangoniscus includes 10 amphibious troglobitic species, with a distribution restricted to caves of the Bambui Geomorphological Group between the northeast and southeast regions of Brazil in the states of Bahia and Minas Gerais. Currently, the genus is well defined morphologically, and the main characteristic is the complex shape of the apex of the endopod of pleopod 2 in males. Xangoniscus chaimowiczi sp. nov. differs from all other species of the genus in having the antennula with twelve long aesthetascs (vs. two in X. aganju Campos-Filho, Araujo & Taiti, 2014, X. lapaensis Campos-Filho, Gallo & Bichuette, 2022, and X. odara Campos-Filho, Bichuette & Taiti, 2016, three in X. ibiracatuensis Bastos-Pereira, Souza & Ferreira, 2017, X. lundi Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, and X. santinhoi Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, four in X. dagua Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, four or five in X. ceci Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, five in X. loboi Campos-Filho, Gallão & Bichuette, 2022, six in X. itacarambiensis Bastos-Pereira, Souza & Ferreira, 2017), pereopod 5 carpus with tiny lobe in proximal margin (vs. absent in all species), pereopod 6 carpus enlarged (vs. not enlarged in all species), and pereopod 6 propodus with longitudinal furrow (vs. absent in all species) (Campos-Filho et al. 2015, 2022 b; Bastos-Pereira et al. 2017; Cardoso et al. 2020).
Natural history.
Xangoniscus chaimowiczi sp. nov. inhabits various areas of the Gruta do Padre cave. Specimens were collected from the river, specifically within the conducto das plaquetas, where they were found living in the sediment. It also inhabits travertine ponds inside the cave. This latter behaviour has been documented in several other Xangoniscus species (Cardoso et al. 2020; Campos-Filho et al. 2022 b).
description: Published as part of López-Orozco, Carlos Mario, Borja-Arrieta, Ricardo, Carpio-Díaz, Yesenia Margarita, Gallão, Jonas Eduardo, Campos-Filho, Ivanklin Soares & Bichuette, Maria Elina, 2024, Describing to preserve – three new species of Xangoniscus (Oniscidea, Styloniscidae) of unprotected caves in dry areas from Bahia state, northeastern Brazil, pp. 79-104 in Subterranean Biology 50 on pages 79-104, DOI: 10.3897/subtbiol.50.139914