Xangoniscus odara, Campos-Filho & Taiti, 2016

Xangoniscus odara View in CoL n. sp.

( Figs. 2–7 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 , 14 View Figure 14 )

Type material. Holotype: 1 ♂ ( MZUSP 34104 View Materials ), Minas Gerais, Itacarambi, PCNP, Lapa do Cipó cave , 15º03’13”S 44º11’38”W, II.2015, leg. J.E. Gallão, D. von Schimonsky & B.G.O. Monte. GoogleMaps Paratypes: 3 ♀♀ ( MZUSP 34105 View Materials ) , 1 ♂ (part in micropreparations), 2 ♀♀ ( MZUF 9615 View Materials ), same data as holotype GoogleMaps .

Description. Body length: ♂ 4.5 mm, ♀ 5.5 mm. Body colorless, elongated with almost parallel sides ( Figs. 2A View Figure 2 , 7A, B View Figure 7 ). Dorsal surface smooth with scattered fringed scale setae ( Fig. 2B View Figure 2 ). Eyes absent. Cephalon ( Fig. 2C, D View Figure 2 ) with large quadrangular antennary lobes; profrons with V-shaped suprantennal line. Posterior corners of pereonites 1–4 right-angled, of pereonites 5–7 progressively more acute; pleonites 3–5 with falciform epimera ( Fig. 2A, E View Figure 2 ). Telson ( Fig. 2E View Figure 2 ) with well pronounced concave sides and broadly rounded apex. Antennula ( Fig. 2F View Figure 2 ) with three articles, proximal and distal articles subequal in length, second article shorter with brush of setae on outer margin and long seta on inner margin, distal article with two long apical aesthetascs. Antenna ( Fig. 2G View Figure 2 ) with fifth article of peduncle slightly longer than flagellum; flagellum with four articles, first article longest, second and third articles subequal in length, fourth article shortest. Right mandible with one penicil and lacinia mobilis leaf-shaped with pointed apex ( Fig. 3A View Figure 3 ), left mandible with two penicils ( Fig. 3B View Figure 3 ). Maxillula ( Fig. 3C View Figure 3 ) outer branch with 5 + 5 teeth, apically entire, and two thick plumose stalks; inner branch with three penicils, proximal penicil longer than two apical. Maxilla ( Fig. 3D View Figure 3 ) with setose and bilobate apex, outer lobe smaller. Maxilliped ( Fig. 3E View Figure 3 ) basis enlarged on distal portion; endite rectangular, outer and medial margins setose, apically with two triangular teeth and large rounded penicil. Uropod ( Fig. 4A View Figure 4 ) with endopod slightly longer than exopod, inserted at same level.

Male. Pereopods 1–4 ( Fig. 4B–E View Figure 4 ) merus, carpus and propodus with fringed scales on sternal margin. Pereopods 4–6 ( Figs 4E View Figure 4 , 5A, B View Figure 5 ) carpus concave on distal half of sternal margin, more evident on carpus 6. Pereopods 5–7 ( Fig. 5A–C View Figure 5 ) propodus much longer than in previous pereopods. Pereopods 5 and 6 ( Fig. 5A, B View Figure 5 ) merus and proximal part of carpus with rows of scales on sternal margin. Pereopod 7 ( Fig. 5C View Figure 5 ) basis with scales of water conduction system, ischium with straight sternal margin, merus and carpus with no distinct modifications. Genital papilla ( Fig. 6A View Figure 6 ) lanceolate, enlarged on median portion, apical part narrow and pointed. Pleopod 1 ( Fig. 6B View Figure 6 ) exopod subtriangular, fringed with fine setae; endopod longer than exopod, with narrow basal article and flagelliform distal article; basipod with triangular medial part fringed with fine and long setae on outer and distal margin. Pleopod 2 ( Fig. 6C View Figure 6 ) exopod triangular, distal margin bearing five setae; endopod of two thickset articles, second article about three times as long as first, with complex apical part: distal margin rounded with narrow transverse process and longitudinal ridge on ventral surface. Pleopod 3 exopod ( Fig. 6D View Figure 6 ) triangular, longer than wide, covering pleopods 1 and 2, fringed with short setae. Pleopod 4 and 5 exopods ( Fig. 6E, F View Figure 6 ) trapezoidal, wider than long, with margins bearing several short setae.

Etymology. The new species is named after Odara, a word of Hindu origin meaning peace and tranquility, commonly used in the Afro-Brazilian religions of Candomblé and Umbanda.

Remarks. The genus Xangoniscus was erected by Campos-Filho et al. (2014) to include the amphibious species X. aganju from a cave at Cariranha, Bahia. The genus is mainly characterized by the male pleopod 2 endopod thickset with distal portion presenting a complex structure.In X.odara n. sp. the male specimens have the pleopods 1 and 2 not visible in ventral view since they are covered by the pleopod 3 exopod ( Fig. 7B View Figure 7 ), probably to protect the complex structure of pleopod 2 endopod. This peculiar arrangement of the pleopods is present also in X. aganju , and is probably typical of the genus.

Xangoniscus odara n. sp. is distinguished from X. aganju by the cephalon without frontal carena, shape of dorsal scale-setae, antennal flagellum of four articles (three in X. aganju ), uropod with exopod shorter than endopod (viceversa in X. aganju ), male pereopod 6 ischium without flattened sternal part, male pleopod 2 exopod triangular (trapezoidal in X. aganju ), and distal portion of male pleopod 2 endopod with rounded, instead of concave, distal margin and lacking a triangular outer lobe.

This species has amphibian habits like X. aganju , and it was collected in pools inside the cave (Supplementar Online Material), with bottom formed by silt and gravels ( Fig. 7C, D View Figure 7 ).