Th ree new species of terrestrial isopods ( Crustacea , Isopoda , Oniscidea ) from Brazilian caves

A second amphibian species of terrestrial isopods in the genus Xangoniscus Campos-Filho, Araujo & Taiti, 2014 and two new species of Trichorhina Budde-Lund, 1908 are described from the Bambuí karst area in the state of Minas Gerais. Xangoniscus odara n. sp. and Trichorhina cipoensis n. sp. were collected in Lapa do Cipó cave, municipality of Itacarambi, and Trichorhina pataxosi n. sp. in Gruta do Sufoco and Gruta do Nei, municipality of Pedro Leopoldo.


INTRODUCTION
Th e Brazilian karst areas have the largest number of caves in the whole South America.Approximately 15,000 caves have been recorded so far (CECAV, 2015), but they represent only about 7% of the estimated total number of caves (ca.100,000) (Auler, 2002;Sallun Filho and Karmann, 2012).Most of Brazilian caves have a Precambrian origin and are mainly constituted by carbonate rocks (limestone and dolomite) (Auler, 2002).Caves in other lithologies, such as iron ore, sandstone and granite are also frequently reported and have a great potential for troglobiotic fauna.Nowadays, the Brazilian caves are distributed in 19 groups or formations, mostly located in northeastern and southern regions (Auler, 2002).
Currently, more than 300 species of troglobiotic terrestrial isopods in 16 families are known, mostly described for caves in the northern hemisphere (Taiti, 2004;Taiti and Gruber, 2008;Taiti and Xue, 2012;Tabacaru and

MATERIAL AND METHODS
Specimens were stored in 75% ethanol and identifications were based on morphological characters.The species were illustrated with the aid of a camera lucida mounted on Wild M5 and M20 microscopes and with pictures obtained with a JSM 6060 Scanning Electron Microscope.For each new species the material examined, description, etymology and remarks are given.The coordinates of the noduli laterales were obtained and figured as in Vandel (1962).The classification of subterranean animals is based mainly on Sket (2008) and Culver and Pipan (2009).

Study Area
Bambuí Group, Peruaçu Caves National Park and Lagoa Santa region, southeastern Brazil: The Bambuí Group represents the largest karstic area in Brazil (ca. 105,000 km 2 ), which corresponds to over half of all karst areas in the country (Auler, 2004;Auler and Piló, 2015) and is located in the states of Bahia, Goiás, Minas Gerais and Tocantins (Dardenne et al., 1986;Auler, 2002Auler, , 2004)).The Bambuí group comprises a sequence of six carbonate-siliciclastic rock formations dated from Late Proterozoic, 950-600 my (Dardenne et al., 1986), with two of them mainly consisting of carbonates: Lagoa do Jacaré and Sete Lagoas (Auler, 2004).The caves of Oniscidean new species occurrence are located in the karst plateau of San Francisco at 500-700 m of altitude.
Lapa do Cipó cave is located in the Peruaçu Caves National Park at Sete Lagoas Formation (Auler and Piló, 2015), biogeographically inserted in Cerrado (Brazilian Savannah-like vegetation) and Paraná Forest Provinces, Chacoan Subregion (Morrone, 2014).The climate domain (sensu Kottek et al., 2006) is Equatorial Savannah Climate with dry winter (Aw) and sclerophyllous vegetation as dominant (Pennington et al., 2006).Lapa do Cipó cave is not touristic and shows an excellent conservation status, including the surrounding vegetation (Fig. 1A, B).This cave has a small drainage inside and terrestrial substrate formed by silt, gravel and organic matter, such as guano and leaf litter.The two caves Gruta do Sufoco and Gruta do Nei are located at Lagoa Santa region and have similar biogeographical, geomorphological and climatological characteristics of Peruaçu karst area.These caves have small extension (ca.200 m) with rocky and miscellaneous organic substrates (roots, guano and leaf litter) and are impacted by nearby mining projects.Description.Body length: ♂ 4.5 mm, ♀ 5.5 mm.Body colorless, elongated with almost parallel sides (Figs.2A, 7A, B).Dorsal surface smooth with scattered fringed scale setae (Fig. 2B).Eyes absent.Cephalon (Fig. 2C, D) 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).Telson (Fig. 2E) with well pronounced concave sides and broadly rounded apex.Antennula (Fig. 2F) 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) 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), left mandible with two penicils (Fig. 3B).Maxillula (Fig. 3C) 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) with setose and bilobate apex, outer lobe smaller.Maxilliped (Fig. 3E) basis enlarged on distal portion; endite rectangular, outer and medial margins setose, apically with two triangular teeth and large rounded penicil.Uropod (Fig. 4A) with endopod slightly longer than exopod, inserted at same level.
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.
Nauplius, 24: e2016001 7B), 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.
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).
Etymology.This new species is named after the locality where specimens were collected: Lapa do Cipó cave, Peruaçu caves National Park, Minas Gerais.
This species occurs in the same cave of Xangoniscus odara n. sp.It was collected from organic matter substrate, such as guano and leaf litter.
Etymology.The new species is named after the native people Pataxós who originally inhabited the Brazilian states of Bahia and Minas Gerais.
Nauplius, 24: e2016001 Remarks.Trichorhina pataxosi n. sp.can be distinguished from Trichorhina cipoensis n. sp. by the different shape of dorsal scale-setae, the maxillula outer branch with inner teeth simple, maxilliped endite with hook-like distal spine, more acute distal part of telson, and male pereopods 1-7 merus and carpus densely setose.This species was collected in guano and leaf litter in two caves of Lagoa Santa region, which are under severe threat by mining.

DISCUSSION
According to the faunistic subterranean classification adopted here, Xangoniscus odara n. sp.can be considered as a stygobiont.As mentioned by Campos-Filho et al. (2014), the troglobiotic condition of the new species of Trichorhina is not certain, since many species in this genus have an endogean way of life, showing similar morphological adaptations to troglobiotic forms.More extensive collections in endogean habitats outside caves are needed in order to determine whether they are troglobiotic or rather troglophilic.
In the last years, biospeleological surveys have been conducted throughout Brazil and many unidentified terrestrial isopods have been reported (e.g.Trajano and Bichuette, 2010;Gallão, 2012;Silva and Ferreira, 2015) but the taxonomic impediment has prevented to describe the numerous subterranean taxa encountered.The Brazilian laws (BRASIL, 1990(BRASIL, , 2008) ) guarantee cave preservation when rare or endemic troglobiotic or stygobiotic species are present (e.g.Campos-Filho et al., 2014;Cardoso et al., 2014).Delay in taxonomic research in subterranean environments may lead to loss of biodiversity in caves, even before the species are discovered and described (e.g.Bichuette and Trajano, 2005;Campos-Filho et al., 2014, 2015).The troglobiotic Xangoniscus odara n. sp. and Trichorhina cipoensis n. sp.coexist in the Lapa do Cipó cave, located in limits of PCNP and protected by environmental laws (Fig. 14).Trichorhina pataxoensis n. sp.from Lagoa Santa region (Fig. 14), is threatened by nearby mining activities which may lead to loss or reduction of the habitat.This karst area should therefore be considered to be of high priority for conservation.