Trichorhina yiara, Campos-Filho & Araujo & Bichuette & Trajano & Taiti, 2014, Campos-Filho & Araujo & Bichuette & Trajano & Taiti, 2014

Campos-Filho, Ivanklin Soares, Araujo, Paula Beatriz, Bichuette, Maria Elina, Trajano, Eleonora & Taiti, Stefano, 2014, Terrestrial isopods (Crustacea: Isopoda: Oniscidea) from Brazilian caves, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 172 (2), pp. 360-425: 401-405

publication ID 10.1111/zoj.12172

publication LSID

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scientific name

Trichorhina yiara



FIGURES 29–31 View Figure 29 View Figure 30 View Figure 31 , 40 View Figure 40

Type material

Holotype: ♂, Brazil, Pará, Altamira, Abrigo do Sismógrafo , 3°17′17″S, 52°13′29″W, 9 April 2009, leg. M.E. Bichuette ( MZUSP 27538 View Materials ). GoogleMaps  

Paratypes: One ♀, same data as holotype ( MZUSP 27539 View Materials ) GoogleMaps   , one ♂ (in micropreparations), one ♀, same data as holotype ( MZUSP 27540 View Materials ) GoogleMaps   ; two ♀, Pará, Altamira, Abrigo do Abutre , 3°15′12″S, 52°11′01″W, 11 April 2009, leg. M.E. Bichuette ( MZUSP 27552 View Materials ) GoogleMaps   .


The name of the new species refers to the Amazonian myth of Yiara, known in Tupi language as the Mother of Waters that lives in the River Amazon. In Amazonian legends she is a beautiful siren who, using her voice, is capable of making all fishermen fall in love with her.


Maximum length: ♂, 2.6 mm; ♀, 3 mm. Body outline as in Figure 29A View Figure 29 . Colour light brown; cephalon with irregular unpigmented spots; pereon with the usual pale muscle spots and a central unpigmented spot on pereonites 3–7, larger on pereonite 3; antennae, uropods, pleon, and telson completely pigmented. Dorsum covered with fan-shaped scale setae ( Fig. 29F View Figure 29 ); one line of noduli laterales per side inserted close to the posterior margin, and far from the lateral margin of the pereonites, b/c and d/c coordinates as in Figure 29B View Figure 29 . Cephalon ( Fig. 29C,D View Figure 29 ) with short lateral lobes, no frontal line, suprantennal line slightly sinuous; eye dark, with ten ommatidia. Pleon ( Fig. 29A View Figure 29 ) slightly narrower than pereon, epimera of pleonites 3–5 well developed, falciform. Telson ( Fig. 29E View Figure 29 ) triangular, concave sides and rounded apex. Antennule ( Fig. 29G View Figure 29 ) of three articles, second article shorter than first and third, third article with four apical aesthetascs. Antenna ( Fig. 29H View Figure 29 ) with fifth article of peduncle slightly swollen; flagellum as long as fifth article of peduncle, second flagellar article about three times as long as first, apical organ short, with free sensilla as long as apical organ. Mandibles ( Fig. 30A,B View Figure 30 ) with molar penicil consisting of at least five setae, left mandible with 2 + 1 penicils and right mandible with 1 + 1 penicils. Maxillule ( Fig. 30C View Figure 30 ) outer branch with 4 + 4 (two cleft) teeth. Maxilla ( Fig. 30D View Figure 30 ) with setose and bilobate apex; outer lobe about twice as broad as inner lobe, with rounded distal margin. Maxilliped ( Fig. 30E View Figure 30 ) basis rectangular, with sparse scale setae; endite with one seta overpassing distal margin, no penicil. Pereopod dactylus with short inner claw, ungual seta and dactylar seta almost reaching tip of outer claw, and simple apex ( Fig. 31A View Figure 31 ). Uropod ( Fig. 30F View Figure 30 ) exopod distinctly longer than endopod; insertion of endopod proximal to that of exopod.

Male: Pereopods 1–3 with brush of setae on sternal margin of carpus ( Fig. 31A View Figure 31 ). Pereopod 7 ( Fig. 31B View Figure 31 ) without distinct sexual dimorphism; ischium with sternal margin slightly convex. Pleopod 1 ( Fig. 31C View Figure 31 ) exopod about twice as broad as long, with rounded distal part; endopod slightly bent outwards, with distal part triangular, acute, bearing few minute setae. Pleopod 2 ( Fig. 31D View Figure 31 ) exopod triangular, with concave outer margin; endopod slightly longer than exopod. Pleopods 3–5 exopods as in Figure 31E–G View Figure 31 .


To date, Trichorhina   includes 63 species, of which 19 are recorded from Brazil ( Schmalfuss, 2003; Souza et al., 2011). The monophyly of the genus is questionable and in need of revision. In the number of ommatidia T. yiara   sp. nov. resembles Trichorhina amazonica Souza-Kury, 1997b   , from which it is readily distinguishable by the shape of the male pleopod 1 exopod, with shorter posterior lobe and endopod much thinner. In the presence of two cleft teeth on the outer branch of the maxillule, the new species is similar to Trichorhina argentina Vandel, 1963   , Trichorhina brasilensis Andersson, 1960   , Trichorhina crassisetae Souza, Araujo & Campos-Filho, 2011   , and Trichorhina paraensis Souza-Kury, 1997b   , from which it differs in the fan-like dorsal scale setae, the number of aesthetascs on antennule, and the shape of the male pleopod 1.