Amazoniscus leistikowi, 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 : 391-395

publication ID	https://doi.org/ 10.1111/zoj.12172
publication LSID	lsid:zoobank.org:pub:246C2229-308B-4A9B-A150-CE1D27D2EBD8
persistent identifier	https://treatment.plazi.org/id/CF6FE30C-FFBE-FFAA-000D-CD5EFCB94F79
treatment provided by	Marcus
scientific name	Amazoniscus leistikowi
status	sp. nov.

Treatment

AMAZONISCUS LEISTIKOWI View in CoL CAMPOS- FILHO, ARAUJO & TAITI SP. NOV.

FIGURES 23–25 View Figure 23 View Figure 24 View Figure 25 , 40 View Figure 40

Type material

Holotype: ♂, Brazil, Pará, Altamira, Abrigo do Sismógrafo , 3°17′18″S, 52°13′30″W, 9 April 2009, leg. M.E. Bichuette ( MZUSP 27534 View Materials ). GoogleMaps

Paratypes: One ♂ (in micropreparation), two ♀, same data as holotype ( MZUSP 27535 View Materials ) GoogleMaps .

Etymology

The new species is named after Dr Andreas Leistikow, for his contribution to the knowledge of Neotropical Oniscidea .

Description

Maximum length: ♂, 4 mm; ♀, 4.4 mm. Colourless body. Body convex, endoantennal conglobation ( Fig. 23A View Figure 23 ). Dorsum smooth, with some scattered triangular scale setae; one line of noduli laterales per side, more or less at the same distance from the lateral margins and close to the posterior margins of the pereonites; no visible gland pores ( Fig. 23G View Figure 23 ). Cephalon ( Fig. 23B–E View Figure 23 ) with frontal shield protruding upwards, frontal margin broadly rounded, no suprantennal line; eyes absent. Pereonites 1 and 2 with no schisma or ventral lobes; pereonites 1–5 with posterior margin straight; pereonites 6 and 7 with posterior margin slightly sinuous at sides. Pleon ( Fig. 23F View Figure 23 ) continuous with pereon, epimera 3–5 well developed, directed backwards. Telson ( Fig. 23F View Figure 23 ) short, more than twice as broad as long, with slight concave sides and rounded apex. Antennule ( Fig. 23H View Figure 23 ) of three articles, third article about twice as long as second, bearing three rows of two aesthetascs each and an apical triangular point. Antenna ( Fig. 23I View Figure 23 ) short and stout, reaching posterior margin of first pereonite when extended back, fifth article of peduncle slightly longer than flagellum, flagellum with two subequal articles, distal article with two rows of two aesthetascs each, apical organ as long as second article of flagellum, and with simple and short free sensilla. Mandibles ( Fig. 23J,K View Figure 23 ) with molar penicil consisting of five setae, left mandible with two penicils, and right mandible with one penicil. Maxillule ( Fig. 24A View Figure 24 ) with inner branch bearing two short penicils, inserted transversely, and a distal triangular point; outer branch with 4 + 6 (four cleft) teeth and a slender seta. Maxilla ( Fig. 24B View Figure 24 ) with outer lobe about twice as broad as medial lobe, distal margin rounded, and covered with trichiform setae; medial lobe rounded, and covered with thick setae. Maxilliped ( Fig. 24C View Figure 24 ) with rectangular basis, sparse scale setae, distal margin with fringe of thin setae; endite rectangular with distal margin rounded with a short penicil and one hook; palp with three tufts of setae, proximal article with one long inner seta. Pereopods with short inner claw, ungual seta long and simple, long dactylar seta simple, and reaching tip of outer claw. Pleopods 1 and 2 with respiratory areas. Uropod ( Fig. 24D View Figure 24 ) with insertion of endopod and exopod at different levels, protopod flattened and enlarged, endopod twice as long as exopod.

Male: Pereopod 1 ( Fig. 24E View Figure 24 ) with merus and carpus with sternal margin covered with short scales. Pereopod 7 ( Fig. 25A View Figure 25 ) ischium elongated with almost parallel sides, carpus twice as long as merus. Genital papilla ( Fig. 25B View Figure 25 ) with narrow ventral shield and subapical orifices. Pleopod 1 ( Fig. 25C View Figure 25 ) exopod rounded; endopod with narrow distal part bent outwards and bearing small triangular setae. Pleopod 2 ( Fig. 25D View Figure 25 ) exopod triangular, with concave outer margin; endopod distinctly longer than exopod. Pleopod 3 ( Fig. 25E View Figure 25 ) exopod subquadrangular, with slightly concave outer margin, bearing one robust seta, inner and outer margins fringed with thin setae. Pleopod 4 ( Fig. 25F View Figure 25 ) exopod triangular, straight outer margin with two robust setae, inner and outer margins fringed with thin setae. Pleopod 5 exopod ( Fig. 25G View Figure 25 ) triangular, with distal part narrow- er and acute, inner and outer margins fringed with thin setae.

Remarks

To date, Amazoniscus includes two Brazilian species: Amazoniscus arlei Lemos de Castro, 1967 , from the states of Amapá, Pará, and Tocantins ( Lemos de Castro, 1967; Schmidt, 2007), and Amazoniscus eleonorae Souza, Bezerra & Araujo, 2006 , from caves in the state of Pará ( Souza et al., 2006). Amazoniscus leistikowi sp. nov. is readily distinguishable from A. arlei by the lack of eyes, the more broadly rounded telson, the male pereopod 7 ischium with sternal margin straight instead of concave, the male pleopod 1 exopod without a narrow posterior point, and endopod distinctly bent outwards. The new species is morphologically similar to A. eleonorae , the other cavernicolous species in the genus, from which it differs in having the antenna with stouter articles of the peduncle, the molar penicil of the mandible with five instead of 11 setae, and the male pleopod 1 endopod distinctly bent outwards in the distal part.