Iuiuniscus iuiuensis

Souza La, Ferreira Rl & Senna Ar, 2015, Amphibious Shelter-Builder Oniscidea Species from the New World with Description of a New Subfamily, PLoS ONE 10 (5), pp. 1-18 : 6-8

Iuiuniscus iuiuensis gen. et sp. nov.

urn:lsid:zoobank.org:act:D5A719D3-51BE-4D85-AB2A-93A011F58EFD ( Figs 1–3 )

Material examined

Holotype: male, dissected and drawn, Lapa do Baixão, Iuiú , BA, Brazil, 20.VII.2007, R. L. Ferreira col., UFBA 1603.

Paratypes: 1 female, dissected and drawn, Lapa do Baixão, Iuiú , BA, Brazil, 20.VII.2007, R. L. Ferreira col., UFBA 1604; 7 males and 1 female, Lapa do Baixão, Iuiú , BA, Brazil, 20. VII.2007, R. L. Ferreira col., UFBA 1605; 3 males and 1 female, Lapa do Baixão, Iuiú , BA, Brazil, 20.VII.2007, R. L. Ferreira col., ISLA 4993.

Etymology

The species name is an adjective derived from the type locality name, Iuiú .

Diagnosis

Same as the genus.

Description

Based in the holotype. Measurements: length— 9.2 mm from anterior margin of the head to the apex of telson; width— 5 mm, from one tip to another of the pereon coxal plate 4. Cephalon semiquadrangular, fully inserted in the first pereonite; there is a line on the vertex which runs along the back of the posterior deep furrows which hold the second antennae, forming a "V" whose tip is positioned medially between the insertion of the antennae. Without eyes and pigment, with convex body. Dorsal integument smooth, not very thin, with setae and more sclerotized on the tips of coxal plates that are all fused with tergites; posterior margins of tergites of pereonites with different kinds of setae. Flexible body capable of folding. Convex pereon tergites, coxal plates of pereonites 1–7 outwardly extended and widely separated, apically acute. Pereonite 1 is of smaller width, but of greater length, coxal plates go down and then fold up and form a concave area in the anterior end; coxal plates of pereonites 1–7 form lateral-distal ends that become progressively more acute, and are especially developed and acute from pereonite 5–7. Sternum of pereonites deeply grooved at the sites of insertion of pereopods (minor groove is at the insertion of pereopod 1). Pleonites 1 and 2 distinct in dorsal view, without apparent pleon-epimera. Pleon-epimera 3–5 with exceptionally long tips; the tips of the fifth are longer than exopods of uropods. Telson distal half depressed in relation to the proximal half, lateral margin slightly sinuous, with acute apex.

First antenna ( Fig 1 A) 3-jointed with nine apical and one lateral aesthetascs on the third article; the three articles are subequal in length. Second antenna ( Fig 1 B) thin; when stretched, it reaches the edge of coxal plate of the pereonite 3; the last article of peduncle is the largest; flagellum with 7 articles, the first one the biggest, the apical one the smallest, with a tuft of free sensory hairs. Mandibles with a pars molaris with a large masticatory surface; left mandible ( Fig 1 C) with three slender penicils between the pars incisiva and the pars molaris, lacinia mobilis robust and apically 3-cuspidate; right mandible ( Fig 1 D) with one slender penicil between the pars incisiva and the pars molaris, lacinia mobilis slender and bipectinate. First maxilla ( Fig 1 E) inner endite with three penicils, two of them are almost equal and the third is the biggest; without laterodistal corner; outer endite with outer group with four strong and simple tooth setae; inner group with three simple tooth setae + one slender and differentiated seta in the inner corner; there are also two long setae wholly and conspicuously bipectinate, that emerge from the inner group of teeth. Second maxilla ( Fig 1 F) apically rounded, with many sensilla and outer lobe not apparent. Maxilliped ( Fig 1 G) with a large basis narrowed in its proximal portion; maxilliped palp with 3 indistinctly delimited distal articles, each of them with a tuft of setae, there is a single setae located below the proximal article; endite distally acute, hairy.

Pereopods 1–3 ( Fig 2 A–2E) pointing to the proximal region of the body; pereopods 4–7 ( Fig 2 F), longer, to the distal; spines on margins of pereopods with an accessory seta each. Pereopod 1 much shorter than the others, flanking the head; dactylus with an outer claw big but slender, with a brownish tip indicating heavy sclerotization. Merus of pereopods 2–4 with protrusion at its frontal face, proximally; merus 6 with dilated and truncated distal part. Dactylus of pereopods 1–7 without conspicuous inner claw. Genital papilla ( Fig 3 A) swollen in the medial part, with extremity constituted of a basal region with folds and a long tip. Pleopod 1

( Fig 3 A) sympodite large; endopodite biarticulate, 2nd article flagelliform, tiny, slender, barely visible in situ. Pleopod 2 ( Fig 3 B) exopodite without marginal setae; endopodite biarticulate,

enlarged, bifurcate at the apex, forming two long tips. Exopodites of pleopods 1 and 2 smaller and 3–5 bigger, but among the latter, the fifth is the smallest; they all close like blades over the endopods. Sympodites of uropods small. Endopodites of uropods about 2/3 the length of exopodites.

Figures

Fig 1. Iuiuniscus iuiuensis gen. et sP. nov. (HolotyPe, UFBA 1603). (A) First antenna, (B) Second antenna, (C) Left mandible, (D) Right mandible, (E) First maxilla, (F) Second maxilla, (G) Maxilliped. Scale bars: 0.1 mm for A; 1.0 mm for B; 0.2 mm for the remainder. doi: 10.1371 / journal. pone. 0115021. g 001

Fig 2. Iuiuniscus iuiuensis gen. et sP. nov. (HolotyPe, UFBA 1603). (A) Pereopod 1, (C) Pereopod 2, (E) Pereopod 3, (F) Pereopod 7. (Paratype, female, UFBA 1604). (B) Pereopod 1, (D) Pereopod 2. Scale bars: 1.0 mm. doi: 10.1371 / journal. pone. 0115021. g 002

Fig 3. Iuiuniscus iuiuensis gen. et sP. nov. (HolotyPe, UFBA 1603). (A) Pleopod 1, (C) Pleopod 2. (Paratype, female, UFBA 1604). (B) Pleopod 1, (D) Pleopod 2. Scale bars: 0.5 mm. doi: 10.1371 / journal. pone. 0115021. g 003