Iansaoniscus Campos-Filho, Araujo & Taiti

Campos-Filho, Ivanklin Soares, Bichuette, Maria Elina, Montesanto, Giuseppe, Araujo, Paula Beatriz & Taiti, Stefano, 2017, The first troglobiotic species of the family Pudeoniscidae (Crustacea, Isopoda, Oniscidea), with descriptions of a new genus and two new species, Subterranean Biology 23, pp. 69-84 : 70-71

Iansaoniscus Campos-Filho, Araujo & Taiti gen. n.

Type species.

Iansaoniscus iraquara Campos-Filho, Araujo & Taiti, sp. n. by present designation.

Diagnosis.

Body convex. Animals unable to roll up into a ball. Cephalon with well-developed antennary lobes, slightly developed triangular frontal shield, laterally interrupted by antennal grooves, frontal line delimiting frontal shield on upper portion, suprantennal line absent. Pereonite 1 epimeron with dorsolateral furrow reduced or absent. Pleon outline continuous with that of pereon. Telson triangular, surpassing uropod endopods. Antenna with flagellum of three articles, second and third articles divided by thin suture. Mandible with molar penicil dichotomized. Maxillula outer branch with some cleft teeth. Uropod protopod sub-quadrangular. Pleopod exopods with no respiratory structures.

Etymology.

The new genus is named after Iansã Orisha, the Afro-Brazilian divinity of the winds and thunderbolts, known as the divinity who commands the storms and the spirit of the dead.

Remarks.

Iansaoniscus gen. n. is included in the family Pudeoniscidae by having the cephalon with a triangular frontal shield, pereonites 1 and 2 with small ventral lobes, telson with distal portion surpassing the uropod endopods, antennal flagellum with second and third articles divided by a slender suture, and the characteristic Pudeoniscidae -type shape of uropods (see Schmidt 2003).

Iansaoniscus gen. n. differs from the other genera of the family in lacking or having a reduced dorsolateral furrow on the epimeron of the pereonite 1 and in pleopod exopods without respiratory structures.

The dorsolateral furrow on the epimeron of the pereonite 1 and pleopodal exopods with uncovered lungs were considered to be diagnostic characters for the family Pudeoniscidae ( Vandel 1963; Lemos de Castro 1973). Thus, regarding these two characters, the diagnosis of the family must be emended as follows: epimera of pereonite 1 with dorsolateral furrows to fit antennae during conglobation, sometimes reduced or absent; pleopodal exopods with respiratory structures, absent in troglobiotic taxa.

The absence of respiratory structures in the pleopodal exopods of the species of Iansaoniscus gen. n. may be due to secondary reduction due to the humid environment in the caves. Other families of Oniscidea are known to have genera with and genera without respiratory structures, e.g. Scyphacidae , Philosciidae , Scleropactidae , and Armadillidae ( Ferrara et al. 1994; Taiti et al. 1998; Schmidt 2002, 2007).