Pectenoniscus Andersson, 1960

Campos-Filho, Ivanklin Soares, Gallo, Jessica S., Gallao, Jonas E., Torres, Dayana F., Carpio-Diaz, Yesenia M., Lopez-Orozco, Carlos Mario, Borja-Arrieta, Ricardo, Taiti, Stefano & Bichuette, Maria Elina, 2022, Expanding the knowledge on the diversity of the cavernicolous Styloniscidae Vandel, 1952 (Oniscidea, Synocheta) from Brazil, with descriptions of two new species from the semiarid karst regions, ZooKeys 1101, pp. 35-55 : 35

Genus Pectenoniscus Andersson, 1960

Type species.

Pectenoniscus angulatus Andersson, 1960 by monotypy (see Schmidt and Leistikow 2004).

Diagnosis.

After Andersson (1960) and Campos-Filho et al. (2019). Animals of reduced size, ≤ 3.5 mm. Body unpigmented and eyes absent. Body slender with lateral sides almost parallel. Dorsal surface of cephalon and pereon bearing small transverse tubercles, conferring granulated appearance, pleon smooth or slightly tuberculate. Cephalon with 4-6 rows of tubercles, gradually reducing in number from posterior to distal portion, pereonite 1 with two or three rows of tubercles, pereonites 2-7 with two rows of tubercles. Dorsal scale-setae triangular. Cephalon with antennary lobes and suprantennal line. Pleonites 3-5 epimera not developed (only developed in P. angulatus ). Telson triangular with lateral sides concave and rounded apex. Antennula of three articles, distal article with aesthetascs arranged in one longitudinal row. Antennal flagellum of 3-5 articles. Mandibles with strong molar process, left mandible with two penicils, right mandible with one penicil (sometimes one penicil on molar process). Maxillula inner endite with three penicils, proximal one longest; outer endite composed of eight or nine teeth plus slender stalks. Maxilla of two lobes covered with thick and fine setae, inner lobe wider. Maxilliped basis with lateral sides almost parallel, endite rectangular bearing one stout penicil. Uropod protopod subquadrangular, exopod longer than endopod, protopod and exopod sometimes bearing glandular pores, endopod inserted proximally. Male pleopod 1 endopod of two articles, distal article flagelliform. Male pleopod 2 endopod consisting of two articles, distal portion stout bearing complex apparatus.

Remarks.

The genus Pectenoniscus was created by Andersson (1960) to allocate the new species P. angulatus from Itá, Nova Teutônia, state of Santa Catarina, Brazil. The author defined the genus by having the cephalon of " Trichoniscus -type", dorsal surface of the cephalon and pereon with rounded tubercles, pleonites epimera large, left mandible with two penicils near lacinia mobilis, right mandible with one penicil near lacinia mobilis plus one in the molar process, maxillula outer endite composed of nine teeth and two slender stalks, inner endite of three penicils and proximal one longer than distal ones, genital papilla pear-shaped with tubelike termination, male pleopod 1 of " Styloniscus -type", male pleopod 2 endopod with distal portion broad and bearing a comb-like formation, and male pleopod 5 exopods with a dorsal lobe to fit the pleopod 2 endopod. Campos-Filho et al. (2019) described P. liliae Campos-Filho, Bichuette & Taiti, 2019 from Caverna Chico Pernambuco, Coribe, Serra do Ramalho karst area, state of Bahia, and added some characters in the diagnosis of the genus. Recently, Cardoso et al. (2020b) described six new species from karst areas of the states of Bahia and Minas Gerais, increasing the knowledge on the diversity of the genus, that now comprises eight species, i.e., P. angulatus , P. carinhanhensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. iuiuensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. juveniliensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. liliae , P. montalvaniensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, P. morrensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020, and P. santanensis Cardoso, Bastos-Pereira, Souza & Ferreira, 2020.