Caecopactes Schmidt, 2007

Campos-Filho, Ivanklin Soares, Sfenthourakis, Spyros, Gallão, Jonas Eduardo, Senna-Horta, Lilia & Bichuette, Maria Elina, 2023, The first troglobitic terrestrial isopod (Isopoda, Oniscidea) from Peru, Nauplius (e 2023003) 31, pp. 1-12 : 5

Genus Caecopactes Schmidt, 2007

Type species. Caecopactes minimus Schmidt, 2007 , by original designation and monotypy.

Diagnosis. Modified from Schmidt (2007). Body pigments and eyes absent, animals with endoantennal conglobation, or rolling, ability, cephalon with frontal shield fused with vertex (not delimited by frontal line), pereonite 1 epimera with schisma on posterior corner, antenulla of 2 articles, antennal f lagellum of 2 articles, mandible with molar penicil simple, maxillula inner endite bearing 2 penicils, maxilla bilobate, maxilliped endite with 2 strong setae on distal margin, pereopod dactylus of 2 claws, inner claw short, uropod protopod enlarged and surpassing distal margin of telson, and exopod inserted on medial margin, and pleopod exopods without respiratory areas.

Remarks. The genus Caecopactes was erected by Schmidt (2007) to include C. minimus from Napo Province, Ecuador. The genus was defined by animals of reduced size, body pigments and eyes absent, endoantennal conglobation ability, pereonite 1 epimera with schisma at the posterior corner, cephalon with concave frons, antennal peduncle with fourth and fifth articles triangular and corners projected ventrally, and antennal flagellum of two articles (see also Schmidt, 2007). The new species described here is tentatively placed into the genus mainly due to the shape of the cephalon,the pereonite1epimera with posterior schisma, and the shape of uropods (see also Schmidt, 2007).

Regarding the characters mentioned by Schmidt (2007), the reduced size of animals, cephalon with concave frons and the triangular shape of the fourth and fifth articles of the antennal peduncle probably represent specific characteristics of C. minimus . Moreover, within the Neotropical Scleropactidae no other genera have a cephalon shape as in Caecopactes , with the frontal shield fused with the vertex. In a loose comparison, the shape of Caecopactes cephalon resembles that of Aulaconiscus Taiti and Howarth, 1997 from Hawaii, and Kithironiscus Schmalfuss, 1995 from Greece; however, the genus differs in the animals having endoantennal conglobation (vs. exoantennal in Aulaconiscus ), the pereonite 1 epimera with posterior schisma (vs. schisma absent in Aulaconiscus ),pereonite 2 epimera without ventral lobe (vs. present in Aulaconiscus ), telson with distal margin rounded (vs. triangular in Aulaconiscus and Kithironiscus ), and uropod exopod inserted on medial margin (vs. on distal margin in Aulaconiscus and Kithironiscus ) (see also Schmalfuss, 1995; Taiti and Howarth, 1997; Tabacaru and Girginca, 2003).