Friday, August 6, 2021

[Crustacea • 2021] Chaimowiczia tatus & C. uai • A New Iuiuniscinae Genus from Brazil (Isopoda: Oniscidea: Styloniscidae) with the Description of Two New Troglobitic Species


Chaimowiczia tatus 
 Cardoso, Bastos-Pereira, Souza & Ferreira, 2021


Abstract
A new genus of Styloniscidae, Chaimowiczia gen. nov., is described with two new species: Chaimowiczia tatus sp. nov. from Gruta do Padre cave (Santana, Bahia) and Chaimowiczia uai sp. nov. from Lapa d’água do Zezé cave (Itacarambi, Minas Gerais). The new genus and species were allocated into the subfamily Iuiuniscinae, hitherto monotypic, by the pronounced rectangular-shaped lateral pereonites epimera, dorsal surface smooth, body outline continuous without a gap between pereon and pleon, and pleonites 3 to 5 developed forming tips. The two species of Chaimowiczia gen. nov. differ in the shape of cephalon antennal lobes, pereonite 1 epimera, pleonite 5 posterior margin and uropod exopod and endopod proportion.

Keywords: amphibious isopods, Cave fauna, Isopoda, Neotropics, São Francisco basin

Figure 5. A Gruta do padre cave main entrance B rock shelter leading to cave main entrance C Pond where the species was collected D Substrate marked by the species activity E Living specimen of Chaimowiczia tatus sp. nov. with approximately 9 mm.

Family Styloniscidae Vandel, 1952

Genus Chaimowiczia gen. nov.
 
Type species: Chaimowiczia tatus sp. nov.

Diagnosis: Body non-volvational. Cephalon with antennal lobes, distinct suprantennal line bent in middle, vertex with lateral grooves. Body outline continuous with pereonites epimera well developed, widely separated, pleonites 1 and 2 bridge the gap between pereon and pleon, pleonites 3–5 with epimera well developed. Telson with subtriangular distal half depressed with rounded apex. Antennula of three articles covered with setae, distal article with two apical aesthetascs. Antenna with flagellum of three distinct articles covered with setae. Mandibles pars molaris large and projected. Maxillula outer ramus with entire teeth and two long and thick setose stalks; inner ramus with three penicils at apex. Maxilla inner lobe wider than outer lobe. Maxilliped basis trapezoidal; endite bearing one penicil between two strong teeth. Pereopods with unbranched dactylar setae. Genital papilla lanceolate. Male pleopod 1 exopod and endopod subequal in length, endopod two-jointed, with flagelliform distal article. Male pleopod 2 endopod with two thickset articles, distal one tapering apically.

Etymology: The genus is named after Dr Flavio Chaimowicz, a physician who provided important contributions for the Brazilian speleology. Gender feminine.

Chaimowiczia tatus sp. nov.
 
Diagnosis: Chaimowiczia tatus sp. nov. is characterized by pereonite 1 epimera directed sideways; quadrangular antennal lobes; pleonites 3–5 epimera tips well developed, pleonite 5 short, not surpassing the apex of telson; and uropods endopod and exopod subequal in length.

Etymology: The epithet “tatus” refers to the “Tatus II project”, an experiment of human permanency inside a cave held in 1987, conducted in Gruta do Padre cave. During the experiment, a group of speleologists stayed for 21 days inside the cave performing topographic and speleology surveys (Chaimowicz, 1987).
 

Figure 9. A external landscape of Lapa d’água do Zezé cave B vertical entrance of the cave C narrow passage inside the cave with a skylight, red arrow indicates the collection site D water table where the species was collected E living specimen of Chaimowiczia uai sp. nov. with approximately 8 mm.

Chaimowiczia uai sp. nov. 
 
Diagnosis: Chaimowiczia uai sp. nov. is characterized by the concave shape of pereonites epimera, with pereonite 1 epimeron directed frontward; round antennal lobes; pleonites 3–5 epimera with tips well developed, pleonite 5 surpassing apex of telson; and uropods endopod longer than exopod.

Etymology: The epithet “uai” refers to the word often used by people from the state of Minas Gerais, Brazil, to express doubt, astonishment or surprise.


 Giovanna Monticelli Cardoso, Rafaela Bastos-Pereira, Leila Aparecida Souza and Rodrigo L. Ferreira. 2021. Chaimowiczia: A New Iuiuniscinae Genus from Brazil (Oniscidea, Synocheta, Styloniscidae) with the Description of Two New Troglobitic Species. Subterranean Biology. 39: 45-62. DOI: 10.3897/subtbiol.39.65305