Research Article |
Corresponding author: Ivanklin Soares Campos-Filho ( ivanklin.filho@gmail.com ) Academic editor: Oana Teodora Moldovan
© 2017 Ivanklin Soares Campos-Filho, Maria Elina Bichuette, Giuseppe Montesanto, Paula Beatriz Araujo, Stefano Taiti.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Campos-Filho IS, Bichuette ME, Montesanto G, Araujo PB, Taiti S (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: 69-84. https://doi.org/10.3897/subtbiol.23.20963
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Approximately 170 species of terrestrial isopods are known from Brazil, but only 12 are considered troglobionts. The family Pudeoniscidae comprises four species in two genera, Brasiloniscus and Pudeoniscus. After the examination of material collected in caves in the state of Bahia, a new genus and two new species have been recognized, Iansaoniscus iraquara gen. et sp. n. from Buraco do Cão cave, Iraquara, and Iansaoniscus georginae gen. et sp. n. from Borboletas cave, Paripiranga. The new genus and new species are placed in Pudeoniscidae on the basis of some morphological characteristics, such as antennal flagellum with second and third articles divided by a slender suture, epimera of pereonite 1 with dorsolateral furrow reduced or absent, and shape of uropods. The Brazilian subterranean environments are now under potential threat because of recent legislation for cave exploitation, and the knowledge of the subterranean biodiversity of the country is thus of primary importance for its effective conservation.
New species, terrestrial isopods, Pudeoniscidae , Neotropical, Brazilian Atlantic Forest
Terrestrial isopods (Oniscidea) constitute one of the most diverse groups within Isopoda, including more than 3,700 described species (
Brazil is considered to be one of the most biodiverse countries in the world due to its great diversity of ecosystems (
To date, approximately 170 species of terrestrial isopods are known from Brazil, of which 34 are recorded from caves (
The family Pudeoniscidae Lemos de Castro, 1973 comprises four species in two genera, Brasiloniscus Lemos de Castro, 1973, and Pudeoniscus Vandel, 1963 (
In the present work, a new genus and two new species of Pudeoniscidae from limestone caves in the state of Bahia are described, representing the first troglobiotic taxa within the family. Moreover, additional characters are proposed as diagnostic to the family, in order to accommodate the new taxa described here.
The material was stored in 75% ethanol and identifications were based on morphological characters. The species were illustrated with the aid of a camera lucida mounted on Wild M5 and M20 microscopes. The final illustrations were prepared using the software GIMP with the method proposed by
Espinhaço Supergroup, Una Group, Irecê metasedimentary Basin, Salitre Formation: Iraquara, Buraco do Cão cave
Buraco do Cão cave is located in an area geographically known as Chapada Diamantina, in the central portion of the state of Bahia, northeastern Brazil (Fig.
Buraco do Cão is part the Talhão-Buraco do Cão-Gruta da Santa system with ca. 6.5 km of mapped passageways (Grupo Bambuí de Pesquisa Espelológicas, ME Bichuette, pers. comm.), and shows a high diversity of substrates that can be exploited by fauna – silt, guano piles, parietal substrate, etc. (Fig.
Buraco do Cão cave is located outside the Chapada Diamantina National Park (CDNP) and part of the cave galleries are visited by tourists since the ‘90s. The cave has no management plan and is subject to local environmental impacts related to poorly regulated speleotourism (
Canudos Supergroup, Vaza Barris Group, Olhos D’agua Formation: Paripiranga, Borboletas cave
The region of Paripiranga is located in the state of Bahia, northeastern Brazil (Fig.
A Landscape of Chapada Diamantina, central portion of the state of Bahia, Caatinga vegetation in the foreground B Buraco do Cão cave, type locality of Iansaoniscus iraquara sp. n., silt and rocky substrates, humid environment C Caatinga vegetation close to Borboletas cave, Paripiranga, Bahia D Borboletas cave, type locality of Iansaoniscus georginae sp. n., silt and rocky substrates, humid environment E Deforested landscape from Paripiranga region.
Iansaoniscus iraquara Campos-Filho, Araujo & Taiti, sp. n. by present designation.
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.
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.
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
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 (
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 (
Bahia, Iraquara, Buraco do Cão cave (12°23'37.32"S, 41°36'8.28"W).
Holotype male (
Body length: 6.5 mm. Body pigmentless, eyes absent. Body outline in lateral view as in Fig.
The new species is named after the Tupi language, spoken by the Brazilian native people, that inhabited the littoral zone. In Tupi, Iraquara means Honey Cave (“Ira” = honey + “quara” = cave). Actually, the city of Iraquara is also known as the “City of the Caves”.
Bahia, Paripiranga, Caverna das Borboletas cave (10°38'12.75"S, 43°51'43.68"W).
Holotype male (part in micropreparations) (
Body length: 5 mm. Body pigmentless, eyes absent. Body outline in lateral view as in Fig.
The new species is named after Dr. Georgina Bond-Buckup for all her contributions to the knowledge of crustaceans, including Oniscidea.
Iansaoniscus georginae sp. n. is readily distinguishable from I. iraquara sp. n. in the shape of the cephalon, epimeron of pereonite 1 with reduced dorsolateral furrow, shape of ventral lobes on pereonites 1 and 2, and shape of the male pleopods 1 and 2.
Iraquara and Paripiranga show different historical sampling efforts: Iraquara has been sampled since 1990, and Paripiranga after 2014 (M.E. Bichuette, pers. obs.). The two species are extremely rare and represent the first records of troglobiotic species in the family Pudeoniscidae. These records increase the taxonomic distinctness of these two regions and, consequently, their importance for conservation (
We are grateful to Profs Marcos Tavares and Maria José from