Abstract
A new marine arthrotardigrade, Ligiarctus alatus sp. nov. found in sediments of the Brazilian continental shelf (100–150 m depth) in the Southwestern Atlantic Ocean, is described in this study. This new species was recorded from sites located in the major oil extraction basins in Brazil (Campos and Potiguar basins). Within the subfamily Floractinae, the genus Ligiarctus characteristically presents primary clavae bent backwards, occupying the reduced lateral edges of the head. The new species is clearly distinguishable from L. eastwardi, the only known species of the genus, by the presence of internal distal notches on all claws, and six aliform cuticular expansions (frontal ala, two anterolateral alae, two posterolateral alae and caudal ala) with continuous digitiform procuticular supports (caesti). Ligiarctus eastwardi has only a caudal ala without caesti and internal notches are present on external claws only. The same pattern of cuticular expansions and caesti exhibited by the new species also occurs in the genus Florarctus, increasing the difficulty of defining the taxonomy of the subfamily Florarctinae, and forcing the emendment of the generic diagnosis of Ligiarctus.
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Acknowledgements
The authors are grateful to Petrobras S/A (Brazil) for providing samples for this study from “Habitats” project and “Projeto de Caracterização Ambiental do Talude da Bacia Potiguar”. During this study, E. Gomes-Júnior was supported by a doctoral grant (IBPG-0648-2.04/15) awarded by FACEPE (Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco), Brazil, and E. Santos was supported by doctoral grant (BEX 13580/13-2) awarded by the program Science without Borders from CAPES (Coordination of Improvement of Higher Level Personnel), Brazil. The researcher P. Santos is partially funded by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 306444/2014-3). The research of P. Fontoura (Portugal) was partially funded by Fundação para a Ciência e a Tecnologia (FCT) through the strategic project UID/MAR/04292/2013 granted to MARE.
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This article is registered in ZooBank under urn:lsid:zoobank.org:pub:AC9E6510-1F08-42CD-8B71-55992579E154
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Gomes-Júnior, E., Santos, É., da Rocha, C.M.C. et al. A new species of Ligiarctus (Tardigrada, Arthrotardigrada) from the Brazilian continental shelf, Southwestern Atlantic Ocean. Mar Biodiv 48, 5–12 (2018). https://doi.org/10.1007/s12526-017-0709-0
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DOI: https://doi.org/10.1007/s12526-017-0709-0