Two extraordinary troglobitic species of Allokoenenia (Eukoeneniidae: Palpigradi) from Brazil: first records of this initially monotypic genus more than a century after its description
Abstract
The diversity of Palpigradi is not evenly distributed among its different branches. The widespread genus Eukoenenia includes 80% of the species, while the other genera are poorly known. Allokoenenia certainly is the most understudied genus because it is represented only by the African species Allokoenenia afra Silvestri, 1913. Its description is short and does not include many features depicted in modern taxonomy of Palpigradi. In this paper, we describe two troglobitic species of Allokoenenia, report the occurrence of a third species represented by an immature specimen from Brazilian caves, and provide brief notes on the morphology of A. afra. Allokoenenia canhembora sp. nov., A. stygia sp. nov., and Allokoenenia sp. differ from A. afra by several morphological features, including more elongated appendages and a greater number of blades on lateral organs. Thus, they are considered troglomorphic. These new species are vulnerable to extinction because they are endemic to a single or few caves directly impacted by mining activities and groundwater exploitation. This study represents the first step for the conservation of these species and their habitats, since Brazilian caves with rare troglobites cannot be irreversibly impacted. Also, it brings important contributions on the distribution and morphology of this enigmatic genus.
References
Ballesteros J.A., Santibáñez López C.E., Kováč Ĺ., Gavish-Regev E. & Sharma P.P. 2019. Ordered phylogenomic subsampling enables diagnosis of systematic errors in the placement of the enigmatic arachnid order Palpigradi. Proceedings of the Royal Society B 286: 20192426. https://doi.org/10.1098/rspb.2019.2426
Barranco P. & Mayoral J.G. 2014. New palpigrades (Arachnida, Eukoeneniidae) from the Iberian Peninsula. Zootaxa 3826: 544–562. https://doi.org/10.11646/zootaxa.3826.3.6
Bu Y., Souza M.F.V.R. & Mayoral, J. 2021. Discovery of the genus Eukoenenia (Palpigradi: Eukoeneniidae) from China and description of a new species. Journal of Arachnology 49: 225–234. https://doi.org/10.1636/JoA-S-20-058
Christian E. & Christophoryová J. 2013. Eukoenenia florenciae (Arachnida: Palpigradi): lessons from a newcomer to central Europe and the island of Tenerife. Biologia 68: 1182–1188. https://doi.org/10.2478/s11756-013-0266-3
Christian E., Kováč L., Ozimec R., Polak S. & Zagmajster M. 2012. Distribution and morphology of the European Karst palpigrade Eukoenenia gasparoi (Arachnida: Palpigradi). Journal of Arachnology 40: 265–273. https://doi.org/10.1636/Ha12-27.1
Christian E., Isaia M., Paschetta M. & Bruckner A. 2014. Differentiation among cave populations of the Eukoenenia spelaea species–complex (Arachnida: Palpigradi) in the southwestern Alps. Zootaxa 3794: 52–86. https://doi.org/10.11646/zootaxa.3794.1.2
Condé B. 1977. Nouveaux palpigrades du muséum de Genève. Revue suisse de Zoologie 84: 665–674. https://doi.org/10.5962/bhl.part.91415
Condé B. 1984. Palpigrades (Arachnida) d’Europe, des Antilles, du Paraguay et de Thaïlande. Revue suisse de Zoologie 91: 369–392. https://doi.org/10.5962/bhl.part.81884
Condé B. 1989. Palpigrades (Arachnida) de grottes d’Europe. Revue suisse de Zoologie 96: 823–840. https://doi.org/10.5962/bhl.part.82064
Condé B. 1992. Un Palpigrade énigmatique de Thaïlande avec une brève revue des grandes divisions de l’ordre. Revue suisse de Zoologie 99: 741–746. https://doi.org/10.5962/bhl.part.79850
Condé B. 1996. Les Palpigrades, 1885–1995: acquisitions et lacunes. Revue suisse de Zoologie hors série 1: 87–106.
Condé B. 1998. Palpigradida. In: Juberthie C. & Decu V. (eds) Encyclopaedia Biospeologica. Vol. 2: 913–920. Société de Biospéologie, Moulis, Bucharest.
Culver D.C. & Sket B. 2000. Hotspots of subterranean biodiversity in caves and wells. Journal of Cave and Karst Studies 62: 11–17.
Giribet G., McIntyre E., Christian E., Espinasa L., Ferreira R.L., Francke O.F., Harvey M.S., Isaia M., Kováč Ĺ., Mc-Cutchen L., Souza M.F.V.R. & Zagmajster M. 2014. The first phylogenetic analysis of Palpigradi (Arachnida) – the most enigmatic arthropod order. Invertebrate Systematics 28: 350–360. https://doi.org/10.1071/IS13057
Harvey M.S. 2002. The neglected cousins: what do we know about the smaller arachnid orders? The Journal of Arachnology 30: 357–372. https://doi.org/10.1636/0161-8202(2002)030[0357:TNCWDW]2.0.CO;2
Harvey M.S. 2003. Catalogue of the Smaller Arachnid Orders of the World: Amblypygi, Uropygi, Schizomida, Palpigradi, Ricinulei and Solifugae. CSIRO Publishing, Melbourne. https://doi.org/10.1071/9780643090071
Mayoral J.G. & Barranco P. 2013. Rediscovery of the troglobious palpigrade Eukoenenia draco (Peyerimhoff 1906) (Palpigradi: Eukoeneniidae), with notes on the adaptations to a cave–dwelling life. Zootaxa 3635: 174–184. https://doi.org/10.11646/zootaxa.3635.2.5
Mayoral J.G. & Barranco P. 2017. A cave-dwelling Iberian palpigrade (Arachnida: Palpigradi) of the Eukoenenia mirabilis group. Zootaxa 4363: 561–568. https://doi.org/10.11646/zootaxa.4363.4.8
Prevorčnik S., Ferreira R.L. & Sket B. 2012. Brasileirinidae, a new isopod family (Crustacea: Isopoda) from the cave in Bahia (Brazil) with a discussion on its taxonomic position. Zootaxa 3452: 47–65. https://doi.org/10.11646/zootaxa.3452.1.2
Rowland J.M. & Sissom W.D. 1980. Report on a fossil palpigrade from the Tertiary of Arizona, and a review of the morphology and systematics of the order (Arachnida). The Journal of Arachnology 8: 69–86.
Silvestri F. 1913. Novi generi e specie de Koeneniidae (Arachnida, Palpigradi). Bollettino di Laboratorio di Entomologia Agraria Portici 7: 211–217.
Souza M.F.V.R. & Ferreira R.L. 2013. Two new species of the enigmatic Leptokoenenia (Eukoeneniidae: Palpigradi) from Brazil: first record of the genus outside intertidal environments. PLoS ONE 8: e77840. https://doi.org/10.1371/journal.pone.0077840
Souza M.F.V.R. & Ferreira R.L. 2016. Two new troglobiotic palpigrades (Palpigradi: Eukoeneniidae) from Brazil. Zootaxa 4171: 246–258. https://doi.org/10.11646/zootaxa.4171.2.2
Souza M.F.V.R. & Ferreira R.L. 2018. Pandora is on Earth: new species of Eukoenenia (Palpigradi) emerging at risk of extinction. Invertebrate Systematics 32: 581–604. https://doi.org/10.1071/IS17049
Souza M.F.V.R. & Ferreira R.L. 2019. Eukoenenia igrejinha (Palpigradi: Eukoeneniidae), a new cave-dwelling palpigrade from southeastern Brazil. The Journal of Arachnology 47: 360–369. https://doi.org/10.1636/0161-8202-47.3.360
Souza M.F.V.R. & Ferreira R.L. 2020. Three new cave-dwelling Eukoenenia (Palpigradi: Eukoeneniidae) from limestone caves in Northern Minas Gerais state, Brazil. Zootaxa 4808: 251–283. https://doi.org/10.11646/zootaxa.4808.2.2
Souza M.F.V.R., Mayoral J. & Ferreira R.L. 2020. A new troglobitic palpigrade from Central Brazil, with notes on a new opisthosomal character (Arachnida: Palpigradi). Zootaxa 4869: 493–514. https://doi.org/10.11646/zootaxa.4869.4.2
Souza-Silva M. & Ferreira R.L. 2016. The first two hotspots of subterranean biodiversity in South America. Subterranean Biology 19: 1–21. https://doi.org/10.3897/subtbiol.19.8207
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