Abstract
A new genus and two new species of Chelodesmidae are described from two caves of the João Rodrigues river system in Bahia state, northeastern Brazil: Strongylosomides troglobius sp. nov. and Rotundotergum elevatum gen. nov., sp. nov. The former species differs from congeners primarily by the gonopods showing the prefemoral process strongly fused caudally along its basal half to the acropodite and, in showing such troglomorphic traits as a nearly unpigmented and fragile body with thin tegument, it seems the first troglobiont to be documented in the genus. Moreover, this new species seems to be so remarkably similar to Leptodesmus stercoriarius Schubart, 1956, from Minas Gerais state, that the following new combination is warranted: Strongylosomides stercoriarius (Schubart, 1956), comb. nov. ex Leptodesmus de Saussure, 1859. The new genus, Rotundotergum gen. nov., seems to be especially similar to Eucampesmella Schubart, 1955, but differs clearly by the absence of a secondary process on the gonopodal prefemoral process, coupled with the latter being unusually long and strongly separated from the acropodite. The type species R. elevatum sp. nov., being partly clearly pigmented, seems to be only troglophilic. The region generally supports a typical dry tropical climate, whereas the caves represent sites with high humidity, this being essential for the survival of these and other species. However, these habitats remain unprotected by Brazilian law, while the João Rodrigues River system is threatened by irrigation projects, potential limestone exploitation, asphalt and road widening or construction that pass across the system and can collapse the rock, and pollution of the subterranean drainage. We hope that the new species described here could help us protect their type localities and the João Rodrigues River system as a whole.
References
Bichuette, M.E. & Gallão, J.E. (2021) Under the surface: what we know about the threats to subterranean fishes in Brazil. Neotropical Ichthyology, 19 (3). [published online] https://doi.org/10.1590/1982-0224-2021-0089
Bouzan, R.S., Pena-Barbosa, J.P.P. & Brescovit, A.D. (2017) Taxonomic review of the genus Atlantodesmus Hoffman, 2000 (Polydesmida: Chelodesmidae). Zootaxa, 4236 (2), 269–290. https://doi.org/10.11646/zootaxa.4236.2.3
Bouzan, R.S., Iniesta, L.F.M. & Brescovit, A.D. (2019) Cladistic analysis and description of a new species of the Brazilian genus Atlantodesmus Hoffman, 2000 (Diplopoda: Polydesmida: Chelodesmidae). European Journal of Taxonomy, 538, 1–17. https://doi.org/10.5852/ejt.2019.538
Bouzan, R.S., Iniesta, L.F.M. & Brescovit, A.D. (2021a) Cladistic analysis and taxonomic review of the millipede tribe Arthrosolaenomeridini Hoffman, 1976 (Polydesmida: Chelodesmidae). Zootaxa, 4970 (2), 201–256. https://doi.org/10.11646/zootaxa.4970.2.1
Bouzan, R.S., Iniesta, L.F.M., Pena-Barbosa, J.P.P. & Brescovit, A.D. (2021b) Six new species of the widespread Brazilian millipede genus Eucampesmella (Polydesmida: Chelodesmidae). Zoologia, 38, e66300. https://doi.org/10.3897/zoologia.38.e66300
Campos, J.E.G., Dardenne, M.A. (1997) Origem e evolução tectônica da Bacia Sanfranciscana. Revista Brasileira de Geociências, 27 (3), 283–294. https://doi.org/10.25249/0375-7536.1997283294
Enghoff, H., Golovatch, S.I., Short, M., Stoev, P.E. & Wesener, T. (2015) Diplopoda—taxonomic overview. In: A. Minelli (Ed.), Treatise on Zoology—Anatomy, Taxonomy, Biology. The Myriapoda. Vol. 2. Brill, Leiden and Boston, pp. 363–453. [https://www.researchgate.net/publication/304620968_Diplopoda_-_taxonomic_overview] https://doi.org/10.1163/9789004188273_017
Gallão, J.E. & Bichuette, M.E. (2018) Brazilian obligatory subterranean fauna and threats to the hypogean environment. ZooKeys, 746, 1–23. https://doi.org/10.3897/zookeys.746.15140
Gallo, J.S. & Bichuette, M.E. (2019) O que mudou na distribuição dos diplópodes Pseudonannolene Silvestri, 1895 nas cavernas do Brasil 18 anos após a sinopse de Trajano e colaboradores (2000)? Espeleo-Tema, Campinas, SP, 29 (1), 41–55.
Gallo, J.S. & Bichuette, M.E. (2020) Pseudonannolene canastra sp. nov. (Diplopoda, Spirostreptida) – a new troglobitic millipede from the southwestern state of Minas Gerais, Brazil. Subterranean Biology, 35, 33–47. https://doi.org/10.3897/subtbiol.35.51183
Galvão, A.L.O., Ferreira, C.F., Rossato, R.M., Reino, J.C.R., Jansen, D.C. & Vilela, C.V. (2012) Breve descrição do patrimônio espeleológico do município de São Desidério - BA. Revista Brasileira de Espeleologia, 2 (1), 13–28.
Godinho, L.P.S. (2020) Geoespeleologia, geomorfologia e geocronologiado sistema carstico de São Desidério, Bahia, Brasil. PhD Thesis, Insitituto de Geociêcias USP, São Paulo, 328 pp.
Golovatch, S.I. & Wytwer, J. (2004) The South American millipede genus Phaneromerium Verhoeff, 1941, with the description of a new cavernicolous species from Brazil (Diplopoda: Polydesmida: Fuhrmannodesmidae). Annales Zoologici, 54 (3), 511–514. [https://www.researchgate.net/publication/233589098_The_South_American_millipede_genus_Phaneromerium_Verhoeff_1941_with_the_description_of_a_new_cavernicolous_species_from_Brazil_Diplopoda_Polydesmida_Fuhrmannodesmidae]
Golovatch, S.I., Gallo, J.S. & Bichuette, M.E. (2022a) Two new species of the millipede family Trichopolydesmidae from Bahia state, northeastern Brazil, including a remarkable threatened troglobiont (Diplopoda, Polydesmida). Zootaxa, 5115 (3), 419–437. https://doi.org/10.11646/zootaxa.5115.3.7
Golovatch, S.I., Gallo, J.S. & Bichuette, M.E. (2022b) Two new species of the millipede family Paradoxosomatidae from Bahia state, northeastern Brazil, including a remarkable presumed troglobiont (Diplopoda, Polydesmida). Arthropoda Selecta, 31 (2), 143–156. https://doi.org/10.15298/arthsel. 31.2.02
Hoffman, R.L. (1971) Chelodesmid studies V. Some new, redefined, and resurrected Brazilian genera. Arquivos de Zoologia, 20 (4), 225–277. [https://www.revistas.usp.br/azmz/article/view/11951] https://doi.org/10.11606/issn.2176-7793.v20i4p225-277
Hoffman, R.L. (1979) Chelodesmid studies. XV. The identity and status of the generic name Strongylosomides Attems. Myriapodologica, 1 (3), 19–26. [https://www.semanticscholar.org/paper/Chelodesmid-studies.-XV.-The-identity-and-status-of-Hoffman/451b267fe325ee86010a44e6ac812903d842e8cb]
Hoffman, R.L. (1980, for 1979) Classification of the Diplopoda. Muséum d’histoire naturelle, Geneva, 237 pp.
Hoffman, R.L. (1981) Chelodesmid studies. XVII. Revalidation of the generic name Odontopeltis Pocock 1894, with the description of a new species and notes on other members of the group. Myriapodologica, 1 (9), 55–62. [https://www.wikidata.org/wiki/Q109377335]
Hoffman, R.L. (1990) Chelodesmid studies. XXIII. Proposal of a new tribe for the disjunct Brasilian genus Macrocoxodesmus (Diplopoda: Polydesmida: Chelodesmidae). Papéis Avulsos de Zoologia, 37 (11), 167–172.
Hoffman, R.L. (2000) Two new genera of chelodesmid millipeds from southeastern Brazil (Polydesmida: Chelodesmidae). Myriapodologica, 6 (12), 101–113. [https://archive.org/details/biostor-201409]
Hoffman, R.L. (2009) A new, disjunct, diplopod genus from Espirito Santo, Brasil (Polydesmida: Chelodesmidae). Papéis Avulsos de Zoologia, 49 (42), 557–562. [https://www.researchgate.net/publication/250984079_A_new_disjunct_diplopod_genus_from_Espirito_Santo_Brasil_Polydesmida_Chelodesmidae] https://doi.org/10.1590/S0031-10492009004200001
Hoffman, R.L. & Reid, J.C. (1990) A new species, genus, and tribe of death-feigning millipeds from Nigeria (Polydesmida: Chelodesmidae). Journal of African Zoology, 104, 29–36. [https://www.semanticscholar.org/paper/A-new-species%2C-genus%2C-and-tribe-of-death-feigning-Hoffman-Reid/4e63608d3ab555d914bb08a1b2f4032fb8d6cddb]
Koeppen, W. (1948) Climatologia. Fondo de Cultura Econômica, México, D.F., 466 pp.
Lobo, H.A.S., Pereira, R.G.F.A., Godinho, L.P.S., Bichuette, M.E., Amaro, G.H.P.A. & Karmann, I. (2013) Carste da Região de São Desidério (Bahia, Brasil): Proteção Ambiental e Gestão Territorial. Anais do 32º Congresso Brasileiro de Espeleologia, Barreirra, 353–362.
Pena-Barbosa, J.P.P., Sierwald, P. & Brescovit, A.D. (2017) On the largest chelodesmid millipedes: Taxonomic review and cladistic analysis of the genus Odontopeltis Pocock, 1894 (Diplopoda; Polydesmida; Chelodesmidae). Zoological Journal of the Linnean Society, 169, 737–764. [https://www.researchgate.net/publication/259557065_On_the_largest_chelodesmid_millipedes_Taxonomic_review_and_cladistic_analysis_of_the_genus_OdontopeltisPocock_1894_Diplopoda_Polydesmida_Chelodesmidae] https://doi.org/10.1111/zoj.12086
Rubbioli, E., Auler, A., Menin, D. & Brandi, R. (2019) Cavernas-Atlas do Brasil Subterrâneo. ICMBio, Brasília, D.F., 340 pp.
Schubart, O. 1956. “Leptodesmidae” brasileiras III. Espécies de Minas Gerais (Diplopoda, Proterospermophora). Revista Brasileira de Biologia, 16 (3), 355–367.
Shear, W.A., Ferreira, F.L., Iniesta, L.F.M. & Marek, P. (2016) A millipede missing link: Dobrodesmidae, a remarkable new polydesmidan millipede family from Brazil with supernumerary rings (Diplopoda, Polydesmida), and the establishment of a new suborder Dobrodesmidea. Zootaxa, 4178 (3), 371–390. https://doi.org/10.11646/zootaxa.4178.3.4
Shelley, R.M. & Smith, J.M. (2018) Expanded concept and revised taxonomy of the milliped family Xystodesmidae Cook, 1895 (Polydesmida: Leptodesmidea: Xystodesmoidea): incorporations of Euryuridae Pocock, 1909 and Eurymerodesmidae Causey, 1951, taxon revivals/proposals/transferrals, and a distributional update. Insecta Mundi, 0660, 1–41.
Trajano, E., Bichuette, M.E. 2010 (for 2009). Diversity of Brazilian subterranean invertebrates, with a list of troglomorphic taxa. Subterranean Biology, 7, 1–16. [https://www.researchgate.net/publication/221675890_Diversity_of_Brazilian_subterranean_invertebrates_with_a_list_of_troglomorphic_taxa/link/0922b4f5cee635abe1000000/download]
Trajano, E., Golovatch, S.I., Geoffroy, J.-J., Pinto-da-Rocha, R. & Fontanetti, C.S. (2000) Synopsis of Brazilian cave-dwelling millipedes (Diplopoda). Papéis Avulsos de Zoologia, 41, 259–287. [https://www.researchgate.net/publication/245535309_Synopsis_of_brazilian_cave_millipides_Diplopoda/link/0c96051d72a30adc97000000/download]