Abstract
During a survey on the benthic invertebrates of the upper reaches of river Eo (Galicia, NW Spain), a dense population of epigean asellid isopods were detected in the source of the river. After examination, these specimens resulted to belong to a new species of the genus Bragasellus Henry & Magniez, 1968. The new species comes to fill a geographical gap between the two alleged ancestral areas of the genus and is characterized by its appendix masculina (male pleopod II endopod), which bears a short but distinct cylindrical cannula and lacks basal process. Other characteristic traits are uniform black pigmentation in live specimens, pereopod I dactylus shorter than the palm of the propodus, smooth (instead of plumose) texture of the marginal setae on male pleopod I exopod, and pleopod III exopod with a straight internal side. In this job, description of the new taxon is provided, as well as a key to all the known species belonging to the genus.
References
Afonso, O. (1984) Bragasellus incurvatus sp. n. (Crustacea, Isopoda, Asellidae) nouvelle espece hypogée du bassin du Douro. Publicaçoes do Instituto de Zoologia “Dr. Augusto Nobre”, 187, 1–9.
Afonso, O. (1989) Un nouvel asellide épigé du nord du Portugal. Bragasellus cortesi sp. n. (Crustacea, Isopoda, Asellidae). Données écologiques et systématiques. Publicaçoes do Instituto de Zoologia “Dr. Augusto Nobre”, 212, 1–16.
Afonso, O., Henry, J.P. & Magniez, G. (1996) Nouvelles données sur le genre Bragasellus (Crustace: Isopoda: Asellidae). Contributions to Zoology, 66 (2), 109–118.
https://doi.org/10.1163/26660644-06602003
Argano, R. & Messana, G. (1991) A new stygobiotic Crustacean in the Ligurian Alps (Italy): Chthonasellus bodoni n. gen., n. sp. (Crustacea, Isopoda, Asellota). Stygologia, 6 (4), 209–215.
Braga, J.M. (1943) Description de l’Asellus seabrai, isopode aveugle nouveau des eaux souterraines du Portugal. Publicaçoes do Instituto de Zoologia “Dr. Augusto Nobre”, 13, 1–17.
Braga, J.M. (1944) Sur un Asellus nouveau des eaux superficielles du Portugal. Memorias e Estudos do Museu Zoologico da Universidade de Coimbra, 154, 1–11.
Braga, J.M. (1946) Quelques Asellides nouveaux du Portugal. Memorias e Estudos do Museu Zoologico da Universidade de Coimbra, 173, 1–25.
Braga, J.M. (1958) Un Asellus remarquable des eaux souterraines du Portugal: Asellus pauloae n. sp. Publicaçoes do Instituto de Zoologia “Dr. Augusto Nobre”, 61, 1–15.
Braga, J.M. (1964) Contribution a la faune d’asellides du Portugal. Asellus frontelum sp. n. Publicaçoes do Instituto de Zoologia “Dr. Augusto Nobre”, 91, 9–18.
Cobo, F. (2017. )iodiversidad acuática continental de Galicia (NW Espana). In: Ramil-Rego, P., Gómez-Orellana, L. & Ferreiro da Costa, J. (Eds.), Conservación e Xestión de Humidais en Galicia. Horreum-Ibader, Lugo, pp. 67–77.
Díaz-Maroto, I.J., Vila-Lameiro, P., Guchu, E. & Díaz-Maroto, E. (2007) A comparison of the autecology of Quercus robur L. and Q. pyrenaica Wild.: Present habitat in Galicia, NW Spain. Forestry: An International Journal of Forest Research, 80 (3), 223–239.
https://doi.org/10.1093/forestry/cpm019
González M.A. & Cobo, F. (2006) Macroinvertebrados de las Aguas Dulces de Galicia. Hercules de Ediciones, La Coruña, 173 pp.
Henry, J.P. & Magniez, G. (1968) Sur la systématique et la biogeographie des Asellides. Comptes Rendus de l’Académie des Sciences, 267, 87–89.
Henry, J.P. & Magniez, G. (1973) Un nouvel Asellide cavernicole d’Espagne centrale: Bragasellus lagari n.sp. (Crustacea Isopoda Asellota). International Journal of Speleology, 5 (3/4), 273–282.
https://doi.org/10.5038/1827-806x.5.3.6
Henry, J.P. & Magniez, G. (1974) Un nouvel Asellide interstitiel d’Espagne méridionale Bragasellus boui n. sp. (Crustace Isopoda Asellota) et considérations sur les genres européens d’Asellides. International Journal of Speleology, 6, 217–230.
https://doi.org/10.5038/1827-806X.6.3.3
Henry, J.P. & Magniez, G. (1976) Bragasellus comasi n. sp., Crustacea Isopoda Asellota cavernicole d’Espagne occidentale. International Journal of Speleology, 8 (4), 359–364.
https://doi.org/10.5038/1827-806x.8.4.4
Henry, J.P. & Magniez, G. (1977) Observations sur Gallasellus heilyi Legrand, 1956 representant d’un nouveau genre d’Asellide sout errain de France. Bulletin de la Société Zoologique de France, 102 (2), 215–222.
Henry, J.P. & Magniez, G. (1978) Bragasellus escolai n. sp., Crustacea Isopoda Asellota cavernicole d’Espagne. International Journal of Speleology, 10, 381–386.
https://doi.org/10.5038/1827-806X.10.3.11
Henry, J.P. & Magniez, G. (1980) Bragasellus aireyi n. sp. (Crustacea Isopoda Asellota), nouvel Asellide cavernicole d’Espagne septentrionale. Bulletin Scientifique de Bourgogne, 33, 23–28.
Henry, J.P. & Magniez, G. (1988) Isopodes Aselloïdes styogobies d’Espagne récoltés par J. Noteboom et I. Meijers II—Le genre Bragasellus et description de sept Nouvelles espèces. Stygologia, 4 (4), 332–362.
Henry, J.P. & Magniez, G. (1992) Isopodes Aselloïdes styogobies d’Espagne récoltés par J. Noteboom et I. Meijers, III—Le genre Proasellus: A—Espèces oculées ou microphthalmes. Bijdragen tot der Dierkunde, 62 (1), 37–54.
Henry, J.P. & Magniez, G. (1995) Présence de Synasellus (Crustacea, Isopoda, Asellidae, Stygobies) dans la province de Huelva (Espagne). Beaufortia, 45 (4), 51–60.
Henry, J.P. & Magniez, G. (2003) Isopodes Aselloïdes styogobies d’Espagne, III—Le genre Proasellus: B—Espèces anophthalmes. Beaufortia, 53 (6), 129–157.
Johnson, W.S., Stevens, M. & Watling, L. (2001) Reproduction and development of marine peracaridans. Advances in Marine Biology, 39, 105–260.
Ketmaier, V. (2002) Isolation by distance, gene flow and phylogeography in the Proasellus coxalis-group (Crustacea, Isopoda) in Central Italy: allozyme data. Aquatic Science, 64, 66–65.
https://doi.org/10.1007/s00027-002-8055-z
Kottek, M., Grieser, J., Beck, C., Rudolf, B. & Rubel, F. (2006) World map of the Köppen-Geiger climate classification updated. Meteorologiche Zeitschrift, 15, 259–263.
https://doi.org/10.1127/0941-2948/2006/0130
Magniez, G. & Bréhier, F. (2004) Bragasellus comasioides, sp. nov., crustacé isopode, asellote stygobie des Picos de Europa (Espagne). Subterranean Biology, 2, 109–112.
Morvan, C., Malard, F., Paradis, E., Lefébure, T., Konecny-Dupré, L. & Douady, C.J. (2013) Timetree of Aselloidea reveals species diversification dynamics in groundwater. Systematic Biology, 62 (4), 512–522.
https://doi.org/10.1093/sysbio/syt015
Rodríguez Guitian, M.A. (2010) Temperate riverside forests without alder trees in the north-west of the Iberian Peninsula: ecology, phytosociological profile and interest for preservation policies. Lazaroa, 31, 9–37.
https://doi.org/10.5209/rev_LAZA.2010.v31.1
Stoch, F., Valentino, F. & Volpi, E. (1996) Taxonomic and biogeographic analysis of the Proasellus coxalis-group (Crustacea, Isopoda, Asellidae) in Sicily, with description of Proasellus montalentii n. sp. Hydrobiologia, 317 (3), 247–258. https://doi.org/10.1007/BF00036474
Sworobowicz, L., Grabowski, M., Mamos, T., Burzynski, A., Kilikowska, A., Sell, A. & Wysocka, A. (2015) Revisiting the phylogeography of Asellus aquaticus in Europe: insights into cryptic diversity and spatiotemporal diversification. Freshwater Biology, 60, 1824–1840.
https://doi.org/10.1111/fwb.12613
Tierno de Figueroa, J.M., López-Rodríguez, M.J., Fenoglio, S., Sánchez-Castillo, P. & Fochetti, R. (2013) Freshwater biodiversity in the rivers of the Mediterranean Basin. Hydrobiologia, 719 (1), 137–186.
https://doi.org/10.1007/s10750-012-1281-z
Wilson, G.D.F. (2008) Global diversity of Isopod crustaceans (Crustacea; Isopoda) in freshwater. Hydrobiologia, 595 (1), 231–240.
https://doi.org/10.1007/s10750-007-9019-z