Abstract
A new monotypic genus of freshwater snail from late Holocene spring deposits in Viesca, Coahuila (Mexico), is described based on shell morphology. Spinopyrgus luismaedai n. gen. et n. sp. has two to three carinate shells with long and wide shovel-shaped spines, strong axial ridges and a pointed protoconch. All sculptural ornamentations on the teleoconch are part of the calcareous shell material and not projections of the periostracum. This combination of shell features and their almost “marine-like” appearance is unknown among North American recent and fossil freshwater snails. Because of its shell characteristics, we placed the new genus tentatively in the Cochliopidae. The springs of Viesca dried up in the second half of the 20th century so that any living occurrence of this species in neighboring areas is unlikely, rendering the new genus and species possibly extinct.
References
Adams, C.C. (1915) The variation and ecological distribution of the snails of the genus Io. Memoirs of the National Academy of Sciences, 12, 1–92. https://doi.org/10.5962/bhl.title.52022
Blásquez, L.L. (1959) Hidrogeología de las regiones desérticas de México. Anales del Instituto de Geología 15. Instituto de Geología, Mexico, D.F, 172 pp.
Bouchet, P., Rocroi, J.-P., Hausdorf, B., Kaim, A., Kano, Y., Nützel, A., Parkhaev, P., Schrödl, M. & Strong, E.E. (2017) Revised classification, nomenclator and typification of gastropod and monoplacophoran families. Malacologia, 61 (1–2), 1–526. https://doi.org/10.4002/040.061.0201
Boulaassafer, K., Ghamizi, M., & Delicado, D. (2018) The genus Mercuria Boeters, 1971 in Morocco: First molecular phylogeny of the genus and description of two new species (Caenogastropoda, Truncatelloidea, Hydrobiidae). ZooKeys, 782, 95–128. https://doi.org/10.3897/zookeys.782.26797
Boss, K.J. (1978) On the evolution of gastropods in ancient lakes. In: Fretter, V. & Peake, J.F. (Eds.), Pulmonates. Vol. 2A. Academic Press, New York, New York, pp. 385–428.
Coote, T., Schmidt, R.E. & Schmidt, K.A. (2021) Rediscovery of populations of Pyrgophorus parvulus (Guilding, 1828) (Gastropoda, Cochliopidae), from a freshwater stream on Montserrat, West Indies. American Malacological Bulletin, 38 (2), 113–116. https://doi.org/10.4003/006.038.0206
Covich, A.P. (2010) Winning the biodiversity arms race among freshwater gastropods: Competition and coexistence through shell variability and predator avoidance. Hydrobiologia, 653, 191–215. https://doi.org/10.1007/s10750-010-0354-0
Czaja, A., Estrada-Rodríguez, J.L. & Romero-Méndez, U. (2014a) Freshwater mollusks of the Valley of Sobaco, Coahuila, Northeastern Mexico—a subfossil ecosystem similar to Cuatrociénegas. Boletín de la Sociedad Geológica Mexicana, 66, 459–469. https://doi.org/10.18268/BSGM2014v66n3a4
Czaja, A., Palacios-Fest, M.R., Estrada-Rodríguez, J.L. Romero-Méndez, U. & Alba Avila, J.A. (2014b) Inland dunes mollusks fauna from the paleolake Irritila in the Comarca Lagunera, Coahuila, Northern Mexico. Boletín de la Sociedad Geológica Mexicana, 66, 541–551. https://doi.org/10.18268/BSGM2014v66n3a9
Czaja, A. & Estrada-Rodríguez, J.L. (2015) Two new species of Tryonia (Caenogastropoda: Cochliopidae) from the late Pleistocene of Coahuila, northern Mexico. The Nautilus, 129, 83–89.
Czaja, A., Estrada-Rodríguez, J.L. & Romero-Méndez, U. (2015) A new species of the genus Mexipyrgus Taylor, 1966 (Caenogastropoda: Truncatelloidea: Cochliopidae) from late Holocene spring deposits in Viesca, Coahuila, Mexico. The Nautilus, 129, 163–168.
Czaja, A., Estrada-Rodríguez, J.L., Romero-Méndez, U. & Orona-Espino, A. (2017) Two new subfossil species of springsnails (Hydrobiidae: Pyrgulopsis) from north Mexico and their relation with extant species from Cuatrociénegas. Boletín de la Sociedad Geológica Mexicana, 69, 199–208. https://doi.org/10.18268/BSGM2017v69n1a9
Czaja, A., Covich, A.P., Estrada-Rodríguez, J.L., Romero Méndez, U., Sáenz-Mata, J., Meza-Sánchez, I.G., Ávila-Rodríguez, V., Becerra-López, J.L., Aguillón-Gutiérrez, D.R. & Castañeda-Gaytán, J.G. (2019) Fossil freshwater gastropods from northern Mexico—A case of a “silent” local extirpation, with the description of a new species. Boletín de la Sociedad Geológica Mexicana, 71, 609–629. https://doi.org/10.18268/bsgm2019v71n3a2
Czaja, A., Meza-Sánchez, I.G., Estrada-Rodríguez, J.L., Romero-Méndez, U., Sáenz‑Mata, J., Ávila-Rodríguez, V., Becerra-López, J.L., Estrada-Arellano, J.R., Cardoza-Martínez, G.F., Aguillón-Gutiérrez, D.R., Cordero-Torres, D.G. & Covich, A.P. (2020) The freshwater snails (Mollusca: Gastropoda) of Mexico: updated checklist, endemicity hotspots, threats and conservation status. Revista Mexicana de Biodiversidad, 91, 1–22. https://doi.org/10.22201/ib.20078706e.2020.91.2909
Czaja, A., Gladstone, N.S., Becerra-López, J.L., Estrada-Rodríguez, J.L., Sáenz‑Mata, J. & Hernández-Terán, F. (2021) A remarkable new genus and species of subterranean freshwater snail from a recently dried-up spring of Viesca, Coahuila, Northern Mexico. Subterranean Biology, 39, 129–141. https://doi.org/10.3897/subtbiol.39.67799
Czaja A., Jorge Luis Becerra-López, J.L., Estrada-Rodríguez, J.L., Romero-Méndez, U., Cardoza-Martínez, G.F., Sáenz-Mata, J., Estrada-Arellano, J.R., Garza-Martínez, M.Á, Hernández-Terán, F. & Cerano-Paredes, J. (2022) The Sabinas River basin in Coahuila, a new hotspot of molluscan biodiversity near Cuatro Ciénegas, Chihuahuan Desert, northern Mexico. Revista Mexicana de Biodiversidad, 93, 1–22. https://doi.org/10.22201/ib.20078706e.2022.93.3588
Davis, A.R., Rees, M.J., Rashni, B. & Haynes, A. (2020) Are spine-bearing freshwater gastropods better defended? Ecologies, 1 (1), 3–13. https://doi.org/10.3390/ecologies1010002
Delicado, D., Arconada, B., Aguado, A. & Ramos, M.A. (2019) Multilocus phylogeny, species delimitation and biogeography of Iberian valvatiform springsnails (Caenogastropoda: Hydrobiidae), with the description of a new genus, Zoological Journal of the Linnean Society, 186, 892–914. https://doi.org/10.1093/zoolinnean/zly093
Dinger, E.C., Hendrickson, D.A., Winsborough, B.M. & Marks, J.C. (2006) Role of fish in structuring invertebrates on stromatolites in Cuatro Ciénegas, México. Hydrobiologia, 563, 407–420. https://doi.org/10.1007/s10750-006-0040-4
Grego, J, Angyal, D. & Beltrán, L.A.L. (2019) First record of subterranean freshwater gastropods (Mollusca, Gastropoda, Cochliopidae) from the cenotes of Yucatán state. Subterranean Biology, 29, 79–88. https://doi.org/10.3897/subtbiol.29.32779
Harrison, A.D. (1984) Redescription of Pyrgophorus parvulus (Gastropoda: Hydrobiidae) from St. Vincent, St. Lucia, and Grenada, West Indies. Proceedings of the Academy of Natural Sciences of Philadelphia, 136, 145–151.
Hershler, R. (1985) Systematic revision of the Hydrobiidae (Gastropoda: Rissoacea) of the Cuatro Cienegas Basin, Coahuila, Mexico. Malacologia, 26, 31–123.
Hershler, R. & Thompson, F.G. (1987) North American Hydrobiidae (Gastropoda: Rissoacea): Redescription and Systematic Relationships of Tryonia Stimpson, 1865 and Pyrgulopsis Call and Pilsbry, 1886. The Nautilus, 101 (1), 25–32.
Hershler, R. & Thompson, F.G. (1992) A review of the aquatic gastropod subfamily Cochliopinae (Prosobranchia: Hydrobiidae). Malacological Review Supplement, 5, 1–140.
Hershler, R., Liu, H.-P. & Landye, J.J. (2011) New species and records of springsnails (Caenogastropoda: Cochliopidae: Tryonia) from the Chihuahuan Desert (Mexico and United States), an imperiled biodiversity hotspot. Zootaxa, 3001 (1), 1–32. https://doi.org/10.11646/zootaxa.3001.1.1
Nava Ferrer, M.L. & Severyn Valbuena, H.J. (2011) Variaciones morfológicas en la concha del gasterópodo Pyrgophorus platyrachis como posible respuesta a factores físico-químicos en el sistema de Maracaibo, Venezuela. Ecotrópicos, 24, 145–163.
Pilsbry, H.A. (1939) Land Mollusca of North America, Monograph 3. Academy of Natural Sciences of Philadelphia, Philadelphia, Pennsylvania, 547 pp.
Radoman, P. (1983) Hydrobioidea a Superfamily of Prosobranchia (Gastropoda): Systematics. Serbian Academy of Sciences and Arts, Belgrade, 256 pp.
Taylor, D.W. (1966) A remarkable snail fauna from Coahuila, Mexico. The Veliger, 9, 152–228.
Wesselingh, F.P. (2006) Molluscs from the Miocene Pebas Formation of Peruvian and Colombian Amazonia. Scripta Geologica, 133, 19–290.
Wilke, T., Haase, M., Hershler, R., Liu, H.-P., Misof, B. & Ponder, W. (2013) Pushing short DNA fragments to the limit: Phylogenetic relationships of ‘hydrobioid’ gastropods (Caenogastropoda: Rissooidea). Molecular Phylogenetics and Evolution, 66, 715–736. https://doi.org/10.1016/j.ympev.2012.10.025
Winsborough, B.M. (2000) Diatoms and benthic microbial carbonates. In: Riding, R.E. & Awramik, S.M. (Eds.), Microbial sediments, Springer-Verlag, Berlin, pp. 76–83. https://doi.org/10.1007/978-3-662-04036-2_10
Wolfe, M. (2013) The historical dynamics of Mexico’s groundwater crisis in La Laguna: Knowledge, resources, and profit, 1930s–1960s. Mexican Studies/Estudios Mexicanos, 29 (1), 3–35. https://doi.org/10.1525/msem.2013.29.1.3