%20from%20Sierra%20de%20Penjamo,%20Guanajuato,%20Mexico.webp "Alfredo Dugès threeband (Humboldtiana dugesi) from Sierra de Penjamo, Guanajuato, Mexico")
NEWS - Alfredo Dugès threeband (Humboldtiana dugesi) was first described as a species from Guanajuato, Mexico and diagnosed based on protoconch with growth lines and granular microsculptures, rounded penis with thick rim that covers half of the penis cavity and long flagellum that is 4x longer than the penis and epiphallus combined.
The new species was assigned to the H. buffoniana species group of the subgenus Humboldtiana based on the nearly smooth protoconch sculpture and the dart gland just above the sac. The H. buffoniana group contains 20 species that range from the border between New Mexico and Texas (H. ultima) to the Mexican Transvolcanic Belt.
H. dugesi can be distinguished from other species in the subgenus Humboldtiana by its protoconch with growth lines and granular microsculptures as opposed to other species of the subgenus where the protoconch lacks sculptures.
Three individuals were collected active in rock crevices during the day and two empty shells were collected from leaf litter at an elevation of 1939 meters. The vegetation of the type site is temperate subhumid oak forest. The epithet is dedicated to the 19th century French-Mexican naturalist Alfredo Dugès. Specimens are only known from the type sites: Guanajuato, Cuerámaro, Sierra de Penjamo, Fuerte de los Remedios.
Most of the species show an insular distribution and are only known from the type site, the researchers only compared the new species with H. potosiana Pilsbry 1927 from the Sierra de San Miguelito, H. salviahispanica Mejía 2009 from Huichapan, H. queretaroana Dall 1897 and H. pinicola Thompson and Brewer 2000 from Pinal de Amoles in the Sierra Gorda.
H. dugesi has a small shell, the number of whorls and shell engravings are similar to H. salviahispanica and H. potosiana, but H. dugesi can be diagnosed by the presence of growth lines and isolated grains in the protoconch which are unique characters in this genus.
The reproductive anatomy has a round penis like H. potosiana, but H. dugesi has a long and cylindrical epiphallus, a long flagellum with 4x the combined length of the penis + epiphallus and has a spermathecal appendix. In contrast, H. potosiana has a short and sturdy epiphallus, a short flagellum with 1x the combined length of the penis + epiphallus and does not have a spermathecal appendix.
Original research
Mejía O, López B (2024) A new species of the genus Humboldtiana (Gastropoda, Stylommatophora, Xanthonychidae) from Sierra de Penjamo, Guanajuato, Mexico. Biodiversity Data Journal 12: e132797, DOI:10.3897/BDJ.12.e132797
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