THERYA NOTES 2020, Vol. 1 (1): 62-66 DOI: 10.12933/therya_notes-20-15 First records of leucism in small rodents for Argentina Primeros registros de leucismo en pequeños roedores para Argentina VERONICA A. BENINATO 1 *, GUSTAVO A. RIVERO-CASTRO 1 , MAURICIO A. PÉREZ 1 , CARLOS E. BORGHI 1,2 , AND STELLA M. GIANNONI 1,2,3 1 CIGEOBIO (Centro de Investigaciones de la Geósfera y Biósfera), CONICET (Consejo Nacional de Investigaciones Científcas y Técnicas), Universidad Nacional de San Juan. Av. I. de la Roza 590 (O), CP. J5402DCS, Rivadavia, San Juan, Argentina. Email: vbeninato@unsj-cuim.edu.ar (VAB), riverogustavo90@gmail.com (GAR-C), elcodorniz81@gmail.com (MAP), cborghi@unsj- cuim.edu.ar (CEB), sgiannoni@unsj-cuim.edu.ar (SMG). 2 Departamento de Biología, Facultad Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan. Av. I. de la Roza 590 (O), CP. J5402DCS, Rivadavia, San Juan, Argentina. 3 Instituto y Museo de Ciencias Naturales, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de San Juan. Av. España 400 (N), CP. 5400, San Juan, Argentina. * Corresponding author Leucism appears in various groups of vertebrates, although it is rare in mammals. For Argentina, we do not know of any documented registry for small rodents. The objective of our work is to report the frst cases of leucism in cricetid rodents in the Puna Desert of Argentina. Field work was carried out in the Multiple Use Provincial Reserve Don Carmelo (San Juan, Argentina), located in the Puna Desert. The animals were captured in 9 grids formed by 36 Sherman-type traps, established in plots located between 3.100 and 3.300 m, in the years 2013-2014. We recorded 6 cases of leucism in 3 species of cricetids: Eligmodontia sp. (n = 3), Abrothrix andina (n = 2), and Phyllotis xanthopygus (n = 1). This work represents the frst report of cases of leucism in small mammals from Argentina. The cases in the studied population could be due to the low gene fow imposed by the high environmental severity of an extreme desert, probably related to genetic causes derived from climatic and ecological factors, as these are non-anthropized environments. Key words: Cricetids; leucism; pigment disorder; Puna Desert; rodents. El leucismo aparece en varios grupos de vertebrados, aunque es menos frecuente en mamíferos. Para Argentina no conocemos ningún re- gistro documentado para roedores pequeños. El objetivo de nuestro trabajo es informar los primeros casos de leucismo en roedores cricétidos en la Puna Desértica de Argentina. El trabajo de campo se llevó a cabo en la Reserva Provincial de Uso Múltiple Don Carmelo (San Juan, Argen- tina), ubicada en la Puna Desértica. Los animales fueron capturados en 9 cuadrículas formadas por 36 trampas tipo Sherman, establecidas en parcelas situadas entre los 3,100 y 3,300 m, en los años 2013-2014. Registramos 6 casos de leucismo en 3 especies de cricétidos: Eligmodontia sp. (n = 3), Abrothrix andina (n = 2) y Phyllotis xanthopygus (n = 1). Este trabajo representa el primer reporte de casos de leucismo en mamíferos pequeños para Argentina. Los casos en la población estudiada podrían deberse al bajo fujo génico impuesto por la alta rigurosidad ambien- tal de un desierto extremo, probablemente relacionándose con causas genéticas derivadas de factores climáticos y ecológicos, al tratarse de ambientes no antropizados. Palabras clave: Cricétidos; desorden pigmentario; leucismo; Puna Desértica; roedores. © 2020 Asociación Mexicana de Mastozoología, www.mastozoologiamexicana.org Genetic abnormalities that afect color expression are known as albinism, leucism, and melanism. Albinism is the condition defned by the total absence of melanin pigment in the eyes, skin and hair (Lamoreux et al. 2010). In leucism, animals have a lighter color or are stained, with pigmented eyes (Miller 2005; García-Morales et al. 2012; Liu et al. 2019). In melanism, animals are overproduced with melanin, result- ing in completely black fur (Jimbow et al. 1976; Silvers 2012). In natural populations, these pigmentation abnormali- ties often occur in isolated and small populations, refect- ing low levels of genetic diversity (Holyoak 1978; Bensch et al. 2000; Brito and Valdivieso-Bermeo 2016; Rubio and Simonetti 2018). They have also been related to contami- nation in urban areas (Il’enko 1960) and radioactive con- tamination, as in the case of areas near Chernobyl (Møller and Mousseasu 2001). Pigmentation abnormalities associated with albinism, such as leucism, appear in various vertebrate groups although they are less frequent in mammals (Dunlop et al. 2019). Cases were reported in fsh (Mena-Valenzuela and Valdiviezo-Riveira 2016; Nugra et al. 2018; Liu et al. 2019); amphibians and reptiles (Krecsák 2008; López and Ghirardi 2011; Escoriza 2012), and birds (Comisso 2012; Chiale and Gerardo 2014; Atauchi 2015; Cadena-Ortíz et al. 2015). In mammals, the leucism was found in various species such as bats (Artibeus fraterculus; Fernández de Córdova et al. 2017), agouti (Dasyprocta azarae and D. fuliginosa; Vil- ges de Olivera 2009; Mejía-Valenzuela 2019), two-furred fur sea wolf (Arctocephalus australis; Abreu et al. 2013), opossum (Didelphis albiventris; Abreu et al. 2013), squir- rel (Funambulus palmarum; Samson et al. 2017), guanaco (Lama guanicoe; Puig et al. 2017), among other.