Morphological, chromosomal and genic differences between sympatric Rattus rattus and Rattus satarae, a sibling, sympatric species of South India

• Published in: Journal of Mammalogy
• Main Authors: Pages, Marie, Corbet, Gordon, Orth, Annie, Volobouev, Vitaly, Michaux, Johan, J., Catzeflis, François
• Other Authors: Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), National History Museum, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Université de Liège, National Institutes of Health-National Institute of Allergy and Infectious Disease (USA) AI-29834, French National Agency for Research ANR 07 BDIV 012
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: cryptic species; Rattus; rodent; South India; RAT; BIOLOGIE DES POPULATIONS; GENETIQUE DES POPULATIONS; espèces cryptiques; [SDV]Life Sciences [q-bio]; Rattus rattus
• Online Access: https://hal.inrae.fr/hal-02643453; https://doi.org/10.1644/10-MAMM-A-033.1

Contact : [e-mail] International audience Two morphological forms of black rats (Rattus cf. rattus) were found living in sympatry in high-altitude dense forests of the Nilgiri Mountains, South India. The 1st one, often brown- or gray-bellied, also is found commensal in lowland settlements and represents Rattus rattus cf. rufescens (Gray 1837), with a diploid number (2N) of 38 chromosomes. The 2nd form, which has most often a pure white belly, has 2N 5 42 chromosomes and is referable to Rattus r. satarae Hinton, 1918, based on morphological comparison with the holotype. A multidisciplinary study indicates that these 2 forms are characterized by clear-cut differences in biochemistry (electrophoresis of homologous isozymes), molecular sequences (mitochondrial and nuclear DNA), and chromosomes (detailed banding analysis). All these data, coupled to diagnostic morphological characteristics, support the hypothesis that Rattus satarae and Rattus rattus are separate, sympatric species, with no gene flow between them. Their similar external morphology is interpreted as the result of convergence through occupying the same ecological niche.