Gonçalves Pablo Rodrigues, de Oliveira João Alves
Núcleo em Ecologia e Desenvolvimento Socioambiental de Macaé (NUPEM), Universidade Federal do Rio de Janeiro, Macaé, RJ, Brazil 27971-550; Email:
Departamento de Vertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil 20940-040; Email: unknown.
Zootaxa. 2014 Jan 30;3760:1-38. doi: 10.11646/zootaxa.3760.1.1.
Recent taxonomic studies on Neotropical mammals have benefited from the use of genetic data to unravel and recognize species diversity in a number of genera, including the Atlantic forest endemic genus Delomys. However, the success of this approach depends on ability to link genetically identified lineages to species names based on voucher specimens that lack genetic data. Cytogenetic studies in the Atlantic forest endemic rodent genus Delomys have revealed two widespread karyotypes, 2n=72/FN=90 and 2n=82/FN=80, which have been respectively ascribed to Delomys sublineatus (Thomas, 1903) and D. dorsalis (Hensel, 1872). More recently, a third karyotype, 2n=82/FN=86, reported from specimens collected on two montaintops in southeastern Brazil, was interpreted as evidence for a third species, D. collinus Thomas, 1917. This nominal form had originally been described as a subspecies of D. dorsalis from Itatiaia, one of the mountain ranges where the third karyotype was later detected. The detection of two sympatric karyotypes at the type locality of D. collinus in the Itatiaia mountain range, Southeastern Brazil, prompted a reevaluation of the association of karyomorphs and species names. In this paper, we assessed the congruence of molecular (cytochrome b), cytogenetic and morphological characters, to diagnose the species in the genus, including data from recently collected series and type specimens. Our results indicate that the genetic and morphological patterns are largely congruent with the recognition of three species, each of which is karyotypically and morphologically diagnosable. Our morphological analyses of sympatric samples from Itatiaia refute the former association of the 2n=82/FN=86 karyotype with the holotype of D. dorsalis collinus (which is more similar to D. dorsalis with 2n=82/FN=80). Instead, we recognize and describe a new species for the 2n=82/FN=86 populations from the highest altitudinal zones of the Itatiaia and Caparaó mountains. The geographical variation in D. dorsalis is also explored and the status of D. d. collinus is discussed in the light of the molecular and morphological evidence. Finally, we discuss biogeographic hypotheses concerning the disjunct distributions of D. dorsalis and the new species.
最近对新热带界哺乳动物的分类学研究受益于利用遗传数据来揭示和识别许多属中的物种多样性，包括大西洋森林特有的德洛鼠属（Delomys）。然而，这种方法的成功取决于能否将通过遗传鉴定的谱系与基于缺乏遗传数据的凭证标本的物种名称联系起来。对大西洋森林特有的啮齿动物德洛鼠属的细胞遗传学研究揭示了两种广泛分布的核型，2n = 72/FN = 90和2n = 82/FN = 80，它们分别被归为亚线德洛鼠（Delomys sublineatus，托马斯，1903年）和背德洛鼠（D. dorsalis，亨泽尔，1872年）。最近，从巴西东南部两座山顶采集的标本中报告了第三种核型，2n = 82/FN = 86，这被解释为存在第三个物种——科氏德洛鼠（D. collinus，托马斯，1917年）的证据。这个命名形式最初被描述为来自伊塔伊亚（Itatiaia）的背德洛鼠的一个亚种，伊塔伊亚是后来检测到第三种核型的山脉之一。在巴西东南部伊塔伊亚山脉科氏德洛鼠的模式产地检测到两种同域分布的核型，这促使人们重新评估核型形态与物种名称之间的关联。在本文中，我们评估了分子（细胞色素b）、细胞遗传学和形态学特征的一致性，以诊断该属中的物种，包括来自最近采集的系列标本和模式标本的数据。我们的结果表明，遗传和形态模式在很大程度上与识别三个物种一致，每个物种在核型和形态上都可诊断。我们对来自伊塔伊亚的同域样本的形态学分析反驳了之前2n = 82/FN = 86核型与科氏背德洛鼠（D. dorsalis collinus）模式标本的关联（该模式标本与2n = 82/FN = 80的背德洛鼠更相似）。相反，我们识别并描述了来自伊塔伊亚和卡帕劳（Caparaó）山脉最高海拔区域的2n = 82/FN = 86种群的一个新物种。我们还探讨了背德洛鼠的地理变异，并根据分子和形态学证据讨论了科氏背德洛鼠的分类地位。最后，我们讨论了关于背德洛鼠和新物种间断分布的生物地理学假说。
