Abreu M S L, Machado R, Barbieri F, Freitas N S, Oliveira L R
Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
Braz J Biol. 2013 Feb;73(1):185-94. doi: 10.1590/s1519-69842013000100020.
Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.
许多热带脊椎动物会出现异常体色。然而，它们在野生种群中被认为是罕见的，大多数动物类群的记录非常少。我们报告了两例哺乳动物异常体色的新病例。此外，通过对1950年至2010年间同行评审文章的全面回顾，我们汇总了所有已发表的关于新热带界哺乳动物异常色素沉着的病例。每一条记录都被归类为白化病、白变症、花斑症或最终归类为未确定的色素沉着。结果，我们报告了巴西南部一只负鼠（Didelphis sp.）白变症标本的新记录，以及乌拉圭一只南美毛皮海狮（Arctocephalus australis）花斑症的标本。我们还发现了31篇科学文章，产生了23条白化病记录、12条白变症记录、71条花斑症记录和92条归类为未确定色素沉着的记录。异常体色在小型陆生哺乳动物中显然很罕见，但在鲸类和小型翼手目动物中更为常见。在这198条记录中，149条发生在鲸类动物中，30条发生在蝙蝠中。与鲸类动物相关的结果表明，色素沉着异常的雄性和雌性在繁殖上是成功的，因此它们在自然种群中的频率越来越高。在蝙蝠中，这一结果可能与这些动物主要通过回声定位来定向，以及它们的栖息地提供了免受光照和捕食的保护这一事实有关。在其他新热带界哺乳动物目中，异常体色可能更频繁地出现，但尚未有正式报道。因此，我们鼓励研究人员公布这些事件，以便更好地理解这一对动物生存有重大影响的现象。
