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.Keywords: albinism, hypopigmentation, leucism, Neotropical mammals, piebaldism.Coloração anômala em mamíferos Neotropicais: uma revisão com novos registros para Didelphis sp. (Didelphidae, Didelphimorphia) e Arctocephalus australis (Otariidae, Carnivora) ResumoColorações anômalas ocorrem em muitos vertebrados tropicais. Entretanto, estas são consideradas raras em populações selvagens, havendo poucos registros para a maioria dos táxons. Reportam-se, neste estudo, dois novos casos de coloração anômala em mamíferos. Além disso, por meio de uma extensa revisão bibliográfica, foram compilados os casos publicados sobre coloração anômala em mamíferos neotropicais entre 1950 e 2010. Cada registro foi classificado como albinismo, leucismo, piebaldismo ou, eventualmente, como coloração indeterminada. Como resultados, reportouse o registro de um espécime leucístico de gambá (Didelphis sp.) no sul do Brasil e de um espécime de lobo-marinho sul-americano (Arctocephalus australis) com piebaldismo no norte do Uruguai. Também foram analisados 31 artigos científicos, resultando em 23 registros de albinismo, 12 de leucismo, 71 de piebaldismo e 92 registros classificados como de pigmentação indeterminada. A coloração anômala aparentemente é rara em pequenos mamíferos terrestres...

There are controversial opinions on whether asexual reproduction is more common on islands than on the mainland. Although some authors consider that the evidences of geographical parthenogenesis support the view that asexual reproduction is more common on islands, comparative data on the modes of reproduction of insular and continental taxa confirming this statement are very limited. In this work, we report the presence of three unisexual forms and three bisexual species of the genus Empoasca (Cicadelloidea, Hemiptera, Insecta) from Madeira Island. Experimentally, the unisexual forms reproduced in the absence of males for several generations. The chromosome analysis has shown that the bisexual species differ from one another in chromosome number, and unisexual forms are apomictic and also each have different chromosome numbers. Of parthenoforms, one is triploid and two are of obscure level of ploidy, 2n or 3n. The results obtained show that for this genus unisexual forms are more common on Madeira Island than in the nearby continental areas. It is suggested that unisexual forms may be more plentiful on islands than on the mainland because if an asexual reproduction event occurs, the relaxing competition in these underexploited and enemy-free habitats may favor the establishment of new parthenogenetic lineages.

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The genus Empoasca comprises more than 600 species, many of them important pests of cultivated plants. The leafhopper Empoasca fabalis DeLong, 1930 is native to the tropical and subtropical regions of America. From here, it has successfully spread to most regions of the continent. Today its range extends from the southern United States, through Central America, and the West Indies to southern South America (Cusipuma & Sanchez 1993, DeLong 1930, Paradell et al. 1990, Poos & Wheeler 1949, Wolcott, 1948). Outside its native area, the species was more recently recorded in the Canary Islands (Lorenzo & Hermoso de Mendonza 2000) and Hawaii (Dietrich & Perreira 2019). Although it is still not known to occur in the European mainland, specimens were collected in 2000 on the island of La Palma (Spain) (Lorenzo & Hermoso de Mendonza, 2000). Until now, it was unknown on the island of Madeira and Portugal.