Case Of Leucism Research Articles

First report of a leucistic Brown Agouti (Dasyprocta variegata) in Bolivia

Abstract Cases of anomalous coloration are regularly reported in Neotropical mammals, including the rodent family Dasyproctidae (agoutis and acouchis) where leucistic and albino individuals have been observed. Here, we document the first case of leucism in the Brown Agouti (Dasyprocta variegata) in Bolivia. During a camera trap survey of the Barba Azul Nature Reserve, we obtained footage of a Brown Agouti with a completely white body. Additional pictures of this individual revealed that it has black eyes, indicating leucism instead of albinism. Previous observations (since 2017) of a white agouti in the area suggest that these anomalously colored individuals can survive in the wild. Rare observations of top predators suggest a relatively low predation pressure in the area. We had only one record of a South-American Puma (Puma concolor) during our camera trap survey. Hence, leucistic individuals of a common prey species might also be indicative of the dwindling population densities of top predators in the region.

Yellowish instead of green - A case of leucism in the Italian pool frog Pelophylax bergeri

Yellowish instead of green - A case of leucism in the Italian pool frog Pelophylax bergeri

Report of leucism in tadpoles of Ceratophrys stolzmanni (Amphibia, Anura, Ceratophryidae) in laboratory

ABSTRACT We report the first cases of leucism in Ceratophrys stolzmanni larvae. The leucistic individuals were recorded in an ex-situ population for conservation and research of the species, within the Conservation Initiative for Threatened Amphibians “Balsa de los Sapos” [Raft for Frogs] at the Pontificia Universidad Católica del Ecuador. These individuals presented different color traits from those of the same cohort and as they grew older their uniform white coloration was defined. The leucistic individuals died as tadpoles, after time periods that exceeded the ones reported and recorded for ending metamorphosis in the species, suggesting a link between the absence of pigmentation and a potential malfunction of the thyroid gland.

Records of avian deformities in Nepal

Abstract Avian deformities have been recorded in a variety of bird species all over the world. However, they have not been studied in Nepal, although there are increasing sightings of these deformities. Injuries, genetic mutations, environmental factors, infections, radiation, and other factors can cause deformities. In our study, we collected data from numerous field trips, conversations with bird watchers and experts, and social media posts in Nepal. We reported 24 cases of avian deformities in 16 different bird species across 12 districts in Nepal, suggesting that certain abnormalities persist in a high proportion of previously unstudied birds. We discovered different types of color abnormalities (6 cases of leucism, 3 albinism, 4 partial leucism, 1 brown mutation, 1 melanism, and 3 unidentified color aberration), 5 cases of avian keratin disorder (AKD), and 1 case of both leucism and AKD. The majority of these cases affected corvids and other birds frequently living and nesting near human settlements, indicating that causative agents such as anthropogenic toxicants and environmental degradation could be important contributors. There is a scarcity of research on avian deformities and diseases in Nepal, thus more research on avian abnormalities, such as the pathophysiology of AKD and genetic studies, should be performed.

Leucism in Callithrix jacchus (Primates: Callitrichidae) and Sciurus aestuans (Rodentia: Sciuridae) in the northeast of Brazil

Phenotypic variation is common in vertebrates, especially if we consider geographic variations, however, mutations such as leucism, melanism, and albinism are not so common. Here, we report two cases of leucism, in common marmoset (Callithrix jacchus) and Brazilian squirrel (Guerlinguetus aestuans), recorded in Atlantic Forest fragments in northeastern Brazil. These reports allow us to better understand this phenomenon, as well as ecological and physiological implications for animals, which have a significant influence on their survival.

Extending records of albinism and skin disorders in American cownose rays to southeastern Brazil.

Albinism is a genetic condition expressed as a lack of integumentary and retinal melanin. Although documented across many vertebrate species, albinism and other skin disorders are rarely observed in elasmobranchs (sharks and rays). The present study describes the first confirmed case of albinism in American cownose ray (Rhinoptera bonasus), and three other juveniles of the species with undetermined skin disorders observed in São Paulo, southeastern Brazil. Pigmentation disorders have already been observed in American cownose rays from the North Atlantic, including two cases of leucism and a possible albinism. Based on the results, it was discussed the possible consequences of albinism for the ray survival as well as the possible causes for the undetermined skin disorders.

A new case of leucism in blue crab, Callinectes sapidus Rathbun, 1896 (Decapoda: Portunidae), in a natural protected area from the southern Gulf of Mexico

A new case of leucism in blue crab, Callinectes sapidus Rathbun, 1896 (Decapoda: Portunidae), in a natural protected area from the southern Gulf of Mexico

First recorded case of leucism in the velvet belly lantern sharkEtmopterus spinax(Squaliformes: Etmopteridae)

The capture of a female specimen of the velvet belly lantern shark Etmopterus spinax with abnormal skin coloration is reported. The specimen was captured off northern Spain (Bay of Biscay, North-eastern Atlantic) in 2021 by bottom trawling. The lack of dermal melanophores combined with a normal retinal pigmentation, lead us to considerate the specimen as leucistic. This is the first case of leucism in E. spinax and the second record of colour aberration in the family Etmopteridae. A comprehensive updated review of published literature on albinism and leucism in chondrichthyans is also provided.

First record of leucism in the polychromatic Amazon tree boa, Corallus hortulana (Serpentes, Boidae) of South America

ABSTRACT Snakes have a wide variety of color patterns that can be related to specific ecological and physiological functions. However, genetic mutations can lead to the appearance of anomalous color patterns, which can directly interfere with the fitness of individuals. Leucism is a chromatic anomaly characterized by the almost total absence of epidermal and dermal chromatophores that produce the color. Corallus hortulana is an arboreal snake with nocturnal habits, widely distributed throughout South America, with a wide range of color patterns, known as polychromatism. Here we report the first case of leucism in Corallus hortulana and discuss the potential ecological implications of this anomaly in this species.

First records of a new color pattern in the Goldblotch Grouper, Epinephelus costae (Steindachner, 1878) (Actinopterygii: Serranidae) and first record of leucism in the European conger, Conger conger (Linnaeus, 1758) (Actinopterygii: Congridae)

In many fish, color patterns are striking features and can play an important role in both natural and sexual selection. Furthermore, details of color patterns are in some cases valid tools for species identification. However, fish can also show some genetic abnormalities, such as albinism and leucism. In this research, we report for the first time a new color pattern for Epinephelus costae (Steindachner, 1878), for which it is known an ontogenetic shift in color pattern, and the first case of leucism in Conger conger (Linnaeus, 1758).

A case of color aberration in a fire salamander (Salamandra salamandra) larva

Color aberrations in salamanders are caused by defective chromatophores or by disrupted synthesis of the pigments, and have been previously reported in Europe. In this paper we report the first case of leucism in a fire salamander larva from a cave-dwelling population in Romania. The leucistic larva was larger and heavier compared to the other larvae from the same breeding habitat.

Primer registro de leucismo en el género Coendou Lacépède, 1799 (Rodentia: Erethizontidae)

Se reporta por primera vez un caso de leucismo en la especie Coendou prehensilis. El individuo fue hallado de forma fortuita en una zona de bosque perturbado en la región de Los Andes en Venezuela.

First records of leucism in small rodents for Argentina

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 first 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 first report of cases of leucism in small mammals from Argentina. The cases in the studied population could be due to the low gene flow 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.

Leucism in the European sardine Sardina pilchardus (Clupeidae)

• First record of leucism in the European sardine. • Leucism in fish as an ecological indicator. • Color abnormality as an indicator of the recent historic decline of sardine. The first case of abnormal leucism in the European Sardine or Pilchard Sardina pilchardus (Walbaum, 1792) is reported. A few sardines with abnormal pigmentation were captured by fishermen in the northern part of the Gulf of Cadiz (SW Atlantic coast), between Portugal and Spain, and one specimen was presented to the authors for examination. Species identification was verified using both morphological and genetic criteria. Despite the relative abundance of sardines along the Atlantic coast of the Iberian Peninsula, the current specimen represents the first known case of leucism in S. pilchardus . The observed colour aberration may have been caused by either heavy metal pollutants and/or a high level of endogamy in this heavily exploited local sardine stock.

Plumage and bill abnormalities in albatross chicks on Marion Island

Accessible colonies of Grey-headed Albatross Thalassarche chrysostoma chicks on Marion Island have been inspected for chicks presenting mouse wounds from 2015, and during these inspections we found several cases of plumage and bill abnormalities. We report on two cases of leucism and three cases of ‘bent-beak syndrome’ in Grey-headed Albatross chicks, and one case of ‘bent-beak syndrome’ in a Light-mantled Albatross Phoebetria palpebrata chick. The leucistic Grey-headed Albatross chicks were found in 2018 and 2019, and both apparently fledged successfully. Three Grey-headed Albatross chicks with deviated upper mandibles were recorded in 2015, 2018 and 2019, and a single Light-mantled Albatross chick with deviated upper mandible was recorded in a study colony in 2014. None of these chicks survived to fledge. These appear to be the first records of leucism for Grey-headed Albatross, and the first records of bill deformities in any albatross species. Although bill deformities may have been overlooked in the past among Grey-headed and Light-mantled Albatrosses at Marion Island, it is worrying that we have had four records in the last few years. Albatrosses have been intensively studied at many colonies for more than 50 years, and we would have expected previous records of the ‘bent-beak syndrome’ if it occurred naturally at low levels, suggesting a novel threat to these seabirds.

TWO LEUCISM CASES IN Turdus rufiventris Vieillot, 1818 (BIRDS, TURDIDAE), IN SOUTHERN BRAZIL

Dois casos de leucismo em Turdus rufiventris (Aves, Turdidae), no sul do Brasil. A presente comunicação reporta dois casos de leucismo em Turdus rufiventris, no Sul do Brasil. Um espécime mutante foi registrado em perímetro urbano, no município de Santa Cruz do Sul, Rio Grande do Sul, Brasil. O indivíduo apresentava rêmiges secundárias totalmente brancas na asa esquerda, e coloração normal no restante do corpo. O segundo espécime foi registrado num fragmento florestal, em área rural no município de Santa Maria, RS. A mutação afetava parte da cabeça, pescoço, peito e cauda.

Occurrence of leucism in Eira barbara (Carnivora, Mustelidae) in Brazil

Abstract The occurrence of anomalous coloration (albinism, leucism and melanism) in mammals is a rare phenomenon in nature, but this phenomenon has been reported for several species of mammals. In this study, we report on the occurrence of leucism in Eira barbara by examining three road-killed individuals and two sightings of live animals in Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. In addition, we examined tayra specimens housed in mammal collections from Brazil and USA. The animals found dead and those sighted had a whitish yellow fur on the body and head, resulting in lighter coloration than the coloring pattern commonly observed in tayras. Despite these lighter color pattern, the specimens showed parts of soft tissue, such as iris and the skin, with pigmentation very similar to that present in individuals with the typical color pattern. This set of factors indicates the specimens recorded were in fact leucistic and not albino. Among the specimens examined in the scientific collections, we found nine individuals from different localities that presented the whitish yellow color pattern. Some studies attribute the higher frequency of cases of leucism due to small populations and / or with some mechanism of reproductive isolation. Thus, analysis of the genetic variability of populations containing individuals with such characteristics should be considered. On the other hand, the occurrence of polymorphic color phenotype in tayras indicates that hypotheses related to the fixation of recessive characteristics, or on possible environmental adaptive advantages of these phenotypes can be tested.

New records of pigmentation disorders in molossid and phyllostomid (Chiroptera) bats from Peru

AbstractPigmentation disorders, either from the complete absence (albinism), partial (leucism), or excess (melanism) of melanin, are rare in vertebrates. Worldwide, only a few records of these disorders had been reported for bats. Thanks to recent fieldwork and examination of museum specimens of the collections of the AMNH and MUSM, we report five species with those conditions in Peru. In this study, we report the first cases of leucism in

A case of leucism in the burrowing owl Athene cunicularia (Aves: Strigiformes) with confirmation of species identity using cytogenetic analysis

Leucism is an inherited disorder, characterized by the lack of pigments in part or all of the body, normal coloration of the eyes and, in birds, in naked parts such as the bill and legs. This kind of disorder is sometimes erroneously designated as albinism or partial albinism. In this study, we present a case of leucism in a wild owl. The studied individual presented completely white plumage, light-yellow coloration of legs and bill and normal coloration of eyes. According to morphological features, this owl is a specimen of burrowing owl, Athene cunicularia (Molina, 1782). To confirm the species identity, we used cytogenetic analyses for karyotypic determination, comparing it to the previously described one in the literature. We also studied a captive female of A. cunicularia to complement the species karyotype, which was described in the literature based only on a single male. The karyotype of the leucistic owl individual was compatible with the previously published one for A. cunicularia, confirming the bird was a male specimen. Cytogenetic analysis of the captive female showed that the W sex chromosome is metacentric and comparable to the seventh pair in size. This is the first description of a case of leucism in A. cunicularia for South America. Long-term studies are needed in the Neotropical region to evaluate survival and breeding success in leucistic birds.

Leucistic southern elephant seal at Marion Island

We observed a light coloured female southern elephant seal juvenile (Mirounga leonina) twice at Marion Island in August 2008 and confirmed that it was leucistic rather than albinistic. Though there have been a few previous reports of light-coloured southern elephant seals, this is the first confirmed case of leucism in this species. Judged to be 1-year old, perhaps 2-years old at the most, and because we have not observed any leucistic pups at Marion Island during the past 2 years despite an extensive monitoring and tagging program, we think that this animal was born at nearby Prince Edward Island or perhaps further afield at Iles Crozet.