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| Pinto,Kalebe S.; Pires,Tiago H. S.; Stefanelli-Silva,Gabriel; Barros,Bruno S.; Borghezan,Elio A.; Zuanon,Jansen. |
| ABSTRACT Several organisms match their skin color to the prevalent background color, granting crypsis against predators. The rate at which body color changes occur varies among organisms as a result of physiological constraints and adaptation to variation in contrasts between objects and the environmental background. Faster darkening of body color is favored in environments that show higher amounts of contrast between common objects and the prevailing background. Soil types in Amazon forest streams (igarapés) create distinct environments with respect to the amount of contrast, a result of the amount of sand and clay, which offers different contrasts against dead leaves. Here, we investigated differences in the rates of color change among populations of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Background matching; Body color; Crenuchus spilurus; Crypsis; Phenotypic plasticity. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000200204 |
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| Sazima,Ivan; Carvalho,Lucélia Nobre; Mendonça,Fernando Pereira; Zuanon,Jansen. |
| Resemblance to dead leaves is a well known type of camouflage recorded for several small vertebrates that dwell in the leaf and root litter on the ground. We present here instances of such resemblance in three species of nocturnal fishes (Siluriformes and Gymnotiformes) that spend the daytime among submersed root-tangle with leaf litter in Amazonian streams. All three species are very difficult to spot visually, due both to their shape and colors which blend with the substrate, as well as to the heterogeneous nature of their cover. Two species were recorded to lie on their sides, which adds to their resemblance to dead leaves. When disturbed, one species may drift like a waterlogged leaf, whereas another moves upwards the root-tangle, exposing its fore... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crypsis; Leaf resemblance; Defence against predators; Siluriformes; Gymnotiformes. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000100013 |
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I made use of the known dates of reclamation (and of afforestations) in the IJsselmeerpolders in The Netherlands to assess evolutionary adaptation in Cepaea nemoralis. At 12 localities (three in each polder), I sampled a total of 4390 adult individuals in paired open and shaded habitats, on average 233m apart, and scored these for genetic shell colour polymorphisms. The results show (highly) significant differentiation at most localities, although the genes involved differed per locality. Overall, though, populations in shaded habitats had evolved towards darker shells than those in adjacent open habitats, whereas a 'Cain & Sheppard' diagram (proportion yellow shells plotted against ‘effectively unbanded’ shells) failed to reveal a clear pattern. This might suggest that thermal selection is more important than visual selection in generating this pattern. Trait differentiation, regardless of whether they were plotted against polder age or habitat age, showed a linear increase of differentiation with time, corresponding to a mean rate of trait evolution of 15–31 kilodarwin. In conclusion, C. nemoralis is capable of rapid and considerable evolutionary differentiation over 1–25 snail generations, though equilibrium may be reached only at longer time scales
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Naturalis | |
| Schilthuizen, M.. |
| I made use of the known dates of reclamation (and of afforestations) in the IJsselmeerpolders in The Netherlands to assess evolutionary adaptation in Cepaea nemoralis. At 12 localities (three in each polder), I sampled a total of 4390 adult individuals in paired open and shaded habitats, on average 233m apart, and scored these for genetic shell colour polymorphisms. The results show (highly) significant differentiation at most localities, although the genes involved differed per locality. Overall, though, populations in shaded habitats had evolved towards darker shells than those in adjacent open habitats, whereas a 'Cain & Sheppard' diagram (proportion yellow shells plotted against ‘effectively unbanded’ shells) failed to reveal a clear pattern. This... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Predation; Crypsis; Contemporary evolution; Gastropoda; Mollusca; Adaptation; 42.73. |
| Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/445782 |
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| Aldrich, B.C.; Molleson, L.; Nekaris, K.A.I.. |
| Titi monkeys (Callicebus), morphologically cryptic primates, have been difficult to survey using traditional sighting-based line transect methods. Callicebus-species regularly engage in loud, ritualized singing bouts, which could allow for the use of alternate, potentially more accurate call-based survey methods to monitor populations. The Andean titi monkey, C. oenanthe, is endemic to a small region of northern Peru, an area subject to widespread and rapid deforestation and human colonization. We conducted a call-based survey of C. oenanthe at Tarangue, a 74 ha private reserve near Moyobamba. Triangulation of calls was used to map groups of titi monkeys on and around the reserve. 73 mapped calls were used to estimate the presence of between three and... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Crypsis; Triangulation; Primates; Tropical Andes; Song; 42.84. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/269614 |
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