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de Souza YCM, Annibale FS, Carvalheiro LG, Vasconcelos TS, Rossa-Feres DC. Differential behavioral responses of benthic and nektonic tadpoles to predation at varying water depths. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2021-0236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Predators influence microhabitat selection and activity level of tadpoles, but it is still unclear how such responses to predators differ among species and how water column's depth influences this predator-prey interaction. Here, we experimentally tested whether the presence of Odonata water-nymphs influenced spatial use and activity of benthic and nektonic tadpoles in different food availability contexts. Benthic tadpoles occupied and consumed more food at the bottom level, irrespective of predator’s presence. However, when predators were at bottom, benthic tadpoles remained close to the cages, suggesting a typical “stay-still” defensive behavior known for Physalaemus nattereri (Steindachner, 1863). Nektonic tadpoles occupied shallower depths on predator's presence, and they also consumed less food and avoided predator by selecting food sources far from it. When predator was at bottom level and food was available, the distance of tadpoles to the cage tended to be smaller. Scinax fuscovarius (Lutz, 1925) tadpoles were more active when food was absent regardless of predator’s presence. When food was available, these tadpoles generally occupied and consumed more food at bottom level. Tadpoles’ responses depended not only on predator’s presence, but on a complex net of factors, which include tadpoles’ habit, anti-predatory behavior, availability and location of food.
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Bertolesi GE, Debnath N, Atkinson-Leadbeater K, Niedzwiecka A, McFarlane S. Distinct type II opsins in the eye decode light properties for background adaptation and behavioural background preference. Mol Ecol 2021; 30:6659-6676. [PMID: 34592025 DOI: 10.1111/mec.16203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/02/2021] [Accepted: 09/10/2021] [Indexed: 12/17/2022]
Abstract
Crypsis increases survival by reducing predator detection. Xenopus laevis tadpoles decode light properties from the substrate to induce two responses: a cryptic coloration response where dorsal skin pigmentation is adjusted to the colour of the substrate (background adaptation) and a behavioural crypsis where organisms move to align with a specific colour surface (background preference). Both processes require organisms to detect reflected light from the substrate. We explored the relationship between background adaptation and preference and the light properties able to trigger both responses. We also analysed which retinal photosensor (type II opsin) is involved. Our results showed that these two processes are segregated mechanistically, as there is no correlation between the preference for a specific background with the level of skin pigmentation, and different dorsal retina-localized type II opsins appear to underlie the two crypsis modes. Indeed, inhibition of melanopsin affects background adaptation but not background preference. Instead, we propose pinopsin is the photosensor involved in background preference. pinopsin mRNA is co-expressed with mRNA for the sws1 cone photopigment in dorsally located photoreceptors. Importantly, the developmental onset of pinopsin expression aligns with the emergence of the preference for a white background, but after the background adaptation phenotype appears. Furthermore, white background preference of tadpoles is associated with increased pinopsin expression, a feature that is lost in premetamorphic froglets along with a preference for a white background. Thus, our data show a mechanistic dissociation between background adaptation and background preference, and we suggest melanopsin and pinopsin, respectively, initiate the two responses.
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Affiliation(s)
- Gabriel E Bertolesi
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Nilakshi Debnath
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | | | - Anna Niedzwiecka
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
| | - Sarah McFarlane
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
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Preuss G, Silverio Righetto Mauad AV, Shinji Akiyama Kitamura R, Santiago de Assis T, Corrêa Scalon M, Domingos FMCB. Lurking in the depth: Pond depth predicts microhabitat selection by Rhinella icterica (Anura: Bufonidae) tadpoles at two different sampling scales. HERPETOZOA 2021. [DOI: 10.3897/herpetozoa.34.e56326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Habitat selection has long been a central theme in ecology and has historically considered both physiological responses and ecological factors affecting species establishment. Investigating habitat selection patterns at different scales can provide important information on the relative roles of the environmental factors influencing the organisms’ abilities to use their surrounding habitat. This work aimed at investigating which environmental factors determine habitat selection by Rhinella icterica tadpoles, and also took the opportunity to investigate how the scale in which tadpoles and environmental data are sampled might influence the habitat selection results. A total of 2.240 tadpoles were counted in the whole sampling area, and while substrate cover and depth were the variables that better explained the abundance of tadpoles at the larger scale (plot level), depth and water turbidity better explained tadpoles’ abundance at the smaller scale (subplot level). The results suggest that avoiding predation by matching the background color is a likely process explaining tadpoles’ occupancy at both scales. Depth is known to influence tadpole habitat use in the tropics, and although its combination with turbidity and substrate cover varied between scales, our study suggests that sampling at different scales might not affect the inferred ecological processes driving habitat selection. This information might also be useful to predict tadpoles’ responses to micro-environmental perturbations and help in guiding the choice of parameters that should be taken into account when analyzing the effects of habitat degradation in Atlantic Forest amphibian populations.
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Guimarães ISC, Hemnani M, Kaefer IL, da Silva Pires TH. Fear of the dark: substrate preference in Amazonian tadpoles. Acta Ethol 2021. [DOI: 10.1007/s10211-021-00374-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Detectability is in the eye of the beholder—the role of UV reflectance on tadpole detection and predation by a passerine bird. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-02983-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Eterovick PC, Mendes IS, Kloh JS, Pinheiro LT, Václav ABHP, Santos T, Gontijo ASB. Tadpoles respond to background colour under threat. Sci Rep 2018; 8:4085. [PMID: 29511273 PMCID: PMC5840337 DOI: 10.1038/s41598-018-22315-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 02/21/2018] [Indexed: 11/09/2022] Open
Abstract
The ability to respond to background colour is an important feature of species that might benefit from background matching camouflage. Tadpole colour patterns vary and could be associated with several functions, including defense. Because tadpoles are exposed to a wide array of visually oriented predators, they represent good models to study defensive colouration and associated behaviours. We tested whether a potentially disruptively camouflaged tadpole with a dark body crossed by yellow bars (Ololygon machadoi) is able to respond differently to matching light and dark natural background colours and an artificial blue contrasting background. We used a syntopic contrasting black tadpole (Bokermannohyla martinsi) as a control, expecting it not to respond to background colour in search for camouflage. Ololygon machadoi tadpoles chose light over blue backgrounds under threat, as expected, however they did not show preferential use of dark vs. blue backgrounds. Bokermannohyla martinsi did not respond to any combination of background colours. Our results suggest that O. machadoi tadpoles are able to respond to background colour, and may favor matching backgrounds under some circumstances. The potentially disruptive colouration of O. machadoi tadpoles may increase their repertoire of escape strategies, background matching being one of the options to escape predation.
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Affiliation(s)
- Paula Cabral Eterovick
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil.
| | - Izabela Santos Mendes
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil
| | - Jéssica Stephanie Kloh
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil
| | - Luan Tavares Pinheiro
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil
| | | | - Thiago Santos
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil
| | - Ana Sofia Buza Gontijo
- Programa de Pós Graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, 30535-610, Belo Horizonte, Brazil
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Costa RN, Solé M, Nomura F. Agropastoral activities increase fluctuating asymmetry in tadpoles of two neotropical anuran species. AUSTRAL ECOL 2017. [DOI: 10.1111/aec.12502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Renan N. Costa
- Programa de Pós-Graduação em Ecologia e Conservação da Biodiversidade; Universidade Estadual de Santa Cruz; Rodovia Jorge Amado, km 16 CEP 45662-900 Ilhéus Bahia Brazil
- Instituto Boitatá de Etnobiologia e Conservação da Fauna; Goiânia Goiás Brazil
| | - Mirco Solé
- Departamento de Ciências Biológicas; Universidade Estadual de Santa Cruz; Ilhéus Bahia Brazil
| | - Fausto Nomura
- Departamento de Ecologia; Instituto de Ciências Biológicas; Universidade Federal de Goiás; Goiânia Goiás Brazil
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Polo-Cavia N, Gomez-Mestre I. Pigmentation plasticity enhances crypsis in larval newts: associated metabolic cost and background choice behaviour. Sci Rep 2017; 7:39739. [PMID: 28051112 PMCID: PMC5209684 DOI: 10.1038/srep39739] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/25/2016] [Indexed: 11/20/2022] Open
Abstract
In heterogeneous environments, the capacity for colour change can be a valuable adaptation enhancing crypsis against predators. Alternatively, organisms might achieve concealment by evolving preferences for backgrounds that match their visual traits, thus avoiding the costs of plasticity. Here we examined the degree of plasticity in pigmentation of newt larvae (Lissotriton boscai) in relation to predation risk. Furthermore, we tested for associated metabolic costs and pigmentation-dependent background choice behaviour. Newt larvae expressed substantial changes in pigmentation so that light, high-reflecting environment induced depigmentation whereas dark, low-reflecting environment induced pigmentation in just three days of exposure. Induced pigmentation was completely reversible upon switching microhabitats. Predator cues, however, did not enhance cryptic phenotypes, suggesting that environmental albedo induces changes in pigmentation improving concealment regardless of the perceived predation risk. Metabolic rate was higher in heavily pigmented individuals from dark environments, indicating a high energetic requirement of pigmentation that could impose a constraint to larval camouflage in dim habitats. Finally, we found partial evidence for larvae selecting backgrounds matching their induced phenotypes. However, in the presence of predator cues, larvae increased the time spent in light environments, which may reflect a escape response towards shallow waters rather than an attempt at increasing crypsis.
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Affiliation(s)
- Nuria Polo-Cavia
- Department of Biology, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain
| | - Ivan Gomez-Mestre
- Ecology, Evolution, and Development Group, Doñana Biological Station, CSIC. E-41092 Seville, Spain
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Gambale PG, Batista VG, Oda FH, Campos RM, Takemoto RM, Bastos RP. Anuran larvae as prey and hosts of invertebrates in Neotropical aquatic habitats. REVISTA CHILENA DE HISTORIA NATURAL 2014. [DOI: 10.1186/s40693-014-0029-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kuo YM, Lee YF, Chu WC. Group Effects and Background Color Patterns Affect the Exploratory Behavior of Tree Sparrows. Ethology 2014. [DOI: 10.1111/eth.12279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Yen-Min Kuo
- Department of Life Sciences; National Cheng Kung University; Tainan Taiwan
| | - Ya-Fu Lee
- Department of Life Sciences; National Cheng Kung University; Tainan Taiwan
| | - Wen-Chen Chu
- Department of Life Sciences; National Cheng Kung University; Tainan Taiwan
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Costa RN, Nomura F. Avaliação de risco e plasticidade comportamental limitada em girinos de Rhinella ornata (Anura, Bufonidae). IHERINGIA. SERIE ZOOLOGIA 2014. [DOI: 10.1590/1678-476620141042162167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Os girinos de anuros são elementos importantes das redes tróficas de ambientes aquáticos, sendo recurso alimentar de diversos tipos de predadores. Desta maneira, os girinos apresentam uma grande variedade de mecanismos de defesa que podem ser morfológicos, comportamentais e/ou fisiológicos. A impalatabilidade, produzida pelo acúmulo de substâncias tóxicas na pele, é um mecanismo comum em muitas linhagens de anfíbios. No entanto, alguns predadores não são afetados por estas substâncias tóxicas, o que pode favorecer o desenvolvimento de mecanismos alternativos de defesa contra predação. Neste contexto, nosso objetivo foi avaliar se girinos impalatáveis de Rhinella ornata (Spix, 1824), podem apresentar mecanismos comportamentais de defesa contra predação na presença de predadores que não são afetados pelas substâncias tóxicas em sua pele. Para testar nossa hipótese, utilizamos dois tipos de predadores aquáticos: um heteróptero aquático do gênero Belostoma e uma larva de libélula do gênero Aeshna. Os girinos foram colocados em aquários com pistas visuais e químicas dos predadores (experimento de risco direto), somente pistas químicas (experimento de risco indireto) e ausência completa de sinais de predadores (controle). Em ambos os casos, o comportamento de natação foi observado durante 5 minutos. Durante os experimentos não houve alteração no comportamento de natação dos girinos.
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