8,723 research outputs found
Colour variation in signal crayfish Pacifastacus leniusculus
Get PDFExternal colouration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the colour expression, the mechanisms of colour perception, and the general mechanisms controlling colour evolution and function. Among all, camouflage from predators and conspicuousness are of particular interest since pose animal to choose between opposite adjustment in colouration. The external colouration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer, and the trade-off between camouflage and communication had lead to a variety of responses, involving signal partitioning, spectral sensibility, changing colouration or signalling behaviour. Here, we used digital images to explore intrapopulation variability of the external colouration of Pacifastacus leniusculus among body regions within an individual and between sexes. We found that i) ventral colouration of claws are more saturated and brilliant than upperparts, ii) males express a more saturated and brightness colouration than females, especially on the lower portion of claws, iii) colour intensity and brightness increases with size differently in different body regions, and iv) brightness is more variable in males than in females. All the above patterns support the hypothesis that colour in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication. The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment
Effetti filogenetici ed ecologici nella diversificazione fenotipica degli Scinchi della Sottofamiglia Mabuyinae (Scincomorpha, Reptilia).
No full textAlan Moore Comics as Performance, Fiction as Scalpel
No full textEclectic British author Alan Moore (b. 1953) is one of the most acclaimed and controversial comics writers to emerge since the late 1970s. He has produced a large number of well-regarded comic books and graphic novels while also making occasional forays into music, poetry, performance, and prose. In Alan Moore: Comics as Performance, Fiction as Scalpel , Annalisa Di Liddo argues that Moore employs the comics form to dissect the literary canon, the tradition of comics, contemporary society, and our understanding of history. The book considers Moore's narrative strategies and pinpoints the main thematic threads in his works: the subversion of genre and pulp fiction, the interrogation of superhero tropes, the manipulation of space and time, the uses of magic and mythology, the instability of gender and ethnic identity, and the accumulation of imagery to create satire that comments on politics and art history. Examining Moore's use of comics to scrutinize contemporary culture, Di Liddo analyzes his best-known works-- Swamp Thing, V for Vendetta, Watchmen, From Hell, Promethea , and Lost Girls . The study also highlights Moore?s lesser-known output, such as Halo Jones, Skizz , and Big Numbers , and his prose novel Voice of the Fire. Alan Moore: Comics as Performance, Fiction as Scalpel reveals Moore to be one of the most significant and distinctly postmodern comics creators of the last quarter-century.Intro -- Contents -- Preface and Acknowledgments -- Introduction -- CHAPTER 1. Formal Considerations on Alan Moore's Writing -- CHAPTER 2. Chronotopes: Outer Space, the Cityscape, and the Space of Comics -- CHAPTER 3. Moore and the Crisis of English Identity -- CHAPTER 4. Finding a Way into Lost Girls -- Conclusion -- Notes -- Bibliography -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- U -- V -- W -- Y -- ZEclectic British author Alan Moore (b. 1953) is one of the most acclaimed and controversial comics writers to emerge since the late 1970s. He has produced a large number of well-regarded comic books and graphic novels while also making occasional forays into music, poetry, performance, and prose. In Alan Moore: Comics as Performance, Fiction as Scalpel , Annalisa Di Liddo argues that Moore employs the comics form to dissect the literary canon, the tradition of comics, contemporary society, and our understanding of history. The book considers Moore's narrative strategies and pinpoints the main thematic threads in his works: the subversion of genre and pulp fiction, the interrogation of superhero tropes, the manipulation of space and time, the uses of magic and mythology, the instability of gender and ethnic identity, and the accumulation of imagery to create satire that comments on politics and art history. Examining Moore's use of comics to scrutinize contemporary culture, Di Liddo analyzes his best-known works-- Swamp Thing, V for Vendetta, Watchmen, From Hell, Promethea , and Lost Girls . The study also highlights Moore?s lesser-known output, such as Halo Jones, Skizz , and Big Numbers , and his prose novel Voice of the Fire. Alan Moore: Comics as Performance, Fiction as Scalpel reveals Moore to be one of the most significant and distinctly postmodern comics creators of the last quarter-century.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
First experimental evidence that proteins from femoral glands convey identity-related information in a lizard
No full textTransferring identity-related information (IRI) to conspecifics may give advantage in effectively tuning intraspecific behaviour. Some lizard species use the secretions of specialized epidermal glands (femoral or cloacal) to convey IRI. Those secretions are made of lipids and proteins, the former been suggested to inform about signaller quality, the latter suspected to communicate IRI to conspecifics. Here we tested the hypothesis that proteins broadcast IRI by analysing the movement patterns of 28 male common wall lizards (Podarcis muralis) under strictly controlled experimental conditions. Lizards were videotaped in plastic terraria where the substrate scent was manipulated by filling it with a solution bearing: i) the proteins extracted from the secretions of the tested lizard (SELF); ii) the proteins from a never-met donor from other nearby populations (NON-SELF); iii) the solvent alone. Lizards showed higher behavioural response to the NON-SELF treatment with respect to both CTRL and SELF ones. Further, protein concentration did not affect behavioural response, suggesting an all-or-nothing effect. Both results agree with the hypothesis that proteins may be used in chemical communication and convey IRI, demonstrating for the first time that they can be used as intraspecific signal
Haemosporidian infections in wild populations of Podarcis muralis from the Italian Peninsula
No full textCorrelated seasonal variations of colour and chemical signals support the occurrence of a multi-channel system of communication in the Italian wall lizard (Podarcis siculus)
No full textThe signals animals use in intraspecific communication are usually extremely conspicuous because they serve to convey honest information about their quality in order to maximize their mating success. Precisely because they are flashy, communication signals tend to increase the possibility of being detected by predators, leading to a reduction of individual fitness. There are different evolutionary solutions to solve this trade-off between the opposing requirements of camouflage and communication, including multi-channel signal systems, in which information is encoded in more than one type of signal. In the March-October 2019 period we characterized the dorsal colouration and the structure of the proteins of the femoral secretions in a sample of 228 male Italian wall lizards captured at the Certosa di Calci (Pi). The results of the analyses support the hypothesis that color and secretions may be part of a multi-channel communication system
Singing in the rice: distribuzione ed attività di canto di tre specie di anfibi in un paesaggio agricolo della Pianura Padana
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