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Structural- and carotenoid-based throat colour patches in males of Lacerta schreiberi reflect different parasitic diseases

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Host species in populations under strong pressures from parasitic diseases may evolve ornaments to signal individual host quality to conspecifics. Colour ornaments in lizards result from the interaction of different layers in the skin. When inner layers of melanin and well-arranged iridophores are combined, UV-blue structural colouration results. On the other hand, when layers of erythrophores are densely loaded with carotenoids, a UV-yellow colouration is seen. The expression of carotenoid-based traits has been frequently studied in relation to parasite infections. However, few studies have explored the relationship between parasitic diseases and structural colouration. In this study, we investigated the expression of UV-blue and UV-yellow throat colour patches in males of Lacerta schreiberi in relation to infection by haemoparasites, ixodid ticks and intestinal nematodes. The brightness of the UV-yellow throat patch (a carotenoid-based ornament) was positively correlated with body condition and negatively correlated with the number of attached ticks, supporting Hamilton and Zuk’s hypothesis. Additionally, individuals that passed nematode eggs in the faeces had UV-yellow throat patches with higher hue values (more greenish colouration). Strikingly, the individuals infected by haemoparasites of the genus Schellackia showed UV-blue throat patches (a melanin-based ornament) with higher values of both UV-blue chroma and hue (i.e., UV-biased throats) than did uninfected individuals, suggesting a key role for melanin in the nuptial colouration of this lizard species. Thus, the combined information from both UV-blue and UV-yellow throat patches may convey integrative information about individual quality in this lacertid species. Significance statement In this study, we present evidence that the striking throat colouration in males of the endemic Iberian green lizard is related to the presence or load of different parasites. The ornament is composed of one UV-yellow patch and one UV-blue patch, which were differentially related to the presence of different parasitic diseases in the individual hosts. These results suggest that different parasitic diseases may differentially constrain the expression of these colour patches. Moreover, the combined display of the two throat patches simultaneously may convey to conspecifics integrative information about the individual quality of the Iberian green lizard.
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ORIGINAL ARTICLE
Structural- and carotenoid-based throat colour patches in males
of Lacerta schreiberi reflect different parasitic diseases
Megía-Palma Rodrigo
1
&Martínez Javier
2
&Merino Santiago
1
Received: 18 May 2016 /Revised: 19 August 2016 /Accepted: 24 August 2016 / Published online: 2 September 2016
#Springer-Verlag Berlin Heidelberg 2016
Abstract Host species in populations under strong pressures
from parasitic diseases may evolve ornaments to signal indi-
vidual host quality to conspecifics. Colour ornaments in liz-
ards result from the interaction of different layers in the skin.
When inner layers of melanin and well-arranged iridophores
are combined, UV-blue structural colouration results. On the
other hand, when layers of erythrophores are densely loaded
with carotenoids, a UV-yellow colouration is seen. The ex-
pression of carotenoid-based traits has been frequently studied
in relation to parasite infections. However, few studies have
explored the relationship between parasitic diseases and struc-
tural colouration. In this study, we investigated the expression
of UV-blue and UV-yellow throat colour patches in males of
Lacerta schreiberi in relation to infection by haemoparasites,
ixodid ticks and intestinal nematodes. The brightness of the
UV-yellow throat patch (a carotenoid-based ornament) was
positively correlated with body condition and negatively cor-
related with the number of attached ticks, supporting
Hamilton and Zuks hypothesis. Additionally, individuals that
passed nematode eggs in the faeces had UV-yellow throat
patches with higher hue values (more greenish colouration).
Strikingly, the individuals infected by haemoparasites of the
genus Schellackia showed UV-blue throat patches (a melanin-
based ornament) with higher values of both UV-blue chroma
and hue (i.e., UV-biased throats) than did uninfected individ-
uals, suggesting a key role for melanin in the nuptial
colouration of this lizard species. Thus, the combined infor-
mation from both UV-blue and UV-yellow throat patches may
convey integrative information about individual quality in this
lacertid species.
Significance statement
In this study, we present evidence that the striking throat
colouration in males of the endemic Iberian green lizard is
related to the presence or load of different parasites. The or-
nament is composed of one UV-yellow patch and one UV-
blue patch, which were differentially related to the presence
of different parasitic diseases in the individual hosts. These
results suggest that different parasitic diseases may differen-
tially constrain the expression of these colour patches.
Moreover, the combined display of the two throat patches
simultaneously may convey to conspecifics integrative infor-
mation about the individual qualityof the Iberian green lizard.
Keywords Hamilton and Zuk .Handicap .Lacertidae .
Parasite .Reptile .Visual communication
Introduction
Intraspecific variation in several phenotypic traits, including
specific behaviours and colouration of chromatic ornaments,
may result from the interaction between the environment and
genetic pleiotropic effects (Tokarz et al. 1998; Ducrest et al.
2008; Almasi et al. 2012;McLeanetal.2015). In this sense,
sexual characters in lizards are influenced by both abiotic and
biotic environmental factors, reflecting the ability of individ-
uals to adapt to local conditions (Bajer et al. 2012; McLean
et al. 2015).
Communicated by K. McGraw
*Megía-Palma Rodrigo
rodrigo.megia@mncn.csic.es
1
Departamento de Ecología Evolutiva, Museo Nacional de Ciencias
NaturalesCSIC. J. Gutiérrez Abascal, 2. E-28006, Madrid, Spain
2
Área Parasitología, Departamento de Biomedicina y Biotecnología.
Facultad de Farmacia, Universidad de Alcalá de Henares. Alcalá de
Henares, E-28871, Madrid, Spain
Behav Ecol Sociobiol (2016) 70:20172025
DOI 10.1007/s00265-016-2205-0
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Lizards are no exception to this rule; properties of their coloration can be correlated with immunological, morphological and behavioural traits (Sacchi et al., 2007;Langkilde & Boronow, 2010). These relationships are often explained by the idea that production and maintenance of coloration are costly in terms of pigment and energy allocation to colour patches (Megía-Palma et al., 2016b, 2018b. ...
... We captured a total of 38 adult males of L. schreiberi, during the 2013 breeding season (May and June), in Segovia province (Spain,40.8864,. Males of this species typically show an intense blue coloration, with one or two peaks in the near-ultraviolet range (Pérez i de Megía-Palma et al., 2016b). However, seven of them lacked the typical blue breeding coloration. ...
... We used the same spectrophotometer as above to quantify the total light reflected by the yellow and blue throat patches in L. schreiberi and by the orange patches in P. algirus. For this purpose, we followed the methodology described by Megía-Palma et al. (2016b). In individuals of P. algirus with only a small orange patch, the coloration is visible only when lizards open their mouth. ...
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... Seddon and Hews (2016a) found that individuals in the more melanistic of two S. occidentalis populations had lower average testosterone. Blue coloration (the component of the ventral badge I measured) is the product of a layer of iridophores selectively reflecting blue wavelengths, while underlying melanophores absorb other wavelengths (Morrison and Frost-Mason 1991;Quinn and Hews 2003;Megía-Palma et al. 2016b). ...
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... nm (Pérez i deLanuza and Font 2010;Megía-Palma et al. 2016a, 2016b. In contrast, the available spectral evidence of the blue coloration in species of the genus Sceloporus (fam. ...
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... We obtained fresh fecal samples from adults and juveniles (N = 231; average ± SE daily sampling rate = 9.24 ± 0.82 lizards, range = 3-17) ( Table 1). We gently massaged the belly of the lizards to obtain the fecal samples (Megía-Palma et al., 2016, and avoided doing so with gravid females, or when individuals did not produce feces after a few tries. This was done in the field within a few minutes after capture. ...
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