scholarly journals Lizard colour plasticity tracks background seasonal changes

2019 ◽  
Author(s):  
Daniele Pellitteri-Rosa ◽  
Andrea Gazzola ◽  
Simone Todisco ◽  
Fabio Mastropasqua ◽  
Cristiano Liuzzi
Keyword(s):  
Phenotypic Plasticity ◽  
Seasonal Change ◽  
Seasonal Changes ◽  
Environmental Heterogeneity ◽  
Colour Variation ◽  
Time Points ◽  
Environmental Background ◽  
Podarcis Siculus ◽  
Colour Patterns ◽  
Italian Wall Lizard

AbstractEnvironmental heterogeneity on spatial and temporal scale fosters organism’s capacity to plastically alter coloration. Predation risk might favour the evolution of phenotypic plasticity in colour patterns, as individuals, which change colour throughout the year, could be able to improve their fitness. Here we explored the change in dorsal pigmentation of the Italian wall lizard (Podarcis siculus campestris) along three time points (March, July and October) during the period of activity. Lizard dorsal pictures were collected on the field, with the support of a reference chart to quantitatively estimate chromatic variables (hue, saturation and value, HSV). At the same time, pictures of grassy coverings (the most representative portion of the environment subjected to normal seasonal change), were collected. Our findings show that lizards are capable of altering dorsal coloration during seasonal change. They vary from green, at the onset of spring, to brownish in the middle of summer, and greyish colour in October. This modification closely followed environmental background colour variation and enhanced lizard crypsis during each season.

scholarly journals Lizard colour plasticity tracks background seasonal changes

Biology Open ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. bio052415
Author(s):  
Daniele Pellitteri-Rosa ◽  
Andrea Gazzola ◽  
Simone Todisco ◽  
Fabio Mastropasqua ◽  
Cristiano Liuzzi
Keyword(s):  
Seasonal Changes ◽  
Environmental Heterogeneity ◽  
Southern Italy ◽  
Preliminary Investigation ◽  
Natural Area ◽  
Colour Variation ◽  
Environmental Background ◽  
Podarcis Siculus ◽  
Colour Patterns ◽  
Italian Wall Lizard

ABSTRACTEnvironmental heterogeneity on a spatial and temporal scale fosters an organism's capacity to plastically alter coloration. Predation risk might favour the evolution of phenotypic plasticity in colour patterns, as individuals who change colour throughout the year may be able to improve their fitness. Here we explored the change in dorsal pigmentation of the Italian wall lizard (Podarcis siculus campestris) at three time points (March, July, October) during a period of activity in a Mediterranean natural area in southern Italy. Following a preliminary investigation conducted in 2018, during 2019 we captured 135 lizards and took a picture of their ventral scales to check for possible recapture over the sessions. Lizard dorsal pictures were collected in the field with the support of a reference chart to quantitatively estimate chromatic variables (hue, saturation and value). At the same time, pictures of the environmental background were collected. Our findings suggest that lizards are capable of altering dorsal coloration during seasonal change. They vary from green at the onset of spring, to brownish in the middle of summer and to a greyish colour in October. This modification closely followed environmental background colour variation and enhanced lizard crypsis during each season.

Four Cases of Complete Melanistic Italian Wall Lizard [Podarcis siculus (Rafinesque-Schmaltz, 1810)] in Southern Italy and Sicily Island

2016 ◽  
Vol 24 (1) ◽  
pp. 63
Author(s):  
Vincenzo Reina ◽  
Filippo Spadola ◽  
Manuel Morici ◽  
Paola Sgroi ◽  
Antonino Marcianò
Keyword(s):  
Southern Italy ◽  
Podarcis Siculus ◽  
Italian Wall Lizard

scholarly journals Biological responses in pesticide exposed lizards (Podarcis siculus)

Ecotoxicology ◽  
2021 ◽  
Author(s):  
Giulia Simbula ◽  
Ginevra Moltedo ◽  
Barbara Catalano ◽  
Giacomo Martuccio ◽  
Claudia Sebbio ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Central Italy ◽  
Parasitic Infection ◽  
Biotransformation Enzymes ◽  
Biological Responses ◽  
Podarcis Siculus ◽  
Parasite Infections ◽  
Italian Wall Lizard ◽  
Detoxification Process ◽  
Accurate Quantification

AbstractThe release of contaminants as herbicides, fungicides and insecticides into the environment has been listed as one of the six major contributors to the global decline of reptiles. Although reptiles may face severe risk from contaminants due to their ecology and physiology, they are currently less studied than other vertebrate groups. In the present work, we investigated if and how different types of field treatment (conventional and organic) affected the health status of Italian wall lizard (Podarcis siculus) individuals in central Italy. We chose a multi-biomarker approach that evaluated the biological responses of lizards to the treatment by means of AChE activity in the nervous system, biotransformation enzymes activities and oxidative stress in the liver, micronuclei frequency measured in the erythrocytes, and rate of intestinal parasitic infection. Our findings showed evidence of effects of treatment in conventional areas and between sexes with significant oxidative stress due to hydroxyl radicals, that caused DNA damage. No difference of intestinal parasite infections was found among treatments. Podarcis siculus seems to be a good bioindicator in ecotoxicological studies and potentially in risk assessment of pesticides, although further analyses in laboratory and in the field are needed to achieve more accurate quantification of specific pesticide effects in relation to known exposure history and to understand if other mechanisms were involved in the toxicity and detoxification process of pesticides for this species.

scholarly journals Invasive lizard has fewer parasites than native congener

2021 ◽  
Author(s):  
Beatriz Tomé ◽  
D. James Harris ◽  
Ana Perera ◽  
Isabel Damas-Moreira
Keyword(s):  
18S Rrna ◽  
Blood Parasites ◽  
Average Intensity ◽  
Invasive Potential ◽  
Lizard Species ◽  
High Prevalence ◽  
Podarcis Siculus ◽  
Species Establishment ◽  
Low Levels ◽  
Italian Wall Lizard

AbstractInvasive species can carry parasites to introduced locations, which may be key to understand the success or failure of species establishment and the invasive potential of introduced species. We compared the prevalence and infection levels of haemogregarine blood parasites between two sympatric congeneric species in Lisbon, Portugal: the invasive Italian wall lizard (Podarcis siculus) and the native green Iberian wall lizard (Podarcis virescens). The two species had significant differences in their infection levels: while P. virescens had high prevalence of infection (69.0%), only one individual of P. siculus was infected (3.7%), and while P. virescens exhibited an average intensity of 1.36%, the infected P. siculus individual had an infection rate of only 0.04%. Genetic analyses of 18S rRNA identified two different haemogregarine haplotypes in P. virescens. Due to the low levels of infection, we were not able to amplify parasite DNA from the infected P. siculus individual, although it was morphologically similar to those found in P. virescens. Since other studies also reported low levels of parasites in P. siculus, we hypothesize that this general lack of parasites could be one of the factors contributing to its competitive advantage over native lizard species and introduction success.

Endocrine changes and their relationship with body weight in growing yaks

2002 ◽  
Vol 74 (1) ◽  
pp. 89-94
Author(s):  
Tian Yongqiang ◽  
Zhao Xingxu ◽  
Wang Minqiang ◽  
Lu Zhonglin ◽  
Zhang Rongchang
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Seasonal Change ◽  
Seasonal Changes ◽  
Significant Positive Correlation ◽  
The Body ◽  
Nutrition Status ◽  
Blood Samples ◽  
Different Seasons ◽  
Grass Growth

AbstractThe concentrations of growth hormone (GH), insulin (Ins), tri-iodothyronine (T3) and thyroxine (T4) in blood samples of growing yaks during different bimonthly seasons were determined by radioimmunoassay. The changes of body weight of growing yaks and composition of grass grazed were measured accordingly. The seasonal changes of hormones were significant (P < 0·01 or P < 0·05). Within season, the variances of hormones depended upon the different growing stages. The body-weight gains in the different groups varied in different seasons, increase being significant in May, July and September, decrease being significant from January to May. Correlation analysis indicated that T4 concentration had a significant positive correlation with the body weight of the growing yaks(r = 0·2509, P < 0·05) and other hormones did not have any significant correlation with body weight. The results showed that the annual cycle of weight loss and gain was attributed to the seasonal change of nutrition status. The seasonal change of the assayed hormones depended on the grass growth.

Drainage and evaporation from fallow soil at Rothamsted

1941 ◽  
Vol 31 (1) ◽  
pp. 74-109 ◽  
Author(s):  
H. L. Penman ◽  
R. K. Schofield
Keyword(s):  
Soil Temperature ◽  
Seasonal Change ◽  
Seasonal Changes ◽  
Pore Space ◽  
Marked Change ◽  
Field Capacity ◽  
Measurable Effect ◽  
Average Value ◽  
Fallow Soil ◽  
Viscosity Changes

1. Study of the automatic records shows:(a) There is a seasonal change in the drainage response after rain which can be almost wholly ascribed to viscosity changes arising from seasonal changes of soil temperature (p. 77).(b) Evaporation occurring after a fall of rain has no measurable effect on the drainage response to that rain (pp. 78, 87).(c) The maximum drainage rates for the 20 in. gauge are much larger than those for the deeper gauges. The maxima change seasonally and are again primarily dependent on viscosity (p. 78).(d) There is no marked change in the field capacity of the gauge during the year. The air-filled pore space at field capacity may change by about 15% of its average value (p. 81).

scholarly journals The Colours of Ophiocomina Nigra (Abildgaard): I Colour Variation and its Relation to Distribution

1962 ◽  
Vol 42 (1) ◽  
pp. 1-8 ◽  
Author(s):  
A. R. Fontaine
Keyword(s):  
Statistical Evidence ◽  
The Body ◽  
Distinct Difference ◽  
Body Colour ◽  
General Body ◽  
Colour Variation ◽  
Geographical Difference ◽  
Orange Yellow ◽  
Two Factors ◽  
Colour Patterns

The ophiuroid, Ophiocomina nigra, is noted for its variability of colour, a phenomenon most pronounced where the species also has its greatest distribution in depth. Observations have been made on two geographically distinct populations, from the vicinities of Millport and Plymouth. The body colour of the observed animals ranges in a continuously graded series from black to orange-yellow. While both populations exhibit analogous variations, there is a distinct difference in the range and tone of coloration which each displays. It is suggested that this geographical difference is correlated in some degree with differences in colour tone of the substratum. It was observed that the incidence of light-coloured phases in each population increased with increasing depths, and some statistical evidence supports this conclusion. Thus, at least two factors, depth and substratum, may affect the distribution of colour variations in O. nigraIn addition to the variations in general body colour, there are two distinct colour patterns found on the disk. These are probably truly polymorphic and may be of cryptic value.A scheme of colour classification is described which facilitates observations in the field and in the laboratory.

Genetic control of phenotypic plasticity in Asian cultivated and wild rice in response to nutrient and density changes

Genome ◽  
2010 ◽  
Vol 53 (3) ◽  
pp. 211-223 ◽  
Author(s):  
Hiroyuki Shimizu ◽  
Masamichi Maruoka ◽  
Naofumi Ichikawa ◽  
Akhil Ranjan Baruah ◽  
Naohiro Uwatoko ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Genetic Control ◽  
Environmental Conditions ◽  
Wild Rice ◽  
Plant Architecture ◽  
Environmental Heterogeneity ◽  
Crop Evolution ◽  
Genetic Changes ◽  
Environmental Signals ◽  
Trait Locus

Phenotypic plasticity is an adaptive mechanism adopted by plants in response to environmental heterogeneity. Cultivated and wild species adapt in contrasting environments; however, it is not well understood how genetic changes responsible for phenotypic plasticity were involved in crop evolution. We investigated the genetic control of phenotypic plasticity in Asian cultivated ( Oryza sativa ) and wild rice ( O. rufipogon ) under 5 environmental conditions (2 nutrient and 3 density levels). Quantitative trait locus (QTL) analysis was conducted for traits affecting plant architecture and biomass production. By analysing the phenotypic means, QTLs of large effects were detected as a cluster on chromosome 7 under all the environmental conditions investigated; this might have contributed to transitions of plant architecture during domestication, as reported previously. Multiple QTLs of plasticity were also found within this QTL cluster, demonstrating that allele-specific environmental sensitivity might control plasticity. Furthermore, QTLs controlling plasticity without affecting phenotypic means were also identified. The mode of action and direction of allele effects of plasticity QTLs varied depending on the traits and environmental signals. These findings confirmed that cultivated and wild rice show distinctive genetic differentiation for phenotypic plasticity, which might have contributed to adaptation under contrasting environmental heterogeneity during the domestication of rice.

scholarly journals Seasonal Changes in the Ovary of the Immature Hake, Merlucius merluccius L.

1935 ◽  
Vol 20 (2) ◽  
pp. 443-461 ◽  
Author(s):  
C. F. Hickling
Keyword(s):  
Seasonal Variation ◽  
Seasonal Change ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Average Diameter ◽  
Ovarian Cycle ◽  
Growth Rings ◽  
Skeletal Structures ◽  
Somatic Tissues ◽  
Spawning Cycle

A seasonal variation is found in the ovaries of immature hake (Merlucius merluccius L.).There appears to be a seasonal change in the rate at which young eggs are formed from resting oocytes, as indicated (1) by the change in the relative abundance of nuclei in synapsis, and (2) by the change in the average diameter of the eggs in the egg-stock in the ovary. These processes show considerable correspondence in their season of incidence with the ovarian cycle of the mature and adolescent fish.A physiological rhythm has now been detected in both somatic tissues and gonad in the immature hake, which foreshadows the physiological rhythm associated with the spawning cycle in the mature hake. The implication of this on the question of the formation of “growth-rings” in the skeletal structures is briefly discussed.

Sign in / Sign up

Export Citation Format

Share Document