Sergio Naretto

• Investigador CONICET
• Researcher at National University of Córdoba

Autotomy in animals, the voluntary loss of a body part at a specific location, is a widespread behaviour observed across various groups. This mechanism provides several advantages, such as predator evasion, escape from entrapments, and even reduced injury costs from agonistic interactions. Lizards display tail autotomy in response to predation and...

ABSTRACT Sexual dimorphism is a fascinating phenomenon that showcases the wide variation of characteristics related to life strategies in organisms. It is driven by two key evolutionary processes: sexual selection and natural selection. Anurans provide an excellent opportunity to study the origin and diversification of sexual dimorphism due to thei...

Sexual selection pressures play a significant role in driving the evolution of color, morphological, and behavioral traits that serve as signals to communicate fighting ability between opponents. In lizards, body and head size often predict the outcome of male-male contests, but these morphological signals are static during and after the contest. H...

Reproductive strategies can be characterized according to how often and when females reproduce, how much they invest, and how reproductive investment is distributed. Plasticity can lead to changes in reproductive strategies associated with some age/size classes. Therefore, elucidating associations between maternal morphological traits and reproduct...

Bite force in lizards is involved in key behaviours such as intrasexual agonistic and intersexual interactions. The relationship between morphology and function is dynamic and sexual pressures can affect bite performance differently between sexes, especially considering the biting position and temporal changes related to the reproductive cycle. The...

The interaction between behavioural and phenotypic traits, such as coloration, plays a specific role at different stages of the predatory sequence. Cryptic coloration involves a match to the background that reduces the risk of detection, and it is usually optimized by immobility behaviour. In lizards, sexual dichromatism and within-individual chang...

La elección de pareja es un aspecto importante de la selección sexual, promoviendo el desarrollo de caracteres sexuales secundarios en los individuos del sexo opuesto, conocidos como ornamentos. El color puede ser entendido como una señal visual ya que puede transmitir información sobre diferentes aspectos de los individuos, como la condición repro...

Reproductive physiology is influenced by environmental pressures, particularly in ectothermic species living in harsh climatic conditions. Studying the period of time in which males exhibit semen availability and their sperm traits constitutes a powerful tool to evaluate the fertility potential of males because sperm size and sperm velocity have be...

The intensity of mating competition varies according to the temporal and spatial distribution of individuals. Measuring sexual dimorphism over time and interpreting the association between individuals is therefore important if we aim to understand how sexual traits are influenced. We examined sex differences in the Achala Copper Lizard (Pristidacty...

La cripsis previene la detección de las presas por parte de los predadores a través de coloraciones semejantes al entorno, pero la visión de los predadores, como aves rapaces, debe ser considerada para interpretar este tipo de camuflaje. En los lagartos el dicromatismo sexual y los cambios de color en un mismo individuo son rasgos que los vuelven m...

Invasive reptilian predators can have substantial impacts on native species and ecosystems. Tegu lizards are widely distributed in South America east of the Andes, and are popular in the international live animal trade. Two species are established in Florida (U.S.A.) - Salvator merianae (Argentine black and white tegu) and Tupinambis teguixin sensu...

The knowledge of sperm ultrastructure of Squamata provides informative traits for phylogenetic analyses. Furthermore, several sperm ultrastructure traits are important for sperm motility and longevity. Here, we provided a detailed ultrastructural description of the spermatozoa of two closely related teiid lizards, Salvator rufescens and S. merianae...

Understanding pre- and post-copulatory mechanisms of sexual selection can provide insights into the evolution of male reproductive strategies. The phenotype-linked fertility hypothesis postulates that male sperm quality and secondary sexual characteristics will positively co-vary, whereas the sperm competition hypothesis predicts a negative associa...

Context Management of the exploitation of resources requires biological information on exploited species. The skins of large reptiles have a commercial value as luxury leather items and Tupinambis lizards from southern South America have historically been exploited for this purpose. Argentina implemented management plans for Tupinambis lizards sinc...

The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sym...

Segregation of habitat resources is an important mechanism that allows the coexistence of species. The diet is an important and dynamic component that can generate interactions among co-existing species. Differences in food resource use between related sympatric species have been associated frequently with divergence in multiple phenotypic traits;...

A major goal in evolutionary biology is to determine the mechanisms responsible for maintaining phenotypic variation. Species that have evolved intersexual differences provide an opportunity to increase our understanding of trait evolution. We hypothesize that phenotypic diversity is related to reproductive strategies of female lizards and therefor...

Lámina de campo de las serpientes comunes de las sierras de Córdoba, Argentina, para libre distribución.

"Reptiles comunes de las Sierras de Córdoba. Lagartos y anfisbenas" es una referencia rápida para identificar los lagartos del Chaco Serrano de Córdoba, Argentina. Este trabajo posee una licencia Creative Commons, que permite su libre distribución sin fines comerciales

In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect is still poorly understood. It has been suggested that an increase in sperm competition pressure could reduce sperm size variati...

Figure S1. Relationship between curvilinear sperm velocity and sperm morphometric traits in Tupinambis.

Sexual dimorphism patterns provide an opportunity to increase our understanding of trait evolution. Because selective forces may vary throughout the reproductive period, measuring dimorphism seasonally may be an interesting approach. An increased male head size may be important in intersexual and intrasexual interactions. In Tupinambis lizards, a b...

Understanding factors that shape ranges of species is central in evolutionary biology. Species distribution models have become important tools to test biogeographical, ecological and evolutionary hypotheses. Moreover, from an ecological and evolutionary perspective, these models help to elucidate the spatial strategies of species at a regional scal...