Liolaemus Lineomaculatus Research Articles

Evolutionary novelty in chemical signalling is linked with chemosensory behaviour in close Liolaemus lizard species (Iguania: Liolaemidae)

AbstractEvolutionary changes, associated with the gain or loss of traits, can occur in signal‐emitting and signal‐detecting organs. Related functionality generally accompanies these changes; however, in some cases there are mismatches and evolutionary innovations do not show an indication of functional advantages. Due to this, the relationship between evolutionary changes and the functionality of sensory organs remains unclear. Lizard species belonging to Liolaemus lineomaculatus section present fast evolutionary state transitions associated with the gain or loss of precloacal pores (chemical signalling glands). In this group, precloacal pores configuration includes species where only males have pores (Liolaemus attenboroughi‐ancestral state), where both sexes lack of them (L. kolengh male‐loss), and species where both sexes have pores (L. zullyae, representing a female‐gain). Here, we test the relationships between evolutionary changes of signal‐emitting glands with different chemical and visual behaviours. We conducted behavioural trials in three species belonging to the Liolaemus lineomaculatus section: L. attenboroughi, L. kolengh, and L. zullyae. We measured individuals' chemical and visual responses to different social scents and to conspecific visual stimuli. Results showed the presence of different social scents recognition ability in both male‐only and female‐gain species, whereas male‐loss species showed no behavioural differences among the chemical trials. Lizards exhibited few responses in the visual trials, although the species with pores used chemo‐sensorial sense in the visual trials, while male‐loss species showed differences in visual displays in the presence of conspecific visual stimuli. These results suggest a link between evolutionary novelties of chemical secretory glands and chemical recognition.

Wintertime tales: How the lizard Liolaemus lineomaculatus endures the temperate cold climate of Patagonia, Argentina.

In temperate, polar and montane environments, ectotherms must find ways to endure throughout the coldest months of the year. Lizards search for microsites where temperatures remain warm or alter their biochemical balance to tolerate freezing or avoid it by supercooling. We evaluated the cold hardiness and potential winter refuges of two populations of Liolaemus lineomaculatus, from a temperate site (42°S) and a cold site (50°S). We analysed the role of possible cryoprotectants by comparing a group of cooled-down lizards with a control group of lizards that were not exposed to cold. The populations of this study are not freeze tolerant and the biochemical analysis showed no evidence of metabolites significantly changing concentration after exposure to cold. However, the species remained several hours at their Supercooling Point (SCP), suggesting they can supercool. The analysis of potential winter refuges showed that lizards using these potential refuges would spend almost no time at all at temperatures close to or below their SCP. Furthermore, lizards from the cold site were able to survive below 0°C temperatures with a lower SCP than lizards from the temperate site. Liolaemus lineomaculatus developed physiological mechanisms that can help them survive when temperatures drop sharply, even when lizards are in suitable shelters.

Running performance with emphasis on low temperatures in a Patagonian lizard, Liolaemus lineomaculatus

Lizard activity and endurance of cold climate is regulated by several factors such as evolutionary potential, acclimatization capacity, physiological tolerance, and locomotion among thermally advantageous microenvironments. Liolaemus lineomaculatus, a lizard inhabiting a wide range of cold environments in Patagonia, provides an excellent model to test interpopulation variability in thermal performance curves (TPCs) and usage of microhabitats. We obtained critical thermal minima and maxima, and performed running trials at eight temperatures using lizards from both a temperate-site (high-altitude) population at 42° S and a cold-site population at 50° S. The availability of environmental temperatures for running performance in open ground and in potential lizard refuges were recorded, and showed that lizards in the temperate site had a greater availability of thermal environments offering temperatures conducive to locomotion. Generalized additive mixed models showed that the two populations displayed TPCs of different shapes in 0.15 m runs at temperatures near their optimal temperature, indicating a difference in thermal sensitivity at high temperatures. However, the rest of the locomotor parameters remained similar between Liolaemus lineomaculatus from thermal and ecological extremes of their geographic distribution and this may partly explain their ability to endure a cold climate.

Morphological Variation, Niche Divergence, and Phylogeography of Lizards of the Liolaemus lineomaculatus Section (Liolaemini) from Southern Patagonia

Abstract: Patagonia is a biodiverse area of high conservation priority, and Liolaemus lizards comprise a large component of the endemic fauna. Recent molecular and morphological studies have revealed cryptic species in several Liolaemus groups, including the Liolaemus lineomaculatus section (22 species recognized to date), which is endemic to Patagonia. Despite being a conspicuous component of this area, little is known about the morphological, ecological, and genetic variation of lizards of the L. lineomaculatus section; moreover species limits and past demographic scenarios are still uncertain for many of these species. In this paper, we characterize the morphological, ecological (niche envelope), and genetic variability of the four southernmost species of the L. kingii group (L. lineomaculatus section). Our main goal is to clarify species boundaries (using integrative taxonomy) as well as to infer evolutionary and demographic histories. For this paper we used a total of 241 specimens, 195 of which wer...

Phylogeography and morphological variation of the northernmost distributed species of the Liolaemus lineomaculatus section (Liolaemini) from Patagonia

Lizards from the Liolaemus lineomaculatus section are endemic to Patagonia, southern South America. Three main groups are recognized within this section, one of which, the L. kingii group includes eleven species. The two northernmost distributed species of this group, L. somuncurae and L. uptoni, are endemic to a small area that partly overlaps with the Provincial Protected Area Somuncurá Plateau (within the Somuncurá massif). Knowledge available for these species is based on limited sample sizes, and mostly limited to their original descriptions; also a recent molecular phylogenetic study showed evidence for a closely related candidate species (Liolaemus sp. 4). In this paper we morphologically and genetically characterize the species L. somuncurae, L. uptoni, and L. sp. 4, and present past demographic hypotheses. We studied eighty lizards, and collected morphological and genetic data for almost all of them. The specific status of L. somuncurae and L. uptoni is supported by molecular, morphological, and distributional evidence, as well as the status of L. sp. 4; for which we recommend further morphological comparisons with other species of the L. kingii group. We also identified two novel lineages from restricted areas south of the Chubut River that we propose as candidate species. We extend previously published evidence (from plants and rodents) supporting the role of the Chubut River as an allopatric barrier. Also, in agreement with previous results based on plants, we found evidence for two refugia in northwestern Chubut, for which we encourage conservation efforts.

New Patagonian species of Liolaemus (Iguania: Liolaemidae) and novelty in the lepidosis of the southernmost lizard of the world: Liolaemus magellanicus.

We describe a new species within the genus Liolaemus from southeast Argentine Patagonia. This new taxon, Liolaemus yatel sp. nov., presents anatomical traits shared with the Liolaemus lineomaculatus section within the Liolaemus lineomaculatus group, especially the absence of precloacal pores in both sexes. However, Liolaemus yatel sp. nov. does not exhibit trifid dorsal scales, which is a diagnostic character of the L. lineomaculatus group. Moreover, this new species differs from other taxa of the L. lineomaculatus group in that dorsal and nuchal scales either completely lack keels or are slightly keeled. We also report, for the first time, the presence of trifid scales in Liolaemus magellanicus, another species included in the L. lineomaculatus section but constituting an independent lineage regarding the L. lineomaculatus group. The phenotypic traits of L. yatel sp. nov. and the presence of trifid scales in L. magellanicus provide additional information for the study of evolutionary relationships among the species of the L. lineomaculatus section, especially the establishment of their diagnostic character states.

Past and present taxonomy of theLiolaemus lineomaculatussection (Liolaemidae): is the morphological arrangement hypothesis valid?

Fil: Breitman, Maria Florencia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Nacional Patagonico; Argentina

How lizards survived blizzards: phylogeography of theLiolaemus lineomaculatusgroup (Liolaemidae) reveals multiple breaks and refugia in southernPatagonia and their concordance with other codistributed taxa

Patagonia was shaped by a complex geological history, including the Miocene uplift of the Andes, followed by volcanism, marine introgressions, and extreme climatic oscillations during Pliocene-Pleistocene glaciation-deglaciation cycles. The distributional patterns and phylogenetic relationships of southern patagonian animals and plants were affected in different ways, and those imprints are reflected in the seven phylogeographic breaks and eight refugia that have been previously proposed. In this study, we estimated time-calibrated phylogenetic/phylogeographic patterns in lizards of the Liolaemus lineomaculatus group and relate them to historical Miocene-to-Pleistocene events of Patagonia and the previously proposed phylogeographic patterns. Individuals from 51 localities were sequenced for the mitochondrial marker (cyt-b) and a subsample of individuals from each mitochondrial lineage was sequenced for one nuclear (LDA12D) and one slow evolving mitochondrial gene (12S). Our analyses revealed strong phylogeographic structure among lineages and, in most cases, no signal of demographic changes through time. The lineomaculatus group is composed of three strongly supported clades (lineomaculatus, hatcheri and kolengh + silvanae), and divergence estimates suggested their origins associated with the oldest known Patagonian glaciation (7-5 Ma); subsequent diversification within the lineomaculatus clade coincided with the large Pliocene glaciations (~3.5 Ma). The lineomaculatus clade includes nine strongly genetically and geographically structured lineages, five of which are interpreted as candidate species. Our findings suggest that some Liolaemus lineages have persisted in situ, each of them in a different refugium, through several glaciation-deglaciation cycles without demographic fluctuations. We also summarize and update qualitative evidence of some shared phylogeographic breaks and refugia among plants, rodents and lizards.

Two new species of lizards from the Liolaemus lineomaculatus section (Squamata: Iguania: Liolaemidae) from southern Patagonia

Two new species of lizards from the Liolaemus lineomaculatus section (Squamata: Iguania: Liolaemidae) from southern Patagonia

New species of lizard from the magellanicus clade of the Liolaemus lineomaculatus section (Squamata: Iguania: Liolaemidae) from southern Patagonia

A new species of the Liolaemus lineomaculatus section is described from southwestern Santa Cruz Province, Argentina. The new species is a member of the monotypic magellanicus clade; morphological, molecular and geographical data are sufficient to diagnose this new species as distinct form from L. magellanicus. The new species differs from L. magellanicus in having higher number of midbody, dorsal and ventral scales, and higher number of infradigital third finger and fourth toe lamellae. The new species also differs in having smaller dorsal blotches on the hindlimbs and a more clearly defined vertebral line, fewer precloacal pores and reduced dorsal scale mucronation, compared to L. magellanicus. Liolaemus caparensis sp. nov. is the second species described for the magellanicus group, and is geographically isolated from L. magellanicus on the Campo Las Piedras Plateau, where it is sympatric with other endemic species of the L. lineomaculatus section.

Two new species of lizards from the Liolaemus lineomaculatus section (Squamata: Iguania: Liolaemidae) from southern Patagonia

Two new species of the lineomaculatus clade of the Liolaemus lineomaculatus section are described from southern Patagonia in Argentina. Liolaemus morandae sp. nov. is found in S Chubut province and Liolaemus avilae sp. nov. inhabits NW Santa Cruz province. Several tests were performed to diagnose these new species as distinct lineages. Univariate analysis of variance (ANOVA), principal component analysis (PCA), discriminant function analysis (DFA), non-parametric multivariate analysis of variance (NPMANOVA), as well as a genetic characterization through molecular analysis of variance (AMOVA) were performed; genetic distances between described and these new species are reported. The new Liolaemus species differ from other members of the lineomaculatus group in morphometric, meristic, qualitative and genetic characters; moreover they inhabit different phytogeographical provinces and districts. With these descriptions, the number of species now recognized in the lineomaculatus section is twenty one (including one more description that is in press).

Thermal relationships between body temperature and environment conditions set upper distributional limits on oviparous species

We determined the thermal biology of the oviparous Liolaemus boulengeri and the viviparous Liolaemus lineomaculatus populations localised at high and low latitude sites in Patagonia, Argentina. We present data of body temperatures in the field ( T b) and preferred temperature in the laboratory ( T pref), micro-environmental and operative temperatures and the effectiveness of thermoregulation. Liolaemus boulengeri and L. lineomaculatus choose different heat sources for active selection of suitable thermal micro-environments for thermoregulation, and the oviparous L. boulengeri is a more effective thermoregulator ( E=0.55) than the viviparous L. lineomaculatus ( E=0.43). Even when L. boulengeri is a better thermoregulator and both species show identical timing in the reproductive cycles, there are constraint factors that impose limitations on the southernmost distribution of the oviparous L. boulengeri.

Running in cold weather: morphology, thermal biology, and performance in the southernmost lizard clade in the world (Liolaemus lineomaculatussection: Liolaemini: Iguania)

The integration or coadaptation of morphological, physiological, and behavioral traits is represented by whole-organism performance traits such as locomotion or bite force. Additionally, maximum sprint speed is a good indicator of whole-organism performance capacity as variation in sprinting ability can affect survival. We studied thermal biology, morphology, and locomotor performance in a clade of Liolaemus lizards that occurs in the Patagonian steppe and plateaus, a type of habitat characterized by its harsh cold climate. Liolaemus of the lineomaculatus section display a complex mixture of conservative and flexible traits. The phylogenetically informed analyses of these ten Liolaemus species show little coevolution of their thermal traits (only preferred and optimum temperatures were correlated). With regard to performance, maximum speed was positively correlated with optimum temperature. Body size and morphology influenced locomotor performance. Hindlimbs are key for maximal speed, but forelimb length was a better predictor for sustained speed (i.e. average speed over a total distance of 1.2 m). Finally, sustained speed differed among species with different diets, with herbivores running on average faster over a long distance than omnivores.

Lizards from the end of the world: Phylogenetic relationships of the Liolaemus lineomaculatus section (Squamata: Iguania: Liolaemini)

The Liolaemus lineomaculatus section is a geographically widely distributed group of lizards from the Patagonian region of southern South America, and includes 18 described species representing the most southerly distributed Liolaemus taxa (the genus includes 228 species and extends from Tierra del Fuego north to south-central Peru). Despite high species diversity, the phylogenetic relationships of this section are unknown. In the present work we sampled all described species in the L. lineomaculatus section as well as currently undescribed candidate species to reconstruct the first complete phylogenetic hypothesis for the clade. Our data set included four anonymous nuclear loci, three nuclear protein-coding loci, and two mitochondrial genes. We compared results obtained with three different phylogenetic methods for the concatenated data set (Maximum Parsimony, Maximum Likelihood and Bayesian Inference) with a coalescent-based species tree approach (BEST), and recovered congruent, strongly-supported topological arrangements across all methods. We identified four main clades within the L. lineomaculatus section: the lineomaculatus, magellanicus, somuncurae, and kingii + archeforus groups, for which we estimated divergence times. We discuss the taxonomic implications of these results and how the future integration of phylogeographic, niche modeling and morphological approaches will allow testing biogeographical hypotheses in this clade.

How do viviparous and oviparous lizards reproduce in Patagonia? A comparative study of three species of Liolaemus

In the cold temperate climate of Patagonia, reproduction and growth of ectotherms are restricted to brief seasons, particularly at high latitudes. This energy constraint has affected the evolution of life history traits such as sexual maturity, clutch size, offspring size, reproductive effort, and fecundity. Limitations on the timing of reproductive events and the allocation of energy to offspring have a vital role in the fitness of the species, and it is expected that oviparous and viviparous lizards respond with inter- and intra-specific differences to different environmental conditions partly because of thermal constraints on the development of nestlings. We studied the reproductive cycles of two populations in Patagonia, Argentina (43° and 46°S), of each of three species: the southernmost oviparous liolaemids, Liolaemus bibronii, and Liolaemus boulengeri, and the viviparous Liolaemus lineomaculatus. The three species showed annual and synchronous reproductive cycles between males and females with birth or hatching occurring at the end of summer, showing common evolutionary paths in their reproductive biology. In addition, the oviparous species seem to have adapted to cold and arid environments at high latitudes, in contrast to a major prediction of the cold climate hypothesis for the evolution of viviparity.