Enrique García-Muñoz

Effects of Copper Sulfate on Growth, Development, and Escape Behavior in Epidalea calamita Embryos and Larvae

Epidalea calamita embryos at Gosner stages 3 and 19, and larvae at Gosner stage 25, were exposed to different copper sulfate concentrations, ranging from 0.05 to 0.40 mg Cu L−1, in 96-h acute toxicity tests. Embryonic and larval mortality, development, growth, and larval escape behavior were evaluated. LC50 at 96 h obtained at Gosner stages 3, 19, and 25 were 0.22, 0.08, and 0.11 mg Cu L−1, respectively. Embryonic and larval developments were delayed after 96 h of copper sulfate exposure. Growth was also affected and individuals in control treatments grew to twice the size of those exposed to copper concentrations over 0.2 mg Cu L−1 during the experiments initiated at Gosner stage 19. Escape behavior was altered after 96 h of copper sulfate exposure; larvae showed shorter distances moved and abnormal displacement types. However, after 4 days of recovery process, most of the larvae showed normal escape behavior. For amphibians that develop in temporary wetlands, increased development time, lower size, and altered escape behavior might have repercussions on the number of individuals that can successfully complete metamorphosis and, consequently, on recruitment.

Wetlands classification for amphibian conservation in Mediterranean landscapes

Habitat fragmentation and alteration have been described as the major factors relating to the decline observed in several amphibian species. In Spain, these processes are mainly associated with the large agricultural land area, the widespread use of toxic substances, and the agricultural practices used. All these aggressions affect wetlands and their watersheds, which are essential aquatic systems for many amphibian species. In an effort to discover where conservation and specific action plans could be more necessary, this study relates the amphibian richness in 28 representative Mediterranean wetlands to their characteristics and the activities carried out on their watershed. The required information considers diverse wetland variables. Our results show that watershed habitat heterogeneity is significantly positively correlated with amphibian richness, while the percentage of the watershed area devoted to olive cultivation is negatively correlated with it. The results allow us to classify wetlands according to their importance for amphibian conservation. Our results also show that 80% of the studied wetlands need specific action plans. Especially, more sustainable cultivation methods are required considering drastic changes in current agricultural practices. Finally, our data provides a baseline to understand future alterations due to agricultural practices.

Ecophysiological Dissimilarities of Two Sympatric Lizards

Abstract:  The lizards Podarcis muralis and Iberolacerta horvathi display an overall similarity in morphology and ecology. Although they are widely sympatric in part of their distribution range of Slovenia, areas of altitudinal segregation have been observed. Ecophysiological traits such as preferred body temperatures (Tp) and rates of evaporative water loss (EWL) are some of the factors likely to be subjacent to this pattern. We expect the species that is more abundant in higher altitudes to have lower Tp and higher EWL (due to lower environmental temperatures at higher elevations) than the species that is more abundant in lowlands. We conducted lab experiments to determine whether intra- and interspecific variation in these two physiological traits exists. Contrary to expectations, the means of Tp were similar between the species, but their seasonal dynamics differed, which indicates that thermal accuracy might be more important. Species differed in seasonal (and daily) variation of Tp, rising from spring to summer more in P. muralis than in I. horvathi. Comparing instantaneous EWL, our results showed interspecific differences with higher values in P. muralis than in I. horvathi. Throughout a 12-h period, the accumulative EWL was also always higher for P. muralis than for I. horvathi, with the greatest differences occurring after 9–12 h of the experiment. Further studies should focus on investigating if these divergent physiological characteristics of both species are associated with their habitat use (in terms of thermal and water environment) and species interaction.

Larval escape behavior in anuran amphibians as a wetland rapid pollution biomarker

Biomarkers represent a promising tool as “early-indicators” of potential pollutant impacts, providing the link between individuals’ responses and higher hierarchical levels, such as populations and communities. In this study we use alteration of escape behavior, caused by exposure to typical agrochemicals, as a biomarker of wetland pollution. Tadpoles from three different Iberian anuran species were exposed to sublethal concentrations of copper sulfate and ammonium nitrate for 96 h. Different behavioral indicators were then monitored: number of stimuli to provoke a displacement, distance moved, and nature of escape movement. All species showed similar behavioral alterations. The endpoints of all the three behavioral indices showed deficits leading to a reduction in the capacity and efficiency of escape. The recovery when larvae were moved to clean water was surprisingly fast. After 96 h in recovery, almost all larvae showed normal escape behavior. This indicates that this larval behavioral biomarker can be used as a warning tool in wetland biomonitoring programs in a continuous runoff or spill pollution context.

Effects of previous sublethal pulse to ammonium nitrate on mortality and total length on Epidalea calamita larvae

Ammonium nitrate is one of the most widespread contaminants related with the viability of natural amphibian populations. In this study we have evaluated in terms of mortality and total length the effects that a previous sublethal pulse to ammonium nitrate generates in Epidalea calamita. Experiments were divided in two phases. In the first one, tadpoles were exposed to two different treatments, with and without a low ammonium nitrate concentration (22 mg NH(4)NO(3) L(-1)). The second phase consisted in static toxicity experiments from both origin treatments with five different nominal concentrations (0, 22, 45, 90 and 180 mg NH(4)NO(3) L(-1)). Results showed that tadpoles that had experienced a previous sublethal exposure showed a negative effect on survival (57% of reduction in the LC(50) value) and total length, throughout an increase in their sensitivity. These results could help us to understand the situation of amphibian populations inhabiting aquatic ecosystems exposed to discontinuous and variable pulses of pollutants.

Lateralization in Escape Behaviour at Different Hierarchical Levels in a Gecko: Tarentola angustimentalis from Eastern Canary Islands

At the individual level, to be behaviourally lateralized avoids costly duplication of neural circuitry and decreases possible contradictory order from the two brain hemispheres. However, being prey behaviour lateralized at higher hierarchical levels could generate different negative implications, especially if predators are able to make predictions after multiple encounters. These conflicting pressures, namely between the advantages for individuals and the disadvantages for populations could be concealed if higher-level lateralization would arise from the combination of lateralized behaviours of individuals which are mutually dependent. Here, we investigated the lateralization patterns in the escape behaviour of the gecko Tarentola angustimentalis undergoing a predatory attack simulation in a “T” maze experiment. Results showed that gecko populations displayed different degrees of lateralization, with an overall dominance of right-biased individuals. This trend is similar to that observed in the Podarcis wall lizards, which share predators with Tarentola. In addition, different morphological parameters plausible to affect refuge selection were explored in order to link directional asymmetries at morphological level with lateralization during refuge selection.

On the occurrence of facultative paedomorphosis in the three newt species of Southern Iberian Peninsula (Amphibia, Salamandridae)

We report the occurrence of facultative paedomorphosis in the three species of newts ( Pleurodeles waltl , Lissotriton boscai and Triturus pygmaeus ) from dry and seasonal Mediterranean areas from southern Spain. These are the first records of paedomorphosis for P. waltl and L. boscai , and the second for T. pygmaeus . Other than the previous T. pygmaeus record, these are the first observations of paedomorphosis in the southern half of the Iberian Peninsula. Most of specimens demonstrating paedomorphosis live in artificially permanent aquatic environments. Nevertheless, a paedomorphic individual of L. boscai was found in a natural yearly temporary brook that held water during the previous two years. Paedomorphs are at low frequency in most cases. However, a single isolated population of P. waltl is probably composed entirely of paedomorphs.

Linking watershed land uses and crustacean assemblages in Mediterranean wetlands

The watershed land uses in Mediterranean wetlands are essential to understand the functioning of aquatic communities. This study was designed to assess the relationship between watershed land uses, wetland characteristics and zooplankton assemblages (branchiopods and copepods) in 24 Mediterranean wetlands of the southern Iberian Peninsula, which greatly differ in both wetland land uses (olive groves, pasture, scrublands, and forest) and in their morphometric and limnological features. Firstly, results from a Principal Component Analysis allowed us to classify wetlands in two categories: impacted and non-impacted. Then, one-way Analysis of Variance was performed to test differences in zooplankton species richness and a Permutational Analysis of Variance was performed to test differences in zooplankton assemblages between categories. Lastly, a Non-metric Multidimensional Scaling analysis was chosen for the lake-by-species ordination. The results support the hypothesis that zooplankton richness and composition were negatively affected by watershed land uses, mainly agriculture practices. Moreover, species zooplankton assemblages were clearly linked to the two different wetlands categories. The present study puts forward the important role of zooplankton community for testing land use effects in Mediterranean wetlands.

Parthenogenetic Darevskia lizards mate frequently if they have the chance: a quantitative analysis of copulation marks in a sympatric zone

Several Caucasian rock lizards of the genus Darevskia of hybrid origin are known to reproduce parthenogenetically. Local communities can be composed exclusively of parthenogens, though syntopy with bisexual members of the genus may occur. In some localities, reproduction between bisexual and parthenogenetic Darevskia has been previously reported based on lizard intermediate morphology and karyology (3n, 4n). However, the frequency of such heterospecific matings remains unknown. We indirectly quantified the reproductive interactions through the inspection of copulation marks in females in a mixed Darevskia community from Kuchak (Armenia) composed of two hybrid parthenogens (D. armeniaca and D. unisexualis), one bisexual species (D. valentini) and their putative backcrosses. A total of 139 adults were randomly collected and photographed. Females were later measured (SVL), inspected for inguinal marks and ranked from 0 (no scars) to 3 (≥ 3 scars). The lizard species and ploidy determination was ensured by a parallel microsatellite analysis. Sex-ratio in the community was extremely biased due to the high abundance of parthenogenetic females. All female types displayed copulation marks with frequencies varying from 80% in D. valentini to 64% in D. armeniaca. Remarkably, 7 out of 11 (64%) backcross females also showed marks. In the most abundant D. armeniaca, the prevalence and intensity of copulation marks increased with body size, just as predicted for polygynous female lacertids. These results indicate that copulation between parthenogenetic and bisexual species in Darevskia mixed communities is common and driven by sexual selection, thus reinforcing previous suggestions of reproductive interaction in syntopy. Evolutionary implications of these findings are discussed.