An energetic perspective on tissue regeneration: The costs of tail autotomy in growing geckos.

Tail autotomy is a crucial antipredatory lizard response, which greatly increases individual survival, but at the same time also compromises locomotor performance, sacrifices energy stores and induces a higher burden due to the ensuing response of regenerating the lost body part. The potential costs of tail autotomy include shifts in energy allocation and metabolic rates, especially in juveniles, which invest their energy primarily in somatic growth. We compared the metabolic rates and followed the growth of juvenile males with and without regenerating tails in the Madagascar ground gecko (Paroedura picta), a nocturnal ground-dwelling lizard.

Economic thermoregulatory response explains mismatch between thermal physiology and behaviour in newts.

Temperature is an important factor determining distribution and abundance of organisms. Predicting the impact of warming climate on ectotherm populations requires information about species' thermal requirements, i.e.

Do female newts modify thermoregulatory behavior to manipulate egg size?

Reproductive females manipulate offspring phenotypes by modifying conditions during embryogenesis. In ectotherms, the environmental control over embryogenesis is often realized by changes in maternal thermoregulation during gravidity. To determine if reproduction influences thermoregulatory behavior in species where females lay eggs shortly after fertilization (strict oviparity), we compared preferred body temperatures (Tp) between reproductive (egg-laying) and non-reproductive female newts, Ichthyosaura alpestris.

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

Background: Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood.

Thermoregulatory strategies in an aquatic ectotherm from thermally-constrained habitats: An evaluation of current approaches.

Many ectotherms employ diverse behavioral adjustments to effectively buffer the spatio-temporal variation in environmental temperatures, whereas others remain passive to thermal heterogeneity. Thermoregulatory studies are frequently performed on species living in thermally benign habitats, which complicate understanding of the thermoregulation-thermoconformity continuum. The need for new empirical data from ectotherms exposed to thermally challenging conditions requires the evaluation of available methods for quantifying thermoregulatory strategies.

Aquatic-to-terrestrial habitat shift reduces energy expenditure in newts.

Many organisms seasonally modify their standard metabolic rates (SMR). However, the diversity of cues triggering the acclimatization response remains little understood. We examined the influence of experimentally induced aquatic-to-terrestrial habitat shift on the thermal sensitivity of SMR in newts.

Predator-prey interactions shape thermal patch use in a newt larvae-dragonfly nymph model.

Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator's food requirement and the prey's necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed 'thermal game model' predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches.

Influence of respirometry methods on intraspecific variation in standard metabolic rates in newts.

Standard metabolic rate (SMR) is both a highly informative and variable trait. Variation in SMR stems not only from diverse intrinsic and extrinsic factors, but also from the use of diverse methods for metabolic measurements. We measured CO(2) production (VCO(2)) and oxygen consumption rates (VO(2)) using two flow-through respirometry modes, continuous and intermittent (stop-flow), to evaluate their potential contribution to SMR variation in Alpine newts, Ichthyosaura alpestris.

Interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator-prey system.

The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system.

Plasticity of preferred body temperatures as means of coping with climate change?

Thermoregulatory behaviour represents an important component of ectotherm non-genetic adaptive capacity that mitigates the impact of ongoing climate change. The buffering role of behavioural thermoregulation has been attributed solely to the ability to maintain near optimal body temperature for sufficiently extended periods under altered thermal conditions. The widespread occurrence of plastic modification of target temperatures that an ectotherm aims to achieve (preferred body temperatures) has been largely overlooked.

Seasonal acclimation of preferred body temperatures improves the opportunity for thermoregulation in newts.

Seasonal acclimation and thermoregulation represent major components of complex thermal strategies by which ectotherms cope with the heterogeneity of their thermal environment. Some ectotherms possess the acclimatory capacity to shift seasonally their thermoregulatory behavior, but the frequent use of constant acclimation temperatures during experiments and the lack of information about thermal heterogeneity in the field obscures the ecological relevance of this plastic response. We examined the experimentally induced seasonal acclimation of preferred body temperatures (T(p)) in alpine newts Ichthyosaura (formerly Triturus) alpestris subjected to a gradual increase in acclimation temperature from 5°C during the winter to a constant 15°C or diel fluctuations between 10° and 20°C during the spring/summer.

The interaction between an introduced fish host and local parasite fauna: Neogobius kessleri in the middle Danube River.

Parasite communities of introduced fish Neogobius kessleri Günther (Gobiidae) were studied at five localities in the Slovak section of the Danube River during 2002-2005. Thirty-three metazoan parasite species were identified. All fish were infected with at least two parasite species; most of the parasite species were generalists.

Triturus newts defy the running-swimming dilemma.

Conflicts between structural requirements for carrying out different ecologically relevant functions may result in a compromise phenotype that maximizes neither function. Identifying and evaluating functional trade-offs may therefore aid in understanding the evolution of organismal performance. We examined the possibility of an evolutionary trade-off between aquatic and terrestrial locomotion in females of European species of the newt genus Triturus.

Identification of Cobitis from the Slovakian part of the Tisza basin.

This study identifies of populations of the genus Cobitis from the Slovakian Tisza drainage area, using karyotype, enzyme electrophoresis and flow cytometry. Pure diploid populations of Cobitis elongatoides were found in drainage basins of the Hornád, Slaná and Bodva rivers (5 populations). Species identifity was proven by analysis of genome and allelic composition.