Reporting guidelines for terrestrial respirometry : building openness, transparency of metabolic rate and evaporative water loss data

DATA AVAILABILITY : No data was used for the research described in the article.Respirometry is an important tool for understanding whole-animal energy and water balance in relation to the environment. Consequently, the growing number of studies using respirometry over the last decade warrants reliable reporting and data sharing for effective dissemination and research synthesis. We provide a checklist guideline on five key sections to facilitate the transparency, reproducibility, and replicability of respirometry studies: 1) materials, set up, plumbing, 2) subject conditions/maintenance, 3) measurement conditions, 4) data processing, and 5) data reporting and statistics, each with explanations and example studies. Transparency in reporting and data availability has benefits on multiple fronts. Authors can use this checklist to design and report on their study, and reviewers and editors can use the checklist to assess the reporting quality of the manuscripts they review. Improved standards for reporting will enhance the value of primary studies and will greatly facilitate the ability to carry out higher quality research syntheses to address ecological and evolutionary theories.An ARC Discovery Project, the United States Department of Agriculture-National Institute of Food and Agriculture and the São Paulo Research Foundation.https://www.elsevier.com/locate/cbpaZoology and EntomologyNon

Does gestation or feeding affect the body temperature of the golden lancehead, Bothrops insularis (Squamata: Viperidae) under field conditions?

Temperature affects physiological performance in reptiles and, therefore, body temperature (Tb) control is argued to have an important adaptive value. Alterations in Tb due to transient changes in physiological state, as during digestion or gestation, are often linked to the potential benefits of a more precise Tb regulation. However, such thermoregulatory responses in nature remain controversial, particularly for tropical snakes. Herein, we measured Tb of the golden lanceheads, Bothrops insularis (Amaral, 1921), at Queimada Grande Island, southeastern Brazil, to test for alteration in selected body temperatures associated with feeding or gestation. We found no evidence that postprandial or gravid snakes selected for higher Tb indicating that, under natural conditions, body temperature regulation in B. insularis apparently encompasses other ecological factors beyond physiological state per se

When Basking Is Not an Option: Thermoregulation of a Viperid Snake Endemic to a Small Island in the South Atlantic of Brazil

It is broadly accepted that snakes are able to regulate their body temperature (T-b) behaviorally, but fundamental differences in this ability have been suggested to exist between temperate and tropical species. Herein, we examined the thermal ecology of the Golden Lancehead, Bothrops Insular's, a critically endangered Neotropical crotaline snake endemic to Queimada Grande Island (QGI), southeastern Brazil. We sampled T-b's of individual snakes found in the field and tested which proximal factors, biotic and abiotic, were potentially relevant for their thermoregulatory behavior and T-b selection. We verified whether T-b regulation would be compensated, through the day and/or seasons, by adjustments in the thermoregulatory effort. Finally, we hypothesized that for a Neotropical snake, the thermoregulatory effort would be lower because the thermal quality of habitat is higher compared to species inhabiting temperate zones. In general, B. insularis conformed to this hypothesis. However, seasonal declines in the thermal quality of habitat during the colder seasons and during nighttime were compensated by increases in the effectiveness of thermoregulation. Overall, T-b of B. insularis is determined largely by environmental variables, particularly air temperature, with some influence of biotic factors, such as body size. Use of open areas for basking, a common thermoregulatory behavior for squamates, was largely avoided; this may be explained by ecological factors, and may be due to foraging constraints and increased risks of predation and dehydration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaporative respiratory cooling augments pit organ thermal detection in rattlesnakes

Rattlesnakes use their facial pit organs to sense external thermal fluctuations. A temperature decrease in the heat-sensing membrane of the pit organ has the potential to enhance heat flux between their endothermic prey and the thermal sensors, affect the optimal functioning of thermal sensors in the pit membrane and reduce the formation of thermal afterimages, improving thermal detection. We examined the potential for respiratory cooling to improve strike behaviour, capture, and consumption of endothermic prey in the South American rattlesnake, as behavioural indicators of thermal detection. Snakes with a higher degree of rostral cooling were more accurate during the strike, attacking warmer regions of their prey, and relocated and consumed their prey faster. These findings reveal that by cooling their pit organs, rattlesnakes increase their ability to detect endothermic prey; disabling the pit organs caused these differences to disappear. Rattlesnakes also modify the degree of rostral cooling by altering their breathing pattern in response to biologically relevant stimuli, such as a mouse odour. Our findings reveal that low humidity increases their ability to detect endothermic prey, suggesting that habitat and ambush site selection in the wild may be influenced by external humidity levels as well as temperature.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Ecophysiology of Amphibians: Information for Best Mechanistic Models

Several amphibian lineages epitomize the faunal biodiversity crises, with numerous reports of population declines and extinctions worldwide. Predicting how such lineages will cope with environmental changes is an urgent challenge for biologists. A promising framework for this involves mechanistic modeling, which integrates organismal ecophysiological features and ecological models as a means to establish causal and consequential relationships of species with their physical environment. Solid frameworks built for other tetrapods (e.g., lizards) have proved successful in this context, but its extension to amphibians requires care. First, the natural history of amphibians is distinct within tetrapods, for it includes a biphasic life cycle that undergoes major habitat transitions and changes in sensitivity to environmental factors. Second, the accumulated data on amphibian ecophysiology is not nearly as expressive, is heavily biased towards adult lifeforms of few non-tropical lineages, and overlook the importance of hydrothermal relationships. Thus, we argue that critical usage and improvement in the available data is essential for enhancing the power of mechanistic modeling from the physiological ecology of amphibians. We highlight the complexity of ecophysiological variables and the need for understanding the natural history of the group under study and indicate directions deemed crucial to attaining steady progress in this field.This research was supported by the Serrapilheira Institute (number G-1709-18372) for SFG, CN, and SESV. Support was also provided by São Paulo Research Foundation—FAPESP (10/20061-6, 14/05624-5, 17/10338-0 to RPB; 14/16320-7 to CAN), by National Council for Scientific and Technological Development—CNPq (166109/2015-0 to RPB, and 303180/2016-1 and 402469/2016-0 to SFG), by Coordenação e Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, Finance Code 001, PNPD fellowship to RPB), CAPES/FAPITEC (88881.157451/2017-01), and by MINECO award grants (CGL2017-86924-P to MT).Peer reviewe

What do data from fieldwork and scientific collections tell us about species richness and composition of amphibians and reptiles?

This is the data set associated with the manuscript that is in review at the South American Journal of Herpetology. It describes the data from collections and field surveys of amphibians and reptiles in the countryside of the São Paulo state

Blood oxygen affinity increases during digestion in the South American rattlesnake, Crotalus durissus terrificus

Digesting snakes experience massive increases in metabolism that can last for many days and are accompanied by adjustments in the oxygen transport cascade. Accordingly, we examined the oxygen-binding properties of the blood in the South American rattlesnake (Crotalus durissus terrificus) during fasting and 24 and 48h after the snakes have ingested a rodent meal corresponding to 15% (±2%) of its own body mass. In general, oxygen-hemoglobin (Hb-O2) affinity was significantly increased 24h post-feeding, and then returned toward fasting values within 48h post-feeding. Content of organic phosphates ([NTP] and [NTP]/[Hb]), hemoglobin cooperativity (Hill's n), and Bohr Effect (ΔlogP50/ΔpH) were not affected by feeding. The postprandial increase in Hb-O2 affinity in the South American rattlesnake can be almost entirely ascribed by the moderate alkaline tide that follows meal ingestion. In general, digesting snakes were able to regulate blood metabolites at quite constant levels (e.g., plasma osmolality, lactate, glucose, and total protein levels). The level of circulating lipids, however, was considerably increased, which may be related to their mobilization, since lipids are known to be incorporated by the enterocytes after snakes have fed. In conclusion, our results indicate that the exceptional metabolic increment exhibited by C. d. terrificus during meal digestion is entirely supported by the aerobic pathways and that among the attending cardiorespiratory adjustments, pulmonary Hb-O2 loading is likely improved due to the increment in blood O2 affinity.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Data from: Biophysical model of water economy can explain geographic gradients in body size in anurans

Geographical gradients of body size express climate-driven constraints on animals, but whether they exist and what cause them in ectotherms remains contentious. For amphibians, the water conservation hypothesis posits that larger bodies reduce evaporative water loss (EWL) along dehydrating gradients. To address this hypothesis mechanistically, we build upon well-established biophysical equations of water exchange in anurans to propose a state-transition model that predicts an increase of either body size or resistance to EWL as alternative specialization along dehydrating gradients. The model predicts that species whose water economy is more sensitive to variation in body size than to variation in resistance to EWL should increase in size with response to increasing potential evapotranspiration (PET). To evaluate the model predictions, we combine physiological measurements of resistance to EWL with geographic data of body size for four different anuran species. Only one species, Dendropsophus minutus, was predicted to exhibit a positive body size–PET relationship. Results were as predicted for all cases, with one species – Boana faber – showing a negative relationship. Based on a mathematical model verified empirically, we show that clines of body size among anurans depend on the current values of those traits and emerges as an advantage for water conservation. Our model offers a mechanistic and compelling explanation for the cause and the variation of gradients of body size in anurans

Gouveia_et_al_Geographical_data_four_species

The following data contain the study species (Species), latitude, longitude, sample size (N), mean snout vent-length (SVL), standard deviation of SVL (sd SVL), and potential evapotranspiration (PET)