Annual changes in corticosterone and its response to handling, tagging and short-term captivity in Nyctibatrachus humayuni

2020 ◽  
pp. 118-125
Author(s):  
Amruta M. Joshi
Keyword(s):  
Breeding Season ◽  
Differential Sensitivity ◽  
Energy Reserves ◽  
Short Term ◽  
Coping With Stress ◽  
Physiological Processes ◽  
Corticosterone Metabolites ◽  
Species Specific ◽  
Effective Conservation ◽  
Growth And Reproduction

Glucocorticoids (GCs) are primarily involved in mobilising energy reserves to various physiological processes including reproduction. During situations of stress, GCs also help in coping with stress by diverting energy away from processes such as growth and reproduction. Hence, studying annual and seasonal changes in GCs of wild populations can help in understanding their role in stress management and reproduction. The quantification of GCs in wild animals involves capturing, handling and restraining, which could be stressful. Moreover, different species may exhibit differential sensitivity to different stressors. Hence, determining species-specific sensitivities and responses to different stressors may help in developing effective conservation measures. In this context, we studied the annual and seasonal variations in corticosterone metabolites of the Bombay night frog, Nyctibatrachus humayuni. In addition, the effects of handling, marking and short-term captivity (24 h) on corticosterone metabolite levels of N. humayuni were determined. Our results show that urinary corticosterone metabolites (UCM) varied significantly annually and between the sexes; in males, the levels were highest during the breeding season, whilst in females, the levels were highest just before the breeding season. Interestingly, UCM levels of both the sexes were not affected by tagging with visual implant elastomer (VIE), and by short-term captivity, suggesting that these manipulations were not stressful in terms of corticosterone responses.

Differential responses of growth, photosynthesis, respiration, and phosphate uptake to copper in copper-tolerant and copper-intolerant strains of Scenedesmus acutus (Chlorophyceae)

1995 ◽  
Vol 73 (8) ◽  
pp. 1295-1303 ◽  
Author(s):  
Czeslawa Nalewajko ◽  
Mary M. Olaveson
Keyword(s):  
Phosphate Uptake ◽  
Sufficient Conditions ◽  
Copper Toxicity ◽  
Differential Sensitivity ◽  
Short Term ◽  
Scenedesmus Acutus ◽  
Physiological Processes ◽  
Photosynthesis And Respiration ◽  
Copper Tolerant

We detected significant differences in copper toxicity to growth and several physiological processes (e.g., photosynthesis, respiration, and phosphate uptake) in three strains of Scenedesmus acutus f. alternans demonstrating differential sensitivity to copper. The copper-intolerant strain (designated X-72) and the two copper-tolerant strains (designated X-Cu and B-4) were tested in long-term (5-day) growth bioassays and short-term (< 24 h) physiological experiments under both nutrient-sufficient and nutrient-limited conditions. The three strains showed the same pattern of sensitivity to copper for growth and for all physiological processes examined: the copper-intolerant strain, X-72, showed the greatest sensitivity, followed by X-Cu. B-4 was most tolerant. Under nutrient-sufficient conditions, growth was more sensitive to copper than photosynthesis or respiration. Depression of the growth rate to 50% of control occurred at 25, 56, and 175 nmol Cu/106 cells in X-72, X-Cu, and B-4, respectively. Photosynthesis and respiration were inhibited in cultures that were preexposed to algistatic copper dosages for 20 h prior to testing. Both processes were equally inhibited in X-72 (to about 8.5% of controls) and in X-Cu (to about 32% of controls), but respiration was more inhibited than photosynthesis in B-4 (to 47.7 vs. 67.1% of control rates). L-buthionine-S,R-sulfoximine (BSO), a known inhibitor of phytochelatin synthesis, significantly reduced the tolerance of photosynthesis to copper in X-72 but not in X-Cu or B-4. Short-term responses among several physiological processes were also examined under phosphorus and nitrogen limitation. In P-limited cultures, phosphate uptake was depressed by 50% at 3 nmol Cu/106 cells in X-72, and at 5.8 nmol Cu/106 cells in X-Cu and B-4. In N-limited cultures, photosynthesis was more tolerant to copper than in nutrient-sufficient conditions in both X-72 and X-Cu but less tolerant in B-4. Key words: copper toxicity, growth, nutrient limitation, nitrogen, phosphate uptake, photosynthesis, respiration, Scenedesmus.

scholarly journals Corticosterone Metabolite Concentration Is Not Related to Problem Solving in the Fawn-Footed Mosaic-Tailed Rat Melomys cervinipes

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Misha K. Rowell ◽  
Rachel M. Santymire ◽  
Tasmin L. Rymer
Keyword(s):  
Problem Solving ◽  
Metabolite Concentration ◽  
Cognitive Responses ◽  
Complex Environments ◽  
Adrenocortical Activity ◽  
Physiological Processes ◽  
Faecal Samples ◽  
Faecal Corticosterone Metabolites ◽  
Corticosterone Metabolites ◽  
Species Specific

Animals can respond physiologically, such as by adjusting glucocorticoid hormone concentrations, to sudden environmental challenges. These physiological changes can then affect behavioural and cognitive responses. While the relationships between adrenocortical activity and behaviour and cognition are well documented, results are equivocal, suggesting species-specific responses. We investigated whether adrenocortical activity, measured using corticosterone metabolite concentration, was related to problem solving in an Australian rodent, the fawn-footed mosaic-tailed rat (Melomys cervinipes). Mosaic-tailed rats live in complex environments that are prone to disturbance, suggesting a potential need to solve novel problems, and have been found to show relationships between physiology and other behaviours. We measured problem solving using five food-baited puzzles (matchbox and cylinder in the home cage, and activity board with pillars to push, tiles to slide and levers to lift in an open field), and an escape-motivated obstruction task in a light/dark box. Faecal samples were collected from individuals during routine cage cleaning. Adrenocortical activity was evaluated non-invasively by measuring faecal corticosterone metabolites using an enzyme immunoassay, which was biochemically and biologically validated. Despite varying over time, adrenocortical activity was not significantly related to problem solving success or time spent interacting for any task. However, as adrenocortical activity is reflective of multiple physiological processes, including stress and metabolism, future studies should consider how other measures of physiology are also linked to problem solving.

scholarly journals Effectiveness of a low-dose Norgestomet ear implant in short-term protocols to induce estrus in ewes during the non-breeding season in Brazil.

2019 ◽  
Vol 48 ◽  
Author(s):  
Dayrton Farias Lima Júnior ◽  
José Victor Pronievicz Barreto ◽  
Fabiana de Andrade Melo Sterza ◽  
Mirela Brochado Souza-Cáceres ◽  
Vanessa Pereira Pontes ◽  
...  
Keyword(s):  
Breeding Season ◽  
Low Dose ◽  
Short Term

Changes in urinary testosterone and corticosterone metabolites during short-term confinement with repeated handling in wild male cane toads (Rhinella marina)

2011 ◽  
Vol 59 (4) ◽  
pp. 264 ◽  
Author(s):  
Edward J. Narayan ◽  
Frank C. Molinia ◽  
John F. Cockrem ◽  
Jean-Marc Hero
Keyword(s):  
Adult Male ◽  
Reproductive Effort ◽  
Hormone Secretion ◽  
Reproductive Hormone ◽  
Cane Toad ◽  
Short Term ◽  
Rhinella Marina ◽  
Testosterone Secretion ◽  
Metabolite Concentrations ◽  
Corticosterone Metabolites

Stressors generally decrease testosterone secretion and inhibit reproduction in animals. Urinary testosterone and corticosterone metabolite concentrations were measured in adult male cane toads (Rhinella marina) at the time of capture from the wild and during 24 h of confinement with repeated handling. Mean urinary testosterone concentrations increased 2 h after capture, were significantly elevated above initial concentrations at 5 h, and then declined. Mean testosterone concentrations remained elevated 24 h after capture. Mean urinary corticosterone concentrations increased after capture, were significantly elevated above initial concentrations at 2 h, and remained elevated thereafter. This is the first report in amphibians of an increase in testosterone excretion after capture from the wild, with previous studies showing either no change or decline in testosterone. This finding may be associated with the mating strategy and maintenance of reproductive effort in the cane toad, a species that shows explosive breeding and agonistic male–male interactions during breeding. The finding that testosterone excretion increases rather than decreases after capture in male cane toads shows that it should not be generally assumed that reproductive hormone secretion will decrease after capture in amphibians.

Evidence for LH-inhibiting activity in ovine peripheral and testicular blood

1990 ◽  
Vol 123 (3) ◽  
pp. 345-352 ◽  
Author(s):  
V. Papapdopoulos ◽  
P. Kamtchouing ◽  
N. Boujrad ◽  
C. Pisselet ◽  
C. Perreau ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Breeding Season ◽  
Specific Binding ◽  
Apparent Molecular Weight ◽  
Rete Testis ◽  
Arterial Blood ◽  
Inhibiting Factor ◽  
Arterial Plasma ◽  
Species Specific ◽  
Venous Plasma

Abstract. Intracellular cyclic AMP and testosterone productions by purified mature rat Leydig cells were stimulated by oLH (25 μg/l) 18- and 12-fold, respectively, after a 5-h incubation period. The replacement of the incubation medium by charcoal-treated testicular venous plasma (40%, v/v) from adult rams in the breeding season induced an inhibition of cyclic AMP and testosterone productions (82 and 66%, respectively, of oLH-stimulated values). Testicular arterial plasma is less effective than testicular venous plasma, even when it originates from non-breeding season rams; in that case, testicular venous and arterial plasma strongly inhibit testosterone productions (84 and 67%, respectively of oLH-stimulated values), which probably indicates that the inhibitory activity is higher in the non-breeding season. The addition of peripheral plasma leads to a testosterone production equal to 35 and 65% of the oLH-stimulated values, respectively, for ram blood collected in non-breeding and breeding seasons. The same concentration of ovine testicular lymph or rete testis fluid is without significant effect on cyclic AMP production; however, testosterone is slightly decreased by lymph but enhanced by rete testis fluid. Increasing amounts of venous or arterial testicular blood induce a dose-related decrease of the specific binding of labelled hCG in both rat and ram testicular membranes. This inhibiting factor is present in peripheral and testicular blood of either control or hypophysectomized or castrated rams, is a protein in nature, heat-sensitive, and has an apparent molecular weight higher than 10 000 daltons. These results suggest the existence of a control of LH-specific binding to its receptors and of Leydig cell cyclic AMP and testosterone outputs; these activities are not species-specific and are more concentrated in testicular venous than in arterial blood. The origin of this inhibiting factor remains to be determined, since it is not confined to the testis and not of pituitary origin.

scholarly journals Wing Morphology and Flight Behavior of Some North American Hummingbird Species

The Auk ◽  
2005 ◽  
Vol 122 (3) ◽  
pp. 872-886 ◽  
Author(s):  
F. Gary Stiles ◽  
Douglas L. Altshuler ◽  
Robert Dudley
Keyword(s):  
Breeding Season ◽  
North American ◽  
Theoretical Models ◽  
Wing Disc ◽  
Territorial Behavior ◽  
Flight Behavior ◽  
Adult Males ◽  
Wing Morphology ◽  
Reversed Sexual Size Dimorphism ◽  
Species Specific

Abstract We explored the relationship between wing morphology and flight behavior with respect to sex and age in five species of North American hummingbirds. We first measured the length, chord or “width,“ and area of entire hummingbird wing planforms. We then calculated additional parameters of wing shape and size, including aspect and shape ratios, degree of taper or “pointedness,“ wing loading, and wing disc loading (WDL). Wings of adult males are not only shorter but also more narrow and tapered than those of adult or immature females; immature males have larger wings and lower WDL, more like those of females. A proposed relationship between WDL and territorial behavior and dominance is not supported, given that adult and immature males show similar feeding territoriality outside the breeding season but females rarely do. The more extreme and divergent wings of adult males probably reflect sexual selection in connection with aerial displays that include species-specific sound effects given during the breeding season. North American species are unusual among hummingbirds in showing reversed sexual size-dimorphism (males smaller, with relatively shorter wings), a feature shared with some other small hummingbirds, notably the “Pygmornis“ hermits. Attempts to explain hummingbird foraging and territorial behavior on the basis of differences in WDL have failed because many aspects of wing morphology, physiology, and flight behavior were not taken into account. Several wing parameters appear more related to other modes of flight than to strategies of nectar exploitation, and the morphology of any given wing represents a compromise between the often conflicting aerodynamic demands of different flight modes. Understanding hummingbird flight will require broad comparative studies of wing morphology and wingbeat kinematics in relation to flight behavior, and new theoretical models and experimental data will be needed to elucidate physiological and aerodynamic mechanisms underlying forward flight and maneuvering. Morfología Alar y Comportamiento de Vuelo de Unas Especies de Colibríes de Norteamérica

Thermoregulation in a saxicolous population of the lizard Urosaurus ornatus from the northern Chihuahuan Desert, Mexico

2020 ◽  
pp. 1-14
Author(s):  
Hector Gadsden ◽  
Rafael A. Lara-Reséndiz ◽  
Nallely F. Minjarrez-Flores ◽  
Ana Gatica-Colima ◽  
Geoffrey R. Smith
Keyword(s):  
Breeding Season ◽  
Global Climate Change ◽  
Chihuahuan Desert ◽  
Global Climate ◽  
Thermal Conditions ◽  
Conservation Strategy ◽  
Urosaurus Ornatus ◽  
Physiological Processes ◽  
Mountain System ◽  
Environmental Temperatures

Abstract Environmental temperatures often regulate the activity and physiological processes of ectotherms. Because environmental temperatures can vary significantly among seasons, lizards exposed to different thermal conditions in different months could differ in how they thermoregulate or behave. Here, we present a combination of field, laboratory, and modeling approaches to examine thermoregulation, habitat thermal quality, and hours of thermal restriction on activity in a saxicolous population of Urosaurus ornatus in two thermally contrasting months (June and October) in a micro-insular mountain system in the northern Chihuahuan Desert in Mexico. Both active and preferred body temperatures did not vary between months. In this population, U. ornatus is an active thermoregulator with highly accurate and efficient thermoregulation despite the thermal quality in both months. However, during the breeding season (June) activity is restricted (i.e., high number of hours of restriction) compared to the non-breeding season (October). Therefore, our results suggest that this saxicolous population of U. ornatus could be threatened by global climate change and it is essential to determine a conservation strategy for this population.

Measuring preferences and the problems of identifying proximate needs

1997 ◽  
Vol 20 ◽  
pp. 19-26 ◽  
Author(s):  
A. B. Lawrence ◽  
A. W. Illius
Keyword(s):  
Psychological Research ◽  
Choice Behaviour ◽  
Short Term ◽  
Environmental Preferences ◽  
Consumer Economics ◽  
Preference Testing ◽  
Considerable Problem ◽  
Simple Preference ◽  
Preference Tests ◽  
Growth And Reproduction

AbstractCurrent methodologies for measuring choices are the product of early psychological research into behavioural mechanisms, particidarly learning. In applied behaviour studies, much of the emphasis has been on the use of preference tests to assess animals’ motivation, and hence proximate need for, various forms of stimulation. Preference tests are based on a modular view of animal behaviour, where animals are presented with physical compartments each containing different resources such as food or social partners. An obvious limitation of the approach is that simple preference tests may do little justice to the complexity of animals’ behavioural organization and environmental preferences. Variability of choice behaviour also poses a considerable problem, as it may prevent us understanding and interpreting short-term choices and consequently describing the proximate needs of the animal. We also believe that the approach of applying consumer economics to quantify the value of resources to animals is increasingly moving preference testing away from measuring proximate to measuring ultimate need. This shift in emphasis does not appear to have been recognized. The risk is that the approach will only identify basic needs (e.g. related to growth and reproduction) but be insensitive to the proximate behavioural needs that it set out to quantify. In general, the focus of welfare-related preference testing should shift from the measurement and description of preferences to the more strategic task of understanding the rules governing short-term choices. We will be unable to measure proximate need unless we can develop a theoretical framework better able to interpret short-term behavioural choices.

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