Estivation

Aestivation is a land of inactivity and metabolic reduction in response to a lack of water or high temperature.

From: Trace Fossils , 2007

Aestivation and Regeneration

Tianming Wang , ... Muyan Chen , in Developments in Aquaculture and Fisheries Scientific discipline, 2015

11.1.1 Definition of aestivation

Aestivation is mostly defined every bit a type of dormancy, which is a survival strategy used to sustain lack of nutrient and other extreme conditions (Pinder et al., 1992; Abe, 1995; Storey, 2002). Animals that aestivate go inactive and stop feeding in response to warm temperatures. Research on aestivation has focused on vertebrates, such as lung fish, amphibians, reptiles, small mammals, and certain invertebrates, such as mollusks. The duration of aestivation varies among species; some enter this state for a few months, others for a longer period. During aestivation, the animals undergo important physiological and biochemical adjustments, such as changes in energy consumption, metabolic activeness, and immune response. The molecular mechanisms underpinning these adjustments mainly include transcriptional and translational regulation, epigenetic modification, adenosine monophosphate (AMP), and Akt-mediated bespeak transduction (Akt is a cytosolic poly peptide kinase too known as protein kinase B, PKB). Hypometabolism is considered key for the response to high temperature, drought, and other extreme weather condition. The decrease in metabolic rate in aestivating animals, which tin can reach 70–lxxx% of the resting value, and nearly 100% in some species, conserves energy to extend survival time (Pinder et al., 1992; Pedler et al., 1996; Guppy and Withers, 1999; Storey and Storey, 2010).

A. japonicus is a shallow-water temperate species and variation in water temperature is known to influence its growth (meet likewise Chapters 8 and 9 viii 9 ). When the seawater temperature rises to a sure level during summertime, virtually individuals of A. japonicus migrate to deeper environments and stop moving and feeding, inbound a dormant state dubbed aestivation, which lasts up to ∼100 days. During this period, the sea cucumber experiences organ atrophy and major weight loss (Li et al., 1996), which has a serious impact on its product through aquaculture. Since body of water cucumber aestivation was outset reported in Japan over a century agone (Mitsukuri, 1897), theoretical models take been developed with research findings in ecology, morphology, physiology, molecular biology, and genomics.

Recently, the internal regulation mechanism of bounding main cucumber aestivation was investigated through a multifaceted arroyo, and basic theories on aestivation were improved. Studies have shown that aestivation in A. japonicus is characterized past the following: decreased metabolic charge per unit (lower oxygen consumption rate and ammonia excretion rate), energetic adjustment (feeding and defecation are cypher and energy stored in the trunk is adjusted to maintain basic physiological activities, such as respiration and excretion), modified immune parameters (body cavity fluid cell decreased concentrations; action of superoxide dismutase (SOD) and catalase (CAT) are adjusted), and degradation of intestinal structure and function (major gastrointestinal deposition and modify in digestive enzyme activity). With the development of research techniques in molecular biology and bioinformatics, the molecular mechanisms underlying ocean cucumber aestivation keep to be explored.

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Dormancy☆

Philip Withers , Christine E. Cooper , in Encyclopedia of Ecology (Second Edition), 2019

Estivation (Summer Dormancy)

Estivation is summer dormancy, that is, long-term torpor during summer for survival of hot and dry periods. Many desert plants survive extended periods of high temperature and low rainfall. Some survive as desiccated seeds (5%–10% water content), peculiarly annual species, but some survive desiccation equally adults. These "resurrection" plants, such as the Rose of Jericho ( Selaginella), can desiccate to almost 5% water content during dry periods, only survive and "come up back to life" after pelting. Pincushion lilies similarly re-activate past regenerating from buds subsequently pelting.

Amidst invertebrates (e.g., earthworms and insects) estivation ordinarily involves an inactive phase with a water-resistant covering. For example, estivating earthworms grade a mucus cocoon to resist desiccation, and many insect pupae are remarkably resistant to water loss. Amongst vertebrates, fishes, amphibians, and reptiles enter a similar estivation state. Fishes and amphibians often form a cocoon of dried mucus (e.k., African lungfishes) or shed epidermal layers (e.thousand., some desert frogs; Fig. 3) to resist epidermal water loss; the cocoon covers the entire body surface except for the nostrils. Reptiles accept a relatively water-impermeable epidermis and do not need to form a cocoon to reduce evaporative water loss. Estivating ectotherms typically have an intrinsic metabolic depression for energy conservation.

Fig. 3

Fig. 3. Estivating frog (Cyclorana cultripes) in a cocoon of shed skin.

 Photo by Thousand. Thompson and P. Withers.

Some mammals also estivate (Table ane). For instance, desert ground squirrels enter a long-term estivation state that is physiologically similar to hibernation except for the higher ambience temperature (T a) and T b. Other mammals such as cactus mice and kangaroo mice use single-day torpor cycles during summertime.

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The Trace-Fossil Record of Vertebrates

Stephen T. Hasiotis , ... Michael J. Everhart , in Trace Fossils, 2007

Modernistic Aestivation and Hibernation Burrows

Aestivation and hibernation burrows are used past extant amphibians, reptiles, and mammals as temporary shelters from farthermost, short-term climatic or environmental atmospheric condition. Aestivation and hibernation behaviors allow animals to occupy a wide variety of habitats and climate settings. For example, the anuran Scaphiopus couchii inhabits California deserts with a mean annual precipitation of less than six cm, no permanent water bodies, air temperatures that attain 50°C, and soil temperatures of over xxx°C at a depth of 25 cm (Pinder et al., 1992). Simple to complex burrows are constructed to create a microenvironment more suitable for the animal's survival. These burrows are occupied from a few months to several years and are generally used just once. Successions of cantankerous-cutting burrows tin result from several years of seasonality producing many generations of burrows originating from the same surface.

Aestivation is a land of inactivity and metabolic reduction in response to a lack of water or high temperature. It is a common part of the life wheel of vertebrates that occupy periodically dry habitats. In general, the animal burrows into moist soil or mud, forms a cocoon to slow water loss, and becomes inactive to conserve energy (Pinder et al., 1992). By creating burrows, aestivators can rely on the soil-buffered burrow microenvironment rather than the surface surround. Daily temperature variation decreases with depth in the soil. Below 40 cm there is picayune to no daily temperature fluctuation. Decreasing moisture levels and increasing temperature are considered the signal for entering and leaving a country of aestivation. Extremes of either environmental variable can lead to extensive periods of aestivation. Some anurans tin can survive upwardly to five years without leaving the aestivation state, although only a small percentage of the population survives (Pinder et al., 1992).

Hibernation is a land of inactivity in response to seasonally low temperatures in loftier-latitude or high-distance environments. Animals have adult a number of responses to these conditions, including physiological means of tolerating freezing, submergence nether h2o, or hibernating on land in a couch to avert freezing (Pinder et al., 1992; Butler, 1995). Burrowing hibernators must deal with prolonged cold and starvation by accumulating fuel reserves and adjusting their metabolic rates. Hibernation burrows must discourage desiccation, retain heat, provide protection from predators, supply environmental cues to trigger emergence, and maintain oxygen levels (Zug et al., 2001).

Fish inhabiting lakes and floodplain ponds in regions subject to drought apply burrows to provide protection from desiccation. Gobies, catfish, mudskippers, and African and South American lungfish employ burrows as aestivation chambers (Atkinson and Taylor, 1991). The African lungfish Protopterus annectens lives in floodplain swamps of the Gambia River (Greenwood, 1986). The climate has alternating wet and dry out seasons in which rainy seasons may last 3–5 months and flood large areas of the alluvial plain. At the end of the rainy season, lungfish couch into the floor of the drying swamps and aestivate while other fish re-enter the river. Protopterus constructs aestivation burrows by biting into the moist sediment of the pond flooring and lateral motion of the body and tail (Greenwood, 1986).

Aestivation is almost mutual among amphibians. Aestivating amphibians may be active for equally few every bit 2 months of the year, their lives condensed into brief active periods during favorable conditions (Pinder et al., 1992). Aestivating anurans (frogs and toads) are mainly terrestrial or freshwater aquatic and inhabit regions with arid to semiarid climates subject area to variable and seasonal rainfall (Pinder et al., 1992). The spadefoot toads of Northward America, Scaphiopus (Pelobatidae), the Australian Cyclorana (Hylidae), and the African bullfrog Pyxicephalus (Ranidae) are some of the best-documented terrestrial aestivators (Zug et al., 2001). These anurans aestivate for 7–10-months per year, and are active for short periods of time subsequently seasonal rains create ephemeral ponds in which they breed (Pinder et al., 1992). The larvae develop quickly and metamorphose into adults before the waters evaporate. Amphibian aestivation burrows vary in depth depending on the season, average temperature, and the density of the soil. Spadefoot toad burrows range from 20–70-cm deep, while African bullfrog burrows are 80–150-cm deep (Pinder et al., 1992). Aestivation burrows are non-randomly distributed, occurring as small areas of high burrow density surrounded by big areas with no burrows. Over 39 spadefoot toad burrows accept been reported from one vi one thousandtwo area (Pinder et al., 1992). Many amphibian aestivators class cocoons equanimous of ane to several layers of shed skin or a layer of secreted mucus in order to reduce evaporative water loss (Pinder et al., 1992). Aquatic anurans form cocoons that reduce evaporative water loss past 90% and enable survival up to 150–250 days in dry soil (Pinder et al., 1992). Some salamanders produce cocoons of dried mucus like to those of lungfish that permit survival for up to 110 days (Pinder et al., 1992).

Hibernation occurs in all major reptile groups in temperate and subtropical regions. In arid regions, aestivation occurs in response to seasonal drought. Due north American gopher tortoises employ underground burrows as a general shelter, nest, and refuge from daily to seasonal temperature fluctuations (Zug et al., 2001). Skinks construct burrows or use those of other animals for winter refuges (Zug et al., 2001; Chapple, 2003). Australian skinks of the genus Egernia construct deep, complex burrow systems with multiple entrances and chambers (Chapple, 2003). While these burrows are used equally permanent dwellings, the entrances are sealed prior to hibernation during wintertime months. Monitor lizards likewise construct simple burrows every bit refuges from daily to seasonal temperature variations (Traeholt, 1995).

Burrowing mammals are present in all continents. Many carnivores and omnivores burrow for denning purposes as well as for shelter from daily to seasonal temperature fluctuations (Butler, 1995). Northward American grizzly bears enter a catamenia of dormancy from October to April. Their winter dens are non natural cavities but are excavated into the soil (Butler, 1995). Most of these dens plummet, yet, during the jump snowmelt and summertime rain, then reoccupation and preservation is unlikely. Grizzly dens are elementary structures, consisting of a tunnel leading to a large interior sleeping accommodation (Butler, 1995).

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Vermiremediation of agrochemicals

Zeba Usmani , ... Majeti Narasimha Vara Prasad , in Agrochemicals Detection, Treatment and Remediation, 2020

14.6 Advantages/challenges in vermiremediation of agrochemicals

Earthworm species have several characteristics such as estivation ability, environmental plasticity, as successful survivors in soil. These features pb to elevated survival rate of earthworms and an adaptability to sustain in adverse environments of very low or very high temperatures (−four to forty°C) and pH (4.3–nine.2 values) ( Contreras-Ramos et al., 2006; Singh et al., 2005). Thus this is the reason that anecic, epigeic, and endogeic earthworms can exist applied to polluted soils to remediate them.

Earthworms require well-defined atmospheric condition such every bit adequate food (Klok, 2007) to survive in soil. Earthworms by and large avert adverse soil weather condition, such as high pH, more salt content, high concentrations of agrochemicals, and heavy metals, which might inhibit the activity and survival rate of earthworms past changing their community construction (Lapied et al., 2009; Eijsackers, 2010; Kooijman and Cammeraat, 2010).

Moreover, climatic weather of the soil must exist adequate for the activity of earthworms. Extreme hot or common cold weather condition may limit their activity. H2o content of the soil should also exist loftier to enable the earthworms to couch through the soil and sustain (Owojori and Reinecke, 2010). The earthworm characteristics and their ecology should also be taken into consideration while remediating the polluted soils. Surface dwellers or the epigeic earthworms can be used in a windrow organisation while the anecic earthworms can exist used during burrowing. Endogeic earthworms on the other hand can be used where horizontal and deeper burrowing is required (Hickman and Reid, 2008).

Environment of the earthworms is really pregnant to determine their behavior in the soil. Their burrowing addiction may transfer the pollutants from deeper layers of soil to the surface, thus enhancing their deposition by aeration and properly mixing them with the microorganisms (Buch et al., 2013; Fernandez et al., 2011).

Major research to study the elimination of pollutants was performed with the aid of East. fetida, an epigeic species, while anecic or endogeic earthworms are more suitable for soil studies. Organic material is the natural environment of E. fetida that is a compost species and utilizes organic waste product. Soil is the natural habitat of the endogeic and anecic earthworms that primarily feeds on soil and associated organic matter. Earthworm species, such every bit P. corethrurus (endogeic) or P. hawayana (anecic), were used for the elimination of pollutants such as carbofuran, glyphosate, and Aroclor (Luepromchai et al., 2002; Buch et al., 2013; Hernandez-Castellanos et al., 2013a,b). Greater pollutant removal was observed when earthworms were employed to the soil compared to no earthworms' condition, and earthworm could tolerate heavy concentrations that imply their potential to remediate the soils.

Notwithstanding, farther research should exist promoted to validate the potential use of anecic and endogeic species to eliminate pollutants. The prime number restriction in the apply of earthworms for remediation of polluted soil was the toll Contreras-Ramos et al. (2006). However the utilize of earthworms has several benefits also. Earthworms will non merely increase the rate of pollutant removal but will also enhance the fertility of soil to improvise the quality of soil. Earthworms deliver a better mixed and aerated soil, with loftier number of microbes and nutrients. Blouin et al. (2013) reported that earthworms heighten dissimilar ecosystem services. More than enquiry should be promoted in field of vermiremediation to increment its application on a larger calibration as the experiment with dissimilar contaminant concentrations and different earthworm species was generally performed in laboratories or in outdoor mesocosms.

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Storage, Ecology of

Caroline Thousand. Pond , in Encyclopedia of Biodiversity (Second Edition), 2013

Hibernation

Hibernation and its hot weather equivalent, aestivation, are periods of inactivity and seclusion, ordinarily accompanied by cooler than normal body temperature, which enable animals to pass through seasons when food is deficient or inaccessible. Hibernation was among the first physiological states in which adipose tissue of wild mammals, reptiles, and amphibians was studied thoroughly. Hibernators depend on their fat reserves while cold and to fuel rewarming but reclaiming the stores is not as straightforward as it beginning seemed.

The enzymatic processes involved in fasting and starvation are essentially similar to those of wearisome exercise, but in that location is a critical departure: during exercise, the body is warm, often slightly warmer than when sedentary, simply in hibernation, the trunk temperature is low, sometimes falling by 35   °C to close to 0   °C. The fat acid composition of triacylglycerols is largely irrelevant to their role as fuel when animals are warm, just information technology is crucial for their utilise during hibernation because enzymes do non work on solidified fats.

Experiments on captive chipmunks (Eutamias amoenus) and golden-curtain ground squirrels (Spermophilus lateralis) evidence that they enter hibernation more readily, remain cooler for longer and are better able to survive long winters when enough of polyunsaturated lipids are included in their diet during the weeks preceding hibernation than when they are fed on saturated fats of similar calorific value. Unsaturated fat acids may lower the melting betoken of the triacylglycerols and the membrane phospholipids, enabling them to remain more fluid, and hence retain their proper affinity for carrier molecules and enzymes, at cooler temperatures. The chemic composition of the storage lipids, together with other aspects of adipose tissue, is thus adjusted to the concrete conditions and its role in whole-body metabolism (Frank and Storey, 1995; Frank et al., 2008).

Squirrels obtain many such unsaturated fatty acids from the seeds and other plant parts that they eat. Hibernation is an agile, physiologically controlled procedure, and specially in mammals, metabolic preparations tin can exist identified days or weeks before the creature really allows its body to absurd. Equally the weather becomes libation and the days shorten in autumn, squirrels, and other hibernatory rodents actively seek nuts and other foods that contain these lipids. The woodchuck or marmot (Marmota flaviventris) selectively retains linoleic acrid (C18:2) before hibernation: the saturated fatty acids are released and oxidized by the muscles, liver, etc. while the beast is warm and active, but the polyunsaturates remain in the adipose tissue, for utilize when the body is cold. Similar other mammals, the squirrels cannot add together more than than one double bond to nigh kinds of long concatenation fatty acids, so they depend on the increased availability in autumn of seeds rich in polyunsaturated lipids. Failure of a seed crop could foreclose successful hibernation and thus lead to death from cold or starvation, fifty-fifty if plenty of other foods were bachelor. Analysis of biopsies of gonadal and inguinal adipose tissue from alpine marmots (Marmota marmota) throughout the yr indicate that selective release of certain fatty acids allows active regulation of the composition of storage triacylglycerols (Cochet et al., 1999). The storage lipids remain fluid during deep hibernation and in the euthermic land past maintaining a high proportion of monunsaturates, both past memory of those from the diet and, if necessary, by synthesis.

Sleeping undisturbed in a absurd, secluded identify uses storage materials only very slowly: small tortoises may lose less than five%, and rarely lose over 15%, of the body mass during v months of hibernation at virtually v   °C. Many reptiles and amphibians sally from hibernation with a surprisingly large proportion of their lipid reserves yet remaining and regain what they lost over the wintertime in a few weeks of feeding. These stores are oft of import for fuelling mating and egg production. The less lipid a hibernator uses during the winter, the more than it has left to fuel breeding the following jump.

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Storage, Environmental Of

Caroline Grand. Pond , in Encyclopedia of Biodiversity, 2003

Vi.B. Migration

In dissimilarity to walking, running, and swimming, the muscle power required to stay airborne by active flapping flight increases disproportionately with increasing torso mass. Other factors existence equal, smaller birds can generate substantially more power than is needed to continue airborne, then they can bear proportionately more fuel, upwards to l% of the body mass if necessary. Larger wings make flight energetically more efficient, so the longest nonstop journeys are undertaken by medium-sized birds, such as sandpipers, knots, turnstones, curlews, and godwits, with a body mass of approximately 100–800   thou.

Small birds with a body mass of approximately 100   thousand that set out with adipose tissue triacylglycerols amounting to 100% of lean tissue mass (i.east., half the body mass is fuel) can fly for 3 or iv   days nonstop or 3000 to 4000   km (depending profoundly on wind direction and other weather condition atmospheric condition). Flying time can exist prolonged by slowing downwards, or it can be shortened by speeding upwardly or by flying into a headwind. In general, larger birds can fly faster, and so arrive at their destination sooner, but considering they can acquit less fuel they ofttimes cannot fly as far as medium-sized birds. Birds with a lean body mass of approximately 100   k lose about 0.seven% of the body mass per hour while migrating, but larger birds of approximately 500   g flying similarly loaded lose 1—1.5% per 60 minutes.

The rate of energy expenditure decreases as the birds become lighter through oxidization of fat. As they set out fully loaded, each gram of triacylglycerols takes them less than half equally far as at the end of their journey, when their fuel is near exhausted, considering flying with one-half the body mass every bit fat uses 3 times equally much muscle power as flight on "empty." A bird that sets out with one-half its total body mass every bit fuel and flies to exhaustion uses 40% more than free energy for the whole journey than i that sets out with a fuel load of 10% of the body mass, flies as far equally it tin can, stops to feed, and continues on the side by side lap, repeating the bike until it reaches its destination. Such a journey is slower because even with unlimited food, birds cannot fatten faster than near 10% of the body mass per day (usually closer to 3–six% per day). Therefore, increasing the body mass by 25% takes at to the lowest degree a week, and 3 or 4   weeks are needed to accumulate maximal fuel reserves.

The corporeality of fuel a large bird can carry is strictly express, and well-nigh journeys begin with a full load and terminate with piddling to spare. Whooper swans (Cygnus cygnus) that fly between northwest Scotland and their breeding grounds in central Iceland are amidst the largest of all migratory birds. The swans set out with adipose tissue triacylglycerols amounting to nearly 20–25% of their lean body mass, the largest load they can take off with. If they see bad atmospheric condition or adverse winds, they land on the bounding main and wait, sometimes for 30   h or more, until traveling weather amend enabling them to continue their journey.

VI.C. Hibernation

Hibernation and its hot conditions equivalent, estivation, are periods of inactivity and seclusion, normally accompanied by libation than normal torso temperature, which enable animals to pass through seasons when food is scarce or inaccessible. Hibernation was amidst the starting time physiological states in which adipose tissue of wild mammals, reptiles, and amphibians was studied thoroughly. They depend on their fat reserves while their body temperature is too low to allow the collection and digestion of food, but reclaiming the stores is not entirely straightforward.

The enzymatic processes involved in fasting and starvation are essentially similar to those of wearisome practice, merely in that location is a disquisitional difference. During exercise, the body is warm, often slightly warmer than when sedentary, but in hibernation the body temperature is depression, sometimes shut to 0°C or 35°C below normal. Enzymes do non work on solidified fats any more than they function in frozen h2o. Animals must even so be able to metabolize the triacylglycerols in their adipose tissue, albeit much more slowly than when they are fully active. The fat acid composition of triacylglycerols is largely irrelevant to their function every bit fuel when animals are warm, just information technology is crucial for their utilize during hibernation.

Experiments on captive chipmunks (Eutamias amoenus) and golden-drapery ground squirrels (Spermophilus lateralis) show that they enter hibernation more readily, remain libation for longer, and are better able to survive long winters when plenty of polyunsaturated lipids are included in their diet during the weeks preceding hibernation than when they are fed saturated fats of similar calorific value. Unsaturated fatty acids may lower the melting bespeak of the triacylglycerols and the membrane phospholipids, enabling them to remain more fluid, and hence retain their proper affinity for carrier molecules and enzymes, at cooler temperatures. The chemical composition of the storage lipids, together with other aspects of adipose tissue, is thus adapted to the physical conditions and its role in whole-body metabolism.

Squirrels obtain many such unsaturated fat acids from the seeds and other plant parts that they eat. Hibernation is an active, physiologically controlled process, and metabolic preparations tin be identified days or weeks before the brute actually allows its body to cool. As the weather becomes libation and the days shorten in autumn, squirrels and other hibernatory rodents actively seek nuts and other foods that contain these lipids. The woodchuck or marmot (Marmota flaviventris) selectively retains linoleic acid (C18:2) before hibernation. The saturated fatty acids are released and oxidized past the muscles, liver, etc. while the animal is warm and agile, but the polyunsaturates remain in the adipose tissue for apply when the body is common cold. Similar other mammals, the squirrels cannot add more than one double bond to nigh kinds of long-chain fatty acids, so they depend on the increased availability in autumn of seeds rich in polyunsaturated lipids. Failure of a seed crop could prevent successful hibernation and thus lead to decease from cold or starvation, even if plenty of other foods were available. Contempo measurements from biopsies of gonadal and inguinal adipose tissue from alpine marmots (Marmota marmota) throughout the yr indicate that selective release of certain fatty acids allows active regulation of the limerick of storage triacylglycerols. The storage lipids remain in an advisable country of fluidity both during deep hibernation and in the euthermic land past maintaining a high proportion of monunsaturates by retentivity of these fat acids from the diet and, if necessary, by synthesis.

Sleeping undisturbed in a cool, secluded place uses storage materials but very slowly. Modest tortoises may lose less than five%, and rarely lose more 15%, of the body mass during five months of hibernation at about 5°C, and much of this loss is water that is lost through evaporation from the lungs. Many reptiles and amphibians sally from hibernation with a surprisingly large proportion of their lipid reserves yet remaining and regain what they lost during the wintertime in a few weeks of feeding. These stores not merely come up in handy during spells of cold weather when nutrient is scarce but likewise are often important for fueling mating and egg production. The less lipid a hibernator uses during the winter, the more it has left to fuel breeding the following leap.

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Environmental Drivers of Behavior

Libin Zhang , ... Hao Song , in Developments in Aquaculture and Fisheries Scientific discipline, 2015

9.2.3 Aestivation

A. japonicus is a temperate species that exhibits a menses of low metabolic activeness known equally aestivation (encounter Affiliate xi for details). The most noticeable features of the aestivation period are cessation of feeding, weakening of activity patterns, gastrointestinal degradation, depressed metabolic activity, and body weight loss. When the water temperature rises to a threshold level (Table nine.3, Dong and Dong, 2009), sea cucumbers gradually stop feeding. During aestivation, they exhibit petty motion, and often remain still, while daily activities are reduced and most individuals are hiding under rocks or artificial substrata. Sheltering behavior during aestivation ways that divers have a hard time finding them. This is therefore a more difficult catamenia for surveying and harvesting sea cucumbers.

Table nine.iii. Threshold Temperatures Enhancing Aestivation in the Body of water Cucumber A. japonicus in Different Locations of its Geographic Distribution

Sites Body Weight (g) Threshold Temperature (°C) References
Nanao Bay, Japan 20 Tokushisa, 1915
Miyagi, Aichi, Tokushima, xix   ∼   22–xviii   ∼   23
Kagoshima, Hokkaido, Japan
Dalian, Sea area, China 20   ∼   24.5 Ji et al., 2007
Dalian, Indoor, China 146.7   ±   5.5 24.5   ∼   25.five Dong and Dong, 2006a
84.0   ±   three.v 24.v   ∼   25.5
42.5   ±   2.1 24.5   ∼   25.v
Penglai, Sea expanse, China 25   ∼   85 24.1 Liu et al., 1996
86   ∼   160 22.ix
>160 21.viii
Qingdao, Ocean surface area, China Big size 20 Yu and Song, 1999
Small size 25
Qingdao, Indoor, China 37.3   ±   4.one 26 Ji et al., 2008

From Dong and Dong, 2009

In Communist china, A. japonicus enters aestivation later on at college latitudes; in mid- to tardily June in the southern coast of Shandong Province, in early or mid-July in northern littoral areas of Shandong, and in mid- to tardily August in the Liaodong Peninsula coast (Dalian area). Notwithstanding, aestivation ends roughly at the aforementioned time everywhere, normally between late October and early on November. Therefore, aestivation lasts a minimum of 2 months and a maximum of virtually four months, depending on the region.

The aestivation of A. japonicus is triggered by internal (metabolic) and external factors (food, light, temperature). Seawater temperature is the most directly and most meaning factor of all. In the waters of northern Cathay, it appears that the temperature that induces aestivation varies between 20.0 and 24.v   °C. Those differences could exist related to the environments in which the sea cucumbers live or to different combinations of physical conditions.

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Thermoregulation in Animals: Some Fundamentals of Thermal Biology☆

Udo Gansloßer Gianna Jann , in Encyclopedia of Ecology (2d Edition), 2019

Torpor and Heterothermy

In temperature conformic ectotherms that are generally unable to increase their temperatures past internal ways, torpor or hibernation in winter or aestivation in hot, dry summers (the latter being shown, eastward.g., by lungfish or desert snails), is superficially similar to torpor in endotherms, however external energy sources are needed to end this state. In insects, a special form of arrested development called diapause, triggered past combination of hormonal, photoperiodic and nutritional factors, is a common strategy. Heterotherm animals are also characterized past changing their body temperatures and basal metabolism according to external atmospheric condition. A further distinction is oftentimes fabricated between homeotherms that are capable of regulating their torso temperatures with a very narrow range, and endotherms, species that are capable of regulating the body temperature at all, just not necessarily within a narrow range of only a few degrees centigrade.

Torpor is a condition which is characterized by a low body temperature and depression BMR. In so far, it seems to be a variation of temperature conformity instead of regulation. However in that location is an of import departure betwixt heterothermy and ectothermy: heterotherms are capable of increasing body temperatures (generally past increasing BMR) by their own, internal means whereas ectotherms demand some external source of warmth or other free energy for this waking up! Thermoregulation is never totally switched off during torpor, instead the setpoint for the onset of thermoregulatory activities is only temporarily lowered. Heterothermy has long been regarded as a primitive character of animals not still gear up for real homeothermy. It is a finely tuned adaptive strategy.

Torpor is farther divided by the regularity and seasonality of its occurrence and triggering mechanisms. Long torpor, mostly in the form of hibernation, is often extended for several months and is characterized by a lowering of body temperatures nether 10°C, and metabolic rate is about v% of BMR during active phases. Notwithstanding even deep hibernating torpor in all species studied so far is interrupted by curt periods of activity at normal body temperature, and these intervals are internally triggered.

Big mammals, such every bit bears, also go into torpor. However, this is only shallow torpor, with a reduction of their body temperatures by about 5°C, heart rates and metabolic rates are reduced by up to xxx%. Even so, hibernating bears can stay in their dens for several months, and their energy needs are covered by called-for fat. Some other physiological adaptations, such equally recycling urea into essential amino acids, and most probably besides calcium storage and recycling, accept been developed in these big carnivores besides. Large bears are non the only carnivores capable of larger torpor. Raccoons and Raccoon dogs at least in parts of their range likewise enter torpor for several weeks.

Short term torpor of several days or even daily torpor is much more widespread also amidst larger mammals: both American and European badgers accept been shown to enter daily or short term torpors, with body temperatures of near 28°C. Daily or brusk term torpor in general reduces trunk temperatures to about 10–30°C, metabolic rates are reduced to values of nearly 30%. Nearly mammal species entering daily torpor are small and nocturnal such as modest marsupials (dasyurids, petaurids and didelphids), mouse lemurs, hedgehogs, tenrecs, shrews, or bats. However, in almost all these taxa (except primates) we also discover species showroom deep torpor with body temperatures around 5°C and durations of x   days to several months (marsupials: Cercartetus nanus, a burramyid, reaches values of 2% of its normal BMR for several weeks, European hedgehog: free energy of about 4% normal rate, Tb around 5°C for at least 10   days, bats: Myotis −   ii°C–+   five°C Tb, energy nearly 1% BMR etc.). Heterothermy among birds is unlike in several aspects: it by and large occurs during the night, Tb is lowered by about 5°C, it also occurs in rather large species such as Turkey vultures, but, and this is a phenomenon whose adaptive significance is nonetheless unclear, energetic need is mostly higher than BMR! Only few species, such as some colibris, tend to reduce Tb to values beneath eighteen°C, some below ten°C, and only ane species of bird, a night jar from Due north America, Phalaenoptilus nuttallii, goes into torpor for several days in consecution, and as well reaches a Tb as low as half-dozen°C. Information technology is not even so totally clear, neither for birds nor mammals, which physiological mechanisms are responsible for reawakening. One hypothesis assumes that a combination of low blood pressure and accumulation of toxic metabolic products in the claret pressure to cleanse the blood from these waste products, another assumes a biological clock (maybe fifty-fifty the cyclic on which is besides being showed by lower body temperatures). In any case, the terminate of a torpor stage is accomplished past agile warming the velocity of which mostly depends on trunk size: small animals of about x   1000 body weight can proceeds almost 1°C/min, species of near 1   kg only accomplish 0.5°C/min and species over 10   kg are existent slow walkers, with increases of about 0.1°C/min. This seems to be a constraint on the capability for deep torpor in large species.

Circadian and circannual changes in metabolic rates, circannual changes in body weight and weight of internal organs, changes in intestinal transport rates (especially peptide transport), and decreases of centre rate with decreasing subcutaneous (hence ambient) temperatures take been demonstrated in cold-adapted ungulates, for example, Cherry-red deer and chamois in the Alps.

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The Imperiled Amphibian and Reptiles of the Seasonally Dry out Forests of Guatemala

Daniel Ariano-Sánchez Johana Gil-Escobedo , in Reference Module in Earth Systems and Environmental Sciences, 2021

The hereafter of the conservation of the imperiled amphibian and reptiles of the dry forest of Guatemala

The endemic herpetological jewels listed earlier are highly susceptible to habitat destruction, fragmentation and climate change as their survival depend on finding suitable habitats for aestivation during the hot and dry season of the twelvemonth. Efforts on constructive habitat protection of intact dry forest, such as Heloderma Natural Reserve (a privately owned protected area), need to be strengthened and expanded in Motagua Valley. Dry out forest conservation, habitat restoration, corridor connectivity, education programs, law reinforcement and improve agronomical practices are fundamental for the long-term survival of these imperiled species in the wild. The practiced news are that conservation efforts leaded past HNR, with the aid of local communities, accept increased the local population of the Guatemalan Beaded Lizard from ~200 individuals in 2004 to ~600 individuals in 2021. In addition, HNR carries out an education program since 2014 that reaches between 550 and 600 children every yr in regional elementary schools. These education programs have been done with the support of the International Iguana Foundation (IIF) and the Danish NGO Forgotten Nature. These programs have had a significant bear upon in saving the Motagua Spiny-tailed iguana and the Guatemalan Beaded Lizards by reducing the number killed by local people for bushmeat (in the case of the iguana), or past the mistaken folklore-based belief that they are dangerous (in the case of the Guatemalan Beaded Cadger) (Fig. four).

Fig. 3

Fig. 4. Local schoolhouse children learn about the Guatemalan Beaded Lizard at Heloderma Natural Reserve.

 Photo by Johana Gil-Escobedo.

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Order Odonata

Frank Suhling , ... Jan van Tol , in Thorp and Covich's Freshwater Invertebrates (Fourth Edition), 2015

Regulated Life Cycles

These life cycles are characterized past a diapause, i.east., endogenous regulation, in 1 or more than than ane life cycle stage. The diapause serves to cope with unsuitable environmental weather, such every bit common cold (hibernation, winter) or drought (aestivation/siccatation, dry out season). The diapause may however be facultative, i.e., absent in populations living in more favorable environments.

Obligate Diapause in the Egg Stage: Hatching from the egg occurs in jump or with onset of the rainy season, and larval evolution takes 2–4   months. The embryonic diapause may take place in various developmental stages. In the temperate zone, it occurs in late summertime and wintertime. The life cycle is obligatory univoltine equally in nigh species of Lestes and sure Sympetrum species.

Facultative Diapause every bit Prereproductive Adult: In these species, imagines aestivate during the dry season when habitats may dry out. Nearly species are univoltine. Examples are phytotelmata and tree-hole breeders in seasonal rainforests, due east.1000., 1000. caerulatus, too as species occurring in savanna habitats (east.g., Crocothemis divisa Karsch, 1898), and species of summer dry subtropics. The variation betwixt populations may be great in species of this type, depending on the surroundings in which they occur. A well-studied example is Sympetrum striolatum, which aestivates for 3–4   months as prereproductive adult in the Mediterranean. In central Europe, aestivation is facultative and shorter; and in northern Europe, it seems to be nonexistent. Also, the egg evolution may be direct or interrupted by a diapause.

Hibernating Adult: An obligate diapause in the prereproductive adult occurs in belatedly summer and winter as in univoltine Sympecma Burmeister, 1839, species. Reproduction occurs in early spring and development lasts 3–iv   months.

Facultative Diapause Mainly in the Larval Stage: This usually occurs in i or more later instars in winter, or in summer and winter. Occasionally there may likewise exist an egg diapause in winter. The development is uni- to partivoltine and requires three or more years (sometimes upwardly to 10   years at or higher up the Arctic Circumvolve). This life cycle type is probably present in virtually temperate and boreal species simply also in many lotic waters and high altitude species in the tropics.

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