Metabolic responses to changing environmental conditions in the brackish water polychaetes Marenzelleria viridis and Hediste diversicolor

1995 ◽  
Vol 121 (4) ◽  
pp. 693-699 ◽  
Author(s):  
D. Fritzsche ◽  
J.-A. von Oertzen
Keyword(s):  
Environmental Conditions ◽  
Brackish Water ◽  
Metabolic Responses ◽  
Hediste Diversicolor ◽  
Marenzelleria Viridis

Wetting and the physiological responses of grain-fed cattle in a heated environment

2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader
Keyword(s):  
Heat Stress ◽  
Experimental Design ◽  
Rectal Temperature ◽  
Environmental Conditions ◽  
Dry Matter ◽  
Physiological Responses ◽  
Dry Matter Intake ◽  
Metabolic Responses ◽  
Hot Days ◽  
Carry Over

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.

scholarly journals Disentangling environmental drivers of circadian metabolism in desert-adapted mice

2020 ◽  
Author(s):  
Jocelyn P. Colella ◽  
Danielle M. Blumstein ◽  
Matthew D. MacManes
Keyword(s):  
Environmental Conditions ◽  
Metabolic Responses ◽  
Environmental Drivers ◽  
Metabolic Phenotyping ◽  
Physiological Adaptations ◽  
Cold Tolerant ◽  
Environmental Transitions ◽  
Summary Statement ◽  
Flow Through ◽  
Peromyscus Eremicus

ABSTRACTMetabolism is a complex phenotype shaped by natural environmental rhythms, as well as behavioral, morphological, and physiological adaptations. Although historically studied under constant environmental conditions, continuous metabolic phenotyping through environmental transitions now offers a window into the physiological responses of organisms to changing environments. Here, we use flow-through respirometry to compare metabolic responses of the desert-adapted cactus mouse (Peromyscus eremicus) between diurnally variable and constant environmental conditions. We contrast metabolic responses to circadian cycles in photoperiod, temperature, and humidity, against those recorded under constant hot-and-dry and constant cold-and-wet conditions. We found significant sexual dimorphism in metabolic responses, despite no measurable difference in body weight. Males seem to be more heat tolerant and females more cold tolerant. Under circadian environmental cycling, the ratio of CO2 produced to O2 consumed (the respiratory quotient or respiratory exchange ratio) reached greater than one, a pattern that strongly suggests that lipogenesis is contributing to the production of energy and endogenous water in this species. This hypothesis is consistent with the results of previous dehydration experiments in this species, which documented significant weight loss in response to dehydration, without other physiological impairment. Our results are also consistent with historical descriptions of circadian torpor in this species (torpid by day, active by night), but reject the hypothesis that this pattern is driven by food restriction or negative water balance, as both resources were available to animals throughout the experiments.SUMMARY STATEMENTContinuous metabolic phenotyping of desert-adapted cactus mice (Peromyscus eremicus) identifies significant metabolic differences between the sexes and circadian patterning consistent with lipogenesis and environmental entrainment.

scholarly journals Characteristic trace fossils from Miocene brackish-water deposits in the Niger Delta, Nigeria

Geologos ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 111-125 ◽  
Author(s):  
Sunny C. Ezeh ◽  
Wilfred A. Mode ◽  
Berti M. Ozumba
Keyword(s):  
Environmental Conditions ◽  
Brackish Water ◽  
Niger Delta ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Fossil Assemblages

Abstract Miocene deposits in the eastern portion of the Greater Ughelli, Central Swamp and Coastal Swamp depobelts contain well-developed brackish-water trace fossil assemblages. Twelve ichnogenera have been identified, namely: Asterosoma, Bergaueria, Chondrites, Gyrolithes, Thalassinoides, Lockeia, Palaeophycus, ?Conichnus, Planolites, Siphonichnus, Skolithos and Diplocraterion. In addition, common non-descript, passively filled burrows and fugichnia (escape structures) have also been observed. The above-mentioned ichnogenera and associated non-descript structures can be arranged into six distinct and recurring ichnoassociations within the Greater Ughelli, Central Swamp and Coastal Swamp depobelts. Each ichnoassociation is comprised of a group of trace fossils which collectively reflect specific environmental conditions during deposition of these Miocene strata. All trace fossil assemblages illustrate deposition in nearshore, restricted settings. Ichnological and sedimentological criteria which may be utilized to recognise brackish-water deposits are discussed and illustrated in pictures of the cores studied.

Pseudo-polymorphism in Clithon oualaniensis

1982 ◽  
Vol 216 (1203) ◽  
pp. 147-157 ◽  
Keyword(s):  
Hong Kong ◽  
Environmental Conditions ◽  
Brackish Water ◽  
First Impressions ◽  
Small Contribution ◽  
Malay Peninsula ◽  
Polygenic Inheritance ◽  
Developmental Physiology ◽  
Secondary Phenomenon ◽  
Apparent Stability

The highly variable brackish-water snail Clithon oualaniensis (Lesson1831) was first studied in Hong Kong, Ceylon and Malaya-Singapore. Populations within these regions are closely similar, but there are consistent differences between regions. Subsequently, particularly round the Malay Peninsula, orderly changes of variants have come to light. This raises the question of how these have come into being and what is responsible for their apparent stability. Contrary to first impressions, most of the variability of Clithon and of certain species of Umbonium and Nerita is pseudo-polymorphic in nature. Conventional polymorphism seems to make but a small contribution. Quasi-continuous variation and pseudo-polymorphism are essentially the same phenomenon. Both arise by the interaction between polygenic inheritance and environmental conditions. Whether the resulting pheno­types are continuous or discontinuous depends on the developmental physiology of the organs or structures involved and is thus a secondary phenomenon.

scholarly journals Contributions to the taxonomy and ecology of the Chironomus plumosus sibling species aggregate (Diptera: Chironomidae): the brackish water populations of Tvärminne area, Finland

2006 ◽  
Vol 17 (4) ◽  
Author(s):  
Mauri Hirvenoja
Keyword(s):  
Baltic Sea ◽  
Sibling Species ◽  
Environmental Conditions ◽  
Brackish Water ◽  
Undescribed Species ◽  
Pupal Exuviae ◽  
Biological Station ◽  
Chironomus Plumosus ◽  
Direct Observations ◽  
Sea Area

Based on pupal exuviae, two sympatric pupal forms of Chironomus plumosus auctt. are present in the museum materials collected in 1952–1962 from the brackish water near the Tvärminne Biological Station at the northern Baltic Sea. The predominating undescribed type of the pupal exuviae is called here the “Balticmarine species” (possible C. plumosus sensu Linnaeus; direct observations by Linnaeus of Tipula plumosa from freshwater are not on record). Its pupal exuviae and the associated female and male from the Tvärminne population are described. Attempts to find larvae of the genus Chironomus in the sea area of Tvärminne for the renewed and more complete studies failed during the 1980s and 1990s. Only two larvae of the undescribed species of the karyological Chironomus plumosus group were captured. The possible reasons for the supposedly changed environmental conditions are discussed.

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