Assessment of Activity-Specific Metabolism of Aquatic Organisms: An Improved System

1992 ◽  
Vol 49 (6) ◽  
pp. 1142-1148 ◽  
Author(s):  
Ronald W. Davies ◽  
Frederick J. Wrona ◽  
V. Kalarani
Keyword(s):  
Oxygen Consumption ◽  
Individual Variation ◽  
Aquatic Organisms ◽  
Size Classes ◽  
Interspecific Differences ◽  
Nephelopsis Obscura ◽  
Highly Sensitive ◽  
Similar Weight ◽  
Flow Through

An improved flow-through respirometer capable of assessing activity-specific metabolism of aquatic organisms is presented and assessed. The system is highly sensitive and versatile, since it continuously monitors and records activity-specific oxygen consumption readings for periods up to 72 h and is capable of detecting differences in metabolism of individual specimens of similar weight. Using this system, we demonstrated individual variation and intraspecific differences in metabolism between two size classes of the freshwater leech Nephelopsis obscura and interspecific differences between N. obscura and another freshwater leech, Erpobdella montezuma, and compared these findings with the metabolism of the amphipod Hyalella montezuma.

Intra- and Interspecific Differences in the Response of Two Lentic Species of Leeches to Seasonal Hyperoxia

1991 ◽  
Vol 48 (6) ◽  
pp. 1124-1127 ◽  
Author(s):  
Ronald W. Davies ◽  
T. E. Gates
Keyword(s):  
Reproductive Success ◽  
Seasonal Movements ◽  
Percent Survival ◽  
Size Classes ◽  
Interspecific Differences ◽  
Nephelopsis Obscura ◽  
Microhabitat Distribution ◽  
Flow Through ◽  
Ecological Success ◽  
Higher Temperature

Intra- and interspecific differences in survivorship of Nephelopsis obscura and Erpobdella punctata exposed to hyperoxia (200 or 300%) at spring (5 °C) and summer (20 °C) water temperatures were examined in a flow-through system. In general, percent survival and time of 50% survival increased with leech size and decreased with higher temperature for both species. All size classes could survive the maximum recorded duration of hyperoxia in the spring, and we conclude that spring hyperoxia probably does not directly affect the ecological success or microhabitat distribution of either species. At 20 °C, medium and large E. punctata had much higher survivorship than N. obscura. As summer hyperoxia can last for 30 d, these differences could contribute to changes in numerical dominance. Intra- and interspecific differences in response to hyperoxia may also influence seasonal movements between different microhabitats of different size classes of N. obscura and E. punctata. We suggest that seasonal and annual variability in littoral hyperoxia regimes can differentially influence the survivorship, reproductive success, and microhabitat distribution of many macroinvertebrates.

Influence of Overwintering Stresses on Respiration Throughout the Life History of the Freshwater Leech, Nephelopsis obscura

1993 ◽  
Vol 50 (4) ◽  
pp. 841-845 ◽  
Author(s):  
Ronald W. Davies ◽  
V. Kalarani
Keyword(s):  
Life History ◽  
Oxygen Consumption ◽  
Dry Weight ◽  
Low Oxygen ◽  
Nephelopsis Obscura ◽  
Stage 4 ◽  
Metabolic Costs ◽  
History Of ◽  
Flow Through ◽  
Low Oxygen Concentration

The effects of overwintering stresses (low temperature, low oxygen concentration) on the life history patterns of activity-specific oxygen consumption by Nephelopsis obscura were determined using a flow-through respirometer system and compared with leeches hatched and maintained under summer conditions. While resting and active oxygen consumption increased with body dry weight, weight-specific resting (Rm) and active (Ra) oxygen consumption and aerobic scope (AS) decreased with increase in body weight in both winter and summer N. obscura. Rm in winter leeches was higher than in summer leeches, probably reflecting the higher metabolic costs of tissue repair and maintenance after winter stresses. Although Ra and AS in winter leeches were initially lower than in summer leeches, by stage 4, compensation in winter leeches was complete and by stage 6, over-compensation occurred. The effects of overwintering on oxygen consumption and AS persisted throughout the life history and help explain some of the differences in allocation of energy storage observed in winter and summer leeches.

Aquatic Oxygen Analysis

2018 ◽  
pp. 43-48
Author(s):  
John R. B. Lighton
Keyword(s):  
Oxygen Consumption ◽  
Aquatic Organisms ◽  
Practical Method ◽  
Oxygen Electrode ◽  
Metabolic Rates ◽  
Consumption Rates ◽  
Common Electrode ◽  
Flow Through ◽  
Common Problems ◽  
Electrode Membrane

Measuring oxygen consumption rates in aquatic media is the only practical method for determining the metabolic rates of cell cultures and aquatic organisms. This chapter describes the three principal variations of aquatic respirometry—closed and open system (or flow-through) respirometry, and headspace respirometry—together with procedures for calibrating aquatic respirometry systems, acquiring data from them, and analyzing the resulting data. Appendix 2 describes the operation of the widely used Clark dissolved oxygen electrode, the characteristics of common electrode membrane materials, and necessary routine maintenance. Common problems are discussed and trouble-shooting guides are included.

scholarly journals An electronic valve controller for current control during the recording of oxygen consumption in aquatic animals

1989 ◽  
Vol 8 (2) ◽  
pp. 74-76
Author(s):  
H. H. Du Preez ◽  
E. Grobler ◽  
J. M. Bell
Keyword(s):  
Oxygen Consumption ◽  
Control System ◽  
Oxygen Sensor ◽  
Aquatic Organisms ◽  
Current Control ◽  
Automatic Recording ◽  
Aquatic Animals ◽  
Power Circuit ◽  
Minute Period

A control system is described which allows the automatic recording of the oxygen consumption of five aquatic organisms and one control. The electronic valve controller operates six three-way valves which permit water from each of the six respiration chambers to flow successively past the oxygen sensor. A 38.4 kHz quartz cristal oscillator ensures a ten minute period and is not affected by disturbances on the power circuit.

Physiological variability in neonatal armadillo quadruplets: within- and between-litter differences

2000 ◽  
Vol 203 (11) ◽  
pp. 1733-1740 ◽  
Author(s):  
B. Bagatto ◽  
D.A. Crossley ◽  
W.W. Burggren
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Ventilation Rate ◽  
Dasypus Novemcinctus ◽  
Genetic Components ◽  
Physiological Variability ◽  
In Captivity ◽  
Flow Through ◽  
Physiological Characters

The role of genetics on neonatal physiological variability was examined in the nine-banded armadillo (Dasypus novemcinctus). Since armadillos give birth to only monozygous quadruplets, the genetic variation within litters is essentially zero. Quadruplets born in captivity were isolated and weighed within 8 h of birth. Oxygen consumption (V.(O2)) was measured in resting neonates by flow-through respirometry, heart rate obtained from an electrocardiogram and ventilation was measured by impedance techniques. Following the measurements, neonates were returned to the mother. Measurements were repeated at 4 and 8 days after birth. Mean heart rate significantly increased from 132 beats min(−1) on the day of birth to 169 beats min(−1) on day 8. Mean ventilation rate significantly decreased from 81 breaths min(−1) on the day of birth to 54 breaths min(−1) on day 8. During this same developmental period, mean mass significantly increased from 100 g to 129 g, and mean mass-specific oxygen consumption significantly decreased from 32.2 ml O(2)kg(−1)min(−1) to 28.6 ml O(2)kg(−1) min(−1). For all variables measured, within-litter variability was always significantly less than between-litter variability, confirming a ‘sibling effect’ that we attribute to the genetic components determining physiological characters.

Flow-through Respirometry: The Equations

2018 ◽  
pp. 94-100
Author(s):  
John R. B. Lighton
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Water Vapor ◽  
Carbon Dioxide Production ◽  
System P ◽  
Flow Through

This chapter demystifies respirometry equations, showing how they can be derived using a simple mental trick: focusing the analysis on the principal gas that is neither consumed nor produced by animals. The effect of dilution of oxygen by carbon dioxide, the enrichment of carbon dioxide by the consumption of oxygen, and the effects of water vapor on the concentrations of both gases are described and quantified. A system of eight equations is derived that allow oxygen consumption and carbon dioxide production to be calculated in practically any feasible flow-through respirometry system.

scholarly journals Preparation and Characterization of Perforated SERS Active Array for Particle Trapping and Sensitive Molecular Analysis

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 93 ◽  
Author(s):  
István Rigó ◽  
Miklós Veres ◽  
Tamás Váczi ◽  
Eszter Holczer ◽  
Orsolya Hakkel ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Silicon Surface ◽  
3D Structure ◽  
Raman Spectroscopic ◽  
Cell Trapping ◽  
Highly Sensitive ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Flow Through

A gold-coated array of flow-through inverse pyramids applicable as substrate for entrapment and immobilization of micro-objects and for surface enhanced Raman spectroscopic measurements was fabricated using bulk micromachining techniques from silicon. Surface morphology, optical reflectance, immobilization properties, and surface enhanced Raman amplification of the array were modelled and characterized. It was found that the special perforated periodic 3D structure can be used for parallel particle and cell trapping and highly sensitive molecular analysis of the immobilized objects.

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