scholarly journals Aquatic and Aerial Respiration Rates, Muscle Capillary Supply and Mitochondrial Volume Density in the Airbreathing Catfish (Clarias Mossambigus) Acclimated to Either Aerated or Hypoxic Water

1983 ◽  
Vol 105 (1) ◽  
pp. 317-338 ◽  
Author(s):  
IAN A. JOHNSTON ◽  
LYNNE M. BERNARD ◽  
GEOFFREY M. MALOIY
Keyword(s):  
Respiration Rate ◽  
Fibre Volume ◽  
Acute Exposure ◽  
Routine Activity ◽  
Breathing Frequency ◽  
Air Breathing ◽  
Aerial Respiration ◽  
Capillary Supply ◽  
Mitochondrial Volume ◽  
Hypoxia Acclimation

Specimens of the African air-breathing catfish Clarias mossambicus were acclimated to either aerated (PwO2 15.3 KPa) or hypoxic (PwO2 2.4KPa) water for up to 27 days at 20 °C. Routine respiration rate for fish acclimated to aerated water was 85.7 mlO2 (kgbodyweight)−1 h−1. Gas exchange across the suprabranchial chambers accounted for 25% of the total. In aerated water the interval between air-breaths varied from 1.4 to 30.6 min. On acute exposure to hypoxia air-breathing frequency was unaltered (6.3 h−1) although aerial respiration rate increased by 70%. This suggests that ventilation of the suprabranchial chambers is variable and that air-breathing frequency is a poor measure of air-breathing effort. Total respiration decreased by 46% on acute exposure to hypoxia (PwO2 2.4 KPa), reflecting a reduction in routine activity. Following acclimation to hypoxia, airbreathing frequency (8.1 h−1) was higher and total routine respiration rate increased from 46.3 to 67.8 mlO2 kg−1h−1. The increased oxygen consumption with hypoxia acclimation was largely the result of an increase in aquatic respiration from 10.4 to 27.5 mlO2kg−1h−1 Measurements were made of mitochondrial volume densities [Vv(mt,f)] and capillary supply to fast and slow myotomal muscles. The fraction of fibre volume occupied by mitochondria was 15 percnt; for slow and 2.5% for fast muscles. Values for [Vv(mt,f)] obtained for fish slow fibres are much higher than for homologous muscles in birds and mammals and show a good correlation with capillary density [NA(c,f)]. Hypoxia acclimation did not result in changes in either muscle Vv(mt,f) or NA(c,f). It is suggested that increased ventilation of the suprabranchial chambers and greater oxygen extraction across the gills obviates the need for modifications in these parameters.

The Transition to Air Breathing in Fishes:: I. Environmental Effects on the Facultative Air Breathing of Ancistrus Chagresi and Hypostomus Plecostomus Loricariidae

1982 ◽  
Vol 96 (1) ◽  
pp. 53-67 ◽  
Author(s):  
JEFFREY B. GRAHAM ◽  
TROY A. BAIRD
Keyword(s):  
Fish Species ◽  
Environmental Effects ◽  
Breathing Rate ◽  
Breathing Frequency ◽  
Rate Reduction ◽  
Air Breathing ◽  
Aquatic Respiration ◽  
Saturated Water ◽  
Important Regulator ◽  
Hypoxia Acclimation

In response to progressive aquatic hypoxia, the armoured loricariid catfishes Ancistrus chagresi and Hypostomus plecostomus become facultative air-breathers and utilize their stomachs as accessory air-breathing organs. Hypostomus initiates air breathing at a higher aquatic O2 tension (Pw, Ow, O2) than does Ancistrus (60 v. 33 mmHg). Once begun, the air-breathing frequencies of both species increase with decreasing Pw, Ow, O2; the frequency of Ancistrus, however, is greater than and increases more with hypoxia than does that of Hypostomus, which appears to be a more efficient air breather. Hypoxia acclimation reduces the air-breathing rate of both species. A larger rate reduction occurs in Ancistrus, which, however, continues to require more frequent breaths than Hypostomus. Hypoxia acclimation does not affect the air-breathing threshold of either species, suggesting that external O2 receptors initiate facultative air breathing. In progressive aquatic hypercapnia Ancistrus has a lower air-breathing CO2 threshold (8.7 mmHg) than Hypostomus (12.8 mmHg). However, in some tests, individual fish of both species did not initiate air breathing even at Pw, COw, CO2 as high as 21 mmHg. Also, air breathing evoked by hypercapnia was short-lived; both species quickly compensated for this gas and resumed exclusively aquatic respiration within a few hours of exposure. Thus, CO2 is not an important regulator of air breathing in these species. Between 25 and 35 °C, the Pw, Ow, O2 air breathing threshold of Ancistrus is temperature-independent, but air-breathing frequency increases with temperature. Ancistrus and Hypostomus do not breathe air in normoxic (air-saturated) water; their air-breathing responses are evoked by environmental hypoxia. This is fundamentally different from other fish species that breathe air in normoxia in order to meet heightened metabolic demands. Also, the facultative air-breathing adaptations of Ancistrus and Hypostomus differ in scope and magnitude from those utilized by species that breathe air in nor-moxia and adapt to hypoxia by increasing air-breathing rate.

The respiratory behaviour of an air-breathing catfish, Clarias macrocephalus (Clariidae)

1987 ◽  
Vol 65 (2) ◽  
pp. 348-353 ◽  
Author(s):  
David J. Bevan ◽  
Donald L. Kramer
Keyword(s):  
Dissolved Oxygen ◽  
Atmospheric Oxygen ◽  
Breathing Frequency ◽  
Dissolved Oxygen Concentration ◽  
Significant Cost ◽  
Air Breathing ◽  
Aerial Respiration ◽  
Travel Costs ◽  
Clarias Macrocephalus ◽  
Do So

Clarias macrocephalus are continuous, facultative air breathers. Individuals (7.6–20.9 g) survived more than 25 days in normoxic water without surface access. Buoyancy decreased and water-breathing frequency increased when surface access was denied, but growth rate and the frequency of air-breathing attempts did not change. We examined air-breathing and water-breathing frequency in shallow (60 cm) and deep (235 cm) water under normoxic (8.0 mg O2∙L−1) and hypoxic (0.3, 0.7, 1.2, and 2.0 mg O2∙L−1) conditions to examine how changes in the travel costs of breathing affected the use of each respiratory mode. Air-breathing and water-breathing frequency increased as dissolved oxygen decreased from 8.0 to 2.0 mg O2∙L−1. Below this level air breathing continued to increase, but water breathing dropped sharply. At higher levels of dissolved oxygen (8.0 and 2.0 mg O2∙L−1), fish in deep water had lower air-breathing and higher water-breathing frequencies than fish in shallow water. Vertical distance travelled and time spent in air breathing increased with increasing depth and with decreasing level of dissolved oxygen. These results support the hypotheses that travel is a significant cost of aerial respiration and that fish respond to increases in this cost by decreasing their use of atmospheric oxygen when dissolved oxygen concentration permits them to do so.

scholarly journals Social dynamics obscure the effect of temperature on air breathing in Corydoras catfish

2020 ◽  
Vol 223 (21) ◽  
pp. jeb222133
Author(s):  
Mar Pineda ◽  
Isabel Aragao ◽  
David J. McKenzie ◽  
Shaun S. Killen
Keyword(s):  
Social Dynamics ◽  
Oxygen Demand ◽  
Routine Activity ◽  
Effect Of Temperature ◽  
Intermittent Flow ◽  
Acclimation Temperature ◽  
Breathing Frequency ◽  
Research Attention ◽  
Air Breathing ◽  
The Individual

ABSTRACTIn some fishes, the ability to breathe air has evolved to overcome constraints in hypoxic environments but comes at a cost of increased predation. To reduce this risk, some species perform group air breathing. Temperature may also affect the frequency of air breathing in fishes, but this topic has received relatively little research attention. This study examined how acclimation temperature and acute exposure to hypoxia affected the air-breathing behaviour of a social catfish, the bronze corydoras Corydoras aeneus, and aimed to determine whether individual oxygen demand influenced the behaviour of entire groups. Groups of seven fish were observed in an arena to measure air-breathing frequency of individuals and consequent group air-breathing behaviour, under three oxygen concentrations (100%, 60% and 20% air saturation) and two acclimation temperatures (25 and 30°C). Intermittent flow respirometry was used to estimate oxygen demand of individuals. Increasingly severe hypoxia increased air breathing at the individual and group levels. Although there were minimal differences in air-breathing frequency among individuals in response to an increase in temperature, the effect of temperature that did exist manifested as an increase in group air-breathing frequency at 30°C. Groups that were more socially cohesive during routine activity took more breaths but, in most cases, air breathing among individuals was not temporally clustered. There was no association between an individual's oxygen demand and its air-breathing frequency in a group. For C.aeneus, although air-breathing frequency is influenced by hypoxia, behavioural variation among groups could explain the small overall effect of temperature on group air-breathing frequency.

scholarly journals Muscle capillary supply in harbor seals

2001 ◽  
Vol 90 (5) ◽  
pp. 1919-1926 ◽  
Author(s):  
Shane B. Kanatous ◽  
Robert Elsner ◽  
Odile Mathieu-Costello
Keyword(s):  
Surface Area ◽  
Skeletal Muscles ◽  
Harbor Seals ◽  
Capillary Length ◽  
Capillary Supply ◽  
Terrestrial Mammals ◽  
Lower Volume ◽  
Fiber Number ◽  
Mitochondrial Volume ◽  
Comparable Size

The purpose of this study was to examine muscle capillary supply in harbor seals. Locomotory and nonlocomotory muscles of four harbor seals (mass = 17.5–41 kg) were glutaraldehyde-perfusion fixed and samples processed for electron microscopy and analyzed by morphometry. Capillary-to-fiber number and surface ratios were 0.81 ± 0.05 and 0.16 ± 0.01, respectively. Capillary length and surface area per volume of muscle fiber were 1,495 ± 83 mm/mm3 and 22.4 ± 1.6 mm2/mm3, respectively. In the locomotory muscles, we measured capillary length and surface area per volume mitochondria (20.1 ± 1.7 km/ml and 2,531 ± 440 cm2/ml). All these values are 1.5–3 times lower than in muscles with similar or lower volume densities of mitochondria in dogs of comparable size. Compared with terrestrial mammals, the skeletal muscles of harbor seals do not match their increased aerobic enzyme capacities and mitochondrial volume densities with greater muscle capillary supply. They have a smaller capillary-to-fiber interface and capillary supply per fiber mitochondrial volume than terrestrial mammals of comparable size.

THE EFFECTS OF ALTERED AQUATIC AND AERIAL RESPIRATORY GAS CONCENTRATIONS ON AIR-BREATHING PATTERNS IN A PRIMITIVE FISH (AMIA CALVA)

1993 ◽  
Vol 181 (1) ◽  
pp. 81-94 ◽  
Author(s):  
M. S. Hedrick ◽  
D. R. Jones
Keyword(s):  
Air Flow ◽  
The Body ◽  
Type I ◽  
Type Ii ◽  
Breathing Frequency ◽  
Breathing Patterns ◽  
Flow Measurements ◽  
Air Breathing ◽  
Gas Bladder ◽  
Amia Calva

The mechanisms and physiological control of air-breathing were investigated in an extant halecomorph fish, the bowfin (Amia calva). Air flow during aerial ventilation was recorded by pneumotachography in undisturbed Amia calva at 20–24°C while aquatic and aerial gas concentrations were independently varied. Separation of aquatic and aerial gases was used in an attempt to determine whether Amia calva monitor and respond to changes in the external medium per se or to changes in dissolved gases within the body. Air flow measurements revealed two different types of ventilatory patterns: type I air-breaths were characterized by exhalation followed by inhalation; type II air-breaths, which have not been described previously in Amia calva, consisted of single inhalations with no expiratory phase. Expired volume (Vexp) for type I breaths ranged from 11.6+/−1.1 to 26.7+/− 2.9 ml kg-1 (95 % confidence interval; N=6) under normoxic conditions and was unaffected by changes in aquatic or aerial gases. Gas bladder volume (VB), determined in vitro, was 80 ml kg-1; the percentage of gas exchanged for type I breaths ranged from 14 to 33 % of VB in normoxia. Fish exposed to aquatic and aerial normoxia (PO2=19-21 kPa), or aerial hypercapnia (PCO2=4.9 kPa) in normoxic water, used both breath types with equal frequency. Aquatic or aerial hypoxia (PO2=6-7 kPa) significantly increased air-breathing frequency in four of eight fish and the ventilatory pattern changed to predominantly type I air-breaths (75–92 % of total breaths). When fish were exposed to 100 % O2 in the aerial phase while aquatic normoxia or hypoxia was maintained, air-breathing frequency either increased or did not change. Compared with normoxic controls, however, type II breaths were used almost exclusively (more than 98 % of total breaths). Type I breaths appear to be under feedback control from O2-sensitive chemoreceptors since they were stimulated by aquatic or aerial hypoxia and were nearly abolished by aerial hyperoxia. These results also indicate that Amia calva respond to changes in intravascular PO2; however, externally facing chemoreceptors that stimulate air-breathing in aquatic hypoxia cannot be discounted. Type II air- breaths, which occurred in aerial hyperoxia, despite aquatic hypoxia, appear to be stimulated by reductions of VB, suggesting that type II breaths are controlled by volume-sensitive gas bladder stretch receptors. Type II breaths are likely to have a buoyancy-regulating function.

Aerial respiration in the catfish, Corydoras aeneus (Callichthyidae)

1980 ◽  
Vol 58 (11) ◽  
pp. 1984-1991 ◽  
Author(s):  
Donald L. Kramer ◽  
Martha McClure
Keyword(s):  
Dissolved Oxygen ◽  
Air Breathing ◽  
Aerial Respiration ◽  
Posterior Intestine ◽  
Partial Pressures

Corydoras aeneus uses the posterior intestine for aerial respiration. Ventilation takes place in a rapid dash to the surface. Air is inspired during the 0.06–0.07 s that the mouth is exposed; expiration occurs via the anus as the fish begins to dive. Air breathing occurs at all dissolved oxygen partial pressures [Formula: see text] from 0 Torr (1 Torr = 133.322 Pa) to at least 140 Torr, but frequency, ranging from 1–45 breaths∙h−1, is negatively correlated with [Formula: see text]. Corydoras aeneus survive at least 9 days without air breathing under normoxic conditions [Formula: see text] but below 15 Torr, only fish able to reach the surface survive. Air-breathing rates are significantly influenced by variations in depth between 10–120 cm but the pattern of response depends on [Formula: see text] and involves changes in activity.

A Functional Analysis of the Aquatic and Aerial Respiratory Movements of an African Lungfish, Protopterus Aethiopicus, With Reference to the Evolution of the Lung-Ventilation Mechanism in Vertebrates

1969 ◽  
Vol 51 (2) ◽  
pp. 407-430 ◽  
Author(s):  
B. R. MCMAHON
Keyword(s):  
Lung Ventilation ◽  
Air Breathing ◽  
Aerial Respiration ◽  
X Ray ◽  
African Lungfish ◽  
Pump Mechanism ◽  
Elasmobranch Fishes ◽  
Breathing Mechanism ◽  
Respiratory Movements ◽  
Branchial Region

1. The anatomy of the head and branchial region of Protopterus has been studied by dissection and section techniques to show the relation between skeletal and muscular elements. X-ray cinematographic, pressure and electromyographic techniques have been used to show how the muscular and skeletal systems interact to produce the respiratory movements. The mechanisms involved in aquatic and aerial respiration in Protopterus have thus been elucidated. 2. The mechanisms of branchial irrigation has been shown to be basically similar to that seen in teleost and elasmobranch fishes, and also similar to that seen in larval amphibia. 3. The aerial cycle is composed of a series of aquatic-type cycles, each of which is modified slightly to serve a specific function in the aerial cycle. Inspiration occurs by a buccal force-pump mechanism. Expiration occurs by the release of compressed pulmonary gas, aided by the elasticity of the lung wall. 4. In this animal the air-breathing mechanism is derived from the aquatic mechanism. The modifications are relatively simple and produce an efficient ventilation mechanism. 5. No movements of the ribs can be seen associated with the respiratory cycles. It is suggested that the aspiratory ventilation mechanisms were not present in the prototetrapods and were not evolved until a later, more fully terrestrial stage was reached. 6. The evidence suggests that the air-breathing mechanism of the tetrapods was powered by a buccal force-pump mechanism which evolved directly from the aquatic system. The evolution of a new mechanism for lung ventilation in the prototetrapods is considered unnecessary.

Sign in / Sign up

Export Citation Format

Share Document