Blood Gases of the South American Lungfish, Lepidosiren paradoxa: A Comparison to Other Air-breathing Fish and to Amphibians

2016 ◽  
pp. 243-254
Author(s):  
Jalile Amin-Naves ◽  
A.P. Sanchez ◽  
M. Bassi ◽  
H. Giusti ◽  
F.T. Rantin ◽  
...  
Keyword(s):  
Blood Gases ◽  
South American ◽  
The South ◽  
Air Breathing

Respiratory Function in the South American Lungfish, Lepidosiren Paradoxa (Fitz)

1967 ◽  
Vol 46 (2) ◽  
pp. 205-218
Author(s):  
KJELL JOHANSEN ◽  
CLAUDE LENFANT
Keyword(s):  
Gas Exchange ◽  
Venous Blood ◽  
South American ◽  
O2 Uptake ◽  
The South ◽  
Mechanical Agitation ◽  
Air Breathing ◽  
Arterial Blood ◽  
Dissociation Curves ◽  
Branchial Arteries

1. Respiratory properties of blood and pattern of branchial and pulmonary gas exchange have been studied in twelve specimens of the South American lungfish, Lepidosiren paradoxa (Fitz). 2. Haematocrit ranged from 14 to 19% and blood oxygen capacity from 4.9 to 6.8 vol. %. The blood had a high affinity for O2 with a P50 value of 10.5 mm. Hg at Pco2 6 mm. Hg and temperature 23° C. The Bohr effect was low. 3. The CO2 dissociation curves show a steep ascending slope resulting in a relatively high CO2 combining power at physiological values of blood Pco2 The Haldane effect was small. Buffering capacity of oxygenated whole blood was high and exceeded that in typical water breathers. 4. Air breathing was prominent and intervals between air breaths varied from 3 to 10 min. Branchial respiratory movements were extremely shallow and showed a labile frequency. Air breathing was stimulated by hypoxic and hypercarbic water while hyperoxygenated water had no effect. Branchial respiratory rate showed a marked acceleration in response to mechanical agitation of the water. 5. Gas exchange was predominantly carried out by pulmonary breathing. In less than 10 min. the PO2 of expired gas dropped from 150 mm. Hg to less than 30 mm. Hg. The shallow branchial breathing with very low ventilation values resulted in a low O2 uptake via the gills. 6. Blood-gas analysis documented a clear selective passage of blood through the only partially divided heart. A consistently higher PO2 in dorsal aortic than in pulmonary arterial blood indicates a preferential passage of pulmonary venous blood to the anterior branchial arteries giving rise to most of the systemic circulation while systemic venous blood was largely conveyed to the most posterior branchial arteries giving rise to the pulmonary arteries. 7. The oxygen uptake for fish resting in water with access to air averaged 53.4 ml./hr./kg. Exposure to air lowered the O2 uptake markedly. 8. The increased importance of pulmonary breathing in Lepidosiren is discussed in relation to the transition from water breathing to air breathing.

scholarly journals Regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the South American sea lion (Otaria byronia)

2016 ◽  
Vol 219 (15) ◽  
pp. 2320-2330 ◽  
Author(s):  
Luis A. Hückstädt ◽  
Michael S. Tift ◽  
Federico Riet-Sapriza ◽  
Valentina Franco-Trecu ◽  
Alastair M. M. Baylis ◽  
...  
Keyword(s):  
South American ◽  
The South ◽  
Sea Lion ◽  
Regional Variability ◽  
Diving Physiology ◽  
Air Breathing ◽  
Marine Predator ◽  
South American Sea Lion ◽  
And Behavior

Aestivation in the South American lungfish, Lepidosiren paradoxa: Effects on cardiovascular function, blood gases, osmolality and leptin levels

2008 ◽  
Vol 164 (3) ◽  
pp. 380-385 ◽  
Author(s):  
Glauber dos Santos Ferreira da Silva ◽  
Humberto Giusti ◽  
Adriana Paula Sanchez ◽  
Jussara Márcia do Carmo ◽  
Mogens Lesner Glass
Keyword(s):  
Blood Gases ◽  
Cardiovascular Function ◽  
South American ◽  
The South

Blood gases and cardiovascular shunt in the South American lungfish (Lepidosiren paradoxa) during normoxia and hyperoxia

2010 ◽  
Vol 173 (1) ◽  
pp. 47-50 ◽  
Author(s):  
Mirian Bassi ◽  
Humberto Giusti ◽  
Glauber S. da Silva ◽  
Jalile Amin-Naves ◽  
Mogens L. Glass
Keyword(s):  
Blood Gases ◽  
South American ◽  
The South

Cnidochloa: A New Genus of Grasses from Brazil (Poaceae: Panicoideae: Paniceae)

2020 ◽  
Vol 105 (2) ◽  
pp. 183-194
Author(s):  
Fernando O. Zuloaga ◽  
Sandra S. Aliscioni ◽  
M. Amalia Scataglini
Keyword(s):  
New Genus ◽  
Phylogenetic Position ◽  
South American ◽  
The South ◽  
South American Species ◽  
Molecular Characters

Generic boundaries of the South American species Panicum longipedicellatum Swallen are explored and compared with allied genera of the tribe Paniceae. On the basis of morphological, anatomical, and molecular characters a new genus, Cnidochloa Zuloaga, is proposed. The phylogenetic position of the new genus within the Paniceae is evaluated.

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