ISSN:
1432-136X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The snake-head fish (Channa argus) is an obligate air-breather inhabiting fresh waters in the temperate zone of East Asia. Ventilation of the air-breathing organ and aerial gas exchange were measured in 1 to 2 kg specimens at 15 and 25°C. Additionally, the ventilatory responses to hypoxia and hypercapnia were studied. Aerial ventilation increased from 1.1 to 2.9 mlbtps·kg−1·min−1 when temperature rose from 15 to 25°C. Concomitantly, O2-uptake through airbreathing increased from 0.1 mlstpd·kg−1·min−1 (15°C) to 0.28 mlstpd·kg−1·min−1 (25°C), whereas aerial gas exchange was less important for CO2-climination as evident from low gas exchange ratios (0.16 at 15°C, 0.29 at 25°C). Ventilation increases only slightly in response to inspiration of hypercapnic gas mixtures or to hypoxic conditions in water. By contrast, inspiration of hypoxic gas mixtures caused marked increases of ventilation in particular at the higher temperature. Aerial ventilation inChanna is low compared to values for ectothermic pulmonary breathers. However, its ventilatory responses to hypoxia strikingly resemble those of reptiles: The most marked ventilatory response to hypoxia occurs at the higher temperature where the demands for O2 are greatest.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01101105
Permalink
