Modulation of gill surface area does not correlate with oxygen loss in .

Air-breathing fish risk losing aerially sourced oxygen to ambient hypoxic water since oxygenated blood from the air-breathing organ returns through the heart to the branchial basket before distribution. This loss is thought to help drive the evolutionary reduction in gill size with the advent of air-breathing. In many teleost fish, gill size is known to be highly plastic by modulation of their anatomic diffusion factor (ADF) with inter-lamellar cell mass (ILCM).

Proportional increment of oxygen consumption, heart rate and core body temperature in the digesting Python bivittatus.

The Burmese python has a remarkable digestive physiology with large elevations of metabolic rate and heart rate following feeding. Here, we investigated the relationship between heart rate, oxygen consumption and core body temperature during digestion in five pythons (Python bivittatus) by implantation of data loggers. The snakes were placed in respirometers at 30±0.

Assessing metabolic rates in zebrafish using a 3D-printed intermittent-flow respirometer and swim tunnel system.

Zebrafish have become a widely used vertebrate model in physiology and reliable measures of their metabolic rate are needed. We have developed a 3D-printed respirometer and swim tunnel system and used it for obtaining accurate measurement of standard metabolic rate (SMR) and maximal, aerobic metabolic rate (MMR) in zebrafish under rest and maximal exercise, respectively. We compared a slow (stepwise) protocol to a fast (continuous) protocol for determining MMR.

Do air-breathing fish suffer branchial oxygen loss in hypoxic water?

In hypoxia, air-breathing fish obtain O from the air but continue to excrete CO into the water. Consequently, it is believed that some O obtained by air-breathing is lost at the gills in hypoxic water. is an air-breathing catfish with very large gills from the Mekong River basin where it is cultured in hypoxic ponds.