Ecomorphological adaptation to oxygen deficiency in Amazon floodplains by serrasalmid fish of the genus Mylossoma
In: Journal of Fish Biology. Fisheries Society of the British Isles: London,New York,. ISSN 0022-1112; e-ISSN 1095-8649, more
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| Keywords |
Anoxic conditions
Aquatic organisms > Freshwater organisms > Fish > Freshwater fish
Biological phenomena > Adaptations
Biology > Organism morphology > Animal morphology
Biology > Physiology > Animal physiology > Fish physiology
Depletion > Oxygen depletion
Morphology
Respiration
Topographic features > Landforms > Flood plains
Water bodies > Inland waters > Lakes
Water masses > Subsurface water
Mylossoma Eigenmann & Kennedy, 1903 [WoRMS]
Fresh water |
| Authors | | Top |
- Saint-Paul, U.
- Soares, G.M.
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| Abstract |
Serrasalmids of the genus Mylossoma are obligate gill-breathers that are encountered in the floodplain lakes of Amazonia, even when the oxygen concentrations here are below 0 multiplied by 5 mg/1. It was shown by experiments that fish of these species are capable of utilizing the oxygen-rich surface layer of the water for espiration, in order to survive periods of habitat-induced hypoxia. This so-called aquatic surface respiration entails an increase in locomotory activity and an ecomorphosis involving the formation of dermal extension on the lower jaw, that apparently has a hydrodynamic function for using the surface layer for gill respiration; when the water is aerated, it retrogresses to its original size. Histological examination showed that the extension is formed by edematous processes in the stratum spongiosum. |
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