, Volume 17, Issue 4, pp 299-308

Oxygen consumption of Astyanax fasciatus (Characidae, Pisces): a comparison of epigean and hypogean populations

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Synopsis

The standard and routine oxygen consumptions of Astyanax fasciatus from one surface population (Rio Teapao) and three cave populations (Chica, Micos and Pachon caves: ‘sAnoptichthys jordani’, the ‘Micosfish’ and ‘Anoptichthys antrobius’) were determined individually over 24 hours by the use of a flow-through respirometer and polarographic oxygen electrodes. The phylogenetically oldest Pachon fish had a significantly lower standard metabolic rate (0.230 ± 0.036 mg O2 g-1 h-1) than the epigean Teapao fish, the hybrid Chica fish and the phylogenetically younger Micos fish (0.314 ± 0.081 mg O2g--1h-1, 0.284 ± 0.048 mg O2g-1h-1, 0.277 ± 0.063 mg O2g-1h-1). No significant differences could be determined among the latter three populations. A significant difference in routine metabolic rate existed only between the Pachon fish (0.309 ± 0.0.56 mg O2g-1h-1) and the Teapao fish (0.415 ± 0.071 mg O2g-1h-1). The Chica fish (0.356 ± 0.084 mg O2g-1h-1) and the Micos fish (0.355 ± 0.080 mg O2 g-1h-1) could not be separated from either the Teapao or the Pachon fish, but a decreasing trend from the surface population through the Chica and the Micos to the Pachon population was obvious. During a starvation period of 29 days the metabolic rate of epigean Teapao and hypogean Pachon fish decreased significantly by 32.5% and 34.8% (standard oxygen consumption rate) and 27.5% and 28.2% (routine oxygen consumption rate), respectively. Body mass loss during the starvation period was 16.3% for the Teapao fish and 9.5% for the Pachon fish.