Abstract
The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport through the permeable interstice and formed an inverted cone of porewater with 93% air saturation in front of the mouth. From dye experiments the mean ventilatory flow rate was estimated at 0.26 +/- 0.02 ml min(-1) (86.9 +/- 7.3 ml min(-1) kg(-1)) (N=3). Expelled water from the gills induced a 1 cm circular plume with <15% air saturation around the gills. During this quasi-steady ventilation mode, fish extracted 86.2 +/- 4.8% (N=7) of the oxygen from the inspired water. However, 13% of the investigated fish (2 of 15) occasionally wriggled their bodies and thereby transported almost fully air-saturated water down along the body, referred to as 'plume ventilation'. Yet, within similar to 30 min the oxic plume was replenished by oxygen-depleted water from the gills. The potential for cutaneous respiration by the buried fish was thus of no quantitative importance. Calculations derived by three independent methods (each with N=3) revealed that the oxygen uptake of sandeel buried for 6-7 h was 40-50% of previous estimates on resting respirometry of non-buried fish, indicating lower O-2 requirements during burial on a diurnal timescale. Buried fish exposed to decreasing oxygen tensions gradually approached the sediment surface, but remained in the sediment until the inspired water reached 5-10% air saturation.
Original language | English |
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Pages (from-to) | 1006-1214 |
Number of pages | 209 |
Journal | J EXP BIOL |
Issue number | 0 |
DOIs | |
Publication status | Published - 2007 |
Keywords
- RESPIRATION
- GRADED HYPOXIA
- PLEURONECTES-PLATESSA
- O-2 EXTRACTION
- HYPOXIA ACCLIMATION
- TELEOST FISH
- BEHAVIORAL-RESPONSES
- PLATICHTHYS-FLESUS
- SEDIMENTS
- MARINUS RAITT
- Biology