TY - JOUR

T1 - Oxygen dynamics around buried lesser sandeels Ammodytes tobianus (Linnaeus 1785): mode of ventilation and oxygen requirements.

AU - Behrens, Jane W

AU - Stahl, Henrik J

AU - Steffensen, John F

AU - Glud, Ronnie N

N1 - Keywords: Animals; Behavior, Animal; Fishes; Geologic Sediments; Oxygen; Oxygen Consumption; Water Movements

PY - 2007

Y1 - 2007

N2 - 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 approximately 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.

AB - 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 approximately 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.

U2 - 10.1242/jeb.000570

DO - 10.1242/jeb.000570

M3 - Journal article

C2 - 17337713

VL - 210

SP - 1006

EP - 1014

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

SN - 0022-0949

IS - Pt 6

ER -