Influence of long-term hypoxia exposure on the energy metabolism of Solea solea. I. Critical 02 levels for aerobic and anaerobic metabolism

Abstract

Long-term hypoxia is a general phenomenon on the Italian Adriatic coastline, and is mainly caused by continuous eutrophication. The sensitivity of sole Solea solea to long-term hypoxia was investigated. Healthy S. solea obtained from trawls were kept at l g°C in aquana for at least 2 mo. The fish were exposed to hypoxia after a preacclimation penod of 30 h at normoxia Oxygen levels dunng normoxla were kept constant at 80% air saturahon (16.6 kPa, 6 . 4 mg I-' OZ); during hypoxia oxygen levels were set at 60, 40, 20, 12 or 6 % air saturation (4.8, 3.2, 1.6, 1.0, 0.5 m g I-'). During the expenment oxygen consumption was measured continuously. At the end of each experiment, blood samples were taken from anaesthetized specimens. Oxygen consumption patterns were statistically analyzed. A novel technique is described for the determination of the standard metabolic rate and the scope for activity of free-slulmmng animals. The resting metabolic rate and the scope for activity showed significant changes at reduced oxygen levels Activ~ty levels declined progressively starting at 40 % air saturation Restlng levels remained constant between 80 and 20 % air saturation, but fell below the standard metabohc rate at 12 and 6 % Blood lactate levels were increased at 12 and 6 % , indicating anaerobic metabolism. Data show that 40% air saturation should be considered as a limiting level, while the incipient lethal level lies between 12 and 20%.

Effects of repeated hypoxic shocks on growth and metabolism of turbot juveniles

“…The increase in plasma Cl -may be related to HCO 3 -decrease, as gill acid-base flux (H + and HCO 3 -) is usually coupled to ion exchanges (Cl -and Na + ). Marked increase in plasma lactate showed that fish resorted to anaerobic metabolism within 4 h, as has previously been observed in turbot under similar hypoxic conditions and in another flat fish species, sole (Solea solea) (Dalla Via et al, 1998;Van den Thillart et al, 1994). Survival was over 95% at the end of the 12-h test, which is in agreement with the survival challenge test results.…”

Influence of ambient oxygenation and temperature on metabolic scope and scope for heart rate in the common sole Solea solea

“…A is the allometric exponent describing the relationship between metabolic rate and body mass (0.8: van den Thillart et al 1994). Background oxygen consumption by micro-organisms was routinely assessed before the fish was transferred into the chamber by recording the oxygen consumption of an empty respirometer.…”

“…Parallel laboratory experiments showed that in 30% air saturated water, both flatfish species were already constrained and displayed negative mean growth (Petersen & Pihl 1995). Because of this relatively restricted behavioural repertoire, flatfish are more liable to be exposed to environment-mediated changes in their biological performance (Duthie 1982, van den Thillart et al 1994. The aim of the present study was to assess the influence of ambient temperature and oxygenation on the metabolism and cardiovascular physiology of a poorly studied but economically important flatfish species, the common sole Solea Influence of ambient oxygenation and temperature on metabolic scope and scope for heart rate in the common sole Solea solea ABSTRACT: The objective of this study was to quantify the constraints exerted by temperature and oxygenation on both metabolic scope and scope for heart rate of the common sole Solea solea.…”

Metabolic performance of the squid Lolliguncula brevis (Cephalopoda) during hypoxia: an analysis of the critical PO2

“…For example, a P c value between 8.6 and 6.7 kPa was derived from aerobic-anaerobic transition or oxygen consumption data in the burrowing marine teleost Lumpenus lampretaeformis (Pelster et al, 1988). In the flatfish Solea solea, the P ranged between 4.0 and 2.4 kPa (van den c Thillart et al, 1994), while the P was 6.7 kPa in Octopus vulgaris (Wells and Wells, c 1995), and between 7.0 and 4.0 kPa in the bivalve Scapharca inaequivalvis (van den Thillart et al, 1992). In some animals, for example the toad Bufo marinus (Portner et al, 1991b), a transient increase in oxygen consumption has been reported to set in at the P c when anaerobic metabolism starts.…”

“…phosphocreatine, phospho-L-arginine) and / or by ATP production through anaerobic metabolism (Portner and Grieshaber, 1993;van den Thillart et al, 1994). Nonetheless, survival under hypoxic conditions is time limited since eventually the energy status becomes impaired, reflected by a drop in the cellular Gibb's freë energy of ATP hydrolysis to possibly limiting levels (Kammermeier, 1987;.…”