Factors affecting oxygen consumption in the coot clamMulinia lateralis(Say)

Abstract

The effects of intrinsic (body size, gill surface area and activity patterns) and extrinsic (temperature, salinity and oxygen concentration and food) factors on oxygen consumption were measured in the mactrid clam Mulinia lateralis. Both acclimated and acute rates of VO, were measured under 9 salinity-temperature combinations and a model is presented which indicates that: 1) body size is the over-riding factor determining VO" 2) acclimation temperature alone has no significant effect on either fed or starved animals 3) the interaction of acclimation temperature and salinity and exposure salinity is the strongest factor influencing VO, after body size, 4) exposure conditions are more likely to determine energy levels of expenditure than acclimation conditions. Small individuals have a greater gill surface area per body weight than larger individuals. The degree of oxygen independence is dependent on both body size and on acclimation temperature and shows a slight increase after exposure to anoxic conditions. .Patterns of shell valve activity were altered and VO, increased in response to algae, charcoal and algal extract.There was no evidence of a complete temperature acclimation even after 3 weeks.The scope for activity indicates that starved animals at high temperatures are at a greater energetic disadvantage than individuals at lower temperatures. Equations are presented for clearance/pumping rate, convection requirements and utilization efficiencies and indicate that metabolism increases faster in relation to body size than does pumping rate resulting in decreased net energy gain as the animals increase in size.Survival of M. lateralis populations appears to be a combination of behavioural and physiological adaptations which allow successful exploitation of favourable conditions while at the same time leaving the animals vulnerable to long term stress conditions.

Nature of relation between ventilation and oxygen consumption in filter feeders

“…At air saturation this corresponds to an extraction efficiency of S 1 %. Extraction coefficients of oxygen recorded in the literature for filter feeding bivalves and other filter feeders usually vary from a few to about 10 % (Mangum & Burnett 1975, Shumway 1983. Such values greatly overlap with the extractions as measured in non-filter-feeding burrowdwelling invertebrates, such as the polychaete worms Pectinaria gouldi (Mangum & Burnett 1975) and Nereis spp.…”

“…The relations between V, and MO, are often studied in feeding experiments where increased filter feeding results from addition of food particles to the water. It has been suggested that part of the increase in M,, may represent the physiological cost of digestion and assimilation, often termed the 'specific dynamic action' of the food (Bayne et al 1973, Bayne & Scullard 1977, Newel1 & Branch 1980, Navarro & Winter 1982, Bayne & Newel1 1983, Shumway 1983). However, Griffiths & King (1979) observed that in Aulacomya ater the M,, increased immediately with increased filter feeding, excluding 'physiological costs of feeding' to have influenced M,,.…”

Metabolic responses of the common mussel Mytilus edulis to hypoxia and anoxia

“…(A) 1.0 kPa (total tissue dried mass 63.58 mg, had a higher degree of respiratory indepen-TDW) and 4.8 kPa (TDW 49 14 mg); (B) 2 3 kPa (TDW 48.89 rng) and dence~ whereas Tay1or & Brand and 9.7 kPa (TDW 49.11 mg). Arrows indicate the onset of a sign~f~cant Shumway (1983) showed that the respiratory anaerobic contribution to the total heat output. Q: rate of heat independence of A. islandjca and M. lateralis dissipation; N: rate of oxygen uptake increased with increasing body size.…”

Long Island Sound

“…lateralis also rapidly colonizes disturbed sediment, and has been known to be a transient opportunist in LIS for over 5 decades Levinton 1970;Valente et al 1992). This suspension feeder exhibits a physiological strategy similar to C. teleta, poised for rapid growth under favorable environmental conditions but exhibiting reduced survival under environmental stress (Shumway 1983;Shumway et al 1993). It survives more poorly than many other infaunal bivalves under anoxic and sulfidic conditions.…”