Comparative effects of temperature on suspension feeding and energy budgets of the pearl oysters Pinctada margaritifera and P. maxima

Abstract

This study assessed the effects of seasonal temperatures on suspension feeding, related physiological parameters and energy budgets in 2 pearl oysters, Pinctada margantifera and P. maxima. Pearl oysters that were acclimatised at approximately 19, 23, 28 and 32°C in the field were tested in the laboratory at these temperatures Clearance rate (CR), absorption efficiency (ae), absorbed energy (AE), respired energy (RE), excreted energy (EE) and the value of (AE -RE) were significantly affected by temperature. They usually Increased with increasing temperature. ae, RE, EE and the value of (AE -RE) differed significantly between the pearl oyster species. P. margaritifera had a significantly higher CR than P. maxima at 19°C. P maxima had higher a e than P. margaritifera at 28 and 32°C. As a result, P. margantifera had greater AE than P. maxima at lg°C, but the latter species had greater AE at 32°C. Temperature significantly affected the RE of P. margaritifera over a wider temperature range (19 to 32°C) than P, maxima (19 to 23°C). However, interspecific Mferences in RE were only significant at 32°C. P maxima had significantly higher EE at 32'C than P. margaritifera, although this energy accounted for a very small portion of AE (<5 %). P. maxima exceeded P. margaritifera in Scope for Growth [SFG = (AE -RE) -EE] at 32"C, but the latter species had greater SFG at 19OC. These results agree with observations of the occurrence of P. margaritifera at higher latitudes and lower temperature habitats. The temperature effects on suspension feeding, related physiological parameters and SFG indicate that there will be marked seasonal variations in growth in both species in environments where water temperatures vary seasonally. In bioenergetic terms, the optimum temperature ranges for these pearl oysters are approximately 23 to 28 and 23 to 32°C for P. margaritifera and P. maxima, respectively.

Viscosity of seawater controls beat frequency of water-pumping cilia and filtration rate of mussels Mytilus edulis

“…The filtration rate in ciliary suspension-feeding invertebrates is another important physiological function, but although a 'filtration rate Q 10 ' is frequently reported in the literature (e.g. Widdows & Bayne 1971, McLusky 1973, Bayne et al 1976, Lei et al 1996, Yukihira et al 2000, Petersen et al 2003), a number of recent studies show that the concept is inappropriately applied to these animals, because it is the temperature-dependent viscosity of the ambient water that mechanically controls the beat frequency of the water pumping cilia and thus the filtration rate. This statement is supported by a number of studies showing that the relationship between filtration rate and temperature is linear (not exponential) in ciliary suspension-feeding invertebrates, e.g.…”

Growth and survival of the blacklip pearl oyster Pinctada margaritifera (Linnaeus) spat reared with various combinations of microalgae in different stocking densities

“…However, significant correlations could not be detected between IGRs and water temperature. A positive relationship between growth rate and water temperature in pearl oysters has been reported by many authors (Yukihira et al, 2000;Pouvreau and Prasil, 2001) in correlation with metabolic rate and feeding activity.…”

Scope for growth of juvenile Cortez oyster, Crassostrea corteziensis fed isocaloric diets prepared with microalgae and cereal flours

“…Cockles for example, can modify the digestive process to maintain a fairly constant e (Ibarrola et al, 1998;Nieves-Soto et al, 2011), while pearl oysters showed increased e at increasing water temperature (Yukihira et al, 2000). Absorption efficiency in the Cortez oyster was higher than that of Anadara tuberculosa (≤ 61%) used for bioremediation (Nieves-Soto et al, 2011), and the pearl oysters Pinctada maxima and Pinctada margaritifera (≤58%) fed the microalgae Tisochrysis lutea (Yukihira et al, 2000). The maximum SFG (103.2 J g -1 h -1 ) of the Cortez oyster was also higher compared to the blood cockle A. granosa, that reached 60 J g -1 h -1 at similar temperatures and salinities (Din & Ahamad, 1995).…”

“…The physiological index Scope for Growth (SFG) determines the energy potentially available for growth and reproduction (Winberg, 1960) and is calculated as the difference between absorbed energy and respired and excreted energy. SFG has been used in marine bivalves to determine, for example, physiological plasticity of native and invasive species (Sará et al, 2008;NievesSoto et al, 2011), feeding range for aquaculture purposes (Ibarrola et al, 1998;Yukihira et al, 1998;Kesarcodi-Watson et al, 2001a, 2001bVelasco, 2007), identifying physical and chemical parameters for optimum growth (Yukihira et al, 2000;Soria et al, 2007), and population health (Din & Ahamad, 1995).…”