The Influence of Current Speed, Body Size and Water Temperature On the Filtration Rate of Five Species of Bivalves

Abstract

The filtration rate of a range of sizes of five species of bivalves has been measured by estimating the abundance of natural particles in sea water before and after it had flowed past the animals. Preliminary experiments showed that the filtration rate was positively correlated with the flow rate and for comparative purposes the flow had to be held to a constant amount. The flow rate also affected the heart rate of Ostrea edulis L., and comparative trials with small Ostrea and Crassostrea showed increased growth at a flow of 180 ml./min compared with 70 ml./min. The specific filtration rates at 19-21 °C of Ostrea and Crassostrea gigas Thunb. were two to three times greater than those of the other three species studied. Crassostrea and Mytilus were the least affected by temperature, Ostrea was intermediate, while Venerupis decussata (L.) and Mercenaria mercenaria (L.) showed a very marked reduction in filtration rate as the temperature was lowered. I N T R O D U C T I O NThe rate of water filtration by bivalves has long excited interest, but it has in practice proved difficult to measure in conditions where the animal is relatively free from constraint. Its estimation is important from a number of aspects: feeding studies; as an indicator of the animal's reaction to its environment; and for predicting the flow of water required for the culture of economically important species. The work reported in this paper started as part of the general programme on shellfish culture in progress at this laboratory. During the development of a suitable method for studying the water requirements it became clear that one factor, water current, had a more important influence than has been generally recognized.In the past, this work has usually been done by one of two methods: either by observing the rate of removal of particles from sea water or by separating the exhalant current from the general water flow and measuring its rate of production. On this basis a distinction is often made between pumping rate -the movement of water through the mantle cavityand filtration rate. Strictly, the first method measures filtration rate and, unless evidence can be produced that all the particles are being retained, this can be less than the pumping rate. On the other hand, it can be questioned whether a wide difference between pumping and nitration rates is part of the normal behaviour pattern if reasonably large particles are used. Pumping water consumes a good deal of energy (Collier, 1959, shows that an oyster pumping 10 l./h is consuming 5 mg oxygen/h). Estimations of the percentage of oxygen removed during the passage of water are usually in the range of 3-10% (Ghiretti, 1966), which suggests that the very large volumes of water moved are primarily for feeding rather than respiration.

Quantifying the historic contribution of Olympia oysters to filtration in Pacific Coast (USA) estuaries and the implications for restoration objectives

“…Early work comparing the gill morphology of Crassostrea species with Ostrea species highlighted the likelihood of differences in their feeding ecology (Elsey 1935). This hypothesis was substantiated in a number of studies comparing C. gigas with O. edulis, which found that C. gigas had filtration rates approximately two times higher per unit DTW (Walne 1972;Mathers 1974;Rodhouse and O'Kelly 1981). Although this is not necessarily the case when comparing O. edulis with C. virginica (Shumway et al 1985), our results support the findings that Ostrea species have lower FR compared to those reported for Crassostrea species at optimum temperature (Fig.…”

“…We have attempted in this study to tease apart some of these factors. Ostrea species generally grow more slowly and have a smaller maximum size than Crassostrea species (Stafford 1913;Walne 1972). Furthermore, while very little is known about the density, patch size, and structure of O. lurida beds pre-commercial exploitation, descriptions of intact habitat in British Columbia suggest that O. lurida typically did not reach as high densities within oyster beds as those formed by C. virginica on the Atlantic coast (Stafford 1915).…”

“…On the other hand, many bivalve species have different thermal optima (Walne 1972), and as there are no previously published estimates of the temperature at which O. lurida achieves maximum filtration, we adopted T o = 25°C, as the filtration rate measured was greatest at this maximum temperature tested. This value is also similar to the optimal temperature for the related species O. edulis (Newell et al 1977;Hutchinson and Hawkins 1992).…”

Quantifying the Loss of a Marine Ecosystem Service: Filtration by the Eastern Oyster in US Estuaries

“…The physiology of oyster feeding and filtration is well studied, and filtration rate is known from laboratory studies to be influenced by a variety of environmental factors such as temperature, flow rate, salinity, seston concentration, and particle size, as well as oyster size (Loosanoff 1958;Walne 1972;Shumway et al 1985;Riisgaard 1988). Although it is recognized that conditions in situ may significantly affect filtration rate (Doering and Oviatt 1986;Powell et al 1992), few studies have sought to quantify rates under field conditions.…”

Interactive effects of temperature and food availability on the growth of Arctica islandica (Bivalvia) juveniles

“…Above that optimal temperature, filtration rate collapses (Winter,423 1978). Moreover, larger body size of the specimens as well implicate higher filtration rate 424 (Walne, 1972;Winter, 1978). Consequently, only at the coldest temperature, the mean of 425 phytoplankton concentration measured in the aquaria was higher than the desired target 426 level for each of the treatments ( 437 We noticed that siphon activity at the 'high' food levels was lower, than at the 'medium' 438 food levels ( Fig.…”