Filtration and Utilization of Laboratory-Cultured Bacteria by Dreissena polymorpha, Corbicula fluminea, and Carunculina texasensis

Abstract

Dreissena polymorpha consumed about 6 x 108 Escherichia coli from 20 ml of artificial pondwater (APW) in 30 min under laboratory conditions. The clearance rate per mussel was 143 +/- 25 ml g-1 dry tissue min-1. The E. coli used in these studies ranged from about 1.7 to 2.9 {mu}m in length. 35S-labeled E. coli were used to demonstrate that bacteria-derived nutrients were incorporated into mussel tissue. Electrophoretic analysis of mussel and bacterial proteins on 12% polyacrylamide gels allowed the visual determination of incorporation of labeled amino acids into bivalve proteins and demonstrated that intact bacteria were not simply trapped in mussel tissues. The conversion of bacterial-labeled amino acids into mussel protein was about 26%. Similarly, we demonstrated that D. polymorpha can use other bacterial species ranging in size from about 1.3 to 4.1 μm, including Citrobacter freundii, Enterobacter aerogenes, Serratia marcescens, Bacillus megaterium, and B. subtilus. The ability of D. polymorpha to take up E. coli was compared with that of two other freshwater mussels, Corbicula fluminea and Carunculina texasensis. On a mussel-dry-weight basis, D. polymorpha cleared bacteria 30 to 100 times faster than Corbicula fluminea and Carunculina texasensis, respectively. The ability to filter E. coli appears to be related to the architecture of the cirri on the latero-frontal cells of the gill. Cirri from Corbicula and Dreissena are similar in size, but Dreissena has a larger gill compared to the tissue dry-weight, and has 102 times more cirri than found in Corbicula. Carunculina, the unionid representative, has smaller and fewer cirri, and has relatively limited ability to capture E. coli.

Minireview: Ciliary filter feeding and bio‐fluid mechanics—present understanding and unsolved problems

“…A ''new explanation'' of particle capture in mussels, based on endoscopic observations of an apparent low angle (ഠ30Њ) of particles approaching the gill filaments and subsequent direct interception, has been proposed by Ward (1996) and Ward et al (1998Ward et al ( , 2000, but Riisgård and Larsen (2000) raised doubt about its bio-fluid mechanic foundation. Other objections, including insufficient optical resolution and image quality of endoscopy, have been advanced against the new explanation by Silverman et al (2000) and Beninger (2000). On the basis of estimates of pressure drop for flow through a LFC screen and fluid mechanical calculations of creeping flow, Riisgård et al (1996a) found it plausible that, during normal beating of the LFC, the through current passes mainly around the LFC in an oscillatory, unsteady, three-dimensional pattern and that only little flow may leak through the branching cilia.…”

“…Large, compound LFC are widespread throughout the Bivalvia (the vast majority of species), with some notable exceptions, all occurring in the relatively few heterorhabdic taxa (Owen and McCrae 1976). The basic particle-capture mechanism in bivalves without LFC remains poorly known (see also Owen and McCrae 1976;Beninger and le Pennec 1988;Beninger et al 1992;Silverman et al 1995Silverman et al , 1996. Gill types with small or lacking LFC-for example, in pectinids and Ostrea edulis-have been found to be less retentive than gills with well developed cirri (Møhlenberg and Riisgård 1978;McHenery and Birkbeck 1985;Riisgård 1988b).…”

“…Because of the geometric and kinematic complexities, scaled-up laboratory models are largely ruled out, and therefore in situ observations are needed. Available observation techniques include high-speed cinefilms recorded through microscopes (Nielsen and Rostgaard 1976;Strathmann 1982;Emlet 1990), regular video microscopy (e.g., Gallager 1988;Nielsen et al 1993;Hart 1996;Petersen et al 1999), confocal laser microscopy (Silverman et al 1996Beninger et al 1997a), and endoscopy (Beninger et al 1992(Beninger et al ,. 1997bBeninger and St-Jean 1997;Ward et al 1996Ward et al , 1998Ward et al , 2000.…”

“…Ciliary filter feeders remove suspended food particles, mainly phytoplankton (2-200 m), but in many cases also free-living bacteria (0.2-2 m), from the water (Jørgensen 1966(Jørgensen , 1975Wotton 1994;Silverman et al 1995Silverman et al , 1997 Riisgård andLarsen 1995, 2001;Gili and Coma 1998). These animals have adapted to life in a nutritionally dilute environment, and they show great variations in particle capture mechanisms and pump design (Foster-Smith…”

Toxicity and Bioaccumulation of Cadmium in the Freshwater Bivalve Corbicula Fluminalis Müller, 1774.

“…Corbicula is known to feed on bacteria and phytoplankton in the water column via filter feeding (Phelps, 1994;Silverman et al, 1995;Boltovskoy et al, 1995), but its effect on the benthos is unknown.…”