Suspension-feeding behaviour in tropical bivalve molluscs:Perna viridis, Crassostrea belcheri, Crassostrea iradelei, Saccostrea cucculata and Pinctada margarifera

Abstract

Filter-feeding behaviours of the mussel Perna viridis and the oysters Crassostrea belchen, Crassostl-ea ~radelei, Saccostrea cucculata and Pinctada mal-garifera were compared during natural tidal vanations in the concentration (6 to 40 dry mg total particulate mass I-') and organic content (6 to 2 2 % ) of seston available in the Merbok mangrove system, Malaysia. In P. viridis, C. belcheriand S. cucculata, declining retention eff~ciencles for the largest available particle slze classes of more than 6 to 12 pm diameter were associated w t h an overall organic enrichment of filtered relative to available matter. As seston avdilab~lity increased, a ~n i n~m u m average of 71°,. of the additional filtered matter was rejected by each species as pseudofaeces prior to ingestion. And in all 5 species, preferential rejection as pseudofaeces of filtered particles with higher average inorganic content resulted in the net organic enrichment of ingested relative to filtered matter. In P. viridis and C. belcheri, the efficiency of that net organic selection declined for seston of lower organlc content. Combining all data from each species, absorption efficiencies from ingested organics increased exponent~ally with the organic content of ingested matter Collective findings suggest that key interrelations between component processes of nutrient acquisition were similar to those that have been established for the modeling of feeding, growth and environmental ~mpact among filter-feeding bivalves froin temperate latitudes However, especially fasl growth in P viridis stemmed from higher average (* 2 SE) clearance rates (13.2 A 7.0 l h-' g-' when particulate organic matter c 1 mg I-'), greater average organic enrichment of filtered relative to available matter (0.99 + 0.67) and greater average organic enrichment of ingested relative to filtered matter (0.63 * 0.03) than have hitherto been recorded in any species of bivalve filterfeeder. In contrast, P. margarifera was least well adapted for the pre-ingestive selection of organic matter, with no differential retention on the gill and little selective rejection as pseudofaeces, representing at least part of the physiological basis for characteristically slow growth in pearl oysters.

Modelling of suspension-feeding and growth in the green-lipped mussel Perna canaliculus exposed to natural and experimental variations of seston availability in the Marlborough Sounds, New Zealand

“…This complements similar recent observations in the mussel Perna viridis and oysters Crassostrea belcheri and Saccostrea cucculata, when significant organic enrichment was associated with declining retention efficiencies for particles within size classes larger than 6 to 12 pm equivalent spherical diameter (Hawkins et al 1998b). Newel1 et al (1989) described how the mussel Mytilus edulis preferentially filtered algal cells relative to inorganic particles of equivalent size from natural seston.…”

“…To obtain a fully comparative measure of feeding rate throughout the complete range of experimental seston concentrations, including experimental conditions when CR and OCF were not measured satisfactorily, we calculated the total rate of filtration not corrected for selective retention on the gills (FROCS, mg h-') ( Table 2). This measure of FROCS is similar to all previous gravimetric measures of filtration rate (mg h-') in bivalve shellfish, except for Hawkins et al (1998b), who were the first to correct for selective retention.…”

“…8). A similar NOIR of 24.8 + 3.6 mg organics h-' was recorded in the green mussel Perna viridis from Malaysia, but this may not have been maximal (Hawkins et al 1998b). The only other experimental measure of maximal feeding rates in another m.usse1 diagnosed the saturat~on of digestive processes when ingestion had reached about 6.5 mg organics h-' in Mytilus edulis of 1 g dry soft tissue ).…”

“…Clearance rates in the cockle Cerastoderma edule ) and the mussels Mytilus edulis and Perna viridis (Hawkins et al 1998b) have been shown to decrease in exponential relation to increasing concentrations of POM (mg I-'). The same occurred here in Perna canaliculus.…”

Site-related differences in the feeding physiology of the green mussel Perna viridis: a reciprocal transplantation experiment

“…Compared with considerable scientific research on Mytilus spp. in temperate waters, much less work has been done on tropical and subtropical species (Ward & MacDonald 1996, Hawkins et al 1998a, Yukihira et al 1999, particularly the warm-water species Perna viridis (L.), though it is of high ecological significance (Seed & Richardson 1999) and has aquaculture value (Guo et al 1999).…”