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

Abstract

Differences in the feeding physiology of the green mussel Perna viridis between 2 aquaculture sites with contrasting hydrographies in Hong Kong were demonstrated. One site, Kat O, is oceanic and characterized by low seston concentrations and high organic contents. The other, Ma Wan, is under the influence of the Pearl River Estuary, hence the water is more turbid and has a low organic content. To determine the extent to which differences in mussel feeding responses were caused by environmental factors, a reciprocal transplantation experiment between the 2 sites was undertaken. Feeding rates (clearance rate, rejection rate, absorption rate and absorption efficiency) and enzyme activities (amylase and cellulase) were determined at various times, up to 8 mo posttransplantation. Complete acclimatization of the physiological responses of transplanted mussels occured 30 d post-transplantation. Transplanted individuals also showed complete morphological acclimatization in terms of palp area and palp:ctenidial area ratio 150 d post-transplantation, with higher ratios being obtained at Kat O, where suspended solid levels were lower, which is in contrast to other mytilids. The physiological differences between the 2 populations are thus largely environmentally induced.

Hydrodynamic effects on the origin and quality of organic matter for bivalves: an integrated isotopic, biochemical and transplant study

“…Immediately after the displacement from the closed pond to the open lagoon, the transplanted mussels showed a sharp scattering of the isotopic signatures compared to those of the mussels in the pond, adjusting their isotopic composition within 90 d and adapting their diet to the available resources of the new environment. Such a finding agrees with earlier reports about the complete acclimatization of enzyme activity in transplanted Perna viridis, which was observed 90 d after the transplantation (Wong & Cheung 2003). Indeed, lagoon mussels face new trophic conditions, displaying isotopic compositions differently to mussels living in the pond.…”

Stable isotope and fatty acid evidence for uptake of organic waste by green-lipped mussels Perna viridis in a polyculture fish farm system

“…In turn, food availability is subject to seasonal or spatial fluctuations. Furthermore, the rapid acclimation of physiological and enzymatic activities of mussels to new food conditions demonstrates the regulation and flexibility of feeding modes in these bivalves (Kreeger & Newell 2001, Wong & Cheung 2003. Generally, mussels are regarded as herbivorous feeders (Page & Hubbard 1987).…”

“…The 3 mo period was assumed to be long enough for the mussels to acclimatize to the environment and completely turn over their body reserve (Freites et al 2002, Wong & Cheung 2003. The epibionts on the collected mussel shell surface were removed and the mussels were cultured in filtered seawater (Whatman, GF/C) for more than 24 h until no more faeces were produced, so as to evacuate the gut content.…”

Seasonal changes in C, N and P budgets of green-lipped mussels Perna viridis and removal of nutrients from fish farming in Hong Kong

“…A beaker without an animal was used as a control. A preliminary experiment showed that a flow rate of 100 ml min -1 was appropriate in order to avoid recirculation of seawater filtered by mussels (Wong & Cheung 2003). Mussels were cultured for 2 to 3 h, depending on the amount of pseudofaeces and faeces produced.…”