BIOTIC Species Information for Mytilus edulis
|Researched by||Lizzie Tyler||Data supplied by||University of Sheffield|
|Refereed by||This information is not refereed.|
||Feeding method||Passive suspension feeder
Active suspension feeder
|Typical food types||Bacteria, phytoplankton, detritus, and dissolved organic matter (DOM).||Habit||Attached|
|Bioturbator||Not relevant||Flexibility||None (< 10 degrees)|
|Height||Insufficient information||Growth Rate||See additional information.|
|Adult dispersal potential||<10m||Dependency||Independent|
|General Biology Additional Information||Mytilus edulis is one of the most extensively studied marine organisms. Therefore, this review is based on comprehensive reviews by Gosling (ed.) (1992a), Bayne, (1976b), Newell (1989), and Holt et al. (1998). Where appropriate the original source references in these reviews are given.
Mytilus edulis is gregarious, and at high densities forms dense beds of one or more (up to 5 or 6) layers, with individuals bound together by byssus threads. Young mussels colonize spaces within the bed increasing the spatial complexity, and the bed provides numerous niches for other organisms (see importance). Overcrowding results in mortality as underlying mussels are starved or suffocated by the accumulation of silt, faeces and pseudofaeces, especially in rapidly growing populations (Richardson & Seed, 1990). Death of underlying individuals may detach the mussel bed from the substratum, leaving the bed vulnerable to tidal scour and wave action (Seed & Suchanek, 1992).
Several factors contribute to mortality and the dynamics of Mytilus edulis populations, including temperature, desiccation, storms and wave action, siltation and biodeposits, intra- and interspecific competition, and predation. But predation is the single most important source of mortality.
Many predators target specific sizes of mussels and, therefore, influence population size structure. The vulnerability of mussels decreases as they grow, since they can grow larger than their predators preferred size. Mytilus sp. may be preyed upon by neogastropods such as Nucella lapillus, starfish such as Asterias rubens, the sea urchin Strongylocentrotus droebachiensis, crabs such as Carcinus maenas and Cancer pagurus, fish such as Platichthys flesus (plaice), Pleuronectes platessa (flounder) and Limanda limanda (dab), and birds such as oystercatcher, eider, scooter, sandpiper, knot, turnstone, gulls and crows (Seed & Suchanek, 1992; Seed, 1993). Important predators are listed below.
Fouling organisms, e.g. barnacles and seaweeds, may also increase mussel mortality by increasing weight and drag, resulting in an increased risk of removal by wave action and tidal scour. Fouling organisms may also restrict feeding currents and lower the fitness of individual mussels. However, Mytilus edulis is able to sweep its prehensile foot over the dorsal part of the shell (Thiesen, 1972, Seed & Suchanek, 1992). Fouling by ascidians may be a problem in rope-cultured mussels (Seed & Suchanek, 1992).
Diseases and parasites
Mytilus edulis is a filter feeding organism, which collects algae, detritus and organic material for food but also filters out other contaminants in the process. Shumway (1992) noted that mussels are likely to serve as vectors for any water-borne disease or contaminant. Mussels have been reported to accumulate faecal and pathogenic bacteria and viruses, and toxins from toxic algal blooms (see Shumway, 1992 for review). Bacteria may be removed or significantly reduced by depuration (removing contaminated mussels into clean water), although outbreaks of diseases have resulted from poor depuration and viruses may not be removed by depuration. Recent improvements in waste water treatment and shellfish water quality regulations may reduce the risk of bacterial and viral contamination. Shellfish should also be thoroughly cooked, not 'quick steamed', to ensure destruction of viruses (Shumway, 1992). The accumulation of toxins from toxic algal blooms may result in paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP) or amnesic shellfish poisoning (ASP). These toxins are not destroyed by cooking. Shumway (1992) suggested that mussels should only be collected from areas routinely monitored by public health agencies, or obtained from approved sources and never harvested from waters contaminated with raw sewerage.
|Biology References||Fish & Fish, 1996, Hayward & Ryland, 1990, Hayward et al., 1996, Tebble, 1976, Gosling, 1992(c), Bayne, 1976b, Seed & Suchanek, 1992, Gosling, 1992(b), Bayne et al., 1976, Dare, 1976, Dare, 1982(b), Raffaelli et al., 1990, Craeymeersch et al., 1986, Marsh, 1986, Richardson & Seed, 1990, Bower, 1992, Bower & McGladdery, 1996, Shumway, 1992, Holt et al., 1998, Baird, 1966, Meire & Ervynck, 1986, Thiesen, 1972, Clay, 1967(d), Gosling, 1992(a), Gray et al., 1997, Carter & Seed, 1998, Seed, 1968, Thompson et al., 2000, Seed 1993, Seed, 1969a, Ambariyanto & Seed, 1991, Hayward & Ryland, 1990, Heidi Tillin, unpub data, Julie Bremner, unpub data,|