Freshwater clams are normally bad in any aquarium, but not for the reasons people think.
Only very few (the family
Unionidae, or swan mussels) have parasitic larvae, and even then, the larvae do little harm and are attached for only a few days. Moreover, the larvae tend to be specific to certain fish, so a swan mussel from Europe is unlikely to parasitise a sunfish from North America.
Anyway, the problem with freshwater mussels is that they need food (no surprise) but being filter feeders they can't simply eat little bits of food or algae from the substrate in the way snails or shrimps do. You need to feed them by hand, two or three times a week, using a pipette. Filter feeder food for this purpose can be obtained from marine aquarium suppliers.
Since the clams like to dig and tend to move about, finding them for feeding time becomes a chore in an aquarium with rocks and plants. If they can't dig themselves in, they tend to be attacked by fish, which peck at the siphons and mantles, which eventually kills the clam or mussel.
In short, freshwater clams 90% of the time end up dying prematurely in fish tanks. Swan mussels can live for 150 years, for example, but in fish tanks rarely last more than a few months. Some are coldwater species anyway (e.g. swan mussels) and die from heat exhaustion, while others are actually brackish water ones and cannot be kept in freshwater permanently. The commonest one in the UK (and likely the US) is the
Asian clam Corbicula fluminea, which is regarded in many places as a pest species. There's a nice page on how to keep them (in their own tank)
here.
Cheers,
Neale
Just a quickie (usual for me!
) Are fresh-water clams ok in Malawi tanks?? There's also a Yellow-Spotted Plec (L001) and some Peppered Cory Catfish in there aswell... would the clams be ok with all these??