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September 14, 2012

When someone says the word ‘Piranha’, some might automatically think of Joe Dante’s 1978 classic film wherein a plague of genetically altered man-eating fish is released upon a summer camp. I guess it depends on how old you are, or in my case, how many R-rated movies I was exposed to when I was a kid. I’ll admit that movies like Jaws and Piranha certainly made swimming a little nerve wrecking at that age. They are, however, just movies and a tropical freshwater fish will certainly not be able to survive the chilly Washington state waters where I grew up. I’m not even going to talk about that “Great White” coming up the pond…

If you have seen the documentaries Planet Earth by the Discovery channel (if you haven’t, I seriously recommend watching them) you probably know there are really only a few species of piranha in very remote locations of South America that may really do any harm to you. Jeremy Wade of River Monsters also proved this when he went in search of the cannibalistic predator in season one. Jeremy found that there was probably only one place deep within Venezuela that you wouldn’t want to dip your toes in. For me, I’d be more worried about that parasitic catfish the locals call Candiru.

While man spends his time avoiding this toothy animal, there are others that actually spend their lives living among them. Metynnis hypsauchen “Silver Dollar” have adopted the same flat, silver body their carnivorous cousins possess. This camouflage allows the fish to “sneak by” where others may end up on the dinner menu. Unlike the Piranha, Silver Dollars are vegetarians that will make short work of almost any plant it comes upon - probably not making it the best candidate for your planted tank. In nature, they are found in large shoals throughout the Amazon basin. I would advise keeping them in groups of at least 5 individuals with plenty of space to be able to reach their 6” maximum size.

Metynnis hypsauchen

Another interesting Silver Dollar type, Myleus schomburgkii “Black Belt Silver Dollar”, is much like its relative, M. hypsauchen, but with a black “stripe” on its side. The red anal fin also grows considerably longer than the common Silver Dollar. Black Belt Silver Dollars spend their time grazing algae and avoiding other predators by swimming in large shoals in Venezuela, Peru, and Brazil. This species will stay a little smaller, reaching just about 5” or so.

Myleus schomburgkii

Silver Dollars may be primarily vegetarians in nature, but they will also love the occasional bloodworm or brine shrimp treat. As mentioned above, they are an avid plant eater. You can try fabric or silk plants, but these are even often confused for real food and picked at by our greedy pets. I would recommend keeping the pH value between 6-7 and the temperature in the upper 70’s. They can be rather skittish so keeping the tank dimly lit would be a good idea. Pieces of bogwood or large rocks would help to make them feel right at home.

That’s it for this week. Like always you can find our retail list under the products link, or by visiting If you have any questions about Silver Dollars, or any other of fish, please feel free to email or call me.

Until next week!

Anthony Perry
Sales Manager