Ask Filipino fish hobbyists what a Silver Dollar is, and most likely, they will
engage you in a short conversation on their experiences about keeping some in their tanks. “Silver Dollar” is a common name given to a number of fish species, mostly in the genus Metynnis belonging to the family Characidae, or what we commonly refer to as the Tetras.
The species often referred to as the Silver Dollar is widely accepted as Metynnis argenteus. However, I personally believe there are maybe 3 or 4 more species of Metynnis
that find their way in the Philippine market under the common name Silver Dollar.
Silver Dollars are always a hit among fishkeepers. In fact once they have graduated from their first tank of common “community fishes” like angelfish, swordtails, mollies, and
the like, fish hobbyists will turn their sights to more exotic, cheap, and easy to keep fishes. The Silver Dollar fits the bill to a T.
The Silver Dollar’s round body shape makes it exotic as compared to the regular body shape
of the average fish.
They grow to a much larger size than what a newbie fish hobbyist would normally start with. They are active swimmers that school together if at least 6 are kept in a tank. There is never a dull moment in the tank once these fishes are in it. More so, these fishes are relatively cheap so everyone can afford to have some.
The Silver Dollar is actually the entry level species for someone who fancies keeping these large round Tetras. Soon, a fish hobbyist will purchase more desirable ones like the Red Hooks (Myleus rubripinnis, identified by a red, hooked anal fin); Barred Red Hooks (Myleus schomburgkii, identified by a red, hooked anal fin with a thin black bar on the body); Emperor Blue Hooks (also known as Myleus schomburgkii, identified by a blue, hooked anal fin with a thick black bar on the body); and the Lamax (identified by a red, hooked anal fin with a black blotch on the body).
For seasoned fish hobbyists, the above species are more desirable than the regular Silver Dollars as they are not common and can be quite pricey. Thus, there is more pride in keeping a school of these large round tetras.
There are actually many species of round Tetras under the genera Metynnis and Myleus. But only the above are commonly available in the Philippine aquarium fish market.
In the past year or so, however, another large, round Tetra made its appearance in the Philippine aquarium trade. This is the Striped Silver Dollar, or the Metynnis fasciatus.
Metynnis fasciatus was first described by German zoologist Christoph Gustav Ernst Ahl in 1931. Like all Silver Dollars, it is a South America Tetra. This particular species comes from the Capiuru River basin in middle Amazon River drainage.
As with the Silver Dollar, the M. fasciatus has the characteristic round body shape. Juvenile specimens seem to be more diamond-shaped. They become rounder as they grow larger.
The base color is silver with a greenish gold sheen on the upper part of the body. The key distinct feature of the M. fasciatus is the vertical stripes found in the body. In fact, its species name, fasciatus, means “banded” in Latin. These stripes are dark grey in color. Some are generally straight from top to bottom while others are crooked.
It is said that no two specimens are identical in terms of body pattern. A dark blotch is located behind the eye. However, this blotch is not always present and I believe this appears or disappears depending on the mood of the particular fish.
The M. fasciatus has a red anal fin which hooks at the tip. The pectoral fins are reddish in color, but the rest of the fins are generally clear. The dorsal fin seems to be quite longer than that of the Silver Dollar.
It is said to grow to a maximum size of 6 inches; personally, however, I believe they grow much bigger. Looking at pictures from the Internet, their large body size seems to suggest a much bigger fish.
Very little is written about the M. fasciatus since this is still a relatively new species of Silver Dollar, not just in the Philippine aquarium trade, but also in the international aquarium keeping community. However, this should not discourage one from
keeping M. fasciatus.
Your experiences in keeping the “Dollars and the Hooks” should teach you techniques and procedures on how to successfully keep the M. fasciatus in an aquarium.
For one, a large tank of at least 75 gallons will be required since these are generally large fishes which are best kept in a school, and very active swimmers. Thus, keeping 6 or more pieces will require a large space. Adequate filtration is required as these are heavy feeders and will produce a large amount of bioload on the filter system. Surface agitation will help as these require a high content of dissolved oxygen in the tank.
Water parameters like pH are best kept between pH 6.0 to pH 7.5; acidity below 6.0 and alkalinity higher than 7.5 will have detrimental effects on the M. fasciatus. Water hardness of soft is best, with medium tolerated. Our local temperature between 28°C to 32°C is best. In times of cold fronts like this time of the year, it is advisable to use a heater and set the thermostat to 27°C.
As always, a well cycled tank with zero ammonia, zero nitrites, and few nitrates is desirable. Good filtration and regular maintenance will keep the water environment to the liking of the M. fasciatus. A weekly water change of 30 to 40% should keep the three dangerous substances in check.
The M. fasciatus is quite hardy and easy to care for. Like most Silver Dollars, they are peaceful and will not initiate quarrels in the aquarium. They can easily be kept with other fishes that are not too big. In fact the M. fasciatus and other species of the Myleus and Metynnis genera are favorite additions to Arowana and exotic fish tanks.
Feeding the M. fasciatus is also not a problem. They are generally not picky in eating food offered to them. They easily take commercial fish food. They are omnivorous and may be primarily fed with vegetable food with occasional meaty food.
The only drawback of keeping the M. fasciatus is its current price; since it is still a relatively new fish in the market, the price is still quite high. An M. fasciatus should cost you a few thousand pesos each; considering that the M. fasciatus is a schooling fish, then it will cost you a small fortune to be able to have some in your tank.
Presently, M. fasciatus is still not very common in the tanks of the typical Filipino fish hobbyist. Stocks are not yet available year round and only the affluent can afford to have some. I have seen hobbyists with 3 or 4 in the company of their favorite Arowanas.
Some hobbyists I know keep a “Dollars and Hooks” tank, opting to keep a tank full of different Myleus and Metynnis species, including the M. fasciatus.
Given a few more years and a little luck, maybe captive breeding of M. fasciatus will increase its stocks and decrease the price, thereby making it more readily available and affordable to the common Filipino fish hobbyist.
If you have any questions or inquiries about the fish discussed here or if you wish to have your fish featured in this column, please write Angel Ampil at AngelAmpil@yahoo.com.
This appeared in Animal Scene’s January 2016 issue.