Characidae. Subfamily: Serrasalminae
This species occurs over much of northern South America. It’s been recorded from Ecuador, Venezuela, Colombia, Guyana, Suriname, French Guiana, Peru and Brazil. It occurs in a number of major river systems, including the Amazon and Rio Orinoco.
Usually found in slower-moving sections of rivers, especially where growth of marginal or overhanging vegetation is dense.
Maximum Standard Length
Aquarium SizeTop ↑
A group of adult fish will require a tank of at least 72″ x 15″ x 15″ (180cm x 37.5cm x 37.5cm) – 265 litres. Length and width are more important than height. Juvenile fish can be housed in smaller aquaria.
Inhabits densely planted river tributaries in the wild. The difficulty in replicating this in captivity is that the species is an avid plant-eater! Hardy plants should be chose but will still need to be replaced regularly. Artificial plants could be used as an alternative as some of the fabric and silk-type plants that are now available make convincing fakes. Redhooks can be nervous fish, so dim lighting and areas of refuge will boost their confidence.
Temperature: 73-81°F (23-27°C)
pH: 6.0 – 7.0
Hardness: Up to 10°H
A herbivorous species, in nature it feeds chiefly on the leaves of submerged or marginal vegetation, including terrestrial plants. Provide a large amount of vegetable matter in the diet, including; courgette, cucumber, peas, spring greens and other green vegetables. Commercial foods such as algae wafers, spirulina and vegetable flake are also recommended. Silver dollars will also accept the majority of aquarium foods and will relish such treats as bloodworm and brineshrimp.
Behaviour and CompatibilityTop ↑
Best kept in groups of at least five fish. Generally peaceful community fish and can be kept with other larger peaceful species. Much smaller fish may be eaten. Metynnis mainly occupy the middle and top areas of the aquarium, so it is a good idea to select tankmates that occupy both the bottom of the tank to add contrast. Larger peaceful catfish such as plecos and doradids would be a good choice.
Not known – male may have longer anal fin.
Not achieved in the hobby.
The Redhook is another species commonly sold as a Silver Dollar in the trade. It can be distinguished from those species as the black-trimmed, red anal fin is much more obvious than any of the metynnis species. The Redhook is also capable of growing much larger than its Silver Dollar relatives. This species was until recently referred to as myleus rubripinnis and is still widel y referred to as such.
The Redhook is sometimes described as a difficult fish to care for but, given a large enough aquarium, correct feeding and good water quality, it should not pose many problems.