Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Myloplus rubripinnis

Redhook metynnis

Redhook metynnis, Myloplus rubripinnisRedhook metynnis, Myloplus rubripinnis
Photos by Andy Rapson


Myloplus: Greek, mylos, -ou = grey mullet + Greek, plus, ploos = movement of a serpent

General Notes:

Although very peaceful Myloplus rubripinnis has the potential to cause a serious injury by biting. This species grows to a good size and is very active which means it needs a lot of open swimming space. All plants will be eaten even the tough bitter ones which most other fish will leave well alone so decorate their aquarium with bogwood roots.  Myloplus rubripinnis is a shoaling species and so keep them in a group of at least five individuals which will help to make them feel more confident. They can be kept with smaller species because it is a herbivore and very peaceful. A large aquarium is essential, if they feel to confined they are prone to panic if something startles them and this could cause an injury, in larger aquariums with companions of their own kind they are far less likely to panic. As the fish matures it develops orange/gold spots on its body.


Myloplus rubripinnis are herbivores and fresh greens are a very important part of their diet. In captivity they will thrive on a diet of skinless processed peas, blanched spinach, algae wafers, pellets or flake, tender aquatic plant cuttings and similar food.


There are no reliable external differences between the sexes.


Myloplus rubripinnis has so far never been bred by hobbyists.

Wild status

Wild populations of Myloplus rubripinnis have not been evaluated, most specimens offered for sale will be wild caught.

Information at a glance

pH: 5 - 7
dGH: 4 - 15
Temperature: 22 - 27°C (72 - 80°F)
Diet: Herbivore
Size: 25cm (10in)
Min tank size: 675 litres
Difficulty level: Intermediate
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Redhook metynnis, Myloplus rubripinnis

Origin: South America: Amazon and Orinoco River basins; north and eastern Guiana Shield rivers

Habitat: Calm slow moving water of main rivers where the vegetation hangs over the river banks.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Serrasalmidae
Genus: Myloplus
Species: M. rubripinnis

Common name :
Redhook metynnis

Synonyms: Myletes rubripinnis, Aphyocharax rubripinnis, Myleus rubripinnis, Myletes luna