Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Semaprochilodus taeniurus

Flag tailed Characin

Flag tailed Characin, Semaprochilodus taeniurusFlag tailed Characin, Semaprochilodus taeniurus
Photos by Andy Rapson


Semaprochilodus: Greek, sema, -atos = flag + Greek, pro = in front of + Greek, cheilos = lip + Greek, odous = teeth

General Notes:

Semaprochilodus taeniurus is generally peaceful with other similarly sized fish but less so with its own kind especially in pairs or very small groups. If kept in a larger group Semaprochilodus taeniurus is more tolerant of conspecifics. Semaprochilodus taeniurus is a very strong swimmer and can leap from the water with relative ease, so keep them well covered. These fish have very specific dietary needs like all herbivores they need to graze constantly so feeding should be carried out on a little and often basis with the correct diet. It is very unlikely that they would thrive if fed on dried food once per day. Due to their diet flag tail characins aren't suitable for planted show tanks because they will eat all the soft leaved plants. Semaprochilodus taeniurus could easily be confused with S. insignis which is an almost identical fish but where as both species are spotted as juveniles only Semaprochilodus taeniurus keeps its spots in to adulthood. Semaprochilodus insignis grows to a larger adult size too.


This fish is a herbivore, in the wild flag tail characins eat all forms of algae and soft leaved aquatic plants. In captivity fresh greens have to make up a major part of their diet. blanched spinach, lettuce, processed peas, cucumber aquatic plant cuttings and algae. Semaprochilodus taeniurus will also accept things like algae wafers and spirulina pellets/flake and the occasional live or frozen bloodworm or similar.


There is little or no reliable way to differentiate between the sexes but adult female flag tail characins are said to be plumper or more rounded than the males. Semaprochilodus taeniurus has not been bred in captivity, In the wild they migrate upstream to spawning grounds swimming through fast water and rapids to do so.

Wild status

The wild population of Semaprochilodus taeniurus is very healthy and is not under any immediate threat and is classes as LC (Least concern).

Information at a glance

pH: 5.5 - 7.5
dGH: 4 - 19
Temperature: 23 - 26°C (73 - 79°F)
Diet: herbivore
Size: 24cm (9.5in)
Min tank size:225 litres
Difficulty level: Difficult
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Flag tailed Characin Semaprochilodus taeniurus

Origin: South America: central portions of the Amazon basin and tributary rivers.

Habitat: Lives in lakes, streams and flooded forest when not breeding. Migrates up the main river channel to breed.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Prochilodontidae
Genus: Semaprochilodus
Species: S. taeniurus (Valenciennes, 1821)

Common name:
Flag tailed Characin

Synonyms: Curimatus taeniurus, Prochilodus taeniurus, Semaprochilodus taenirus, Semiprochilodus taeniurus.