Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Systomus rhomboocellatus

Rhombo barb

Systomus rhomboocellatus, Rhombo barbSystomus rhomboocellatus, Rhombo barb
Photos by Andy Rapson

General Notes:

The Systomus rhomboocellatus, Rhombo barb is a beautiful species with shines with iridescence it is also one of the most reliably peaceful of all barbs even with long finned fishes. Systomus rhomboocellatus, Rhombo barbs demand soft acidic water if they are to thrive but captive bred specimens will be a little more tolerant and forgiving than wild caught fish.


Very undemanding, Systomus rhomboocellatus, Rhombo barbs will accept all flake and suitably sized pellet food to which regular treats of  live or frozen food such as blood worms, daphnia, cyclops are given.


Very peaceful with all small and medium sized community fish as long as the fish are to big to be swallowed whole. It may become shy and timid with larger and rowdier species.


As with lots of other similar barbs the adult females tend to be larger and plumper than the adult males.


Systomus rhomboocellatus, Rhombo barbs are egg scatterers which will spawn quite freely if given good care. Post spawning they show no interest in their eggs other than to eat them.
The eggs will hatch after about 30 hours depending upon the temperature and the fry will be free swimming after a further three or four days. The fry are vey tiny and will need a supply of infusoria or a liquid fry food until they are large enough to accept newly hatched brine shrimps.

Wild status

The wild status of these fish has not been evaluated but they are not thought to be under any immediate threat and almost all the fish available in the hobby have been commercially bred.

Additional information

Rhombo barbs are very social and prefer the company of their own species. They should be housed as a mixed sex group of at least eight individuals.

Information at a glance

pH: 5.5 - 6.5
dGH: 4 - 10
Temperature: 23 - 28°C (74 - 82°F)
Diet: Omnivore
Size: 8.8cm (3.5in)
Min tank size: 250 litres
Difficulty level: Easy
Aquarium type: Community
Swimming level: All levels

Distribution and habitat

distribution map for Systomus rhomboocellatus, Rhombo barb

Origin: West and Central Kalimantan in Borneo, Indonesia.

Habitat: Slow moving lack water forest streams and pools.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Systomus
Species: S. rhomboocellatus (Koumans, 1940)

Other common names:
Rhombo barb, snake skin barb

Synonyms: Puntius rhomboocellatus,  Barbus rhomboocellatus, Barbus kahajani.