Hyphessobrycon rosaceus DURBIN, 1909

Rosy Tetra

Classification

Order: Characiformes Family: Characidae

Distribution

Guyana, Suriname and Brazil. The species is found in several river systems, including the Rio Essequibo, Rio Corantijn and Rio Suriname. The vast majority of fish sold in the trade are mass bred on commercial farms. In the UK, most of these originate from Eastern Europe.

Habitat

Primarily inhabits forested areas, in sluggish tributaries off the main river channels. The water in these biotopes is often stained brown with tannins and other chemicals released from decaying organic material, and is very acidic as a result.

Maximum Standard Length

1.6″ (4cm)

Aquarium SizeTop ↑

A small group would need a tank of around 24″ x 15″ x 12″ (60cm x 37.5cm x 30cm) – 70 litres in size.

Maintenance

A biotope setup would be very simple to arrange. Use a substrate of river sand and add a few driftwood branches (if you can’t find driftwood of the desired shape, common beech is safe to use if thoroughly dried and stripped of bark) and twisted roots. A few handfuls of dried leaves (again beech can be used, or oak leaves are also suitable) would complete the natural feel. Aquatic plants are not a feature of this species‘ natural waters. Allow the wood and leaves to stain the water the colour of weak tea, removing old leaves and replacing them every few weeks so they don’t rot and foul the water. A small net bag filled with aquarium-safe peat can be added to the filter to aid in the simulation of black water conditions. Use fairly dim lighting.

Alternatively, it’s a popular and well-suited choice for the high maintenance, heavily planted tank. Although it will survive in a more simple, sparsely arranged tank, it’s colours will often become washed out and it tends to be shy.

Water Conditions

Temperature: 75-82°F (24-28°C)

pH: 5.5-7.5. Although it will survive in slightly alkaline water, it tends to be more colourful when kept in acidic conditions.

Hardness: 1-12°H

Diet

Feeds chiefly on small invertebrates in nature. In the aquarium it proves unfussy. Feed a mixture of dried flakes and granules along with small live and frozen foods.

Behaviour and CompatibilityTop ↑

It’s a very peaceful species that won’t compete well with very boisterous or much larger tankmates. Ideally, keep it with other South American species, such as other Hyphessobrycon or Hemigrammus species, pencil fish, Apistogramma and other dwarf cichlids, Corydoras and small Loricariids. In a more general community, it can be combined with smaller rasboras, barbs, Anabantoids and West African dwarf cichlids such as Pelvicachromis species. Due to its shape, it’s also safe to be kept with larger cichlids such as angel fish or discus.

Always buy a group of at least 6 of these, preferably 10 or more. It’s a shoaling species by nature, and will fare much better when in the company of its own kind. Like most tetras it actually looks far more effective when maintained like this anyway. You’ll also see some stunning displays of fin flaring by rival males if several are present.

Sexual Dimorphism

Males develop extended dorsal and anal fins as they mature. They also tend to be larger, slimmer and a bit more colourful than females.

Reproduction

Can be bred in a similar way to other species in the genus. You’ll need to set up a separate tank if you want to raise decent numbers of fry. Something around 18″ x 10″ x 10″ in size is fine. This should be very dimly lit and contain clumps of fine-leaved plants such as java moss or spawning mops, to give the fish somewhere to deposit their eggs. Alternatively, you could cover the base of the tank with some kind of mesh. This should be of a large enough grade so that the eggs can fall through it, but small enough so that the adults cannot reach them. The water should be soft and acidic in the range pH 5.5-6.5, gH 1-5, with a temperature of around 80-84°F. Filtering the water through peat is useful, as is the use of RO water. A small air-powered sponge filter bubbling away very gently is all that is needed in terms of filtration.

It can be spawned in a group, with half a dozen specimens of each sex being a good number. Condition these with plenty of small live foods and spawning should not present too many problems.

Alternatively, it can be spawned in pairs. Under this technique, the fish are conditioned in male and female groups in separate tanks. When the females are noticeably full of eggs and the males are displaying their best colours, select the fattest female and best-coloured male and transfer them to the spawning tank in the evening. They should spawn the following morning.

In either situation, the adults will eat the eggs given the chance and should be removed as soon as eggs are noticed. These will hatch in 24-36 hours, with the fry becoming free swimming a 3-4 days later. They should be fed on an infusoria–type food for the first few days, until they are large enough to accept microworm or brine shrimp nauplii. The eggs and fry are light sensitive in the early stages of life and the tank should be kept in darkness if possible.

NotesTop ↑

A beautiful species that is very similar to a host of others in the genus, some of which are undescribed. The most common of these in the hobby is H. bentosi. The two are so similar in appearance that H. rosaceus was once considered to be a subspecies of H. bentosi. The easiest way to distinguish them is by the presence of a dark marking just behind the operculum in H. bentosi, which is lacking in H. rosaceus.

As with the closely related Hemigrammus, the taxonomic status of all species in the genus Hyphessobrycon is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for over well over 100 species of small characin. Most experts agree that a full revision is required, with the likely outcome that many species will be placed into new or different genera.

References

1. Durbin, M. L., 1909 - Annals of the Carnegie Museum v. 6 (no. 1): 55-72
   Reports on the expedition to British Guiana of the Indiana University and the Carnegie Museum, 1908. Report No. 2. A new genus and twelve new species of tetragonopterid characins.