Care
The Gold Tetra is known from the slower moving portions of rivers and their tributaries, plus coastal creeks and floodplains, where they sometimes enter slightly brackish waters. These fish are actually fairly modest in colour, but in some regions, populations are exposed to a certain type of trematode parasite which induces a cutaneous reaction; the fish excreting guanin as protection, in turn rendering the fish a dazzling metallic colour (hence the common name). This has led to some taxonomic confusion in the past, with the golden coloured tetras initially being described as a new species - H. armstrongi - but now that the skin reaction is well documented, this is now considered a synonym of H. rodwayi. It's highly likely that the slimmer silver fishes seen in the trade are actually Hyphessobrycon saizi, with rodwayi being deeper bodied and more rarely seen. Tank bred fish do not display the gold or silver colouration, as they are not exposed to the parasite in captivity. Wild imports of metallic fish are available from time to time, and these highly reflective specimens are truly spectacular.
The aquarium for these fish should be well-established and contain soft, acidic water. There should be a sandy substrate and an abundance of driftwood tangles for the fish to explore, along with some dried Indian almond leaves (Terminalia catappa) scattered on top of the sand (these will require periodic replacement). The tannins leached from the wood and leaves should impart a clear, tea-coloured tint to the water, which will not only help to acidify the environment, but will also ensure the fish feel more secure and will bring out their natural colours. Peat added to the aquarium filter will also be very beneficial. Plants are not abundant in the natural habitat of this species, but may make the tank more aesthetically pleasing. Gold Tetras are a peaceful shoaling species that should always be maintained in good sized groups; we would suggest a minimum of 6 specimens, but preferably 10 or more. Tankmates should be small and peaceable and enjoy the same softwater conditions. Other peaceful Hemigrammus or Hyphessobrycon spp. tetras, pencilfish, hatchet fish, dwarf cichlids (Apistogramma sp. and Mikrogeophagus sp.), Corydoras catfish, and smaller Loricariids (suckermouth catfish) make excellent companions. Acclimatisation should be carried out carefully, and be sure to keep up with small regular water changes to keep nitrogenous wastes at a minimum. Filtration should be efficient but water movement not too vigorous.
Feeding
Offer a varied diet including a good quality flake, micropellets, and small frozen foods such as bloodworm, white mosquito larvae, vitamin-enriched brineshrimp, and daphnia.
Breeding
This egg-laying species is relatively easy to breed, and in the confines of a well planted tank, you may see small numbers of young appear from time to time. Bear in mind that the young will not display the metallic sheen of their parents. However if you wish to raise a good number of fry, a small separate breeding aquarium should be set up for the purpose. This tank should also contain soft, acidic water, and the temperature should be set towards the high end of their preferred range. Prior to the spawning attempt, condition your fish on plenty of small meaty live or frozen foods. Clumps of Java moss or a few bunches of fine-leaved plants should be added to the breeding tank to give the fish somewhere to scatter their eggs, and very gentle filtration should be provided via an air-driven sponge filter (a small bag of peat can be incorporated here). No dedicated lighting should be used, as eggs and fry tend to be light sensitive. Acclimatise a mix of both sexes across to the new tank very carefully during the evening, and in the morning, when sunlight hits the tank, spawning should commence. The parents should be removed immediately after spawning ceases as they will predate on the eggs. Some aquarists like to use a fine mesh in the tank so that the scattered eggs can fall to safety, away from the attention of the adult fish. Ideally try and keep the tank in darkness once eggs have been scattered, to protect them and the resultant sensitive young fry from being damaged by bright light. The eggs should hatch within 24-36 hours (temperature dependent) and the young will initially feed from their yolk sacs. Once free-swimming (usually after 3-4 days), microscopic foodstuffs such as infusoria/Paramecium should then be offered, followed by baby brineshrimp (Artemia nauplii) and microworm as they grow.
