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Contents
Overview
The red rainbowfish (Glossolepis incisus) is probably the reddest rainbowfish of all. Mature males grow a very tall back and turn tomato or salmon red with silvery scale highlights, while females are golden to olive, slimmer and more subdued.
It's endemic to Lake Sentani in New Guinea (Indonesia), an ecosystem threatened by pollution and introduced species. Aquarium fish are captive-bred, and they are hardy, long-lived and very active. Store juveniles are silvery and plain; the red only shows up from about 2.5-3 in (6-8 cm), so patience pays off. This is a fish for big tanks, not small community setups.
Care and tank setup
It's one of the large rainbows: males reach about 4.7 in (12 cm) and never stop swimming. Plan on at least 65 gallons (250 L) and a 5-foot (150 cm) tank for a group; a 4-foot tank is the absolute minimum. It prefers hard, alkaline water with good oxygen and moderate flow.
- Keep 6 or more with several females per male: males constantly chase and display.
- Hardy plants along the sides and back (vallisneria, anubias, Java fern) and a big open swimming area.
- Always use a lid: it's a powerful jumper.
It does well with other large rainbows, robust peaceful barbs, larger corydoras, plecos and calm Central American cichlids of similar size. Its pace overwhelms slow or long-finned fish, and dwarf shrimp usually become snacks. The classic mistake is keeping it in a short tank, where it stays pale and stressed.
Feeding
A hungry omnivore. Feed a quality pellet as the staple and add frozen foods (brine shrimp, mysis, bloodworms, chopped krill) plus some plant matter such as spirulina flakes or blanched peas. Carotenoid-rich foods (brine shrimp, krill, color-enhancing pellets) help deepen the red. Two moderate feedings a day; don't overfeed, since it gets chubby.
Breeding
It breeds like other rainbows: it spawns almost daily for weeks into fine plants, Java moss or a yarn mop and gives no parental care. The practical approach is to move the mop to a separate container every few days. Fry hatch in 7-10 days and need infusoria, then baby brine shrimp. Don't mix it with other rainbows if you want to avoid hybrids.
Compatible tank mates
Species from our database that share water parameters, size and temperament with the Red rainbowfish. Calculated from the data in each profile.
Bristlenose pleco Ancistrus sp. 26 gal (100 L) · 72–81 °F (22–27 °C) 
Betta fish Betta splendens 7 gal (25 L) · 75–82 °F (24–28 °C) 
Bronze cory Corydoras aeneus 21 gal (80 L) · 72–81 °F (22–27 °C) 
Zebra danio Danio rerio 16 gal (60 L) · 64–77 °F (18–25 °C) 
Guppy Poecilia reticulata 14 gal (54 L) · 72–82 °F (22–28 °C) 
Cherry barb Puntius titteya 16 gal (60 L) · 73–81 °F (23–27 °C) 
Tiger barb Puntigrus tetrazona 26 gal (100 L) · 72–79 °F (22–26 °C) 
Nerite snail Neritina natalensis 5 gal (20 L) · 72–82 °F (22–28 °C) 
Horned nerite snail Clithon corona 5 gal (20 L) · 72–82 °F (22–28 °C) 
Common goldfish Carassius auratus 79 gal (300 L) · 50–75 °F (10–24 °C) 
Panda cory Corydoras panda 16 gal (60 L) · 68–77 °F (20–25 °C) 
Dwarf gourami Trichogaster lalius 16 gal (60 L) · 75–82 °F (24–28 °C) Check the compatibility of your whole tank →
What not to keep it with
Popular species you shouldn’t house with the Red rainbowfish, and why.
- Discus: incompatible temperatures, incompatible pH
- Oscar: one may eat the other due to size, incompatible temperaments
- Celestial pearl danio: one may eat the other due to size
- Ember tetra: one may eat the other due to size
- Amano shrimp: eats shrimp
- Cherry shrimp: eats shrimp
Recommended equipment
What you need to keep the Red rainbowfish healthy, checked against Amazon stock.
Frequently asked questions
How many liters does a Red rainbowfish need?
At least about 250 liters for a group of at least 6 fish. More space always helps keep the water stable.
What water temperature does the Red rainbowfish need?
Between 22 and 26 °C, with a pH of 7 to 8.
What fish can live with the Red rainbowfish?
Based on water, size and temperament, it fits with species such as Bristlenose pleco, Betta fish, Bronze cory, Zebra danio and Guppy. Use our compatibility calculator to check your whole tank.
Can the Red rainbowfish be kept with shrimp?
Not recommended: because of its size or instinct, it will eat shrimp.
