Rosy Tetra

Rosy Tetra (Megalamphodus rosaceus) 

Care and Breeding Notes

Another very striking tetra with white fleck to fins and when they colour up they show a deep purple colour . I currently have a group of six as the tank has only recently completed its cycle. Over the next week I’ll continue monitoring water parameters and performing any necessary water changes before increasing the shoal.

Natural Habitat

Rosy Tetras  native to flowing, plant‑rich rivers across Brazil, Guyana, and Suriname

Size & Lifespan

• Adult size: ~5 cm (2")
• Lifespan: 3–5 years in captivity

Aquarium Setup

Water Parameters

• Temperature: 24–28°C
• pH: 6.0–8.0
• KH: 5–20°
• My current setup: 24.5°C, pH 6.8, KH 5

Rosy Tetras adapt well to a wide range of conditions. Planted and floating plants, botanicals and driftwood make excellent décor and help replicate their natural environment.

Diet

These fish are omnivores and benefit from a varied diet. Mine receive a rotation of:

• Micro granules
• Flake food
• Daphnia
• Baby Brine Shrimp
• Bloodworms

Breeding Project

As part of my ongoing project with this species, I’ll be attempting to breed them.

Sexing

Mature males often with brighter colours and longer dorsal and anal fins. Mature females fuller bodied.— especially noticeable once they mature. This may take some time after purchase.

Breeding Tank Setup

Rosy Tetras are egg scatterers, females will scatter eggs in plants and the male will fertilise them so a dedicated breeding tank is essential to prevent the eggs from being eaten.

Recommended setup:

• Soft, tannin‑rich water (achieved with leaves, botanicals, or peat filtered through floss)
• A cycled sponge filter
• Raise temperature slighlty to 26.5C
• A plastic grid or mesh to protect eggs from the adults or add fine leaved plants like Java Moss or spawning mops. 
• 1–2 females with 1 male

Spawning Method

1. Introduce the fish to the breeding tank and leave them undisturbed.
2. After 24–48 hours, perform a 50% water change using freshly collected rainwater.
3. The following day, perform a 75% rainwater change.
4. Repeat this cycle as needed.
5. If spawning doesn’t occur, remove the male, feed the females well for a few days, then reintroduce him and restart the water‑change routine.

This method is commonly used for other tetra species, so with luck, it should also prove successful for Rosy Tetras.

If you'd like, I can also format this into a care sheet, a YouTube script, or a branded AquaExotics‑style guide.