The Critical Period for Arowana Coloration

1 The Critical Period for Arowana Coloration

When Do Arowana Start to Color?

For red arowana there is no exact date, but when the fish reaches about 25 cm, faint color usually appears on the gill plates. At this stage the size of the colored area matters less than how deep the color is.

At around 30 cm, the first scale frame on the front half of the body also begins to color, followed soon by the second frame, and the gill-plate color keeps growing and deepening. Some keepers think coloring has stopped at this point, but it has not—it is simply less obvious.

Once the fish reaches about 50 cm, the overall color becomes richer, but this stage is long and trying: some red arowana color beautifully while others stall or even fade. Patience and persistence are essential for a high-quality fish.

Coloring is closely tied to water quality, food, and lighting. For good color, provide stable, clean water, varied and suitable food, and appropriate light—these factors strongly affect how the fish colors.

Do not focus so much on color that you neglect body shape. Body development is especially critical before age 3. Coloration is a very long process, but a fish’s growth period lasts only about 2–3 years. In the juvenile stage, make sure the fish gets enough nutrition; if you do not, its adult size will stay small. Such a fish, however vividly red, will lack its commanding presence.

Note: Never fixate on a red arowana’s color at the expense of its health. Its growth window is limited and will not come again. Before age 3, pay more attention to body condition; otherwise even a beautifully colored adult will fall short of its full stature.