Breeding the Splash Tetra
Copella arnoldi spawns on surfaces above the waterline; the male splashes water onto the eggs for 36-72 hours until they hatch and drop into the water.
Overview
Copella arnoldi is notable for one of the most unusual reproductive strategies among aquarium fishes. According to Seriously Fish, spawning and egg deposition occur on overhanging vegetation or other surfaces above the water surface, and the male then keeps the eggs moist until they hatch.
Sexing
Males grow significantly larger, develop more extended fins, and are more colorful than females. During the spawning season a broad dark band may extend along the body behind the gill cover, with silvery-white patches on the flank scales and thin black fin margins.
Breeding Conditions
- Temperature: 20-28 °C
- pH: 4.0-7.5
- Use an air-powered sponge filter and plenty of floating plants
- Leave a gap of about 10 cm between the water surface and the cover, with a smooth surface (such as the cover glass or a leaf) for egg deposition
Spawning
The male selects a spawning site by repeatedly leaping out of the water. At the climax of courtship the pair jump out of the water together and cling to the chosen surface with their pelvic fins, remaining there for up to about 10 seconds while eggs and milt are released. Typically 10-12 eggs are deposited during a single leap, and the total brood is normally 100-200 eggs. Eggs may be placed on almost any suitable surface, including the side of the aquarium or the cover glass.
Egg & Young
After spawning, the male keeps the eggs moist by using his caudal fin to splash water at them. This behavior pauses during darkness and is repeated roughly every minute, continuing for the next 36-72 hours until the eggs hatch, at which point the larvae fall into the water.
Common Challenges
Success depends on providing a suitable above-water spawning surface and an adequate air gap beneath the lid so the male can reach and splash the eggs. Allowing the eggs to dry out or removing the male before hatching will cause the clutch to fail.