Introduction

Copella arnoldi, known as the splash tetra or spraying characin is an old favourite that is notable both for its beauty and remarkable breeding behaviour. This species is the only one known to lay their eggs above the water surface. In the wild, overhanging leaves are used whilst in aquaria a suitable alternative will be the tank sides or cover. It was described as Copeina arnoldi by Charles Tate Regan in 1912.

Distribution and Availability

The splash tetra is found in Guyana, Suriname, French Guiana and Brazil. It lives in slow-moving water courses and flooded forests. It needs overhanging vegetation to breed. It has been introduced to Trinidad and Tobago.

Splash tetras are not often offered for sale so if you see some snap them up. They are occasionally seen at auctions and club meetings as they are popular with hobbyists.

Description

A medium-sized torpedo-shaped tetra. Pinkish body with a horizontal stripe through its eye and mouth. The caudal fin is deeply forked with the upper lobe being larger than the bottom lobe which has a scarlet flash. The dorsal fin has a black strip with a white and pink border. Large pelvic fins are used when spawning. The adipose fin is absent.

Males – up to 7cm with exceptional specimens exceeding this. Fins are more elaborate than the females.

Females – up to 5cm.

Requirements

A fairly easy fish to care for and can easily be kept in a community tank with other peaceful fishes.

• Tank size: 90cm minimum. Smaller for breeding. Keep the tank well covered.
• Decoration: fine-leaved and floating plants
• Temperature: 25 – 29^oC
• pH: 6 – 7.5
• Hardness: requires soft water, 2 – 8^odH

Feeding

A good quality flake food with live foods such as newly hatched brine shrimp and grindal worms fed two or three times a week will keep your tetras in excellent condition.

Breeding

There fish are quite easy to breed and their unique and truly remarkable behaviour is something that every aquarist should try to witness.

Place a pair or trio in a smallish tank with a sponge filter and lots of floating plants and Java moss. Drop the water level to around 10cm from the top. Arrange it so that the water from the sponge filter is splashing the water surface and tank sides making a moist microclimate between the water surface and the cover glass.

The fish will spawn on the glass sides or even the cover. The male and female co-ordinate their jumps and use their enlarged pelvic fins to cling to the chosen spawning site. They will lay about a dozen eggs during each leap and can lay over 100 eggs. If more than one female is available the male will mate with them all. The nests can be in the same place or there can be multiple nests.

When the spawning is complete the females should be removed. The male will now guard the eggs and every few minutes will deftly flick water on them using his tail. It’s now he earns his nickname of “splash” or “spraying” tetra.

If the male has multiple nests to tend to he remembers where they are and splashes each nest in turn. If the eggs are fertile they will hatch after two or three days and the fry will drop into the water. At this point the male should be removed.

The fry are small and require the finest of live foods to begin with. Infusoria and paramecium are adequate and they will also find food within the Java moss and floating plants. After about ten days the fry will be large enough to eat vinegar eels and newly hatched brine shrimp. Carry out partial water changes to keep on top of the water quality.

Summary

Copella arnoldi is truly a beautiful and fascinating little fish. Easy to keep and a delight to breed it’s only drawback is it is so rarely offered for sale.

References

1. Baensch, H. A., Riehl, R.(1982): Aquarium Atlas – Amazon
2. Fishbase species summary