Etroplus suratensis - Green Chromide

Cichlidae. Subfamily: Etroplinae

India and Sri Lanka.

It inhabits coastal areas, occuring in large schools in estuaries, lagoons and rivers. It is also seen in fresh water at certain times of the year.

18" (45cm), although 12" (30cm) would be considered a good size in captivity.

48" x 24" x 24" (120cm x 60cm x 60cm) - 450 litres.

This is a brackish species and requires the addition of marine salt to its tank. Aim for around a quarter the salinity of full marine conditions (sg 1.005). Provide cover in the form of rocks arranged to form caves, driftwood, plant pots etc. Live plants can be used but will usually not survive for long under saline conditions, plus they will most likely be consumed by the fish. Plastic alternatives may be considered.

73-79°F (22-26°C)

7.0-9.0

12-30°H

An unfussy eater, it will accept most live, frozen and dried foods. Keep the diet varied and try to ensure the addition of some vegetable matter.

A peaceful cichlid but it will intimidate small fish with its sheer size. Good tankmates include larger brackish species such as archer fish, scats, monos, and some gobies. It is gregarious by nature and should be maintained in a group if 6 or more unless spawning. A large tank is therefore required.

Almost impossible to sex except when spawning, and even then, the only reliable difference is in the shape of the genital papillae, which is more pointed in male fish.

Not an easy species to spawn. Bi-parental substrate spawner.

It is a seasonal spawner in nature, so a raise in temperature and salinity may induce spawning. The best way to obtain a pair is to purchase a group of 6-8 young fish and condition them well on a varied diet. Once a pair forms, it is better to remove the other fish from the aquarium, or move the pair. The breeding aquarium should be at least 48" in length and should be set up as suggested above. Slightly brackish, alkaline water is essential and a warm temperature of 25-28°C is preferable.

Pre-spawning, the pair will clean the chosen site thoroughly. This may be a rock or other surface in open water, or the fish may select a cave. Up to 1000 eggs may be deposited and are attached to the surfaces by short stalks. The eggs hatch in 36-48 hours and are guarded vigorously by both parents. They become free swimming after another 7 days or so.

During the initial period the fry can often be seen clinging to the flanks of the female, and it is thought that she excretes a nutritious mucous, in a similar fashion to discus. The fry are relatively large, and can be offered brine shrimp nauplii and powdered dry foods once they are free swimming. They are very sensitive to changing water conditions and regular small water changes are best, so as to maintain stable chemistry. It takes some time for them to exhibit the adult patterning.

The green chromide is one of only a handful of cichlid species known from Asia. In nature it has an interesting relationship with its smaller relative E. maculatus , which acts as a cleaning fish for it in a similar fashion to some marine wrasses. It can survive in freshwater (and also full-strength marine water), but is more susceptible to disease and often loses its colour. It is also very sensitive to deteriorating water quality, so a strict maintenance regime is essential to its good health. Not a species for the general community, but one which provides many rewards to the dedicated hobbyist.