Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Trichogaster lalius

Dwarf gourami

Dwarf gourami, Trichogaster laliusDwarf gourami, Trichogaster lalius
Photos by Andy Rapson

Etymology:

Trichogaster: Greek, thrix = hair + Greek, gaster = stomach

General Notes:

There are now lots of aquarium bred colour morphs for this fish all with different trade names but they are still Trichogaster lalius and they all require the same basic care. In recent years captive bred dwarf gouramis have had a poor reputation because a disease has spread throughout the population.
Dwarf gourami iridovirus causes the fish to develop sores, internal swelling and premature death, most specimens lasting only a few weeks or months. The disease is incurable and a few other species have proved to be susceptible to it.
Healthy dwarf gouramis should live for three to four years with good care. As with all other gouramis they need easy access to the water surface where they will occasionally take a gulp of air, dwarf gouramis sometimes live in water with a low oxygen level and they have an adaptation which allows them to breathe from the air. Their gills can no longer supply all their oxygen requirements and so if they are denied access to the surface they will drown. Dwarf gouramis are generally quite peaceful and make great community fish.

Feeding

Wild dwarf gouramis are omnivores and eat small insects, crustaceans, worms and plant matter. In captivity they are easy to please and accept all commercially prepared foods of a suitable size, they need a varied diet which should include fresh food and some live or frozen food on a regular basis.

Sexing

Dwarf gouramis is easy for fish with the wild colouration because the males are well coloured while the females are silvery grey. Aquarium morphs which have the same colours for both sexes are more difficult to tell apart.

Breeding

Dwarf gouramis is relatively straight forward. A separate tank is essential and can be bare apart from some floating plants. The pair need to be kept apart and conditioned by feeding them lots of live or frozen food such as blood worms. If the two fish are introduced together before the female is ready to spawn the female will be attacked. The male will begin to build a nest of small bubbles and this is where the eggs will be ket. When the female is ready to spawn the male will display to attract her to the nest where he will wrap around her and both eggs and sperm will be released together. The eggs are buoyant and will float up to the nest and any which stray away will be collected up and placed there. Once spawning is complete the male will once again become aggressive toward the female and she must be removed. The male alone will care for the brood although with so much line breeding in captivity this instinct isn't very strong in some individuals. The eggs hatch after about 36 hrs and the fry become free swimming after a couple more days. At this point the male should be removed for safety. The fry will take infusoria, liquid fry food, hard boiled egg yolk until they are big enough to accept newly hatched brine shrimps.

Wild status

The ICUN Redlist of Threatened Species lists Dwarf gouramis as 'least concern' the fish is wide spread but may face over exploitation by the aquarium trade in parts of its range.

Information at a glance

pH: 6 - 8
dGH: 5 - 19
Temperature: 25 - 28°C (78 - 82°F)
Lighting:
Diet: Omnivore
Size: 5cm (2in)
Min tank size: 60 litres
Difficulty level: Easy
Aquarium type: Community
Swimming level: All levels

Distribution and habitat

distribution map for Dwarf gourami, Trichogaster lalius

Origin: Bangladesh; India (Arunachal Pradesh, Assam, Bihar, Manipur, Uttaranchal, Uttar Pradesh, West Bengal); Nepal; Pakistan. Dwarf gouramis have also been widely introduced beyond their natural range.

Habitat: Fresh water only, slow moving streams, rivulets and lakes with plenty of vegetation. Also from rice fields, irrigation channels and other agricultural lands.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Osphronemidae
Genus: Trichogaster
Species: T. lalius (Hamilton, 1822)

Common name:
Dwarf gourami

Synonyms: Trichopodus lalius, Colisa lalius, Polyacanthus lalius, Colisa unicolor