Guppy (Poecilia recticulata): Guppy, hailing from central America is one of the most popular ornamental fish worldwide falling under the category of live bearer fishes ie. Fishes that give birth to live young ones. Apart from guppy, molly, platy and sword tail are other live bearer fishes. There are different varieties of guppies classified based on their colour and fin patterns. The males are brightly coloured, slender are generally smaller than female. The anal fin of male guppy is modified into a rod-like structure known as gonopodium used for fertilizing the females. They mature by 3 months and start giving birth to young with gestation period one month. The price of guppies varies from Rs. 5 to Rs.1000 depending on the varieties.  Some of the varieties are snakeskin, tuxedo, lace, grass, dumbo ear, ribbon, fan tail etc.

Gold fish (Carassius autatus): Gold fish originates from Asia and has been introduced to different parts of the world. It’s an omnivour and can grow up to maximum length 45 cm. It attains sexual maturity by six months. The male fishes on maturity may develop small white spots like projections on the operculum  called tuberciles and its first pectoral fin ray becomes thick and serrated. Gold fishes eggs are adhesive which stick to substrates on spawning and may hatch in 2-3 days time.  There are several varieties of goldfish developed by selective and cross breeding such as ranchu, oranda, ruykin,  lion head, SK, pearl, blackmoor etc.

Koi carp (Cyprinus carpio): Koi carp is native of Japan. It’s a colour variant of common carp an edible fish cultured widely. The fish attains sexual maturity by six months. The male fishes may develop tubercles and serration similar to that of goldfish. On pressing the abdominal region (near anus) of the fish white coloured fluid milt may ooze in male and egg may come out in female after excreta. Breeding is similar to that of goldfish. There are different varieties of koi carp based on their colour like Kohaku, Sanke, Utsuri etc. The price may vary from hundreds to thousands of rupees.

Angel fish (Pterophyllum scalare): The Angel fish originates from Amazon region and normaly can grow to about 15 cm in a large tank. The body is disc shaped ie. laterally compressed with large and elongated fins. It matures in 6 to 8 months time. It’s difficult to distinguish the sex. Live feed such as artemia nauplii is a must for larval rearing. The various varieties are black, marble, golden, platinum, altum, red eye, veil tail etc.

Blue Gourami (Trichogaster trichopterus): This blue coloured fish is a native of south-east Asia. The variety with three spots on the body is known as three spot gourami. It’s an air-breathing fish which matures by 6- 8 months and can grow up to a length of 15cm. The male has large pointed dorsal fin while the female has short rounded dorsal. The males build a bubble nest and take care of the eggs after spawning and show parental care. The other variant of gouramies based on the colour and size are white, yellow, dwarf, neon etc.

Fighter or Siamese fighting fish (Betta splendens): This fish is a native of south-east Asia and can grow to 6 cm length. The name fighter comes from the fact the adult male fishes fight with each other. So two adult males cannot be put in a tank as they fight till one is completely defeated and killed. The breeding and behaviour is similar to that of gourami. Males have enlarged enormously sized dorsal, anal and caudal fins which are kept folded until they see another male and flair. Females are smaller with short fins compared to that of male. They are fairly peaceful in the community tank and can even be housed singly in a glass bowl. The common varieties are half-moon, crown tail, plakat etc.

Zebra barb (Brachydanio rerio): Zebra Danio originates from north east India. It has several steel – blue and creamy white stripes running across the body and into the tail fin, hence the name zebra fish. They can grow up to 5 cm and attain maturity at 2cm size. The males are smaller and slimmer than female. These fishes don’t care about their eggs and may eat them as soon as it’s released. The incubation period is 2-3 days. The common varieties are albino, white and blue.

Neon tetra (Paracheirodon inneri ): It occurs in the slow-moving rivers of South America. The body is greenish olive coloured with a metallic blue stripe which runs along the side from nose to tail, below this line it has a red stripe running from abdomen region to tail. In case of cardinal tetras this red stripe runs from nose to tail. The fish grows up to 4 cm in length. The female is larger than male, and on maturity, the blue stripe on it gets curved while in males it’s straight as they are slimmer.  It is one of the most preferred and traded ornamental fish globally along with guppy. The fish reaches sexual maturity in 3 to 4 months. They prefer darkness for breeding and generally eat the eggs after spawning.  Other similar tetra varieties are green, black neon and glowlight tetra.

Contributor: Dr. B. Pradeep, Subject Matter Specialist- Fisheries ICAR-Krishi Vigyan Kendra,ICAR-IISR, Peruvannamuzhi, Kozhikode 673528 Kerala, Email: pradeep@spices.res.in