Production of Climbing Perch

The climbing perch, Anabas testudineus is a small sized fish that inhabits both freshwater and brackish water habitats. It is a slender fish with large scales and spines on the gill cover. The fish is hardy in nature and thrives even in oxygen-depleted waters with the help of accessory respiratory organ (labyrinthine organ) situated on the upper part of gill chamber. The fish is called climbing perch due to its ability to wander or crawl across land.

It is an omnivore, feeding mainly on insects and small fish, but the larvae and juvenile thrive mainly on plankton. The fish is generally shy, but become aggressive during spawning period. In nature, the fish is known to mature at 70-100 mm size and breeds prolifically with the onset of monsoon in natural habitats such as paddy fields and seasonal ponds having 10-25 cm water depth. It grows to a maximum length of 25 cm, but commonly not seen more than 16 cm. There is a fast growing strain named ’Koi Anabas’ which attains 400 g in 4-5 months compared to local strain, which reaches only 100 g size in 9 months.

The fish is much popular for good flavor and prolonged freshness even after catch. It is a preferable diet for sick and convalescent people. The flesh of the fish contains 17% protein and 13% lipid on wet weight basis. The fish also contains high iron and copper content, which are essentially required for haemoglobin synthesis.

Seed Production

The breeding season of climbing perch usually starts from March and continues till late August with a peak in May-June. Under captivity, it attains sexual maturity in the first year at a size of 8.0-9.2 cm (14-18.2 g). Although the fish spawn naturally once in a year, multiple spawning is possible by hormonal administration.

Broodstock management

Fish weighing a minimum of 40 g is procured, disinfected and stocked at a density of 5-7 no./m² in outdoor cement cistern having 2-4 m diameter and 1.2 m height. All other aspects of broodstock management are similar to that explained for the walking catfish.

Selection of brooder

Broodstock kept in outdoor cement cistern is regularly checked for its gonadal development. Sexual dimorphism is not distinct till breeding season, except that male often tends to be smaller and slender than the female. The male and female develop secondary sexual characters during the breeding season. The ripe female develop prominent outgrowth at the vent in the form of genital papilla. Even on slight pressure on the abdomen, the eggs are released. The mature male is dark and has longer anal fin than the female and the ripe male oozes out white milt upon gentle pressure on its abdomen. During breeding season, fully mature fish are collected and males and females are kept separately in FRP tanks. Maturity stage of female can be examined by catheterisation. The female is suitable for breeding when the diameter of egg is 0.6-0.8 mm. The healthy and mature fish is induced to breed in March. After prophylactic treatment with potassium permanganate, the same fish is maintained separately with utmost care for next breeding. Within 50-60 days, it will be ready to breed again.

Spawning

The conditioned fish are selected in 2:1 male to female ratio and induced to spawn by the administration of synthetic hormones like Wova- FH @ l ml/kg body weight as a single dose. The hormone is injected intramuscularly in single dose during evening. Proper care must be taken to avoid injury by the sharp spines of the fish during handling. The injected fish are released to an FRP tank for spawning. After administration of hormone, it takes 7-14 hours to spawn. Lowering of water level in the tank to 20 cm, in conjunction with frequent water exchange induces the fish to spawn.

The climbing perch spawns at night and each brooder spawns several times by changing its partner. Both courtship and spawning occur in the water column. Spawning is preceded by the courtship period that continues for 3-7 hours, after the hormone injection. Usually, male follow a female trying to snuggle up to its side, half way to the female. If the female do not respond or try to escape, the male exhibit an aggressive behaviour, including bumps and bites.

The female which is ready to spawn turns around by 180° around the male head, and get in a position of “head to tail,” and then the pair forms a ring “nose to the tail” and performs one to two circular motions after which they move apart. Another variant is when both partners perform several convulsive ‘S’ shaped bends with the body and release the gametes. After this, the partners move apart, but almost immediately resume spawning. Sometimes the spawning stops for several minutes, after which it is resumed. In case of disturbance, the fish easily descend to the water column but rise rapidly in quiet water. The fertilised eggs are floating, translucent and non-adhesive with 0.9-1.0 mm diameter while the unfertilised eggs are opaque. The fecundity of female is 100- 200 no./g body weight. The climbing perch shows no sign of parental care, but feed upon their own eggs and young ones.

Incubation

The fertilised eggs are cleaned, disinfected and kept for incubation similar to that explained for the walking catfish. Hatching takes place by 10 hours at 26-30°C. While resting free embryo is seen scattered near the water surface with their yolk sac upward. During active movement in the water column, wrigglers turn over into natural position. This phenomenon is observed up to the yolk resumption stage. The hatchling measures 1.6-1.8 mm in length and rests at the bottom of the tub in an upside down position.

Rearing of hatchling

Just before completing yolk sac absorption (usually 2-3 dph), the larva is transferred from incubation unit to indoor nursery rearing unit. The other aspects may be carried out similar to that explained for the walking catfish.

Rearing of fry

It is similar to that explained for the walking catfish.

Farming in Pond

Monoculture system is usually practiced for the farming of the climbing perch.

Selection of pond

Stone pitched pond is ideal as the fish exhibits climbing behaviour. The pond having a size of 0.05-0.2 ha is ideal. To prevent the escape of fish, 75° slope for embankment or fencing the sides of the pond with poles and net upto a height of 60 cm is provided.

Pond preparation

In order to avoid predation by birds, the pond is covered with net. Pond preparation practices including removal of predatory and unwanted fish, liming, manuring etc are to be followed as explained for the farming of the major carps. The pond is provided with floating aquatic plants like Eichhornia up to least 20% of water-spread area to simulate their natural habitat.

Water quality parameters

The water quality parameters required for the farming of climbing perch are given below:

• Temperature  : 20-30⁰C       
• pH  : 6-8.5
• Salinity  : <10 ppt   
• TAN : <0.5 ppm

Stocking

The fish seed having an average size of 5-7 g is stocked at a rate of 10 no./m². The stocking density can be increased to 30 no./m², provided that weekly water exchange of 25% is ensured. In cage culture, stocking density of 200 no./m³ is preferred. This fish is suitable for farming in RAS with high stocking density of 400-500 no./m³.

Feeding

It is fed with a floating pelletted feed having 30-35% protein or chopped fish. The fish being primarily an insectivore, fixing a hanging light just above the tank/pond/cage is a really good way to attract insects, which provide an additional source of food.

Harvesting

The fish attains a marketable size of 100 g in 8-10 months. Complete harvesting can be done by dewatering the pond and the fish can be collected by hand picking.

Source : Department of Fisheries, Government of Kerala