Culture of Climbing perch fish

Species profile

Climbing perch (Anabas testudineus) belongs to Anabantidae family (order Perciformes). It is widely distributed in Asia especially India to Wallace line including China. Two Anabas species have been reported in India, namely A. testudineus and A. oligolepis. The A. testudineus is commonly known Koi or Kavai and this fetches a good value in Indian market especially in the states of West Bengal, Assam, Tripura, Manipur and Bihar.

The Climbing perch is a native air-breathing fish, typically found in freshwater and brackish water; it is a potamodromous species. They can tolerate wide temperature, ranging from 22 to 30^OC. A. testudineus is widely found in the canal, lakes, ponds, swamps and estuaries, but the adults are present in the rivers, brooks, flood areas, and stagnant water bodies with dense vegetation. It can withstand extremely unfavourable water conditions; they are mainly associated with turbid and stagnant water bodies. It has an additional respiratory organ which if kept moist can help it to survive for several days without water. It is recognized as the tastiest fish and is sold live in the fish markets.

The IUCN has categorized A. testudineus as a threatened species due to over-exploitation. Hence conservation measures are necessary to be taken. Artificial propagation has successfully been developed and is practiced across the country.

Broodstock management

Climbing perch attains age at first maturity in the first year and measures 8 – 10 cm length and weighs 15 – 20 g. The breeding season starts from March to August but peaks during May and June. The sexual dimorphism is apparent during the season of reproduction. The male exhibits reddish colour on pectoral and ventral fin, diamond shaped blackspot on caudal peduncle; white milt oozes out when gently pressed on the abdomen towards the genital pore. Males are darker with longer dorsal fin when compared to the female. The females have faint reddish pectoral and ventral fins, and the black spot is oblong and slightly diffused. Mature female exhibits budged abdomen, prominent growth at the vent in the form of the genital papilla and oozing ova at the gentle press on the abdomen.

Two or three months prior to breeding season, the brood fishes weighing 30 – 50 g are collected from the commercial brood pond and kept separately in cement cisterns. The egg quality and health of fry depend on the health of the brood fish. The number of eggs and egg quality are profoundly affected by the broodstock maintenance condition, their husbandry, broodstock nutrition, ration, and environment condition and stress factors including those created during handling and spawning induction. There is need to monitor the water quality parameters especially the chemical parameters such as dissolved oxygen, pH and ammonia at regular intervals to maintain the health of brood stock. The supplementary feed is to be provided to the brood fishes at 3 – 5 percent of body weight (30 – 35 percent protein) in two rations per day. The brood fishes must be recruited from the natural source (canal, lakes, ponds, swamps) and other farmers once in a year for better quality production of eggs. The photoperiod adversely affects spawning period of fish.

Artificial propagation

For breeding, the recommended sex ratio is 2:1(male: female). For administration, the pituitary or the ovaprim is commonly practiced; the desired dose of ovaprim (1 µg/g of body weight of fish) is injected to the male and female by the intramuscular method. The courtship starts after 6 hrs of injection. The male wraps in the female body and fertilizes the eggs which are laid by the female. Climbing perch does not build a nest to protect the eggs, unlike other anabantids. The female release a minimum of 4000 eggs and a maximum of 68000 eggs; around 200 eggs each time. Fecundity is about 350 – 400 eggs/ g of body weight of fish.

The fertilized eggs are transparent and unfertilized eggs are opaque. The fertilized egg size ranges between 0.80 – 0.90 mm in diameter and, the eggs float on the surface of the water when water is hardened. The fertilized eggs are incubated in stagnant water by using FRP cistern. It takes about 18 – 22 hrs for hatchling after injection. The hatching period depends on the water temperature (28 – 32^OC). Multiple breeding has successfully been done and reported in India.

Fry rearing

A newly hatched larva of climbing perch has a length of 1.6 – 2.0 mm. The yolk sac is completely absorbed within 96 hrs of post-hatchlings at a water temperature of 27 – 30^OC. All larvae mouth are opened after 28 hrs, and after 32 hrs, the digestive tract is fully developed and starts to consume the rotifer. The larvae are fed with rotifer up to 10 dph (days of post-hatchling). The larvae of the age of 8 – 10 days (TL 3.94 – 4.97 mm) consume the rotifer and Moina. Larvae aged more than 11 days (TL 5.51 mm) consume only Moina. The larvae of age 14-15 days (TL 7.34 – 12.60 mm) intake both the Moina and pellet. More than 16-day of age, larvae start to consume only artificial feed.

If there is no live feed, the plankton has to be collected from the earthen ponds. Bigger size copepods and insects are to be removed through a filter. The larvae can be reared in small size tanks (500l capacity tank) in indoor condition, with a water depth of 40 – 50 cm. Around 30 – 40 percent of surface water area is roofed by aquatic plants such as Pistia and Eichhornia to attain better survival and growth. The ideal stocking density is about 1000 – 1500/m² for initial couple of weeks. During this stage the larvae feed on zooplankton mixed with the feed consisting of Groundnut oil cake and rice bran (30 – 35% protein).

Fingerlings

Fingerlings are reared in cement cistern with a lower water depth of 75cm. Growth variation prevails in this stage, due to differential consumption of food. Maximum care should be taken to segregate shoot fry at regular intervals to get better survival.

Grow out

Culture in pond

A smaller size pond of 0.05 – 0.2 ha is ideal for grow-out of climbing perch. The pond preparation and fertilization are same as that of carp grow out. Climbing perch walks from one pond to another pond during the rainy season. Thus, pond dyke should be set at 75-degree angle, which prevents fish escapement. The stocking density of 5 – 6 nos/m² is preferred; by lower the stocking density (3 nos/m²) an improved growth rate has also been recorded.

The fingerlings come up to the water surface for atmospheric air, and there is a chance for them to be predated by birds. Hence bird fencing is to be taken up to avoid this.

The supplementary feed (3 – 5 percent of body weight) is essential to achieve better growth. The water quality parameters are regularly monitored. Fish attains the marketable size of about 50 – 60 g in a year. Harvesting is done by hand picking after complete dewatering of pond water.

Culture in tank

Cement cistern is preferred for grow-out production rather than pond because it curtails the fish escape from the tank and is easy to manage. By offering soil base of 15 – 20 cm in cisterns, the fish health condition and growth can be enhanced. The tank water surface area is to be covered (about 30 – 40 percent) by aquatic plants such as water hyacinth and Pistia, which provides the natural environment to the fishes. About 5 g (6.5 cm) fingerlings are suited for tank culture, with a stocking density of 65 – 70 nos/m². The supplementary feed is provided at 3 – 5 percent of the body weight of the fish (two rations per day).

Culture in cage

The climbing perch are also reared in cages (3m x 2m x 1.5m), with a stocking density of 550 nos/cage (measures 0.6 – 0.8g weight and 2 cm average length). In addition to natural feeds, the supplementary feeds such as finely soaked freshwater dry fish is also offered to achieve improved growth rate. The individual fish grows to an average weight of 62 g in 4 months. Climbing perch of Tai strain can be practiced under monoculture and polyculture conditions through cage culture. The stocking density of 60nos/m² (5.8 g and 12 cm) is preferable for monoculture, with a survival rate of 67 percent. The stocking density of 80 and 100nos/m² has shown poor growth performance and survival. A stocking of 5.8 g (12 cm) fingerling reaches around 40 g (6.1 cm) in 4 months.

References

1. Amornsakun, T., Sriwatana, W. and Promkaew, P., 2005. Some aspects in early life stage of climbing perch, Anabas testudineus larvae. Warasan Songkhla Nakharin (Sakha Witthayasat lae Technology).
2. CIFA, 2016.Training programme on “Seed Production of Anabas, Magur and Murrel” 26-30 August 2016. Central Institute of Freshwater Aquaculture, Bhubaneswar, India.
3. Kumar, K., Kumar, R., Mohanty, U.L., Sahoo, M., Mohanty, A.K., Sahu, A.K. and Jayasankar, P., 2012. Seed Production of climbing perch, Anabas Testudineus. Central Institute of Freshwater Aquaculture, Bhubaneswar.
4. Uddin, K.B., Moniruzzaman, M., Bashar, M.A., Basak, S., Islam, A.K.M., Mahmud, Y., Lee, S. and Bai, S.C., 2016. Culture potential of Thai climbing perch (Anabas testudineus) in experimental cages at different stocking densities in Kaptai Lake, Bangladesh. Aquaculture, Aquarium, Conservation & Legislation-International Journal of the Bioflux Society (AACL Bioflux), 9(3).
5. Zalina, I., Saad, C.R., Christianus, A. and Harmin, S.A., 2012. Induced Breeding and Embryonic Development of Climbing Perch (Anadas testudineus, Bloch). Journal of Fisheries and Aquatic Science, 7(5), p.291.