A freshwater fish (Anabas testudineus) of tropical Asia, having modified gills allowing it to breathe air and pectoral fins adapted for traveling on land.

Anabas testudineus

FAMILY

Anabantidae

TAXONOMY

Anthias testudineus Bloch, 1785, Japan. The diverse distribution and morphology of A. testudineus indicate that it may comprise more than one species.

OTHER COMMON NAMES

French: Perche grimpeuse; German: Kletterfisch; Spanish: Perca trepadora.

PHYSICAL CHARACTERISTICS

Length 9.8 in (25 cm). Robust body with wide, large head. Body shape ranges from oval and compressed to elongate and subcylindrical. Posterior edges of opercular bones, especially opercle, and subopercle, with strong spination. Without teeth on the palatine in contrast to most anabantids. Dorsal fin has 16–19 strong spines and 7–11 soft rays. Anal fin has 9–11 spines and 8–12 soft rays. Pelvic girdle without connection to pectoral girdle. Scales on the head rigidly attached to the skull bones. Scales strongly ctenoid. Lateral line interrupted at level of posterior part of spinous dorsal fin and continued two scale rows lower down to caudal peduncle. Supra-branchial organ exceptionally large and complexly folded. Coloration light beige with darker spots. A conspicuous black spot at the posterior edge of the gill cover between two prominent areas of projecting strong opercular spines and a large black ocellus on the caudal peduncle. No sexual dimorphism or dichromatism.

DISTRIBUTION

Widely distributed in Asia: Sri Lanka, India, Burma, Indochina, Taiwan, Sundaland (the western part of Indonesia, namely the islands of Java, Sumatra, and Kalimantan), but also introduced east of Huxley's Line (a zoogeographic distributional divide between the fauna of peninsular Southeast Asia and the Sunda islands [Sumatra, Java, and Borneo], and the fauna located on islands further to the east such as Australia, Papua New Guinea, Sulawesi, and the Philippines). This wide distributional range and the diverse physical morphology encountered indicates that more than one species is most certainly involved, but this species has not been thoroughly studied. The climbing perch has also been accidentally released in the United States.

HABITAT

Found in all types of fresh water, also survives in brackish water and tolerates water conditions unsuitable for most other fishes.

BEHAVIOR

Well known for its behavior to travel overland, first reported more than 200 years ago; uses its spiny opercular bones and a side-to-side wriggling of the body to move itself forward on land. Obligatory air breather that drowns if kept from rising to the surface to gulp air. Can survive longer periods of drought buried in the mud of the drying water bodies.

FEEDING ECOLOGY AND DIET

Omnivorous. Feeds on macrophytic vegetation, different invertebrates, and small fish.

REPRODUCTIVE BIOLOGY

No parental care. Typical spawning clasp lasts only a few seconds. Several thousand, buoyant, small (0.04 in; 1 mm) spherical eggs are spawned during one spawning phase. Eggs contain a single large oil globule. Hatching occurs after 24 hours at 82.4°F (28°C).

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

A common and popular food fish in Southeast Asia. Easily transported to the markets in buckets without water as long as the skin is kept moist, and it may survive in this condition for several days.