ANABAS (CLIMBING PERCH)

Contents hide

1) Introduction

2) Classification of Anabas (Climbing Perch)

3) Geographical Distribution of Anabas (Climbing Perch)

4) Habit and habitat

5) General Characteristics of Anabas (Climbing Perch)

6) Ecological Importance

7) Conservation Status of Anabas (Climbing Perch)

8) Special features

9) Identification

Introduction

The genus Anabas, particularly the species Anabas testudineus (commonly known as the climbing perch), is a freshwater fish native to South and Southeast Asia. This remarkable fish is well-known for its ability to breathe air and survive outside water for extended periods. In addition, it exhibits the unique behavior of “walking” on land, using its pectoral fins and gill plates to move across damp terrain in search of new habitats.

Anabas thrives in a variety of aquatic environments, including ponds, lakes, rivers, and even brackish water. Its tolerance to extreme conditions, such as low oxygen levels and poor water quality, makes it one of the hardiest freshwater fish. It is a staple in local diets in many parts of its native range, valued for its nutritional benefits. In some regions, Anabas is used in traditional medicine and is culturally significant, often symbolizing adaptability and survival.

However, this resilience has a downside when Anabas is introduced to non-native ecosystems. It can outcompete native species for resources, leading to ecological imbalances. Conservation measures are essential to ensure the sustainability of Anabas in its native habitats while controlling its spread in non-native regions.

Classification of Anabas (Climbing Perch)

Phylum :- Chordata (Dorsal tubular nerve cord, notochord and gill-slits present.)
Group :- Craniata (Cranium with brain present.)
Sub phylum :- Vertebrata (Vertebral column present.)
Division :- Gnathostomata (Jaws and paired appendages present.)
Super Class :- Pisces (Paired fins, gills and skin with scales.)
Class :- Osteichthyes (Bony fishes. Skin contains dermal scales. Paired lateral fins present. Gills, air bladder present. Cleavage meroblastic.)
Sub-Class :- Actinopterygii (Modern fishes. Vertebrae amphicoelous. Caudal fin homocercal, Scales cycloid or ctenoid. Nostrils do not communicate with mouth cavity.
Superorder : Teleostei (Bony fish proper)
Order :- Anabantiformes (Perches. Dorsal and anal fins with spiny and soft fin rays. Pectoral arch attached to skull by forked post-temporal.)
Family :- Anabantidae
Genus :- Anabas

Geographical Distribution of Anabas (Climbing Perch)

Anabas is distributed in Myanmar, India, Africa, Philippines, Sri Lanka and Malayasia Archipelago. Upper Cretaceous to Recent.

Native Range

Anabas testudineus, commonly known as the climbing perch, is widely distributed across tropical and subtropical regions of South and Southeast Asia. Its native distribution includes:

South Asia:
- India (especially in the northeastern and coastal regions)
- Bangladesh
- Sri Lanka
- Nepal (lowland regions)
Southeast Asia:
- Myanmar
- Thailand
- Vietnam
- Cambodia
- Laos
- Indonesia (Sumatra, Java, and Borneo)
- Malaysia
- The Philippines
China:
- Found in southern provinces, particularly in areas bordering Southeast Asia.

Introduced and Invasive Range

Anabas has been introduced intentionally or accidentally to various regions due to its hardiness and economic value. In some areas, it has become invasive:

Australia:
- Observed in Northern Australia, where it poses a potential threat to native species.
Africa:
- Introduced to certain regions, particularly in aquaculture or ornamental fish trade.
Pacific Islands:
- Found in parts of Papua New Guinea and nearby islands.

Habitat Preferences Across Its Range

Prefers warm, shallow freshwater ecosystems such as ponds, lakes, swamps, ditches, and rice paddies.
Can tolerate brackish water in estuarine regions, extending its range into coastal zones.

The broad geographical distribution of Anabas reflects its exceptional adaptability and ecological resilience, making it both an asset and a potential invasive species in non-native areas.

Habit and habitat

Anabas is a common South Indian fresh-water fish. It can live out of water for a long period. It i& predator on shrimps, ostracods, gastropod shells and young fishes. Male exhibits parental care.

Habit

Behavioral Traits:
- Anabas is a hardy, adaptable fish with air-breathing capabilities, enabling survival in oxygen-depleted water.
- Known for its unique ability to “walk” on land, it uses its pectoral fins and gill plates to migrate between water bodies, especially during droughts.
- Predominantly nocturnal, it actively forages at night, feeding on smaller fish, invertebrates, plankton, and detritus.
- Displays solitary behavior but can form loose aggregations in favorable habitats.
Feeding Habits:
- Omnivorous diet, including insects, crustaceans, zooplankton, and plant material.
- Acts as both predator and scavenger, contributing to nutrient recycling in aquatic ecosystems.

Habitat

Natural Environment:
- Found in freshwater environments like rivers, lakes, ponds, canals, swamps, and paddy fields.
- Thrives in stagnant or slow-moving waters with dense vegetation.
- Capable of surviving in extreme conditions such as polluted or brackish water.
Geographical Range:
- Native Range: South and Southeast Asia, including countries like India, Bangladesh, Myanmar, Thailand, Vietnam, and Indonesia.
- Invasive Range: Some regions in Australia and Africa due to accidental or intentional introduction.
Adaptability:
- Survives in low-oxygen environments due to its labyrinth organ, which allows it to extract oxygen from the air.
- Often found in seasonal water bodies, showing resilience to droughts and habitat variability.

Unique Habitat Adaptations:

Anabas prefers shallow, warm water with abundant aquatic vegetation.
Often migrates overland to find new habitats when water sources dry up.
Its presence in brackish water highlights its salinity tolerance, making it highly versatile.

This versatility in habit and habitat underscores Anabas‘ ecological resilience and significance in its native and introduced ranges.

General Characteristics of Anabas (Climbing Perch)

Commonly known as climbing perch.
Fish measuring about 30 cm is olive green in colour.
Body of the fish covered by cycloid scales and divided into head, trunk and tail.
Head is conical containing large eyes, nostrils and mouth. Jaws, prevomer and parasphenoid with fixed conical teeth.
In front of eyes is a pre-orbital bone containing spines. Small spines also occur along the edge of operculum.
Dorsal fin consists anterior dorsal fin and posterior dorsal fin. Similary anal fin divided into anterior anal fin and posterior anal fin. Caudal fin is fan shaped.
Ventral are anteriorly situated almost below pectorals.
Accessory respiratory super-branchial organ is well developed, having thin and folded bony laminae covered with mucous membrane. Air bladder physoclistous.
Tail is perfectly symmetrical.

Ecological Importance

Nutrient Recycling: Plays a role in the food web as both a predator of small aquatic organisms and prey for larger animals, including birds and mammals.
Habitat Engineering: Contributes to nutrient cycling in aquatic ecosystems by feeding on detritus and organic matter.
Indicator Species: Its ability to thrive in polluted waters makes it an indicator of environmental health and resilience.
Prey-Predator Dynamics: Regulates populations of smaller aquatic organisms, maintaining ecological balance

Conservation Status of Anabas (Climbing Perch)

Currently classified as Least Concern by the IUCN due to its wide distribution and adaptability.
Local threats include:
- Habitat destruction from urbanization and agriculture.
- Overfishing in some regions where it is heavily harvested for food.
- Water pollution affecting spawning grounds and juvenile survival.
Conservation Measures:
- Habitat restoration and protection of wetlands.
- Sustainable fishing practices to prevent overexploitation.
- Monitoring of populations in both native and invasive regions to prevent ecological disruptions.

Special features

Anabas is able to walk on land by spines in search of earthworms. The crows and kites attack them and take their bodies over trees, and thus the fish is called as climbing perch, .as the fish might have climbed trees. But the fish cannot climb the tree.
Anabas is so much dependent on atmospheric oxygen that it is asphyxiated if kept in water with no access to air. Fish can live out of water for a long period.
Air-Breathing Adaptation: Possesses a labyrinth organ, allowing it to extract oxygen from the air, enabling survival in oxygen-poor waters.
Land Migration: Capable of moving on land using its pectoral fins and gill covers, often in search of new water bodies during droughts.
Hardiness: Tolerates extreme environmental conditions, including pollution and fluctuating salinity levels.
Economic Importance: A valuable food source in its native range, with high market demand due to its taste and nutritional value.
Invasive Potential: Invasive in non-native ecosystems, where it can disrupt local biodiversity due to its aggressive feeding and adaptability.