The Indian mottled eel is a moderately-sized fish. It lives in the waters of India and the surrounding countries. It has a pale body with dark mottling, which gives it its name. It most commonly lives in quiet streams with muddy, rocky bottoms, but is also found in other water bodies.
Like all freshwater eels, it migrates from the sea to freshwater at birth. Then, it migrates from freshwater back to the ocean when it’s time to spawn. The eels spawn en masse when they become sexually mature and die shortly after.
Carnivorous hunters and scavengers, Indian mottled eels prefer fish and invertebrates.
These eels are culturally significant across their habitat. They are an important, nutritious food source, and their mucous is used for medicine.
Threats to this species are currently unknown. Still, threats are likely similar to threats facing other eel species.
What Is The Indian Mottled Eel?
The Indian mottled eel is known scientifically as Anguilla bengalensis bengalensis. It is a type of eel from the family Anguillidae and genus Anguilla. It is the most common eel in the waters of inland India.
Their bodies are long and tubular, and their heads are shaped like a cone that is flat on top. They have giant, prominent mouths with rows of small, sharp teeth.
Their nostrils are prominent and long, protruding from their faces to aid in smell. These eels primarily hunt through scent, so their long nostrils are critical.
Hundreds of tiny scales are embedded in their skin. Their skin is sensitive to the touch and helps them navigate the murky waters.
Most Indian mottled eels have pale bodies that are yellow to olive brown. Their skin is mottled with dark brown patches. Juveniles lack the mottling displayed in more mature individuals. Their bellies are lighter in color than their backs and do not display mottling.
Common names for these eels include:
- Bommidayalu — in the Telugu language
- Mananjil — in the Malayalam language
- Raj Bamm — in the Napali language
- Vaamb — in the Marathi language
- Vealangu meen — in the Tamil language
- Baam maach or Tambu maach — in the Bengali language
These eels grow to decently long sizes of 6.6 ft (2 m) and can weigh up to 13.2 lbs (6 kg). Still, the average length of these eels is only 2.6 ft (0.8 m)
Common Names: Indian mottled eel, Indian longfin eel
Electric Eel Scientific Name: Anguilla bengalensis bengalensis
Origin: Indian subcontinentent
Length: Up to 2 m (6.6 ft)
Habitat
These eels live throughout the Indian subcontinent in freshwater areas. They also live in the neighboring regions, including:
- Pakistan
- Sri Lanka
- Burma
- East Indies
Besides the areas surrounding India, Indian mottled eels live as far west as East Africa. Their habitat spans from the rivers of East Africa to coastal regions of the Indian Ocean. Then, their habitat spans all the way to mainland India.
They are most common in streams but will also live in freshwater pools and reservoirs. They prefer quiet and undisturbed areas, seeking deep water and muddy, rocky substrates. Indian mottled eels also enjoy the faster-flowing rock pools common in larger rivers.
Behavior & Temperament
Like all freshwater eels, Indian mottled eels live in freshwater most of their lives. At the end of their lives, they migrate to saltwater. They begin their lives in the ocean and end their lives there after spawning.
Diet
Indian mottled eels are carnivorous hunters and scavengers. They eat smaller fish, mollusks, crustaceans, and worms. Fish, shrimp, and prawns make up the majority of their diet. Crabs and megalopa larvae also make up a decent amount of their diet. Worms and algae make up only a tiny part of their diet.
Reproduction & Life Cycle
Freshwater eels spend most of their lives in freshwater waterbodies. Yet, they begin and end their lives in the ocean. They are “semelparous,” which means they only spawn once as adults and die shortly after.
Leptocephalli Larvae
Adults spawn in the ocean, producing millions of eggs. Fertilized eggs hatch into tiny, transparent, leaf-shaped leptocephallii larvae. The leptocephallii immediately begin their long journey from the sea to freshwater. They drift along the currents, feeding on microscopic zooplankton.
Glass Eels
As the larvae reach the entrance of their freshwater habitats, they become “glass eels.” Glass eels are still transparent. Yet, their bodies more closely resemble that of adult eels. Glass eels begin their journey up the river, seeking pure fresh water.
Elvers
As they travel upstream, their bodies continue to transform, and they become “elvers.” Elvers are still juvenile eels. Still, their bodies change from transparent to darker in color.
Yellow Eels
Once they reach their freshwater destination, they transform one last time. Now, they will have become “yellow eels.” Yellow eels are still juveniles, though they resemble adult eels. They will spend the majority of their lives in this stage.
Silver Eels
In their last stage of life, the eel’s become sexually mature “silver eels.” Their bodies become more tapered and streamlined. Their eyes grow bulbous to prepare them for their upcoming journey. Eels only spend a fraction of their lives as adults — their sole purpose now is to reproduce and die.
Adult silver eels usually complete their migratory process between April and September. The migratory process often takes five to six months, during which the eels don’t stop to rest and do not eat.
Once they reach their spawning grounds, they reproduce in a mass spawning event. Females release millions of eggs. Males release sperm into the water column to fertilize eggs. Shortly after, all the adult eels die.
Cultural Significance
The Indian mottled eel is valued throughout the regions it lives as a tasty and meaty food source. The eels are highly nutritious, and there is a large export market of live elvers and silver eels. The mucus it produces is also used as a treatment for arthritis. Medical practitioners mix the mucus with rice or wheat flour and use it as a poultice.
Conservation
Little is known about this species and the threats they face. Still, they likely face the same threats as other freshwater eel species, including:
- Migration barriers
- Pollution
- Habitat destruction
- Climate change
- Unsustainable fishing
Indian mottled eels are considered “vulnerable” in Bangladesh. They received this status because of habitat loss and degradation.
FAQs
The International Union for the Conservation of Nature assessed the population status of the Indian mottled eel. They assessed the eels in 2019. They determined them to be “near threatened” with an unknown population trend.
No data or research suggests that Indian mottled eels are poisonous or venomous. Similar species, like the New Zealand longfin eel, have toxic blood. Their blood can cause swelling if you come in contact with it. The Indian mottled eel may have similarly toxic blood, but no research has been done to confirm or deny this.
