Got a photo? Identify fish instantly with the Fishby app.
Open the appDescription
Anguilla reinhardtii, commonly known as the Estuary Eel or Australian Longfin Eel, is a species of catadromous eel native to the freshwaters and estuaries of eastern Australia and some Pacific islands. It is characterized by its elongated, snake-like body, prominent lower jaw, and long dorsal and anal fins that are confluent with the caudal fin. These eels undertake remarkable migrations, spending most of their lives in freshwater before migrating to the ocean to spawn.
Physical Characteristics
- Body shape
- eel-like
- Coloration
- Dorsal surface typically dark olive-green to brown, often mottled or marbled. Ventral surface is paler, yellowish to off-white. Coloration can vary with habitat and age.
- Scale type
- cycloid
- Mouth position
- terminal
- Distinctive features
- Very long dorsal fin originating well forward of the anal fin, extending almost to the head., Prominent lower jaw that extends beyond the upper jaw., Small, embedded scales that are not easily visible., Large, well-developed pectoral fins.
- Dorsal fin
- Very long, originating far forward, confluent with caudal fin.
- Tail fin
- Rounded, confluent with dorsal and anal fins.
- Pectoral fin
- Large and fan-like, located just behind the head.
- Distinctive fins
- Absence of pelvic fins.
Identification Tips
Dorsal Fin Origin
The dorsal fin originates significantly further forward than the anal fin, often closer to the head than the vent. This is a key differentiator from other Anguilla species in its range.
Lower Jaw
The lower jaw is noticeably longer and protrudes beyond the upper jaw.
Coloration and Pattern
Often exhibits a mottled or marbled pattern on its dorsal surface, which can help distinguish it from the more uniformly colored Short-finned Eel (Anguilla australis).
Pectoral Fins
Relatively large and fan-shaped pectoral fins.
Habitat
- Water type
- brackish
- Depth
- Typically found in shallow to moderate depths, but can inhabit deeper pools and rivers.
- Environment
- Primarily freshwater rivers, lakes, and impoundments, but also estuaries and coastal marine waters during migratory phases. Prefers areas with abundant cover such as submerged logs, rocks, and dense vegetation. Often burrows into soft substrates.
- Geographic range
- Eastern Australia (Queensland, New South Wales, Victoria, Tasmania), Lord Howe Island, Norfolk Island, New Caledonia, and possibly New Zealand.
Aquarium Information
- Care level: advanced
- Temperament: aggressive
- Diet: carnivore
- Minimum tank size: 500 gallons (for adult specimens)
- Temperature: 18-26°C (64-79°F)
- pH level: 6.5-8.0
- Hardness: 5-20 dGH
- Compatibility: Generally not compatible with other fish due to their predatory nature. Can be kept alone or with very large, robust, and fast-moving fish that they cannot swallow. Requires a secure lid to prevent escape.
- Special requirements: Requires a very large, well-filtered aquarium with plenty of hiding places (PVC pipes, caves, dense planting). Substrate should be soft to prevent injury. Excellent filtration is crucial due to their messy eating habits. Eels are escape artists, so a tightly fitting, heavy lid is essential.
Wild Information
- Conservation status: least concern
- Seasonality: Adult eels migrate to sea for spawning during late summer and autumn. Juveniles (glass eels) return to freshwater in spring and early summer.
- Market price: Variable, depending on region and demand. Can be high in some Asian markets.
- Commercial importance: medium
- Taste: Rich, oily, and distinctively savory.
- Texture: Firm, flaky, and somewhat gelatinous.
- Cooking methods: Smoked, Grilled, Fried, Stewed, Baked
- Nutritional value: High in protein, Omega-3 fatty acids, and vitamins A, D, and E.
Key Facts
Catadromous Migrationbehavior
Estuary Eels are catadromous, meaning they live in freshwater and migrate to the ocean to spawn. Their exact spawning grounds are still largely unknown but are believed to be in deep oceanic waters.
Long Lifespaninteresting
These eels can live for many decades, with some individuals recorded to be over 50 years old in freshwater before their spawning migration.
Voracious Predatorsbehavior
As adults, Estuary Eels are apex predators in their freshwater habitats, feeding on a wide range of aquatic organisms.
Glass Eel Stageevolution
After hatching in the ocean, their larvae (leptocephali) drift for months before transforming into transparent 'glass eels' that migrate back into estuaries and rivers.
Sexual Dimorphism in Sizeinteresting
Female Estuary Eels typically grow significantly larger than males, often reaching lengths of over 1.5 meters, while males rarely exceed 1 meter.
Safety Information
Handle with care- Safety level: caution
- Venomous: No
- Edibility: edible
- Handling notes: Eels are extremely slippery and powerful. They can deliver a painful bite if handled carelessly, especially larger specimens. Their skin is covered in a thick layer of mucus, making them difficult to grip. Use thick gloves and exercise caution when handling. They are not venomous, but bites can become infected.
Similar Species
Short-finned Eel
Anguilla australis
The dorsal fin originates much further back, closer to the anal fin. The lower jaw is typically equal to or slightly shorter than the upper jaw. Generally has a more uniform, less mottled coloration.
New Zealand Longfin Eel
Anguilla dieffenbachii
While also a longfin eel, A. dieffenbachii is endemic to New Zealand and has a more robust body, a more pronounced lower jaw, and typically a darker, almost black coloration in adults. Its dorsal fin origin is also further forward than its anal fin, but subtle differences in fin length and body proportions exist.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Actinopterygii
- Order
- Anguilliformes
- Family
- Anguillidae
- Genus
- Anguilla
- Species
- Anguilla reinhardtii
Explore Estuary Eel
Identify fish anywhere
Free on iOS, Android, and Web. Photo identification, full species details, and more.