Peacock Eel

 

fish description – Peacock Eel Care Guide ($Macrognathus\ siamensis$)

Category	Detail
Scientific Name	$Macrognathus\ siamensis$
Common Name	Peacock Eel, Spot-Finned Spiny Eel, Siamese Spiny Eel
Origin	Slow-moving rivers and swamps of Southeast Asia (Thailand, Vietnam, Cambodia)
Adult Size	8–12 inches (20–30 cm)
Temperament	Peaceful, shy, nocturnal, ambush predator (will eat small fish)
Lifespan	8–18 years
Care Level	Intermediate (sensitive skin/burrowing needs, picky eater)

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Appearance and Sexual Differences

 

• Short Description: This fish has a long, eel-like, elongated body with a compressed tail and a long, pointed, fleshy snout (rostrum). Its name comes from the small, eye-like ocelli (peacock spots) along the base of the rear dorsal fin, near the tail.
• Coloration: Generally a yellowish-brown or tan base color with dark brown mottling and a distinct dark lateral line. The spots near the tail are the most colorful feature. Females are typically larger and noticeably plumper/fuller-bodied than males. Sexing is generally difficult outside of breeding condition.
• Fins: The dorsal fin is long and spiny, running along the back.
• Behavior: Primarily nocturnal and spends the day hidden. It is a dedicated burrower, often burying its entire body in the substrate with only its snout protruding. It is an escape artist and can squeeze through tiny gaps.

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Tank Requirements and Water Parameters

 

• Minimum Tank Size: 35 gallons (132 liters) is the minimum for a single adult. A 40-gallon tank or larger is better due to their length and potential lifespan. The tank should be longer than it is high.
• Schooling: Can be kept singly or in small groups (5 or more) if the tank is large and provides ample separate hiding spots. Aggression can occur with other eel species.
• Temperature: Tropical range: $75^\circ$–$82^\circ\text{F}\ (24^\circ$–$28^\circ\text{C})$.
• pH Level: Soft, neutral to slightly acidic water: 6.0 to 7.5 (ideal $6.5$–$7.0$). They are sensitive to poor water quality and do not tolerate copper-based medications.
• Aquascape: Fine, soft sand substrate is mandatory (at least 2–3 inches deep) to allow for safe burrowing and prevent skin abrasions. Provide numerous hiding places like caves, PVC pipes, dense plants, and driftwood tangles. Dim lighting and diffused surface light (floating plants) are preferred. A tight-fitting lid is essential.

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Diet and Feeding

 

The Peacock Eel is a carnivore that typically prefers live/frozen foods.

• Staple Diet: Consists mainly of benthic insect larvae, worms, and small crustaceans in the wild. Will often refuse dry foods (flakes or pellets).
• Supplementation: Must be fed a protein-rich diet of high-quality frozen or live foods: Bloodworms, Tubifex worms, Brine Shrimp, Daphnia, and chopped earthworms.
• Schedule: Feed once daily, always in the evening/night when they are active. They can be picky eaters and require patience and persistence to accept prepared foods.

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Compatibility

 

• Caution: Will eat any fish small enough to fit in its mouth (e.g., Neon Tetras, Guppy fry). Avoid aggressive fish that might damage their skin or eyes. They are highly susceptible to White Spot Disease (Ich).
• Good Tank Mates: Peaceful, medium to large-sized fish that occupy the mid-to-upper water column and are too large to be consumed. Examples include larger Rasboras, Rainbowfish, Gouramis, Corydoras catfish, and peaceful Loaches (Botiid species).