© Vassil / CC0Black Ghost Knifefish
The Black Ghost Knifefish is a weakly electric fish from South America, instantly recognizable by its jet-black body accented with two white rings near the tail and a white stripe on its nose. Lacking a dorsal and caudal fin, it moves forward and backward with equal ease by rippling its long anal fin, gliding through the water like its namesake. It's nocturnal, tending to hide during the day and becoming active after dark. Reaching 45-50cm at full size, it needs a spacious tank to thrive, and its mysterious presence and distinctive swimming style have made it a favorite among experienced aquarists.
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Apply as a breederBlack Ghost Knifefish key facts
- Care level
- Advanced
- Lifespan
- 8-12 years
- Size
- 45-50cm
- Temperature
- 23〜27℃
- Diet
- Frozen bloodworm, Tubifex, prawn, sinking meaty foods
- Tank
- LiveAquaria gives a 568 litre (150 gallon) minimum. It is nocturnal and hides by day, so provide dark refuges such as wide pipes and driftwood, over a fine sand substrate.
- Water Temperature & Quality
- LiveAquaria gives 23-27C (73-80F), pH 6.5-7.0 and 0-10dKH; FishBase records 23-28C, pH 6.0-8.0 and 5-19dH in the wild. Its small scales make it sensitive to medication and deteriorating water.
- Tank Mates
- LiveAquaria rates it semi-aggressive. It is carnivorous and will eat fish small enough to swallow. Conspecifics interfere via their electric signals, so keep one alone unless the tank is very large.
- Diet & Feeding
- Carnivorous. Offer meaty foods such as bloodworm, Tubifex and prawn, ideally after dark; settled fish also take sinking dried foods.
- Breeding & Spawning
- Neither FishBase nor Wikipedia documents a captive breeding protocol, and spawning in home aquaria is not commonplace.
- Health & Notes
- With small scales it is sensitive to medication, so dose cautiously when treating parasites. It hides by day, so check feeding response and skin condition after dark when it becomes active.
About Black Ghost Knifefish
A South American weakly electric fish that swims forward and backward using its anal fin. Nocturnal, growing to 45-50cm, and best suited to experienced keepers.
7 things to know before welcoming a Black Ghost Knifefish
1A Large Tank Is Essential
Since adults reach 45-50cm, you'll need to set up a large tank in advance to accommodate their full-grown size. A cramped tank won't give them enough room to swim and can lead to stress.
2Nocturnal and Fond of Hiding Spots
During the day it tends to stay hidden and motionless, becoming active and swimming around at night. Provide a hiding spot, such as a PVC pipe or driftwood, large enough for its whole body to fit inside.
3A Fish That Emits Weak Electric Signals
It generates a weak electric field to sense surrounding objects and water currents as it swims. This ability is what allows it to move freely in the dark without relying on eyesight.
4A Distinctive Way of Swimming
It lacks a dorsal and caudal fin, instead swimming by rippling its long anal fin. This motion lets it move backward as easily as forward, giving it a swimming style unlike almost any other aquarium fish.
5Best Suited to Experienced Keepers
Its adult size, water quality needs, and tankmate compatibility all require careful management, making it a fish best suited to experienced keepers. It's recommended to build up some aquarium experience before bringing one home.
6Choosing Tankmates Carefully
It has a calm temperament, but small fish that fit in its mouth may be eaten. Choose tankmates of similar or larger size with a peaceful nature, and keep an eye on how the tank dynamics play out.
7Sensitivity to Water Quality Changes
It can be sensitive to sudden changes in water quality, so performing small, frequent water changes and keeping temperature and water parameters stable will help support its health.
Frequently asked questions about Black Ghost Knifefish
- Q.Can beginners keep a Black Ghost Knifefish?
- A.This species is considered suitable for experienced keepers. It's best to gain experience managing large tanks and water quality before taking one on.
- Q.How large a tank does it need?
- A.Since adults reach 45-50cm, a large tank sized for that full-grown length is necessary. It's best to prepare it in advance with future growth in mind.
- Q.Can it be kept with other fish?
- A.It has a calm temperament and can be kept with tankmates, but small fish that fit in its mouth may be eaten. Choose peaceful fish of similar or larger size.
- Q.Is it inactive during the day?
- A.As a nocturnal species, it tends to stay hidden and still during the day and becomes active at night. Providing a hiding spot helps it feel secure.
- Q.Is it subject to CITES regulation?
- A.The Black Ghost Knifefish is not subject to CITES.
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