# Knifefish (*Gymnotus carapo*) Knifefish are sleek, silver fish with long bodies that look like sharp knives. They glide gracefully through the water, using their electric senses to find food and communicate with each other. - **Category:** [Fish](https://www.snappit.app/explore/categories/fish) - **Rarity:** Common - **Danger:** 2/5 · Low - **Habitat:** Freshwater - **Also known as:** Brown Ghost Knifefish, Electric Knifefish ![Knifefish](https://res.cloudinary.com/drieglelr/image/upload/v1771425806/objects/6188.jpg) ## Appearance The Knifefish has a long, flattened, ribbon-like body, often pale or translucent. Its continuous, undulating anal fin runs along most of its underside, giving it a unique rippling movement. It lacks prominent scales and typically has very small eyes. ## Taxonomy - **Kingdom:** Animalia - **Phylum:** Chordata - **Class:** Actinopterygii - **Order:** Gymnotiformes - **Family:** Gymnotidae - **Genus:** Gymnotus ## Interesting facts - Knifefish can hover perfectly still in the water, thanks to their specialized fins. - Some knifefish species are completely transparent, almost invisible in the water! - Their eyes are very tiny, as they rely more on electric senses than sight. - These fish have almost no visible tail fin, making them look like a swimming knife! ## Special abilities - **Electric Sense:** Knifefish can generate weak electric fields that help them 'see' in the dark or murky water, sensing objects and other fish. - **Backward Navigator:** Knifefish has a unique undulating fin that allows it to swim both forwards and backwards with incredible precision. ## Measurements & details - **Length:** 10-50 cm - **Weight:** 0.01-0.1 kg - **Lifespan:** 3-8 years - **Swim Speed:** 5 km/h - **Maximum Depth:** 5 m - **Water Type:** Freshwater ## Diet & Feeding Knifefish are hunters that eat small insects and tiny aquatic creatures. - **Age differences:** Younger knifefish primarily eat zooplankton, while adults add larger insects and small fish. - **Primary Foods:** Insect larvae, Small crustaceans, Worms, Zooplankton, Small fish - **Foraging Method:** Ambush ## Ecological connections - **Eaten by:** Peacock Bass (*Cichla ocellaris*) — A large predatory fish. - **Eaten by:** Wolf Fish (*Hoplias malabaricus*) — Hunts them in the same rivers. - **Eats:** Midge Larvae (*Chironomus plumosus*) — A key food source in riverbeds. - **Eats:** Water Flea (*Daphnia pulex*) — Tiny prey for young knifefish. ## Traits - [Wildlife](https://www.snappit.app/explore/traits/wildlife): Wildlife encompasses all undomesticated animal and plant life existing in their natural habitats. - [Camouflaged](https://www.snappit.app/explore/traits/camouflaged): Camouflaged describes organisms that possess coloring or patterns that allow them to blend into their environment. - [Piscivorous](https://www.snappit.app/explore/traits/piscivorous): Piscivorous organisms are animals that primarily subsist on a diet of fish. - [Longevous](https://www.snappit.app/explore/traits/longevous): This trait characterizes organisms with an exceptionally long lifespan compared to others of their kind. - [Electrogenic](https://www.snappit.app/explore/traits/electrogenic): This trait describes organisms capable of generating electric fields or electric shocks. - [Freshwater](https://www.snappit.app/explore/traits/freshwater): Freshwater habitats include non-saline aquatic environments such as rivers, lakes, ponds, and wetlands, vital for numerous species. - [Aquatic](https://www.snappit.app/explore/traits/aquatic): Aquatic habitats encompass environments where organisms live predominantly in water, including oceans, rivers, lakes, and wetlands. - [Nocturnal](https://www.snappit.app/explore/traits/nocturnal): Nocturnal animals are primarily active during the nighttime hours, typically resting or sleeping during the day. ## Collections - [Fish](https://www.snappit.app/explore/collections/fish) ## Safety **Danger:** 2/5 · Low Always observe knifefish from a safe distance and never disturb their natural habitat. ## Frequently Asked Questions ### How to identify Knifefish? Look at body shape, where the fins sit and their outline, mouth position, stripes and spots. Young fish and breeding adults can wear different patterns, and aquarium color varieties can look nothing like wild fish. Fish Identifier: upload a photo and compare the visible details. ### How long is Knifefish? 10-50 cm ### How much does Knifefish weigh? 0.01-0.1 kg ### How long does Knifefish live? 3-8 years ### What does Knifefish eat? Knifefish are hunters that eat small insects and tiny aquatic creatures. ### How fast can Knifefish swim? 5 km/h ### Where is Knifefish usually found? Freshwater ### How does Knifefish hunt? Ambush ## Where to spot - [Belle Isle Aquarium](https://www.snappit.app/guides/places/belle-isle-aquarium) — US · Zoo ## More Fish - [Rainbow Trout](https://www.snappit.app/explore/rainbow-trout) (*Oncorhynchus mykiss*) - [Brown Trout](https://www.snappit.app/explore/brown-trout) (*Salmo trutta*) - [Brook Trout](https://www.snappit.app/explore/brook-trout) (*Salvelinus fontinalis*) - [Lake Trout](https://www.snappit.app/explore/lake-trout) (*Salvelinus namaycush*) --- Source: [Knifefish: Characteristics, Facts & Places to See — Snappit](https://www.snappit.app/explore/knifefish)