Knife Livebearer
Brachyrhaphis episcopi
Knife Livebearer (Brachyrhaphis episcopi) — Easy care, Semi-aggressive, under Livebearer & Killifish. Minimum tank in the app: 32 US gal min; aim for 75–82°F and pH 6.8–8.2. The Knife Livebearer is a captivating choice for those who appreciate a dynamic, social species with a hint of intrigue due to its semi-aggressive tendencies.

Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
Americas / Africa (varies)
- Africa
- South America
- Central America & Mexico
Regional colours match the stocking calculator’s origin map.
Knife Livebearer Tank Setup
Provide a spacious environment with ample swimming room complemented by strategically placed plants and decorations to create visual barriers. A gentle flow and a substrate that allows for foraging will enhance their environment, while moderate lighting can encourage natural behaviours without overwhelming them.
What Do Knife Livebearers Eat?
As omnivores, Knife Livebearers exhibit varied feeding speeds; competition can arise during feeding time, so providing diverse food options can reduce stress. Pay attention to their health through diet, as a varied diet can enhance their coloration, making them more vibrant.
Knife Livebearer Tank Mates
Ideal companions include similarly sized, peaceful species that occupy different swimming zones to minimize conflict. Be cautious of pairing with overly aggressive fish or those that occupy the same mid-water space, as this can incite territorial aggression. Within their own species, maintaining larger groups helps diffuse any aggression among males.
Are Knife Livebearers Good for Beginners?
In App-aquatic we file this under easy care. That still means a cycled tank, realistic stocking, and parameters that do not swing every weekend. A common oversight is keeping too few individuals, which can lead to heightened stress and aggression, particularly among males. neglecting to create a well-structured environment may result in territorial disputes and a lack of confidence in their behaviour.
Building a community? Run the full list through the stocking calculator before you add anything else.
Log tests and reminders in App-aquatic—free, same data you see here.




