Aggressive & semi-aggressive fish
32 species are rated aggressive or semi-aggressive.
These species carry an aggressive or semi-aggressive flag. They need volume above their listed minimum, plant cover or rockwork that breaks line of sight, and a stocking plan that often comes down to one species per tank. The order you add fish matters too: an established cichlid will defend its half of a tank against any newcomer, regardless of size or temperament label on the newcomer's profile.
These species need volume above the listed minimum, real breaks in line of sight, and almost always a stocking plan with one centrepiece species and a few peripheral peacekeepers. The order you add them in matters as much as the litres. Established residents will defend territory against any new addition, so rearranging decor and quarantining newcomers are part of the routine, not an emergency response.
Every row is a real profile in the live library; filters are field-driven, not hand-curated blurbs.
Best choices (on this filter)
- Agassiz’s dwarf cichlid
semi-aggressive · intermediate · min 80L
- American Flagfish
semi-aggressive · intermediate · min 60L
- Angelfish
semi-aggressive · intermediate · min 150L
- Apistogramma Borellii
semi-aggressive · intermediate · min 80L
- Apistogramma Macmasteri
semi-aggressive · intermediate · min 100L
- Apistogramma Trifasciata
semi-aggressive · intermediate · min 80L
- Banded leporinus
semi-aggressive · intermediate · min 300L
- Betta
semi-aggressive · beginner · min 20L
- Black ghost knifefish
semi-aggressive · advanced · min 500L
- Cockatoo / crested Apistogramma
semi-aggressive · intermediate · min 100L
- Convict cichlid
semi-aggressive · beginner · min 200L
- Electric Blue Acara
semi-aggressive · intermediate · min 150L
- Firemouth Cichlid
semi-aggressive · intermediate · min 200L
- Ghost Shrimp
semi-aggressive · beginner · min 40L
- Golden Wonder Killifish
semi-aggressive · intermediate · min 80L
- Kribensis
semi-aggressive · beginner · min 100L
- Opaline gourami
semi-aggressive · intermediate · min 150L
- Paradise fish
semi-aggressive · intermediate · min 120L
- Pea Puffer
semi-aggressive · intermediate · min 40L
- Rainbow / red-tailed black shark
semi-aggressive · intermediate · min 200L
- Senegal bichir
semi-aggressive · intermediate · min 300L
- Serpae Tetra
semi-aggressive · intermediate · min 100L
- Severum
semi-aggressive · intermediate · min 250L
- Swordtail
semi-aggressive · beginner · min 80L
- Tiger Barb
semi-aggressive · intermediate · min 80L
- Yoyo Loach
semi-aggressive · intermediate · min 200L
Caution
- African Cichlid
aggressive · intermediate · min 200L
- Green Terror
aggressive · intermediate · min 300L
- Jack Dempsey
aggressive · intermediate · min 200L
- Jaguar cichlid
aggressive · advanced · min 500L
- Oscar
aggressive · intermediate · min 300L
- Red-tailed catfish
aggressive · advanced · min 2000L