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Figure 8 Pufferfish

Figure 8 Pufferfish

Posted by Max Gandara on on 6th Jul 2025

Figure 8 Pufferfish Care Guide

Personality-Packed and Adorably Spotted

Looking for a unique, intelligent, and interactive fish that will keep you entertained? The Figure 8 Pufferfish (Tetraodon biocellatus) checks all the boxes! With their quirky behavior, big expressive eyes, and charming polka-dotted pattern, these puffers are a favorite among aquarists looking to venture into brackish or species-focused aquariums.

Quick Facts:

  • Scientific Name: Tetraodon biocellatus

  • Common Name: Figure 8 Puffer, F8 Puffer

  • Origin: Southeast Asia – Borneo, Malaysia, and Indonesia

  • Maximum Size: 3 inches

  • Temperament: Semi-aggressive / territorial

  • Lifespan: 8–10 years

  • Tank Size: Minimum 15–20 gallons for one adult

Appearance:

Figure 8 Puffers are small, bright greenish-yellow puffers adorned with black spots and figure-eight shaped patterns on their back. Their belly is white, and their fins are often translucent. Their adorable expressions and ability to follow their keepers around make them feel more like a wet puppy than a fish.

Behavior:

These fish are intelligent and full of personality. They often recognize their owners, beg for food, and explore their environment with curiosity. While they are entertaining, they can also be territorial, especially toward other fish. Most aquarists keep them in a species-only setup or with very carefully chosen tank mates.

Brackish Water Requirements:

Though many Figure 8 Puffers are sold as freshwater fish, they thrive best in low-end brackish water as they mature.

  • Salinity: Specific Gravity (SG) 1.005–1.008

  • Temperature: 75–82°F

  • pH: 7.5–8.5

  • Water Type: Brackish (mix marine salt with dechlorinated freshwater)

  • Filtration: Strong and stable—puffers are messy eaters and need pristine water

Diet:

Figure 8 Puffers are carnivores with specialized needs. They require hard, crunchy foods to help wear down their continuously growing teeth.

Best Food Options:

  • Snails (ramshorn, bladder snails, etc.)

  • Crustaceans (frozen or live shrimp, krill, mysis)

  • Clams, mussels, or crab legs (in the shell)

  • High-quality frozen or freeze-dried meaty foods

❗ Avoid flake and pellet foods—they rarely accept them and they don’t help with tooth maintenance.

Tank Mates:

Caution is advised when housing Figure 8 Puffers with other fish. While small and cute, they can nip fins or become aggressive toward tankmates. Best kept solo or with fast, brackish-tolerant species in large setups.

Possible tank mates (with space & caution):

  • Mollies

  • Archerfish

  • Bumblebee Gobies

  • Scats (only when older and in more brackish conditions)

Special Considerations:

  • Teeth trimming: If not given the right diet, their teeth can overgrow and may need manual trimming.

  • No copper-based medications: Puffers are highly sensitive to copper.

  • Lid required: Puffers can and do jump out of tanks.

  • Interaction: These fish are highly aware of their surroundings—don’t be surprised if they “greet” you every time you approach the tank!

Why Choose a Figure 8 Pufferfish?

✅ Unique spotted pattern and lively personality
✅ Interactive and intelligent—fun to observe
✅ Perfect introduction to brackish setups
✅ Manageable size for smaller tanks

Final Thoughts:

The Figure 8 Pufferfish is a rewarding choice for aquarists ready to dive into brackish water care and want a fish with true character. They may require a bit more effort than your average freshwater community fish, but their engaging behavior and striking looks make every bit of care worth it.