Yellow Assessor
Assessor flavissimus
| Stock | Variations | Price | Quantity |
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Saturday 12 PM – 4 PM
Sunday 12 PM – 9 PM
Healthy, stable animals from vetted suppliers — inspected before packing, shipped overnight. Decades of experience built this model so we can deliver premium livestock at 30%+ less than you'd pay elsewhere.
| Care Level | Moderate |
|---|---|
| Temperament | Peaceful |
| Reef Safe | Yes |
| Functional Benefit | Ornamental Only |
| Diet Type | Carnivore |
| Mininum Tank Size | 30 gallons |
| Max Size | 3 inches |
| Temperature | 72–78°F |
| pH Range | 8.1–8.4 |
| Specific Gravity | 1.022–1.025 |
The Yellow (Gold) Assessor Basslet (Assessor flavissimus) is a small reef-safe basslet known for its solid yellow body with fine red edging along the fins. It spends much of its time around rockwork, using caves and overhangs as its home base while still making regular appearances in the water column, especially around feeding time.
What You’ll Observe:
- Hovering and “perching” behavior around ledges, caves, and shaded rock structure
- Short, controlled swims out into open water, then returning to the same favorite shelter
- A consistent routine of showing up quickly when food hits the water
- Steady, active movement patterns once it’s settled into a chosen area
To help this assessor thrive, provide plenty of live rock with multiple cave options and stable reef parameters. Offer small meaty foods (like mysis, finely chopped frozen blends, and similar fare) at least twice daily. It does best in a calm community where it can keep a chosen cave and feed without being crowded.
Is it normal for a Yellow Assessor to swim upside down or sideways?
Yes’keepers commonly report this as typical behavior, especially when it’s under ledges or “on the ceiling” of a cave.
How do I get a new Yellow Assessor to accept prepared foods?
Many hobbyists have success starting with small plankton-sized frozen foods (like calanus) and then mixing in mysis and pellets over time as it recognizes feeding cues.
Will I actually see it during the day?
In most tanks it becomes a regular daytime sight once it has a secure cave and a predictable feeding schedule, often making repeated loops between its shelter and open water.
Can Yellow Assessors be kept as more than one in the same system?
Some aquarists keep multiples successfully when the tank has lots of separated caves and sight breaks, so each fish can claim its own “spot.”
Can they breed in captivity, and what would I notice?
They are reported as paternal mouthbrooders; if a pair forms, keepers may notice the male holding and guarding an egg mass rather than actively feeding for a period.
Each fish is checked for strong appetite and activity before we approve it for your tank.
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