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Fish

Yellow assessor

Assessor flavissimus
French name : Assesseur jaune

The yellow assessor is a small marine fish in the family Plesiopidae, native to reefs of the Great Barrier Reef and Coral Sea in the western Pacific. It is a uniform bright golden-yellow with delicate blue edging on the fins, and it often swims in an unusual belly-toward-the-rock orientation, hovering in caves and overhangs. It is a peaceful, somewhat shy species that appreciates shaded rockwork with caves and ledges where it can retreat and orient upside down. It does well in a reef aquarium and is fully reef-safe, coexisting with corals and invertebrates. Small groups can be kept if space allows, though it may squabble with its own kind in tight quarters. It is a mouthbrooding species, with males incubating the eggs. It feeds on small meaty foods such as mysis and finely chopped seafood, and suits intermediate marine keepers.

Water
Marine
Origin
Great Barrier Reef and Coral Sea
Adult size
6 cm
Diet
Carnivore
Temperament
Peaceful
Difficulty
Intermediate
Yellow assessor (Assessor flavissimus)
Illustration

Water parameters

Temperature24 – 27 °C
pH8.1 – 8.4
Carbonate hardness (KH)8 – 12 °dKH
Salinity33 – 35 SG

Tank & stocking

Minimum tank volume75 L
Volume budget per individual 20 L — adds up with tank-mates

“Minimum tank volume” is a reasonable floor, not an absolute limit. The per-individual budget is used by the Aqua app to estimate how heavily a tank is stocked.

Frequently asked questions

What size aquarium does Yellow assessor need?

Provide at least 75 litres to keep Yellow assessor in good conditions.

What water parameters does Yellow assessor need?

A temperature of 24–27 °C, pH 8.1–8.4, saltwater.

Is Yellow assessor peaceful or aggressive?

Its temperament is peaceful.

What does Yellow assessor eat?

Its diet: carnivore.

How big does Yellow assessor get?

Around 6 cm as an adult.

Is Yellow assessor suitable for beginners?

Care level: intermediate.

Planning a tank with Yellow assessor?

AquaTender turns these parameters into live advice: it checks whether your tank is big enough, how heavily it's stocked, and whether your fish are compatible — then tracks water tests, photos and maintenance for you.

➕ Add Yellow assessor to my tank Discover AquaTender
« Add to my tank » opens AquaTender — sign in (free) and pick your aquarium.

Fish from the same biotope

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