Yellow Assessor
Assessor flavissimus
Saltwater Fish
Species Group: Basslets
Family: Pseudochromidae
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Water parameters
Temp
76-80 F
Temperature
Maintaining a stable and appropriate temperature is critical for the survival of aquatic life.
pH 7.8 - 8.4 potential of HydrogenMeasuring the acidity or alkalinity of water on a 0–14 scale, where 7 is neutral, 7 is alkaline.
NO3 1-20 ppm NitrateWhile less toxic than ammonia, high nitrate levels (above 40–80 ppm) are important to monitor because they can cause fish stress, stunted growth, and harmful algae blooms.
NO2 <0.0001 ppm NitriteIt is a highly toxic, intermediate compound in the nitrogen cycle produced from broken-down ammonia
PO4 0.01 - 0.1 ppm PhosphateIt is essential for plant development but must be managed, as excess levels trigger nuisance algae blooms and inhibit coral calcification.
NH3 <0.1 ppm AmmoniaIt is the primary killer of aquarium fish, causing gill damage, stress, and death
Ca 380 - 450 ppm CalciumSupporting the growth, skeletal structure, and shell formation of corals, mollusks, crustaceans, and coralline algae
KH 8 - 12 dKH AlkalinityIt acts as a shield, neutralizing acids to prevent dangerous pH "crashes" that can harm fish, corals, and plants.
Mg 1200 - 1400 ppm MagnesiumIt enables coral growth by supporting skeletal formation, assists in metabolic processes, and ensures that calcium is available for corals, clams, and coralline algae.
SG 1.023 - 1.026 SG SalinityEssential for maintaining stable, natural water parameters, proper osmoregulation, and stress-free environments for marine fish and corals
ORP 250 - 400 mV Oxidation-Reduction PotentialA higher positive mV indicates clean, oxygen-rich water with high water quality, while low readings indicate high pollution.
About Yellow Assessor
General information
The Yellow Assessor is a popular saltwater fish among aquarists due to its bright yellow coloration and active behavior. It is a relatively small fish, reaching up to 2 inches in length, and can be kept in a tank of at least 20 gallons. They are peaceful fish and can be kept in groups of three or more.
Diet & nutrition
The Yellow Assessor is an omnivore and feeds on a variety of small crustaceans and zooplankton in the wild. In captivity, they can be fed a varied diet including frozen and live foods such as brine shrimp, krill, and small pieces of fish.
Determining sex
There are no noticeable external differences between male and female Yellow Assessors.
Breeding & spawning
Breeding and spawning in captivity are challenging and have not yet been widely successful. It is recommended to purchase captive-bred individuals to reduce the impact of wild collection.
Diseases
Yellow Assessors are generally hardy and disease-resistant. However, they can be susceptible to common saltwater fish diseases such as ich and velvet. Proper quarantine and observation before introducing to a display tank can help prevent disease outbreaks.
Origination
Yellow Assessors are found in the Western Pacific, specifically in the waters of the Philippines and Indonesia.
Cautions
Yellow Assessors are generally considered safe to handle, but like many fish, they have a spine on their dorsal fin that can be sharp and cause injury if mishandled. It is important to handle them with care.
Acclimation process
Yellow Assessors should be acclimated slowly to their new tank environment over a period of at least an hour to prevent stress and potential shock. A drip acclimation method is recommended.
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