A vivid royal-blue damsel with a bright yellow tail, widely regarded as one of the more peaceful and well-behaved damselfish. Hardy, inexpensive, and reef-safe, it is a great splash of color for beginner reef tanks and can sometimes be kept in a small group if introduced together.
ℹ️
Educational only. KinStation content is reviewed by licensed veterinarians but cannot replace an in-person exam. Always consult a licensed veterinarian or board-certified specialist for diagnosis, treatment, or any decision affecting your pet's health.
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Western Pacific: the Coral Triangle and surrounding reefs from the Philippines to Melanesia
Origin
Old World
Climate
🌴 Tropical
Water type
🌊 Marine
Family
Pomacentridae
Genus
Chrysiptera
Part of the Damselfish & Chromis
Small, hardy, often brilliantly colored reef fish of the family Pomacentridae, including the schooling chromis and the bolder damsels. Popular, inexpensive, and largely reef-safe, they range from peaceful planktivores to feisty, territorial species.
From the minimum an animal needs to be kept humanely, up to the ideal setup. Bigger is almost always better — minimums are floors, not targets.
Photo coming soon
Minimum
Reef with rockwork
30 gal / 110 L reef
Chrysiptera parasema is one of the more peaceful damsels (~7 cm). Reef with abundant rockwork, peaceful tankmates, and stable params. Single or pair.
Photo coming soon
Recommended
Larger mature reef
55 gal / 200 L+
More rockwork dilutes territorial aggression. Reef-safe and hardy. Group of 3+ only in larger systems to spread aggression.
Photo coming soon
Ideal
Mature mixed reef
75 gal+ / 280 L+ mixed reef
Spacious reef with abundant rock and varied tankmates. Electric blue body with yellow tail fully visible; reduced aggression at scale.
Life & growth stages
How this animal changes through its life — each stage often has its own care, diet and space needs.
Photo coming soon
Egg
Fish eggs are small, translucent spheres, often laid in clutches on plants, substrate, or in a nest — or carried/brooded by a parent in livebearing and mouth-brooding species. A dark eye spot and the curled embryo become visible inside as development progresses.
Photo coming soon
Fry
Newly hatched fry are tiny and semi-transparent, frequently still carrying a yolk sac that fuels them before they feed freely. They lack full fin structure and adult coloration, staying near cover until they can swim and forage on their own.
Photo coming soon
Juvenile
Juveniles look like miniature adults but with developing fins and muted or different markings; many species shift pattern and color as they mature. Growth is rapid at this stage given clean water and steady feeding.
Adult
Adults show the species' full size, finnage, and mature coloration, and are sexually mature. Many fish develop sex-specific differences in size, color, or fin shape, which can intensify during breeding.
Habitat & enclosure
Keep a single fish in 75 litres (20 gallons) or more, or a small group together in 150 litres (40 gallons) or more with abundant cover. Keep temperature 24-27 C (75-82 F), pH 8.1-8.4, specific gravity 1.020-1.026 (salinity ~30-35 ppt), with ammonia and nitrite zero and nitrate low.
Provide live rock with caves and crevices to define territories and ease any squabbling, plus moderate flow. Standard reef lighting is fine. It is an adaptable, undemanding fish that thrives in mature reef systems.
Substrate
A fine aragonite sand bed over plentiful live rock is ideal, offering the caves and ledges the fish shelters in and biological filtration. Well-structured rockwork helps a small group establish separate territories.
Equipment & setup
A cycled marine system with live rock, a protein skimmer, a reliable heater, and a powerhead for moderate flow covers all its needs. Standard reef LED lighting is sufficient; no special equipment is required.
Diet
An easy omnivore that takes marine flake and pellet, frozen mysis and brine shrimp, chopped meaty foods, and marine algae or nori. Feed once or twice daily. In nature it feeds chiefly on zooplankton and algae near the reef.
Behavior & temperament
One of the more peaceful damsels and reliably reef-safe, the yellowtail rarely bothers corals or invertebrates and is calmer than the blue devil. It can still be mildly territorial, so add it before more timid fish is not required, but a small group should be introduced simultaneously to spread aggression. It mixes well with clownfish, gobies, and other peaceful community fish, and its modest temperament makes it one of the few damsels suited to community reefs.
Health
Very hardy and disease-resistant, but still able to carry or develop marine ich and marine velvet, so quarantine new fish. Stress from overcrowding or unstable water can lower its resistance, so keep parameters steady. Otherwise it is among the most trouble-free marine fish. (Health information is educational only and not a substitute for advice from an aquatic veterinarian.)
Tips, DIY & hacks
If keeping more than one, add them all at the same time to a roomy tank with plenty of rockwork to spread out territories and reduce fighting. Drip-acclimate and quarantine for 2-4 weeks despite the fish's hardiness. Its calm temperament makes it a good first damsel for a peaceful community reef.
