The Yellowtail Damselfish (Chrysiptera parasema) is a small, electric-blue fish with a bright yellow tail that instantly grabs attention in any saltwater aquarium. Hardy, active, and widely available, it’s often recommended for beginners—yet it also has a feisty side that deserves respect. Understanding its behavior and needs will help you decide if this popular damselfish is right for your reef.
Natural Behavior, Temperament, and Compatibility
Yellowtail Damselfish come from the coral reefs of the Western Pacific, where they dart in and out of rock crevices in large numbers. In aquariums, they keep that same bold, busy attitude, spending most of their time in the open water column near their chosen territory.
They are generally considered one of the less aggressive damselfish species, but they can still be territorial, especially in smaller tanks. Expect them to defend a favorite rock or cave from newcomers.
- Minimum tank size: 20 gallons for a single Yellowtail Damselfish.
- Temperament: Semi-aggressive, more assertive as they mature.
- Best tank mates: Clownfish, dottybacks, wrasses, and other similarly robust fish.
- Avoid pairing with: Very timid nano fish that may be bullied.
If you’re planning a community tank, you may want to add your Yellowtail Damselfish after more peaceful fish have settled in. For more ideas on building a balanced stocking plan, see our guide on beginner saltwater fish.
Tank Setup and Care Requirements
One of the biggest advantages of Yellowtail Damselfish is their hardiness. They tolerate a range of water conditions better than many reef fish, making them ideal for newer systems—though stable, clean water is still essential.
Water Parameters
- Temperature: 24–27°C (75–81°F)
- Salinity: 1.023–1.026 specific gravity
- pH: 8.1–8.4
- Ammonia & Nitrite: 0 ppm; Nitrate: < 20 ppm (preferably lower in reef tanks)
Provide plenty of live rock with caves and overhangs. This breaks up line of sight and reduces aggression while giving the fish natural hiding spots. A moderate current and good surface agitation help maintain oxygen levels and mimic their reef habitat.
Hobbyist Tip: If you want more than one Yellowtail Damselfish, add a small group (3–5) at the same time to a larger tank (40+ gallons) with lots of rockwork. Introducing them together helps spread out aggression.
Yellowtail Damselfish are reef-safe and will not bother corals or most invertebrates, making them a good fit for mixed reef systems. For broader guidance on creating a stable environment, check out our article on how to cycle a saltwater tank.
Diet, Feeding, and Long-Term Health
In the wild, Yellowtail Damselfish feed on plankton and tiny crustaceans. In captivity, they adapt quickly to prepared foods and are not picky eaters.
- High-quality marine pellets or flakes as a staple.
- Frozen foods such as mysis shrimp, brine shrimp, and finely chopped seafood.
- Occasional algae- or spirulina-based foods for variety.
Feed small portions 1–2 times per day, only what they can consume in a minute or two. Overfeeding can quickly degrade water quality, especially in smaller tanks. A varied diet enhances their coloration and supports a strong immune system.
With proper care, Yellowtail Damselfish can live 5–7 years or more in a home aquarium. Regular water changes, consistent testing, and a thoughtful stocking plan will keep them thriving. For additional inspiration on hardy community options, see our overview of peaceful reef fish.
In summary, the Yellowtail Damselfish is a vibrant, durable, and active addition to many marine aquariums. While their semi-aggressive nature requires some planning, especially in smaller tanks, their beauty and resilience make them a rewarding choice for both beginners and experienced reef keepers.
Sources
- Michael, S. (2001). Damselfishes & Anemonefishes. Microcosm Ltd.
- Fenner, R. (2001). The Conscientious Marine Aquarist. TFH Publications.
- FishBase: Chrysiptera parasema species summary (accessed 2024).
By
