Description
Four Stripe Damselfish (Dascyllus melanurus)
Overview
The Dascyllus melanurus, commonly known as the Blacktail Damselfish or Four-Striped Damselfish, is a small, hardy, and highly active fish. While it is undeniably beautiful with its alternating black and white vertical bands, it is also one of the most notoriously aggressive damselfish species in the hobby.
- Temperament: Very aggressive and territorial, especially as it matures.
- Size: Grows to approximately 8–10 cm.
- Behavior: Highly active, constantly moving, and quick to defend its chosen territory.
- Hardiness: Exceptionally hardy, making it a “bulletproof” fish, though its personality often causes problems for other tank inhabitants.
Care Requirements
- Tank Size: Minimum 120 litres for a single individual. For a community setup, 220 litres is recommended to provide enough space for other fish to escape its aggression.
- Temperature: 22–26°C.
- Salinity: 1.020–1.025 SG.
- pH: 8.1–8.4.
- Environment: They thrive in tanks with plenty of live rock featuring many caves, crevices, and hiding spots. This rockwork is essential for them to claim a territory, which helps them feel secure.
Maintenance
- Water Quality: Like most damsels, they are tolerant of minor fluctuations, but optimal health requires low nitrates (<20 ppm).
- Routine: Weekly 10–20% water changes.
- Equipment: Robust filtration is needed because these fish are messy eaters.
Diet
- Type: Omnivore.
- Staples: They are unfussy, opportunistic feeders. Offer a varied diet of high-quality flake food, sinking pellets, frozen mysis shrimp, brine shrimp, and chopped seafood.
- Feeding Habits: They feed aggressively and will often dart out to steal food from more timid tankmates.
Behavior and Compatibility
- Social: Often intolerant of their own species unless kept in a very large, open system where territories can be spread far apart.
- Tankmates: Only compatible with other robust, semi-aggressive to aggressive species (e.g., large angelfish, tangs, large wrasses, or triggerfish).
- Avoid: Never house with peaceful, shy, or smaller species (e.g., Firefish, Blennies, or small Gobies), as the Blacktail Damselfish will persistently harass and likely kill them.
- Reef Safety: Generally safe with corals, but they may be disruptive to small, sensitive inverts or shrimp.
Reproduction
- They are substrate spawners. During courtship, the male performs elaborate displays to attract a female to a prepared nest site.
- Once eggs are laid and fertilized, the male aggressively guards and aerates the nest until hatching.
- As with most damselfish, raising the larvae in captivity is highly technical and requires specialized live food cultures.
Tips
- The “Last Addition” Rule: If you are determined to keep this species in a community tank, it should be the very last fish added. This prevents it from establishing its territory before the other tankmates have a chance to settle in.
- Aggression Management: Be prepared to remove the fish if it becomes too disruptive. Once they reach adulthood, their aggressive nature rarely subsides.
- Caution: Think twice before adding this fish to a peaceful reef tank. Its beauty is often outweighed by the havoc it can cause to a carefully curated community.
Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.
Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.
