Double Saddle Butterflyfish
Double Saddle Butterflyfish
Goes well with:
FAQs Answers to the most common questions.
Will a Double Saddle Butterflyfish reliably eat aiptasia and other nuisance anemones in a reef tank?
Yes, it may eat aiptasia, but it is not a guaranteed “clean-up” fish and should never be bought for that purpose alone. Double Saddle Butterflyfish are more coral-nipping and invertebrate-focused than true aiptasia specialists, and individual behavior varies a lot. If you keep one in a reef, expect a real risk to fleshy LPS corals, soft corals, feather dusters, tube worms, and small ornamental crustaceans. It is much better suited to a fish-only or fish-only-with-rockscape setup.
What tank size and aquascape does a Double Saddle Butterflyfish need to thrive long term?
A single adult should be kept in at least a 100-gallon tank, with larger being better because this species is active, nervous, and constantly browsing. They do best with lots of open swimming room plus abundant live rock with crevices for picking at. A mature reef-style rockscape is ideal, but not a coral reef display if you want to protect invertebrates. They are easily stressed by cramped quarters and sparse shelter, and stress often leads to feeding refusal.
How do I get a Double Saddle Butterflyfish to eat prepared foods instead of only live rock foods?
Offer a varied menu from day one: mysis shrimp, finely chopped seafood, enriched brine shrimp, clam, krill, and quality marine butterflyfish pellets or soft marine flakes. Many specimens start on frozen foods if the tank is calm and the fish is already grazing on live rock. Feeding several small meals daily works better than one large feeding. If it arrives finicky, try feeding on a small shell or clip, since the species often responds well to natural picking behavior. Avoid forcing it into a bare quarantine box for too long without hiding places, because this species can crash from stress before it learns to eat.
Is a Double Saddle Butterflyfish reef safe with corals and ornamental invertebrates?
No, not reliably. It is considered unsafe for most reef aquariums because it commonly nips at soft corals, LPS polyps, anemones, worms, and other sessile invertebrates. Even if an individual seems well behaved at first, it can suddenly develop a taste for coral tissue once settled in. It is best kept in a fish-only system or a carefully chosen display where you are willing to lose ornamental invertebrates.
Can a Double Saddle Butterflyfish be kept with other butterflyfish or aggressive tankmates?
It can be kept with some other peaceful to moderately assertive marine fish, but mixing with other butterflyfish is risky unless the tank is very large and the fish are added carefully. This species can be shy at first, so very boisterous tankmates may outcompete it for food and stress it into hiding. Suitable companions are generally calm, non-fin-nipping fish of similar size. Avoid highly aggressive tangs, triggerfish, puffers, and hyperactive feeders in smaller systems, because the Double Saddle Butterflyfish is more likely to lose the competition for food and become withdrawn.
All listed sizes are approximate, not guaranteed, and may vary slightly.
The Double Saddle Butterflyfish, Chaetodon ulietensis, is a beautifully patterned saltwater fish distinguished by its pearly white body, fine vertical gray-black lines, and two prominent dark saddle-shaped markings across the upper body. A bold black eye band contrasts with the bright yellow posterior body and fins, while a dark marking near the caudal peduncle completes its unmistakable appearance. It is also commonly known as the Pacific Double-Saddle Butterflyfish or False Falcula Butterflyfish.
Native to the Indo-Pacific, this species inhabits coral-rich lagoon reefs and, less commonly, seaward reef environments. Adults are typically encountered singly, in pairs, or in small groups as they browse reef structure for plant and animal foods. Its active but graceful swimming style and bold contrasting coloration make it an attractive display fish.
Reaching approximately 6 inches as an adult, the Double Saddle Butterflyfish is well suited to a spacious fish-only or fish-only-with-live-rock aquarium. It is considered one of the more adaptable butterflyfish once established, but its natural feeding behavior includes corals and other sessile invertebrates, making it unsuitable for most traditional reef aquariums.
Quick Care Guide
Care Level: Moderate
Minimum Tank Size: 120 gallons
Temperament: Peaceful
Diet: Omnivore
Reef Safe: No
Region: Indo-Pacific
Scientific Name: Chaetodon ulietensis
Tank Requirements
Provide a mature marine aquarium with substantial rockwork, caves, and sheltered passages along with generous open swimming space. Although relatively modest in adult length, the Double Saddle Butterflyfish is an active cruiser and benefits from a long aquarium with room to move comfortably throughout the display.
Established live rock provides valuable shelter and natural browsing surfaces. Arrange the aquascape so the fish can investigate rockwork without being confined by narrow passages or excessively dense coral structures.
Moderate water movement, good oxygenation, efficient filtration, and stable water quality are recommended. A secure aquarium cover is also advisable, particularly during acclimation when newly introduced butterflyfish may make sudden movements if startled.
Diet and Feeding
The Double Saddle Butterflyfish is an omnivorous reef browser that naturally consumes both plant and animal material, including algae and a variety of small benthic invertebrates. Coral polyps, anemones, worms, and other sessile organisms may also be investigated as food.
In captivity, offer mysis shrimp, enriched brine shrimp, finely chopped shrimp, clam, mussel, krill, and quality frozen marine blends. Butterflyfish preparations containing marine invertebrate ingredients can provide additional variety.
Spirulina-based foods, marine algae preparations, and high-quality omnivore pellets can also be incorporated once the fish is feeding confidently. Feed two to three smaller meals per day when practical.
Temperament and Tankmates
The Double Saddle Butterflyfish is generally peaceful toward unrelated marine fish and works well with many appropriately sized community species. Suitable tankmates include tangs, rabbitfish, peaceful wrasses, clownfish, larger gobies, and compatible angelfish.
Adults naturally occur alone, in pairs, or in small groups. A compatible pair may be maintained in a sufficiently spacious aquarium, although two unrelated specimens should not automatically be expected to pair successfully.
Use caution with other butterflyfish, particularly similar-looking species, as territorial behavior may occur. Avoid highly aggressive tankmates that could intimidate the fish or interfere with feeding.
Reef Compatibility
The Double Saddle Butterflyfish is not considered reef safe. Its natural feeding behavior includes coral polyps and other sessile invertebrates, and captive specimens may nip or consume stony corals, soft corals, mushroom corals, zoanthids, anemones, and tubeworms.
Clam mantles and other exposed fleshy invertebrates may also be investigated. Frequent feeding does not guarantee that a specimen will ignore desirable reef organisms.
A fish-only or fish-only-with-live-rock aquarium is the most dependable long-term environment.
Water Parameters
Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH
Stable salinity, good oxygenation, and consistently clean water are more important than attempting to maintain an exact value within these ranges.
Common Considerations
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Not reef safe: Corals, anemones, tubeworms, and other sessile invertebrates may be nipped or consumed.
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Mature aquarium preferred: Established rockwork provides shelter and natural browsing opportunities.
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Varied diet is important: Offer a combination of marine invertebrate foods, frozen preparations, and algae-based foods.
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Butterflyfish compatibility: Use caution when combining it with other butterflyfish, particularly similar species.
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Active swimmer: Despite its moderate adult size, generous horizontal swimming space is important for long-term housing.
