Double Saddle Butterfly

Description

The Chaetodon ulietensis has an oval, laterally compressed body with a gleaming silver-white base colour accented by two broad black “saddles”—one mid-body and one at the caudal peduncle. Fine grey lines run diagonally across the flanks, and the posterior of the dorsal and caudal fins are bright yellow, creating a vivid contrast. A vertical black band runs through the eye, typical of butterflyfish species, enhancing its distinctive facial appearance.

Adults reach up to 15 cm (6 inches) in length and display elegant, continuous swimming patterns through open water and around reef structures.

Aquarium Requirements

Minimum Tank Size: 300 litres (80 US gallons)

Temperature: 24–28 °C (75–82 °F)

pH: 8.1–8.4

Specific Gravity (Salinity): 1.020–1.025

Alkalinity: 8–12 dKH

Ammonia & Nitrite: 0 ppm

Nitrate:< 20 ppm

Aquascape and Environment:
Provide a spacious, well-established aquarium with abundant live rock for grazing and exploration. This species appreciates open swimming areas as well as caves and overhangs for shelter. A combination of rock structures and open space helps replicate its natural reef-slope habitat.

Stable conditions and excellent water quality are essential, along with moderate to strong water flow and high oxygenation. The Double Saddle Butterflyfish adapts well to captive life when provided with a mature environment rich in natural microfauna.

Diet and Feeding

In its natural habitat, Chaetodon ulietensis feeds on benthic invertebrates, algae, and small amounts of coral mucus or polyps. In captivity, it is among the easier butterflyfish to feed, often accepting prepared foods readily once settled.

Recommended Foods:

• Frozen mysis shrimp, enriched brine shrimp, and finely chopped seafood (clam, shrimp, squid)

• High-quality marine omnivore pellets and flakes

• Specialized sponge- or algae-based frozen preparations for butterflyfish

• Occasional live foods (blackworms, copepods) to encourage natural foraging behaviour

Feed 2–3 times daily in moderate portions. Regular feeding helps prevent coral picking behaviour and maintains vibrant coloration.

Temperament and Compatibility

The Double Saddle Butterflyfish is peaceful and well-mannered, making it one of the more sociable members of its genus. It can be kept singly, in pairs, or even in small groups in sufficiently large aquariums.

Suitable Tankmates:

• Peaceful community fish such as tangs, angelfish, wrasses, anthias, and gobies

• Other non-aggressive butterflyfish in large systems (450+ litres / 120+ gallons)

• Peaceful invertebrates such as shrimp and snails

Avoid:

• Aggressive or territorial species (e.g., triggers, large wrasses, dottybacks)

• Very small ornamental crustaceans that may be mistaken for food

Reef Compatibility

⚠️ Caution – Semi Reef Safe

While generally less coralivorous than many butterflyfish, the Double Saddle Butterflyfish may nip at soft and stony coral polyps as well as tube worms or feather dusters. Many aquarists, however, report success keeping this species in mixed reef tanks, particularly when well-fed and housed with resilient or less palatable coral species.

Best suited for FOWLR aquariums or cautiously selected reef environments with close observation.

Additional Information

Maximum Size: 15 cm (6 inches)
Lifespan: 7–10 years in captivity (with proper care)
Difficulty Level: Moderate (relatively hardy for a butterflyfish)
Natural Behaviour: Active swimmer, social, forager; often seen in pairs or small groups in the wild
Origin: Indo-Pacific – from Indonesia and the Philippines to Tahiti, Great Barrier Reef, and Micronesia
Colouration: Silvery-white body with two black saddles, yellow posterior fins, and dark facial band

Summary

The Double Saddle Butterflyfish (Chaetodon ulietensis) is a stunning and comparatively hardy species known for its distinctive twin black saddles and graceful movements. Peaceful, adaptable, and highly active, it is one of the most suitable butterflyfish for aquarists seeking a striking yet manageable species. While some caution is warranted in reef tanks, a mature system with regular feeding and stable water quality allows this beautiful butterflyfish to thrive—bringing elegance and motion to the midwater regions of any marine aquarium.