DescriptionThe Chaetodon blackburnii displays a rich golden-yellow body marked by delicate vertical lines and a prominent black eye bar extending from the dorsal fin through the eye to the lower gill cover. The posterior portion of the dorsal fin and the caudal fin are distinctly black with a blue edging, creating a bold contrast that enhances its appearance under aquarium lighting.This species has a laterally compressed, oval body typical of butterflyfish, and reaches a maximum size of about 14–15 cm (5.5–6 inches). Its graceful swimming and alert, deliberate movements make it an elegant presence in a display aquarium.Aquarium RequirementsMinimum Tank Size: 300 litres (80 US gallons)Temperature: 24–28 °C (75–82 °F)pH: 8.1–8.4Specific Gravity (Salinity): 1.020–1.025Alkalinity: 8–12 dKHAmmonia & Nitrite: 0 ppmNitrate:< 20 ppmAquascape and Environment:Provide a mature aquarium with abundant live rock, offering natural grazing surfaces and hiding areas. This butterflyfish enjoys exploring crevices and coral branches, foraging for small invertebrates. Maintain a mix of open swimming space and structured reef zones to allow natural behaviour.Ensure excellent water quality and stable parameters, as Chaetodon species are sensitive to rapid environmental changes. Moderate water flow and strong oxygenation will support optimal health.Diet and FeedingIn the wild, the Blackburn’s Butterflyfish feeds primarily on coral polyps, small benthic invertebrates, and algae. In captivity, it may take some time to accept prepared foods but can adapt with patience and variety.Recommended Foods: Frozen mysis shrimp, enriched brine shrimp, and finely chopped seafood (clam, shrimp, squid) Specialized sponge- and algae-based frozen diets for butterflyfish and angelfish Live blackworms or copepods to stimulate feeding response during acclimation High-quality marine omnivore pellets and flakes once established Feed 2–3 times daily in small portions. Offer food near areas where the fish naturally forages to encourage feeding confidence.Temperament and CompatibilityThe Blackburn’s Butterflyfish is peaceful to semi-aggressive, generally maintaining a calm disposition but potentially territorial toward other butterflyfish or similarly shaped species. It does best singly or as a bonded pair in large aquariums.Suitable Tankmates: Peaceful reef-associated fish (e.g., tangs, wrasses, gobies, anthias, and small angelfish) Non-aggressive butterflyfish in very large systems (600+ litres) Other peaceful marine species that won’t outcompete it for food Avoid: Aggressive or fast-feeding fish (e.g., triggers, dottybacks, large wrasses) Similar-looking butterflyfish species in smaller aquaria Reef Compatibility⚠️ Not Reef SafeLike many butterflyfish, Chaetodon blackburnii naturally feeds on coral polyps and sessile invertebrates. It may nip at both hard and soft corals, tube worms, and feather dusters. It is best suited to a FOWLR (Fish-Only With Live Rock) system rather than a reef aquarium.Additional InformationMaximum Size: 14–15 cm (5.5–6 inches)Lifespan: 7–10 years in captivity (with proper care)Difficulty Level: Moderate (requires acclimation and stable environment)Natural Behaviour: Solitary or paired, coral grazer, active midwater swimmerOrigin: Western Indian Ocean – East Africa, Madagascar, Mauritius, RéunionColouration: Bright yellow body with fine lines; black eyestripe; dark posterior with blue trimSummaryThe Blackburn’s Butterflyfish (Chaetodon blackburnii) is a stunning and uncommon species known for its brilliant coloration and bold contrasting markings. Native to the reefs of the western Indian Ocean, it makes an elegant addition to large, mature marine aquariums maintained by experienced aquarists. Though not reef safe, it thrives in stable FOWLR setups with a varied diet and pristine water conditions. With patience and attentive care, this golden beauty becomes a captivating and rewarding specimen for any advanced marine enthusiast.
