Atlantic Blue Tang (Adult)

Adult Atlantic Blue Tang (Acanthurus coeruleus), highlighting its transformation from its juvenile yellow phase: 1. Appearance & Coloration Adult Coloration: As they mature past their juvenile yellow phase, their body transitions into a deep, striking cobalt blue or purplish-blue. Their dorsal, anal, and caudal fins are often edged with brilliant electric blue or violet lines. Morphology: They feature a compressed, oval-shaped body typical of surgeonfish and possess the characteristic sharp, retractable scalpel-like caudal spine on either side of their tail base for defense. Size: They grow into substantial, deep-bodied fish reaching adult lengths of 10 to 15 inches (25 to 38 cm). 2. Native Origin & Habitat Geography: Native to the Western Atlantic, including the Caribbean, Florida, Bermuda, and the Gulf of Mexico. Environment: Found inhabiting shallow coral reefs, clear-water reef flats, surge zones, and seagrass beds where they constantly scour substrate and hard surfaces for algae. 3. Tank Requirements Minimum Tank Size: Requires a large, spacious aquarium of at least 125 to 180+ gallons to accommodate their active swimming behavior and full adult size. Aquascaping: Provide extensive open swimming lanes paired with robust live rock structures, caves, and overhangs for grazing and resting. Water Parameters: Temperature: 74°F – 80°F (23°C – 27°C) Salinity (Specific Gravity): 1.023 – 1.025 pH: 8.1 – 8.4 4. Diet & Feeding Natural Diet: Herbivores that spend their entire day grazing on filamentous and microalgae. Captive Diet: Essential to provide a heavy plant- and algae-based diet to maintain their immune health and brilliant coloration. Offer regular sheets of dried nori (green, red, or brown) on a feeding clip, spirulina flakes, marine algae pellets, and occasional frozen herbivore preparations. Feed them multiple times a day. 5. Reef Compatibility Status: Reef Safe Behavior: Completely safe with corals, clams, and other sessile invertebrates. They will not damage or nip at coral tissue, making them exceptional additions to large mixed reef systems. 6. Temperament & Tank Mates Temperament: Semi-active and generally peaceful toward other unrelated species, though they can become more assertive and territorial toward other tangs or closely shaped herbivorous fish as they mature. Compatibility: Can be housed with a wide variety of community fish, wrasses, and angelfish. Avoid keeping them with overly timid species that might get outcompeted for food, or other aggressive tang species unless housed in an exceptionally large system with plenty of established territory.