Paracanthurus is a saltwater fish genus in the family Acanthuridae. Fast Aquatics catalogs Paracanthurus hepatus under 2 common-name pages. Each species page below has the full care guide - parameters, diet, compatibility, breeding/propagation, common diseases, and live vendor availability.
Quick answer: Paracanthurus is a surgeonfish genus (family Acanthuridae) with a single living species, Paracanthurus hepatus, known in the hobby as the blue tang, regal tang, palette tang, or hippo tang. It lives on coral reefs across the Indo-Pacific, can reach about 30 cm (12 in), and needs a large, mature marine aquarium with open swimming room. The two cards below are common-name pages for this same fish.
Paracanthurus is a genus of aquarium species commonly kept in home aquariums. The genus contains a single species, Paracanthurus hepatus, sold under several common names. Aquarists choose Paracanthurus for its combination of visual appeal, wide availability, and well-documented husbandry - unlike fringe species that require specialist care, Paracanthurus sits in the sweet spot of mainstream aquarium keeping.
Wild populations of Paracanthurus originate from tropical aquarium environment. The species in this genus have been kept in aquariums for decades, and most are now available as captive-bred or aquacultured specimens. Captive-bred Paracanthurus ship healthier than wild-caught and acclimate to closed-system parameters within 7-14 days, vs. the 30-60 day acclimation typical of wild imports.
The genus Paracanthurus is monotypic, meaning it contains one species: Paracanthurus hepatus. It belongs to the surgeonfish family Acanthuridae, alongside genera such as Acanthurus, Zebrasoma, and Naso. It occurs widely across the Indo-Pacific, from East Africa into the western and central Pacific. Adults are royal blue with a black palette-shaped marking and a yellow tail. Like other surgeonfish it carries a sharp, scalpel-like spine on each side of the tail base, so move it with a container or net rather than bare hands.
Adults can reach about 30 cm (12 in), so plan the aquarium around the adult size rather than the small juvenile you buy. This is an active open-water swimmer that also wants rock caves to retreat into, so a long tank with open swimming space matters more than height. Many aquarists treat 125 gallons as a practical minimum for an adult, consistent with the 125g+ guidance on the species cards. Stable, well-oxygenated water, a diet with marine algae plus meaty foods, and strict quarantine all help, since blue tangs are well known for susceptibility to marine ich.
Shopping for one? See current tang and surgeonfish listings, compare it with a close alternative in Blue Hippo Tang vs Powder Blue Tang, and plan a quarantine method before it reaches the display tank.
Paracanthurus is rated intermediate care difficulty across the genus, though specific species can vary. The dominant care requirements are:
For reef tanks (where most Paracanthurus belong if it is coral or marine), maintain stable parameters: alkalinity 8-9 dKH, calcium 420-450 ppm, magnesium 1300-1400 ppm, nitrate 5-10 ppm, phosphate 0.03-0.05 ppm. Daily alkalinity swing should not exceed 0.5 dKH/24h. For freshwater Paracanthurus, target stable temperature (within 2°F daily swing), pH appropriate to native habitat, and weekly 25-30% water changes.
Visual inspection at point of purchase prevents 70%+ of post-purchase losses. For Paracanthurus, evaluate:
Reputable Fast Aquatics vendors disclose collection origin on every Paracanthurus listing. Browse current availability with carrier-tracked Buyer Protection on every order, and a 2-hour DOA window starting at carrier-reported delivery.
The first 60-90 minutes after delivery determine whether Paracanthurus thrives or limps for weeks. Drip acclimation is the safest universal protocol:
Most Paracanthurus species are compatible with peaceful community tankmates that share their water-chemistry needs and adult-size range. The general compatibility rules:
For specific tankmate compatibility, browse the linked Paracanthurus species pages below - each individual species page has a tankmate-compatibility table cross-checked against the Fast Aquatics husbandry database.
Most Paracanthurus diseases come from skipped quarantine, parameter swings, or stress. The most common conditions to watch for:
Quarantine all new Paracanthurus for 21-30 days minimum (saltwater) or 14-21 days (freshwater) in a separate tank with prophylactic treatment. The single highest-impact husbandry practice for any aquarist.
Paracanthurus is a genus of aquarium species commonly kept in home aquariums. Its only species is Paracanthurus hepatus.
Paracanthurus requires intermediate care difficulty: standard light, moderate flow, varied diet. Stable parameters are critical - daily alkalinity swings under 0.5 dKH (reef) or stable temperature within 2°F (freshwater).
The only species is Paracanthurus hepatus, sold as the blue tang, regal tang, palette tang, or hippo tang. Check the individual species pages for specifics.
Paracanthurus pricing varies by tier: budget specimens $5-50, mid-tier $25-200, premium grade $100-2,000+. Captive-bred or aquacultured specimens command a premium but ship healthier.
Fast Aquatics connects to vetted vendors of Paracanthurus across all 50 US states with overnight FedEx shipping, climate-aware hold logic, and 2-hour DOA window.
Paracanthurus reef-safety varies by species. Most are considered reef-safe with caution; verify on individual species pages.
Common morphs: multiple natural color morphs.
One. Paracanthurus is a monotypic genus, and its only species is Paracanthurus hepatus. The many names you see for sale, including blue tang, regal tang, palette tang, hippo tang, and blue hippo tang, all refer to this same fish. When comparing listings, check the scientific name rather than the common name, because tang common names are used loosely and other fish called blue tang, such as the Atlantic blue tang (Acanthurus coeruleus), belong to a different genus.
Adult Paracanthurus hepatus can reach about 30 cm (12 in) in total length, although most aquarium specimens are sold as small juveniles of a few inches. Growth is gradual, but buyers should plan the tank around the adult size, not the size at purchase. A fish that will approach a foot long and swims actively all day needs a long aquarium with open water plus rock caves for shelter.
Paracanthurus hepatus is an omnivore that feeds on zooplankton and algae in the wild. In aquariums, a good routine is marine algae sheets or seaweed offered daily, plus quality marine pellets and frozen foods such as mysis or enriched brine shrimp. Feeding small amounts more than once a day suits its grazing habit and helps keep its weight and color up.