Write-Up Wednesday: Blue Caribbean Tang (Acanthurus coeruleus)

After my Yellow Bellied Hippo Tang (Paracanthurus hepatus var.) decided zoanthids were lunch and after several other Hippo Tangs in client tanks decided to pick on other corals, I needed a blue tang that would leave coral alone, yet still provide some sizzle to my saltwater tanks. The answer was sitting right off the Florida coast: the Blue Caribbean aka “Atlantic Blue” Tang.

The Blue Caribbean tang is actually yellow in it’s juvenile state. Blue shows up only around it’s eyes and on the edges of the dorsal and caudal fins.

My Blue Caribbean Tang

My Blue Caribbean Tang

As the fish matures, its body becomes bright blue with white streaks and may retail its yellow tail. Watching a fish change color as an adult is not only fun to watch but also rewarding as you know the fish is growing up and thriving.

Like all tangs, the Blue Caribbean tang is used to covering large areas of reefs foraging for algae. Therefore, I’ll only put a Blue Caribbean in a tank that is at least 180 gallons. And while the maximum size of a Blue Caribbean tang is 9 inches (23 cm), most reach 6-7″ (15-18cm) in hobbyist tanks. I also always try to purchase juvenile specimens as I prefer to grow out my fish as this way the fish is used to the aquarium life.

Another reason I like the Blue Caribbean Tang is that for us living in North America, the fish lives in water just off the Florida coast. This proximity means a shorter supply chain which means less handling and transport of the fish which results in stronger and healthier specimens.

Tangs in the Acanthurus genus have a reputation for having a bad attitude and I’ve found the Blue Caribbean Tang to be mild mannered if not a bit shy.

Move over Dory, you’ve been replaced!


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Comments for this article (11)

  • Mike Connell says:

    Hi Mark.

    I have tried unsuccessfully twice with juvenile Blue Caribbean Tangs and both have quickly succumbed to ICH. I have talked to numerous other aquarists who have reported the same thing, even when running UV. What do you suggest to have them prosper?

    I also feed nori almost every day as well as New Era marine grazers.


  • Mike…all my fish for my 450g tank go through 2 weeks of copper treatment. This knocked out any ich that the fish might have had.

  • Allen Frady says:

    I wonder how large the Hippo tangs get before you see the behavior. I had one that was a model citizen around zoas and went from 2 to about 6 inches. He got too big for my 90g and went to another reefer in the area. For some reason i was thinking this behavior was less common but now it seems like more and more people are voicing this so maybe it isn’t as uncommon as i had previously thought.

  • Eric says:

    I have had the same problem with dory she is a model citizen then bang out of no where crazy.

  • mark F. says:

    My trio of tangs, Atlantic, Hippo and Purple did great for 14 years till the Hippo died last year and now the Atlantic beats the crap out of the Purple. Never had any of them pick on anything…

  • John says:

    “As the fish matures, its body becomes bright blue with white streaks and may retail its yellow tail.”

    How much does a yellow tail retail for?

  • Ellery says:

    I wish my Hippo would eat all my Palythoa.

  • John…I’ve never seen a yellow tail Blue Caribbean tang for sale.

  • Richard Allen says:

    I used to collect fish back when it was legal in the Florida Keys. Later as an instructor and dive shop owner, I led trips to the Florida Keys, Bahamas, Mexico, Caymans and other areas. I have always liked Atlantic Blue Tangs in the wild. They are not the most robust fish and seemed to have more problems with collection and transport than the average reef fish. In captivity, their colors seem to fade. If you get them acclimated in a large tank with good water quality they do fine. I finally stopped collecting them because of their mortality rates. They are a beautiful fish.
    As to yellow tail versions. Besides the changing process in young adults, I have never seen a yellow tailed copy in captivity or on the reef. They maybe a regional mutation/ variation somewhere. I have heard on of Tangs in South America that do keep some yellow on their body. We see very few fish from the lower part of the South American Atlantic here in North America and that is where the rumors are from.


  • Justin DeRange says:

    I have a atlantic blue got him at 4″ now he is 7″ out of all my 14 tangs my atlantic blue is the biggest ass hole he has been mean from day one and i have him for 2 years now in a 350 gallon

  • Richard says:

    I’ve been researching tangs that will be comfortable in a 65g as an early growout tank (I also have a 180 when the fish inevitably outgrows). Beyond a few of the Ctenochaetus species (Kole, Tomini, etc), I haven’t really found a tang that I think would be okay in a 65 for a couple years. Now I live in Florida so I see the Atlantic Blues fairly regularly but never honestly thought of them….how do you think a juvenile would do in a smaller setting for one to two years? Other tank mates planned for this tank are relatively peaceful: a couple reef safe wrasses, an algae blenny, and a few chromis.
    BTW I keep a full time QT setup and separate hospital tank – start the fish in 2 weeks of copper before moving out to QT/observation before coming out to the display systems, typically a 5 week process.

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