Expert Only

Cubicus Boxfish

Ostracion cubicus


(1 Reviews)

The Yellow Cubicus, Ostracion cubicus, also known as the Cubicus Boxfish, Yellow Boxfish, Polka Dot Boxfish, or Cube Boxfish, This fish is one of the most unique marine fish species available. At the juvenile stage, they are easily identifiable as they have a yellow box-shaped body with brown spots. But in the  adult stage, the yellow will fade and become brown.  Their incredibly unique box-shaped body makes them a fun and entertaining fish to watch in your tank. However, the Yellow Cubicus is fickle and should only be cared for by expert and  experienced aquarists. They can reach a size of 15 inches, and should be kept in a tank no less than 100 gallons, with plenty of live rock and a sand substrate. It is a great reef fish as long as it is not kept with larger, more aggressive or speedy fish. Be sure not to house the Yellow Cubicus with cleaner type fish as well,  as it has sensitive skin, and they do secrete poison from skin glands when stressed or in danger. This poison may kill fish in the aquarium very quickly.  Also be sure to keep the lid on your tank tightly sealed to prevent jumping. The Yellow Cubicus can pick on smaller inverts and tubeworms once it gets larger so plan accordingly. The Yellow Cubicus should be fed an omnivore diet. When first introduced to the tank, the Yellow Cubicus prefers a diet of live Brine shrimp or Bloodworms. And when acclimated, their diet should include chopped Squid, Clams, Mussels, and herbivore preparations for variety. They will thrive in a temperature range of  72-78?? F and a pH of 8.1-8.4.

Expert Only: Items designated as expert only require special care such as a species specific environment, special diet or care, and an expert level, experienced aquarist. Not for beginners. Expert Only items qualify for our live arrival guarantee only, and are exempt from our extended 8 day guarantee.

Cubicus Boxfish

Expert Only

Cubicus Boxfish

Ostracion cubicus


(1 Reviews)

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With $179.00 or more in Marine Life.
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Care Facts

Size: 1.5-2 inches
Care Level: Expert
Temperament: Peaeful
Diet: Omnivore
Origin: Indo Pacific
Acclimation Time: 3+ Hours
Reef Safe: Yes
Coral Safe: Yes
Invertebrate Safe: Monitor
Minimum Tank Size: 100+ Gallons
The Yellow Cubicus, Ostracion cubicus, also known as the Cubicus Boxfish, Yellow Boxfish, Polka Dot Boxfish, or Cube Boxfish, This fish is one of the most unique marine fish species available. At the juvenile stage, they are easily identifiable as they have a yellow box-shaped body with brown spots. But in the  adult stage, the yellow will fade and become brown.  Their incredibly unique box-shaped body makes them a fun and entertaining fish to watch in your tank. However, the Yellow Cubicus is fickle and should only be cared for by expert and  experienced aquarists. They can reach a size of 15 inches, and should be kept in a tank no less than 100 gallons, with plenty of live rock and a sand substrate. It is a great reef fish as long as it is not kept with larger, more aggressive or speedy fish. Be sure not to house the Yellow Cubicus with cleaner type fish as well,  as it has sensitive skin, and they do secrete poison from skin glands when stressed or in danger. This poison may kill fish in the aquarium very quickly.  Also be sure to keep the lid on your tank tightly sealed to prevent jumping. The Yellow Cubicus can pick on smaller inverts and tubeworms once it gets larger so plan accordingly. The Yellow Cubicus should be fed an omnivore diet. When first introduced to the tank, the Yellow Cubicus prefers a diet of live Brine shrimp or Bloodworms. And when acclimated, their diet should include chopped Squid, Clams, Mussels, and herbivore preparations for variety. They will thrive in a temperature range of  72-78?? F and a pH of 8.1-8.4.

Expert Only: Items designated as expert only require special care such as a species specific environment, special diet or care, and an expert level, experienced aquarist. Not for beginners. Expert Only items qualify for our live arrival guarantee only, and are exempt from our extended 8 day guarantee.

Great little fish. He was on hunger strike since his arrival 2 weeks ago but has finally started to eat...with much hesitation. He will be in quarantine for longer than the normal month I usually do. I am not medicating him in quarantine cause he is sensitive to copper. Luckily no ich yet. Also he won't eat if I look at him. Very stubborn already. But boy am I in love with him. Hope he makes it.


Reviewed by: Vin Augello on May 11, 2017

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