This little guy is just beyond adorable and will eventually become 20" long. Their body becomes more elongated as they age (see adult video) and they will need a very large tank. Live foods may be needed to induce a feeding response. Gut load any live mysis or live brine with good nutritious food about 1/2 hour before feeding so the little moo-moo gets a quality meal! Have a crop of algae for them to feed from as well. The name Cowfish comes from the long horn like projections on each side of their heads. As a tiny baby, such as this little "calf," the horns have not formed yet, however, these horns max out then stay the same size, so as they become full grown adults, the horns appear "smaller" although they are the same. Place with very peaceful fish and keep stress levels low to prevent tank poisoning.
This age, when their horns are long is where the name Longhorn Cowfish comes from. Although yellow as babies and juveniles, once they are adults they are not as bright yellow, but they still have their "sunny" personality! Like little tiny boxy water dogs, these fish endear themselves to their owners who rightly keep them in a 250 gallon tank with very peaceful tank mates. They can be startled if the room is completely dark and the lights come on, forcing them to "flee" which can cause them to get caught up in decorations and rock. This stress can cause them to release a toxin that can poison the tank! Like having a standard Poodle, which stress and act out in a loud and/or busy household....... if you keep everything calm, your Cowfish will be fine!
The Polka-Dot Boxfish, also called the Yellow Boxfish or Cube Boxfish is another fish that thinks it's a dog! They need to be fed at least 3 times a day or more, and never fed floating food since they will develop buoyancy problems if they ingest air. They are very peaceful and need lots of places to hide when first added to the tank. They will not eat for up to a week and if startled or stressed will jump out of the tank or release a toxin that, while in the wild is quickly diluted by the ocean, yet in captivity can wipe out an entire tank. If they are near death or tank mates are irritating it, remove promptly as this toxin has no remedy. They reach over 17" and need a tank that is at least 125 gallons and need an advanced aquarist who understands their delicate nature.
The adult coloring of the Polka-Dot Boxfish is what has earned it the name Yellow boxfish, since the intense black dots fade as they age. Growing to almost 1.5 feet long, they need a tank that is at least 125 gallons with plenty of open space along with caves and areas to hide. They like a meaty diet and are very peaceful, although should only be kept by advanced aquarists due to their specific needs. If a tank mate picks on them or a fast swimming tank mate startles them badly, they can emit a toxin that will kill the entire tank, including themselves. Put a lid on it..... quite literally, because they can jump from the tank! However, them jumping out of the tank may be a better alternative than releasing toxin. Both situations are not desirable, so leaving them in the ocean may be the best choice.
This baby Polka-Dot Boxfish is so adorable! With that bright yellow body and little black spots, no wonder they are purchased with excitement. Be aware, however, that this little guy will need a very large tank that is at least 180 when it is full grown. Add your Polka-Dot Boxfish FIRST and any fish after him should be very docile, peaceful, slow eating and slow swimming fish. While these fish may be okay when your boxfish is young, be aware that when they can fit into his mouth as an adult, he may eat them! Beware of cleaner wrasses, because they can annoy the boxfish into releasing a toxin that will wipe out the entire tank.
As you can see the Polka-Dot Boxfish is a large fish, reaching up to 18" and needing at least 180 gallons with proper filtration. Similar to seahorses, they have a "skin" over their carapace, and stinging corals can harm them. These fish will release a toxin that will kill everyone in the tank if it is startled. Do not allow children to slap the glass. Tank mates would include other genus of boxfish or cowfish, but in a 300 gallon tank or more. They are best left in the wild, since in captivity they only live 4-7 years.
Shown in the ocean, this Polka-Dot Boxfish is still in the sub-adult stage. At this point they have round dots all over with white or blue centers. They are a mustard yellow with bright yellow fins. Boxfish will emit a toxin into the water when frightened or startled. While this is not an issue in the ocean, it is a huge problem in captive systems. Keep activated carbon going all the time just in case. A tank no smaller than 180 gallons is needed and they will stress if they do not have enough swimming room.