Marine Betta


Family: Plesiopidae Picture of a Marine Betta or CometCalloplesiops altivelis
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I have my comet fish for a year now. It eats pellet now! I immersed the pellet in water. Made it soft before feeding. Comet doesn't like hard pellet that is... (more)  Alfred Cheng

   The Marine Betta or Comet is probably one of the most interesting of salt water fish!

   The eye spot at the base of the dorsal fin fools prey into thinking the mouth of the fish is at the wrong end! When the Marine Betta or Comet hunts it approaches its prey sideways (very neat to watch) and when the prey tries to escape by way of the tail, it turns out ot be the mouth and the fish is caught! Another theory is that the eye spot resembles the head of a moray eel, a very good defense against predators.

   The Marine Betta or Comet is harder to keep than other groupers since it much prefers live food and is slower to eat than many other aquarium fish. For this reason, It is recommended that this fish be kept as a single specimen or in a very sparsely populated tank!

For more Information on keeping this fish see:
Guide to a Happy, Healthy Marine Aquarium

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Plesiopidae
  • Genus: Calloplesiops
  • Species: altivelis
Marine Betta Fry Juveniles (Calloplesiops altivelis)
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Video showing various stages of Marine Betta baby growth!

This video is from the company that has tank bred Marine Bettas! The fry at 16 days develop a big white spot on the sides of their bodies. This white spot is gone by 7 months old. These very peaceful fish only grow to about 7" and are compatible with most fish except the very small Green Clown Goby sized fish, aggressive or large fast moving fish that will keep them from coming out. A male and female will do well in a 75 gallon, but 2 males need a 6' tank!

marine betta eats live fish (Calloplesiops altivelis)
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Great video of the sized fish a Marine Betta will eat

This video shows how Marine Betta fish will hunt. It is a very quick catch in this case, but shrimp are more methodically hunted, making for an interest display! Only very small fish like Clown Gobies shouldn't be housed with your Marine Betta. Avoid aggressive fish and large fast moving fish that may prevent the Betta from getting enough food. This tank should have more ledges for the Marine Betta to hide under. The best tank mates are anthias, larger flasher wrasses, fairy wrasses, cardinal fish, small more peaceful hawkfish, more mellow dwarf angelfish, mellow chromis and larger mellow damsels, large gobies, larger blennies, jawfish and clownfish. Juveniles of these fish added after the Marine Betta is established may be eaten. Add your Marine Betta before your dwarf angelfish, which should be added last.

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Maintenance difficulty:    The Marine Betta or Comet is difficult to keep mainly because it needs special attention in order to eat. Although there may be cases where this fish will eat prepared foods, we have not seen it. Normally they will only eat live fish about the size of a guppy or very small goldfish.
   They also need plenty of time to stalk and capture their prey. If they are in a tank with other predaceous fish, like lions and groupers, they will most likely starve because they are not fast enough to get a good share of the food.

Maintenance:   Feed all kinds of live foods. If you are interested in trying prepared foods, squid, clams, shrimp, chopped fish, lancefish, or silversides. Although lionfish primarily eat live food also, many have been trained to eat lancefish or silversides in the aquarium.

Habitat: Natural geographic location:    Found in the Indo-Pacific.

Foods:    Like most groupers it is a meat eater that preys on small fish.

Social Behaviors:    This fish is a solitary predator that hangs out among the rocks waiting for prey.

Sex: Sexual differences:    Unknown.

Light: Recommended light levels:    No special requirements.

Breeding/Reproduction:    Unknown.

Temperature:    No special requirements.

Length/Diameter of fish:    The Marine Betta or Comet grow to a length of 16 cm (6.5 inches).

Minimum Tank Length/Size:    A minimum 50 gallon aquarium is recommended.

Water Movement: Weak, Moderate, Strong    No special requirements.

Water Region: Top, Middle, Bottom    No special requirements. Provide rockwork large enough for the fish to hide.

Availability:    This fish is readily available.

Author: David Brough. CFS.
Lastest Animal Stories on Marine Betta

Alfred Cheng - 2017-08-04
I have my comet fish for a year now. It eats pellet now! I immersed the pellet in water. Made it soft before feeding. Comet doesn't like hard pellet that is difficult to chew. It started eating live shrimp only at the beginning. It did not eat fishes, even a small fishes. It was shy and hided in a cave and waiting for food. I gradually change the food from live shrimp to frozen food - brine shrimp, mysis shrimp and blood worm. It took 3-6 months. I then gradually changed the food to pellet. Mixed pellet with frozen food. Feed at the same time. After about 9 months, it fully adopt to pellet. It swam around like other fishes waiting for my feeding. It stared at the pellet. Picked the one that was moving, or just after moved. Kept the habit of predator hunting live food :)

  • Joshua Alderson McDonald - 2019-08-10
    My fish is now 3 years old. Eat almost everything. I didn't feed live food for a long time.
Chris Karmazin - 2012-03-03
I've had my betta one year and almost everything I have read does not apply. My betta (comet) will eat whatever fits in his mouth. And will beat my lionfish when eating. He is also free swimming, but alittle timid with sudden movement.

  • Jeremy Roche - 2012-03-04
    You are very lucky. That is extremely rare. Are you feeding live food? Whatever you are doing, keep doing it!
David B. Romsey - 2008-01-20
I have a 150 gallon reef tank in which I have been keeping a Marine Betta (Calloplesiops altivelis) for over 2 years. The tank contains 150 lbs. of live rock with a number of caves and crevasses. Its tank mates are: 1-8" Vlaming's Unicorn fish, 2-5" Yellow Tangs, 1-6" Blue Tang, 1- 7" Sailfin Tang, 2 large Blue Velvet Damsels, 1-6" Picasso Tang, 1-4" Lawnmower Blennie and 1-2" Green Mandarin. All of these fish (with the exception of the Mandarin) including the Betta have been living and thriving on a diet of TetraMin flake food and dried Red Algae sheets for a couple of years. Every 2 weeks I toss in some chopped up smelt fish. There is no protein skimmer on this tank. The Betta waits in either back corner of the tank until feeding time and rises to the top to grab the flakes as they float by. So I guess the statement that Marine Betta are "finicky" about what they eat has at least one exception, which I believe is notable if it's that significant.

Will - 2007-03-27
I have had my Marine Betta for a few months now and he is by far one of the most coolest fish I have ever had. We feed him frozen shrimp for the most part but once or twice a week we toss in about a dozen guppies! I like watching him go after them instead of some of the other predator fish we have because he is so tactical on how he hunts. Where some of our other fish just shoot across the tank to get them you can see him just watching and waiting then bam! Love this guy.