Marine Betta (Calloplesiops altivelis): Ultimate Care Guide


Marine Bettas (Calloplesiops altivelis), also known as Comet, are some of the most beautiful fish that you could ever consider adding to your fish tank. They’re a great choice for aquarists of any skill level. They may be a little timid at first, but once they get comfortable in your tank, they will surely become a new favorite in your tank.

Marine Betta are saltwater fish native to the Indo-Pacific Ocean. They are also known as Comet, and this name comes from their gorgeous black and white pattern that is reminiscent of a starry night. Despite being called a Marine Betta, they are not related to Betta fish (Betta splendens). Marine Betta do not live in freshwater and their needs are vastly different. They are called Bettas only because they have similar body shapes and long fins to the Betta fish.

Marine Betta Care

Marine Bettas are considered difficult to care for. Due to their specific care requirements, they can be intimidating for some inexperienced aquarists. One of the reasons why they can be challenging to take care of is because they prefer live fish food. They prefer to hunt for the live food. This feeding preference can make it difficult for new fishkeepers. However, Marine Betta that are well-acclimated to an aquarium environment may accept fresh or frozen food.

Are Marine Betta Hardy?

Marine Betta are known to be hardy species. Marine Bettas are known to live in rocky crevasses as far down as 45 meters. Their hardy nature makes them more resilient and resistant to most illnesses and diseases. Despite their sturdy nature, you should not neglect your Marine Bettas. Neglect and poor care will quickly lead to a shorter life for your gorgeous fish.

Marine Betta (Calloplesiops altivelis)
Marine Betta (Calloplesiops altivelis)

Marine Betta Temperature

Warmer water is preferred by Marine Bettas, which makes sense as their native habitat of the Indo-Pacific Ocean is a warm ocean. The recommended water temperature for a tank that features a Marine Betta is around 72°F – 80°F or 22°C – 27°C. That range is pretty average for tropical fish, which means you can easily put a Marine Betta into a community tank, and it should thrive.

Marine Betta Water pH

Marine Bettas can withstand various tank conditions thanks to their hardy nature. When you keep any species in a tank, you should ensure that your tank emulates its native environment. Marine Bettas prefer the water in their tank to be alkaline with a pH level between 8.0-8.4. That pH level can easily be achieved by adding crushed coral to your substrate. You should check the pH level regularly to ensure you can catch any fluctuations before they worsen.

Marine Betta Size

Marine Bettas are a gorgeous species of fish with long flowing fins. Those long-flowing fins are one of the few reasons they’re known as the Comet. The long fins just add to their overall size. Marine Bettas can reach up 8 inches in length. That size means they will not fit comfortably into a small tank. You need at least a medium tank in order to keep them well-accommodated and comfortable.

Marine Betta Tank Size

When housing a Marine Betta, you need to ensure that the tank is large enough to accommodate their needs. 50 gallons is the recommended starting point for tank size. That may seem like a lot for a fish that only reaches 8 inches in length. But in their native habitat, Marine Bettas are known to swim deep into caves and rocks. That means you need to have enough room in your tank to create your own tanks with rocks.

Marine Betta Food & Diet

Marine Bettas are a carnivorous species that prefer to hunt and kill their own food. That diet may be intimidating to some aquarists. But those that have owned Marine Bettas in the past have stated that once they become acclimated and comfortable in your tank, you can begin to transition them into already dead food. Early in their stay in your tank, you need to feed them live food; some people have had luck with live black worms. After that, you can begin to try feeding them frozen foods, which some Marine Bettas may reject at first.

Marine Betta Lifespan

The lifespan of any pet, especially fish, is entirely dependent on care. You may believe that the hardy nature of Marine Bettas means you don’t need to give them the attention and care that you would give to other species – that is not true. Marine Bettas have an expected lifespan of 10 years, but that number can increase if you care for your fish correctly.

Marine Betta Tank Setup

When setting up a tank for any species, you need to try and emulate their native environment inside of the tank. Marine Bettas are native cave dwellers, which means you need to have plenty of rocks in your tank, as well as caves. Marine Bettas will likely spend most of their time inside those caves, emerging mainly to eat. You’ll need more caves if you decide to have more than one Marine Betta in your tank or if you decide to add other cave-dwelling fish.

How to set up an ideal habitat for Marine Bettas

If you plan on setting up an ideal tank for a Marine Betta, there are a few things you definitely need to include. You need to ensure that the temperature is adequate for them, around 72°F – 80°F. pH level is almost essential, be sure it’s within the range of 8.0-8.4. Caves are also very crucial for a tank that includes Marine bettas. They love to hide in caves; it’s where they will spend most of their time.

Are Marine Betta Reef Safe?

Marine Bettas are somewhat reef-safe. They won’t eat any of the reef, which means you shouldn’t have a problem if they’re the only species in a reef tank. The problem is that Marine Bettas are predatory, which means they will not hesitate to eat most of the other species in a rift tank, such as smaller shrimps or other species of fish. If you carefully plan a tank that you want to include both a reef and Marine bettas, there shouldn’t be any issues.

Marine Betta Breeding

Many people like to try their hand at breeding Marine Bettas. That is likely because they aren’t too difficult to breed, and they can fetch a high price if you plan on selling them. Their ease of breeding comes from their hardy nature. As well as the fact they can change sexes based on social and environmental demands. If you have a group of Marine Bettas that are primarily male, the largest will likely stay male while the rest slowly change into females.

Marine Betta Disease

Marine Bettas are incredibly hardy. They don’t really ever get sick or ill in any way. They aren’t even known to be susceptible to Ich, which is highly contagious and easy to catch in some tanks. That means you shouldn’t really ever have to worry about your Marine Bettas coming down with any sort of infection. But that doesn’t mean you should neglect them, it is your responsibility to give them a healthy and happy life.

Marine Betta Tank Mates

Marine Bettas are hardy, saltwater fish, and their temperature and pH needs aren’t too outlandish. That means you shouldn’t have much difficulty in finding compatible tank mates for them. With enough research, you can easily find plenty of possible options to add to a tank that includes a Marine Betta. If you keep reading, you’ll find plenty of great options, as well as a few species you should avoid.

Are Marine Betta Aggressive?

Despite their eating and predatory habits, Marine Bettas are not usually aggressive. Marine Bettas will only show aggression towards the fish species they are hunting to eat. That means they will only be aggressive towards species that can fit into their mouth. If you carefully plan your tank and the species going into it, you shouldn’t have any issues with aggression.

Compatible Tank Mates for Marine Betta

Finding a compatible tank mate for a Marine Betta shouldn’t be too difficult. They’re a peaceful species that prefer pretty average tank conditions, which opens up plenty of possibilities. A common option is a Clownfish. Clownfish are pretty friendly and grow large enough to where Marine Betta shouldn’t try to eat them. Some other great options are Jawfish and Anthias. You can find tons more with some careful research.

Incompatible Tank Mates for Marine Betta

Despite their peaceful nature, Marine Bettas will not hesitate to eat any species that can fit into its mouth. That means that cleaner shrimp are very incompatible; the Marine Bettas will not hesitate to make a snack out of the tiny crustaceans. Tangs, who are fast swimmers, wouldn’t be a smart choice for a tank mate. That is because fast swimmers tend to intimate Marine Bettas causing them to not want to leave their caves to feed.

Where can I find Marine Betta for Sale?

Due to their exotic nature, Marine Bettas are not cheap to purchase. That is if you can find any to buy. Online shops are likely your best bet for buying a Marine Betta. Online, their prices range anywhere from $60 – $200. It is highly recommended that you only purchase them from a reputable dealer. You may find some in-person at specialty stores, but they may not be prevalent due to their price and exotic nature.

Marine Bettas are absolutely gorgeous; they’re one of the most beautiful species you can potentially add to your tank. With the proper care, you’ll be sure to enjoy seeing them in your tank. But the hefty price tag they come with means you should definitely put in the proper research before you take that plunge. If you think you’re up for the task – and have deep enough pockets, don’t hesitate to add this beauty to your tank.

Fish Laboratory

With decades of collective fishkeeping experience, we are happy to share the fish care tips that we've picked up along the way. Our goal at Fish Laboratory is to keep publishing accurate content to help fishkeepers keep their fish and aquarium healthy.

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