The Rainbow Shark is a freshwater fish that is often used in community tanks. It’s native to Southeast Asia, and it can live up to around 6 years. This article is going to look at the eating habits and diet of these beautiful fish. So, what do rainbow sharks eat? The rainbow shark is well known for being an algae eater but its diet also includes small invertebrates. Rainbow sharks will happily eat most of the food that can be commonly purchased from pet stores such as pellets, wafers and flakes. They also enjoy the occasional treat of bloodworms, tubifex worms, brine shrimp and daphnia, which again can be bought frozen or freeze-dried from most pet stores. And believe it or not rainbow sharks will also eat some vegetables!
Keep reading to find out more about rainbow sharks and what they eat!

Do Rainbow Sharks Eat Algae?
Yes, the rainbow shark is an algae eater. They love to graze on the algae in their freshwater tank. Because they’re an algae eater, they are a good fish to have as they help to keep the tank clean. It is quite fun to watch them graze and get rid of the algae in their tank.
Are Rainbow Sharks Bottom Feeders?
Rainbow sharks do feed primarily at the bottom of their aquarium. They can often be seen sifting through the substrate looking for food. Although they spend most of their time grazing at the bottom of their tank, rainbow sharks are also known to take a break from grazing and swim around.
How Often Do Rainbow Sharks Eat?
Rainbow sharks will often graze throughout the day. It can be a really interesting experience to watch them feeding and grazing on the algae in their tank. You should provide them with additional food, such as flakes or pellets and occasionally something like brine shrimp or tubifex worms, 2 or 3 times a day to make sure they get a good balanced diet, full of all the nutrients they need to stay healthy. Pay close attention to how much you feed at any one time to make sure that they are well fed but not overfed – when feeding, all the food should be gone within about 3 to 5 minutes, if it’s not you’ve put in too much.

Do Rainbow Sharks Eat Snails?
Rainbow sharks do not tend to eat snails and will even get along reasonably well with them in their tank in most circumstances. It has been known for rainbow sharks to harass snails but this is usually more to do with their territorial tendencies than an attempt to eat the snail; rainbow sharks can be very territorial – check out this article on rainbow shark aggression!
Do Rainbow Sharks Eat Shrimp?
Rainbow sharks will eat shrimp if they get the chance so I wouldn’t suggest putting anything like a Cherry Shrimp in your tank if you have or are planning to have a rainbow shark. Ghost shrimps, however, can make a good tank mate for a rainbow shark – they’re pretty much see through which makes it difficult to spot them and thus rainbow sharks tend to leave them alone!

What Vegetables Can Rainbow Sharks Eat?
Many people don’t realise that fish, including rainbow sharks love to eat vegetables! A piece of cucumber is a really healthy snack for your rainbow shark and they will also eat lettuce, spinach, peas and you may find they quite enjoy some blanched carrot or zucchini!
Try some every now and then and see if the shark eats them, just remember to remove any pieces before they start to rot and pollute tank.
Do Rainbow Sharks Eat Plants?
Rainbow sharks do like to eat plants such as cattails. The cattail is commonly found in the wetlands of North America and Asia where rainbow sharks also live, so it’s no surprise that they enjoy eating plants like this one.
Rainbow sharks are able to break down cellulose due to their digestive enzymes which enable them to eat many different types of plant matter including leaves, stems and roots. In the wild, they will even venture into shallower waters looking for more edible food sources such as aquatic vegetation and algae-covered rocks or tree trunks.
In an aquarium a rainbow shark may eat plants such as water lettuce and java moss which can be grown in aquariums.
If you’re not too keen on having your rainbow shark munching away at your aquarium plants make sure you are feeding them enough greens. If they have are getting all their requirements from algae, wafers and even vegetables like spinach they may be less inclined to nibble on your plants – there’s no guarantee though!

Do Rainbow Sharks Eat Neon Tetras?
There is every chance that you will experience your rainbow shark eating a neon tetra or two – particularly the smaller ones. Larger neon tetras are less likely to be the on the menu but you may still find the rainbow shark being aggressive towards them if it feels like it doesn’t have enough space or that its territory is being invaded.
If you have mature, larger neon tetras, a tank with plenty of room for the rainbow shark to feel comfortable and the neon tetras don’t tend to go down to where the rainbow shark is very often, they may live quite happily together.
(We have an article on suitable neon tetra tank mates which you can read here!)
Do Rainbow Sharks Eat Guppies?
It’s unlikely that a rainbow shark would be able to eat a guppy. Guppies are pretty quick and tend to stay in the upper regions of the tank while a rainbow shark spends most of its time at the bottom of the tank. Providing there is enough space in the tank and the rainbow shark is fed properly there shoudl be much chance of guppies being eaten.
Do Rainbow Sharks Eat Other Fish?
Rainbow sharks are omnivores so they sometimes do eat other small fish along with invertebrates like bloodworms. Having said that, they predominantly eat algae and scavenge for food at the bottom of the tank.
As I’ve said a few times, rainbow sharks can be very territorial so if you are seeing one attack other fish it may well be more to do with asserting dominance than an attempt to eat it.
Do Rainbow Sharks Eat Fry?
Rainbow sharks are known to eat fry but it is not their main diet and they would much prefer a small invertebrate like a bloodworm. If there is fry in the tank a rainbow shark may well see it as a tasty snack and may even take it out of the mouths of other fish such as guppies. However, a well fed rainbow shark may have no interest in the fry and leave them alone.
Do Rainbow Sharks Eat Each Other?
Rainbow sharks don’t tend to eat each other but they are not immune to cannibalism if the opportunity arises – a rainbow shark may pick on another weak or sick rainbow fish if it sees it as an easy meal. It is rare for this to happen though.
If you have more than one rainbow shark in a tank you might being seeing them attacking each other often. This is common behavior but has nothing to do with hunger or the desire for food. As stated a few times above, this sort of aggression is all about territory and dominance. For most aquarists keeping more than one rainbow shark in a tank is not advisable because of how territorial they can be, often attacking and harassing other fish, particularly other rainbow sharks, that they see as a threat to their territory and competitors to their food sources. This aggression often leads to the death of the bullied fish.

Do Rainbow Sharks Eat Dead Fish?
Rainbow sharks will eat dead fish if they are hungry, but the fact is that rainbow sharks do not usually feed on corpses. Rainbow sharks are far more interested in eating algae and scavenging bits of leftover food at the bottom of the tank than they are in making a meal out of a dead fish.
I feel I have to point out that if a fish does die in your aquarium you should remove it as soon as possible to stop any of your other fish, rainbow shark or not, from eating it as doing so can spread disease and that is something you definitely don’t want!
What Do Rainbow Sharks Eat? - Conclusion
Rainbow sharks are omnivores, meaning they eat both meat and plants. They will typically eat wafers, pellets and flakes from the pet store but and will scavenge for leftover food at the bottom of their tanks. For an occasional treat they enjoy invertebrates such as tubifex worms and bloodworms. Although they do sometimes eat other smaller fish and fry this isn’t too common particularly if they are well fed and in a suitable, spacious environment.
Hopefully this article has answered all your questions on what rainbow sharks eat. Thanks for reading!