Most fish commonly found in aquariums eat insects in the wild to one degree or another, including Livebearers, Rainbowfish, Tetras, Killifish, Betta, Gourami, Hatchetfish, and many species of Cichlids (such as Apistogramma & Convicts). Insectivorous fish primarily feed on aquatic insects, terrestrial insects, insect larvae and pupae. They may actively hunt insects by jumping out of the water, or grab those that drop into the water from overhanging vegetation. These fish have evolved to effectively utilize the unique combination of nutrients these small creatures provide, which would suggest that their absence could leave the diet seriously lacking in essential nutrients.

While the diet of omni-insectivores and omni-larvivores is primarily insects and larvae, they don’t stop and ask the little creatures in their environment if they’re larvae before they eat them. Therefore, most of these fish also ingest cohabiting creatures such as invertebrates, crustaceans, fry, and eggs. If they’re not strict carnivores, they’ll often dine on algae or other plant matter as well (hence the term ‘omni-insectivorous’). Further complimenting their diet can be food they inadvertently ingest through their prey, from gut contents to pollen.

So why don’t more fish foods include a healthy dose of insects? They’re expensive! One wouldn’t think of bugs as expensive, but they’re not commonly farmed, difficult to harvest, and low-heat drying processes are expensive to operate. They must also be certified as clean and uncontaminated with pesticides.  Since first publishing our observations and formulating Buggy Bottom Bites, one insect farm in Canada has entered the fish food sector by drying Black Soldier Fly larvae. It’s now an ingredient in fish food sold under brands like Hagen, Fluval and Nutrafin.

Paracheirodon axelrodi - Red_Cardinal_Tetra Insectivore
Red Cardinal Tetra (Paracheirodon axelrodi) – Almost all Tetras are insectivores.

The Key is in the Details

For fish who eat insects and small crustaceans all day, every day, fishmeal as a main ingredient isn’t going to cut it. Their wild diet of insects, worms, invertebrates and crustaceans is rich in protein, calcium, phosphorus, magnesium, potassium, copper, iron, zinc, manganese, and selenium. It’s presented with unique combinations of fatty acids, carotenoids and other antioxidants, and chitin. Their digestive system is built to process, uptake and utilize nutrients from those unique sources.

To truly formulate an optimum diet, especially for breeding and growing fish, one must understand the types of lipids that are ingested by our specific aquatic creatures in the wild. For example, how many times have you heard someone refer to ‘wax esters’ in reference to fish food? Yet they are a major lipid storage reserve in insects, crustaceans and zooplankton, and are therefore considered to be an important energy source for many species, especially insectivores.

It’s also important that freshwater omni-insectivorous fish receive a balanced combination of EPA, DHA, and AA fatty acids for egg formation, healthy larval development, and early fry survival. A study on the Rainbowfish Melanotaenia splendida found that a balanced diet of these three fatty acids, “…produced eggs with a 100% survival to eyed embryo and hatching rate. They also had the highest number of eggs, highest number of spawns, and the shortest average spawning interval when compared to results from the other trials in the study.” [Badger, 2004 via Home of the Rainbowfish]

Natural Diet of Melanotaenia Rainbow Fish
Melanotaenia Rainbowfish – Rainbows are omni-insectivores.

This level of understanding allows us to formulate a diet that will better meet the nutritional requirements of omni-insectivores, as well as increase optimum reproduction and growth. It is only the beginning of the in depth knowledge we draw upon in our premium fish food formulations. Anyone can throw together a few ingredients and call it fish food, but formulating specialized diets and using specialized ingredients is not a game for the uneducated to play. Know your fish, fully understand their requirements, and take great care to ensure the fish food you purchase or make yourself is formulated with comprehensive knowledge.

Increasing Insect Intake

The most common concern with the captive feeding of insectivores is the lack of variety available in captivity, which is critical for a healthy, balanced diet. Each insect, crustacean or invertebrate can offer a drastically different nutritional profile which, when combined, is a complete diet.

There are some insects and larvae on the market that may be fed to fish, such as crickets, mealworms and bloodworms. A wide variety of invertebrates and crustaceans can be found at most fish stores, including krill, daphnia, and shrimp.  Alternately, you could breed your own live food for insectivores, such as wingless fruit flies, daphnia or gammarus.  Some hobbyists collect wild insects for their fish, but we discourage this due to the high risk of pesticide or other contamination.

You may wish to formulate your own fish food recipe that is based on omni-insectivore requirements. This allows you to easily bring in other ingredients to help balance the mix, such as seaweed, algae, and natural supplements like calcium montmorillonite clay.

Wild-type Xiphophorus nezahualcoyotl Swordtail - omni-insectivorous
Wild-type Xiphophorus nezahualcoyotl – Swordtails are omni-insectivores.

All Natural Pet Care Blog CommentWe’d love to hear about your experiences with feeding omni-insectivorous fish in the comments below.

Bernard, Joni B. Feeding Captive Insectivorous Animals: Nutritional Aspects of Insects as Food
Home of the Rainbowfish
Badger, A. C. The effects of nutrition on reproduction in the Eastern Rainbowfish, Melanotaenia splendida splendida. Masters (Research) thesis, James Cook University. 2004.
Ortaz, M. The diet of the neotropical insectivorous fish Creagrutus bolivari (Pisces: Characidae) according to the “graphic” and “relative importance” methods.
James Sales, Geert. Nutrient requirements of ornamental fish. Aquat. Living Resour. 16 (2003). Faculty of Veterinary Medicine, Belgium.
Halver, J.E. Fish Nutrition. Second ed. Academic Press, San Diego, CA, USA. 1989.
Winfree, Robert A. Nutrition and Feeding of Tropical Fish. Aquariology Fish Anatomy, Physiology, and Nutrition. First ed. Tetrapress, Morris Plains, NJ 1992.
Coletti, Ted D. Aquarium Care of Livebearers (Animal Planet Pet Care Library)Aquarium Care of Livebearers (Animal Planet Pet Care Library). 2008.
Dreyer, Stephan. Feeding Tropical Fishes the Right way. TFH Publications. 1998.
Robert, Helen E. Fundamentals of Ornamental Fish HealthFundamentals of Ornamental Fish Health. 2009.

✔  You may also be interested in reading:

Natural Prevention and Treatment of Aquarium Fish Parasites

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52 thoughts on “The Natural Diet of Omni-Insectivorous Aquarium Fish ©

  1. I’ve learned so much fromt his post and now I’m going to find as much information about fish diets as possible. I’ve never been comfortable feeding something so unnatural from a container.

  2. I still give my fish some store food but these days I find myself giving them more and more real food. They definitely respond well to the change but I don’t always have time.

  3. What a great read! I’m going to try changing up my fish diet and we’ll see what happens.

  4. All of my fish devour your insectivore food and they’re as healthy as can be. I like the information you provide so we can do it ourselves but it’s so much easier to let you do it for me, plus they get all the other benefits. Thanks for giving us a choice and fr bringing the quality level of fish food up a bunch of notches.

    If I owned a fish food company I would hire you to be my secret weapon ROFL 😉 😉

  5. Our fish go wild for insects too. I know what they like best isn’t always best for them so it’s good to know insects are something they can attack and improve their health on.

  6. Thank you so much for this information, I can’t find anything about fish online that the average newbie book doesn’t already say. We keep a few rare fish and it’s hard to know if we’re feeding them the right food without a website like yours to help.

  7. That’s exactly right and I’m as shocked as everyone else to see it on a website. 😉
    The fish food industry has profited by convincing us our fish need this and not that. Like this website says “No Manufacturer or Supplier Should Fear an Educated Consumer” but I bet they fear you! 😉 They should do what the security industry does with hackers and hire you to be on their side, maybe then we’d get some decent fish food in stores.
    Keep fighting the good fight and keep making Bottom Bites even if a fish food company hires you. 😉 Hopefully I’ll get hired by the same company because I’m going studying to work in the fish industry. Thanks for providing studies and other information that helps me in my studies.

  8. Great blog post. A favorite of my fish is black ants. I lure them out with a piece of fruit in a jar and then swish them into the aquarium.

  9. The bottom bites came in the mail and let me just say that I won’t have to refer to this aricle anymore because your taking care of it for me. They love the food and I don’t have to worry about them missing some important nutrient. We’re all happy.

  10. I catch fish food in the forest and streams around my home every summer and the fish look very healthy by fall.

  11. Fabulous fish facts! It’s crazy how convoluted feeding pets has become, making common sense a novelty.

  12. I can’t believe how excited I am to find this information about the natural diet of ranibowfish but I am! I’m going to make the gelatin homemade food asap.

  13. You are seriously good at this fish thing! Thank you very much for your hard work!

  14. I don’t think of my fish as insectivores but you do have a valid point regarding unique nutrients.

  15. You should publish your articles in fish magazines to spread the word (I added a link to one). Such good information shouldn’t be lost among the cyberpoop.

  16. They absolutely love your buggy bottom bites & I now feed them more blackworms & crickets too.

  17. It has always striked me as odd that more fish food doesn’t have worms in it too. With the concerns about overfishing maybe we’ll see more mass production of worms and insects to bring the price down on them. Thanks for getting everyone talking about it.

  18. Insects should be in every fish food when you consider it from this angle. I too will buy more variety of the suggested items.

  19. I love the rainbowfish site and my fish are fat & happy that you have expanded on this topic. 😉

  20. Where do you learn so much about fish diet? No matter, you share what you know as appreciated!

  21. OK I’m convinced too and will grab some of those fish foods this week. 🙂

  22. Oh MAN do the fish love that insect food of yours! They’re already spoiled with frozen food but you’d think they had been raised on cheap flakes the way they went at your food lol. Thank you very much!

  23. I’ve wondered about that too. I’ve never met a fish that turned up its nose at insects.

  24. Good info on how to balance a fish’s diet with different fish food products that are available on the shelf and also on how to make your own.

  25. My fish and snails love crickets, tubifex, shrimp, krill and daphnia. They even get escargot when I find it on sale!

  26. Why doesn’t anyone talk about this??? I can find information about insectivores but most fish eat insects and hardly any are just insectivores. Thanks for providing useful articles.

  27. Yup you’ve done it again! Impressive research & writing about fish care is always a pleasure to find.

  28. Dorrie you can get live crickets at pet-smart but for most fish you’re probably better off with dried insects.

  29. I appreciate the input from my fellow fish-keepers, thank you! 🙂

    Dorrie, you will usually find freeze-dried crickets in pet stores that carry food for reptiles, birds, etc. They may not be in the fish food section. They’re usually quite expensive, unfortunately.

  30. My fish love bloodworms, mealworms and your bug food and they’re really healthy.

  31. I can speak for rainbow and apisto dietary requirements & confidently agree with the insect requirement. My fish were fine before a focus on insects but now they’re spectacular!

  32. I’ve heard that some fish like Killie fish like ants too. Has anyone tried ants for fish food?

  33. Fantastic information from someone whose obviously well informed about fish & what makes them tick (or should I say “swim”?) 😉

  34. crustaceans are overflowing with good nutrition for fish & insects are too. it can be tough to find variety but the internet helps and its worth it. they’re constantly breeding & grow into healthy fish when they’re given the right diet.

  35. Insects and larvae are healthy for fish and they LOVE THEM! The buggy bites came in today and you should see my fish fighting over them! Great job…I can’t wait to see what you come up with next!

  36. I agree that most fish eat insects and little critters. I breed 7 species of rainbowfish, bettas and platties and they get as much of that stuff as I can afford. I’m going to try your buggy fish food too!

  37. that’s true Dantella and make sure you only buy Rainbows from good sellers to avoid disease too.

  38. I’ve had Rainbows for several years and I have found their diet is the most important key to keeping them well. They can be prone to bacterial infections more than other fish but they can fight them off if they’re healthy. They love crushed crickets and any kind of worm plus they need algae.

  39. You know so much about fish but yet you make it easy to understand. I can’t wait to receive the new Buggy Bottom Bites & thanks for whipping them up.

  40. Very helpful information. I’ll check out what my fish store has available this weekend when I can take my time. I’m getting my pond ready for the Summer this weekend too.

  41. It’s nice to see someone is thinking about fish food instead of just buying what’s on the shelf.

    • Wow….an article that doesn’t contain the same old tired…..and usually biased or incorrect…..information about fish nutrition. I hope you’re planning to write more about it!

  42. That’s a fantastic point! All omnivore fish are at minimum opportunistic insect eaters. I’ll be adding the bug food to my next order and I’ll look around for the other food you suggested.

  43. I hope with environmental concerns the amount of insect protein will increase in fish food and result in a better food for fish as a happy coincidence.

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