Home | Amphibians | Vitamin and Mineral Supplementation for Aquatic Frogs, Turtles & Newts – Part 2

Vitamin and Mineral Supplementation for Aquatic Frogs, Turtles & Newts – Part 2

Clawed Frog PairIn Part 1 of this article we discussed vitamin/mineral supplements for aquatic animals that accept prepared/non-living foods; included among these are African Clawed Frogs, Sharp-Ribbed and many other newts, and most water-dwelling turtles.

Live Prey Specialists

Animals that take live prey only are especially troublesome when it comes to supplementation, as one cannot coat live aquatic food animals with powders.  Popular live food specialists include Dwarf African Clawed Frogs, Mata Mata Turtles, Surinam Toads, Mudpuppies and the larvae of most salamanders. 

Providing a healthful diet to the food animals of such creatures is critical to their health and longevity…fortunately, this is easy to do.

Terrestrial Invertebrates

Crickets, roaches, sow bugs and earthworms readily consume fruits, vegetables, commercial gut-loading products and tropical fish flakes (please see articles below).

Rather than rely on a single commercial product or fruit, use a great variety…this is especially important in situations where crickets or earthworms will form the bulk of an animal’s diet, or when rearing larvae and young amphibians.


Minnows, shiners, guppies and other fishes, while a good source of calcium and other nutrients “as is”, should be pre-fed in the case of specialists such as Surinam Toads, Mudpuppies and Mata-Mata Turtles, which accept little else (Note: earthworms are often taken by fish-eaters).  Feed your fishes with several of the hundreds of available high-quality fish foods, along with brine shrimps, blackworms and crickets.

Minnows and shiners should be housed in filtered aquariums, preferably located in a cool location.  Guppies, mollies and other tropical fishes fare best at 75 F or so.  Goldfishes may be offered on an occasional basis, but have caused health problems in several herp species when used as a mainstay.

EarthwormWhere legal, consider collecting small native fishes, which will provide nutrients hard to obtain elsewhere.  Clip the sharp dorsal spines of sunfishes and similar species, and avoid using catfishes – even tiny ones have several sharp, venom-bearing spines.


Blackworms are often the only suitably-sized live food available to those rearing Dwarf Underwater Frogs and salamander larvae. Blackworms will consume a surprising array of foods, including dead fishes, fish food flakes and shrimp pellets, and are best housed in cool, filtered aquariums.

Brine shrimp alone are not an appropriate diet for tiny aquatic amphibians, but fine to offer on occassion; they may be enriched via feedings of Spirulina Discs and commercial gut-loading products.

Further Reading

Prepared Diets for House Crickets

Rearing Earthworms

Gut-Loading and Breeding Brine Shrimps


Earthworm image referenced from wikipedia and originally posted by s shepherd


  1. avatar

    Hi Frank, It’s Kathy here, who has a cat that wants us to raise frogs! We now have 3 frogs that he has brought in; the bullfrog raised from a tadpole and now 2 Pacific Tree Frogs. They are ~1.25″ nose to vent, green with dark stripe through the eyes, white undersides and triangular when legs all tucked in. The first was brought in 5 days ago followed by another 3 days ago. Having grownup outside they are very shy compared to the bullfrog.

    The tree frogs are in a 12x12x18h tank with Eco Earth on top of gravel covered with water and lots of climbing and hiding places. I’ve set them up with small crickets and flightless fruit flies, but they don’t seem to be eating. I’ve left the crickets in the tank with their own food supply.

    Looking online I see healthcare items for reptiles that try to stimulate appetite and others that are for hand feeding sick reptiles from lack of eating. Are these ok to use with these tiny frogs? Or, should I get a bug nabber – zoo med – to get small insects that they are used to eating?

    Also, I’m unsure if it is appropriate to keep these frogs. My thinking for housing them the first night was to see if they had any injuries from being carried in the cat’s mouth. If I release them the cat is probably going to find them again and they may not survive another carry. Also, there’s the potential that I’ve introduced a pathogen that could infect others. So, here they sit.

    Bullfrog Update:
    The Bullfrog is now 3+” and in a 20 gal tank with 6″ of water, a waterfall and boulders. She happily consumes CA dusted crickets, wild caught insects and minnows. The tank is in a bay window with a view of the backyard. The 10 gal tadpole tank is now the feeder fish tank and sits next to the frog’s tank. So she watches the spiders spin and capture as well as the movements of the fish. After a visit to the fishing pond, she immediately goes to the wall with the fish and watches them for a long time. Our current project is to get her to fish on her own inside her tank. I’ve cobbled together an in-tank fishing pond with a large Zilla water bowl on top of a 3 legged turtle platform so that it sits above the level of the tank water. She watches me put the water and fish in the pond, but will not go into it on her own. It seems she likes getting into the ‘beam-me-up-Scotty” container and being put in the pond. Once there she quickly catches 3-4 minnows and leaps out to watch the fish in the big feeder tank.

    Looking forward to your thoughts and thank you for all the great pieces you put-up on your blog!

    • avatar

      Hello, Frank Indiviglio here.

      Thanks for the kind words and the most interesting update. “Cat that wants you to keep frogs”….well put! I’ve heard of cats that specialize (a single cat belonging to a lighthouse keeper is credited with driving a flightless bird to extinction single-handed!) but never with frogs…treefrogs generally have noxious skin toxins, I’ve seen related species rejected by snakes, so all the more odd!

      I’d release the Pacific Treefrogs; wild caught adults can be difficult to habituate, and even captives tend to favor moths, spiders, caterpillars – arboreal insects that are hard to keep on hand. Also, with the season change they will be preparing for hibernation – may already be in non-feeding mode; warmer house temps may complicate their adjustment. I’d say cat is unlikely to find same ones…but who knows with your cat! But better to chance it. I wouldn’t worry about introducing anything; however, they will be harboring parasites so don’t use same tools etc. with your bullfrog.

      Great to hear about the bullfrog and your thoughtful efforts! Keep up with the minnows and good care and you’ll have a long-lived pet.

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  2. avatar

    Hi Frank,

    Thank you for your thoughts, especially yiur advice for releasing the Pacific Tree Frogs. As you can imagine we have become attached to them – there are now three… Their behavior is so different from the bullfrog. We are finding it a nice mix to experience these extremes. Can you recommend a small captive bred frog we could purchase and feed crickets, easily wild caught insects and/or earthworms? Their size and communal nature is part of their attraction to us. Do all frogs require live food? Are there plant eaters?

    Thank you for your help!

    • avatar

      Hello Kathy, Frank Indiviglio here.

      Thanks for the feedback; my pleasure.

      Fire-bellied Toads are a great choice – small, colorful, communal, active by day and may even breed; the “toad” part of the name is misleading, as they are semi-aquatic. Please see this article for a bit of info, photos, and write back if you decide.

      White’s treefrogs are always captive bred, but get much larger than fire bellies, although smaller than bullfrogs. Native US treefrogs are rarely bred, although some do well as pets – Gray, Green and Barking especially. Red-eyed treefrogs commonly bred but highly nocturnal, need heat.

      Only 2 frogs have been documented as feeding on vegetation, and then rarely – Marine Toads will take salad when very hungry and a treefrog in SA seems to eat berries regularly. However, African Clawed Frogs will do well for decades on dry prepared diets; they are entirely aquatic; very responsive, take food from hand, live into their 20’s and will breed.

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio

  3. avatar

    Diseases that cause hormonel imbalances and improper habitat temperatures
    also increase the risk of MBD. The Fiji crested iguana, Brachylophus vitiensis,
    is now listed as Critically Endangered on the IUCN Red List.
    They’re also far too small even for a juvenile iguana.

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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