Home | General Reptile & Amphibian Articles | Caring for Reptiles and Amphibians: Useful Products from the Aquarium Trade – Using Frozen and other Foods for Turtles, Aquatic Salamanders and Tadpoles – Part 1

Caring for Reptiles and Amphibians: Useful Products from the Aquarium Trade – Using Frozen and other Foods for Turtles, Aquatic Salamanders and Tadpoles – Part 1


Many items marketed for tropical fish are of great value to reptile and amphibian enthusiasts. Please see: Caring for Reptiles and Amphibians: Useful Foods, Medications and other Products from the Aquarium Trade – Introduction and Feeding Accessories for background information and notes on other products.

Frozen Foods for Turtles

Frozen silversides, krill, beef heart, sand eels, mussels and similar foods provide a convenient means of increasing dietary variety for many reptile and amphibian pets.  They are readily accepted by nearly all aquatic turtles, including soft-shells, sliders, cooters, map turtles, snake-necks and musk turtles.

Diamondback Terrapins – Estuarine Specialists

Marine foods, such as sand eels, should not be used as a dietary staple for freshwater turtles, but rather as a supplement each 7-14 days.  However, diamondback terrapins, which inhabit estuaries and other brackish environments, should be offered mussels, krill and other such foods at most meals.

These gorgeous, variably-patterned turtles have an undeserved reputation as difficult captives.  Indeed, when kept in what is the proper manner for, let’s say, a painted turtle, a diamondback will usually fail to thrive.  However, when kept in brackish water and fed shellfish, krill, marine fishes and other natural food items, they make active, long-lived pets.

Other Salt Marsh Turtles

Snapping turtles often enter brackish environments…indeed some populations are specifically adapted to such.  I have had good success in raising snapper hatchlings on diets composed of approximately 50% marine-based organisms.

The eastern mud turtle (Kinosternon subrubrum) is another “freshwater” turtle that is often associated with estuarine environments.  In New York State, it occurs only on Long Island and Staten Island, where it is almost always found in salt marshes.  Mud turtles also fare well on a diet high in marine foods such as mussels and krill.

A Note Concerning Krill

Krill are shrimp-like creatures native to marine environments.  As such, I would normally recommend they be used in the diets of fresh water turtles on an occasional basis only (except for the estuarine species mentioned above).  However, some years ago a colleague raised a group of Blanding’s turtle (Emydoidea blandingii) hatchlings on a diet composed entirely of freeze dried krill and Reptomin Food Sticks.  The turtles grew quickly, matured into adults with perfectly-formed shells, and have, I believe, reproduced.

Since then, I have used frozen and freeze dried krill as a substantial part of the diet of spiny soft-shelled turtles, a number of Australian snake-necked turtle species, red-headed side-necked turtles, midland painted turtles, axolotls, tiger salamander larvae, red-spotted newts, sharp-ribbed newts, African clawed frogs and many others…with fine results in each case.  I heartily recommend that you include krill as part of the diets of your aquatic reptile and amphibian pets.

Frozen Foods for Large and Small Aquatic Salamanders

Amphiumas, mudpuppies and sirens will accept most of the aforementioned items, and newts of all types relish krill.

Beef heart was long used as a staple diet for laboratory colonies of Mexican axolotls and African clawed frogs, and countless generations were raised and bred on this food item alone.  Although I favor a more varied diet for these creatures, certainly frozen beef heart is a very useful food that should be offered regularly.

Click here to read the 2nd part of this article.



  1. avatar

    The more processed the food is the lower the nutritional value. Fresh is best. Remember to keep the reptile’s calcium needs in mind.

    Roger from All About Reptiles.

    • avatar

      Hello Roger, Frank Indiviglio here. Thanks for your interest in our blog.

      You raise an interesting point. The question of processed vs. fresh foods is quite complicated…much depends upon factors such as the food item and species in question, and the composition of the balance of the diet being offered.

      Some problems are well documented – while working with the nutrition department at the Bronx Zoo some years ago, I was involved in research which implicated diets consisting solely of frozen marine fish in Vitamin E absorption problems…this is typically seen in captive crocodilians and penguins, but is not a concern for most hobbyists.

      On the other hand, freeze-dried, frozen and canned invertebrates, vegetables, rodents and other food items retain most, and in some instances all, of their nutritional value. The importance of such products lies in their providing the opportunity to offer captives a far wider variety of food items than would be possible in most situations. This is especially true for insectivorous reptiles and amphibians (and fishes), which if limited to live food diets would in most collections be forced to subsist on a very limited number of prey species.

      Processed foods in the form of “complete” (or, more accurately, “nearly complete”) diets are, in many case, also of immense value to hobbyists and professional animal keepers alike. A great deal of research has gone into the preparation of balanced diet-type products for commercially valuable animals, and a good deal of this information has found its way into the pet trade. Extrapolating from the nutritional needs of a predatory, commercial-raised fish (i.e. trout) to an aquatic turtle or amphibian is a bit of a stretch, but in this case it has worked out well. Reptomin, in particular works well as a dietary staple for African clawed frogs and various newts, and, to a slightly lesser extent, for a number of turtle species.

      Similar spin-offs from the work of zoo nutritionists has resulted in nutritionally sound commercial diets for other pet trade reptiles and amphibians, as well as for birds, mammals, fishes and invertebrates. When I first started at the Bronx Zoo, we cooked our “softbill” diet from scratch, but now there are “complete” diets for animals ranging from hummingbirds to moose (literally!).

      As mentioned, there are of course a great many factors to be considered – animals eating commercial foods often consume a more balanced diet (as they cannot pick and choose favorites), but get all of their calories in a few minutes as opposed to foraging over time, for example. Also, the requirements of certain animals cannot yet be fully met by currently available processed diets – Mexican axolotls will thrive and breed for generations on a diet of 90-100% Reptomin or trout chow (or, for that matter, beef heart!), while commercial tortoise, turtle, monitor, bearded dragon and iguana diets should be regularly supplemented with fresh produce, insects, fish and rodents, as the case may be.

      Best regards, Frank Indiviglio.

  2. avatar

    Hello Frank,

    I’m currently rearing a group(est 17) of Pleurodeles waltl larvae in hopes of establishing a breeding colony of them and being able to offer them to a few pet stores etc. around here(perhaps it might convince them to bring in fewer paddletails and orientalis). Also think of putting together a group of Triturus karelinii(reared in the past, also seems relatively hardy/prolific).

    Currently larvae are taking chopped blackworms. This would be prohibitive if raising large numbers as far as expense goes. I’m thinking raising them in well matured tanks/pools and perhaps supplementing with daphnia. At what point do you think they could be switched to prepared foods and what would you reccomend? Salmon pellets/trout chow seem to get high marks from many breeders but I don’t know a local source for them.


    • avatar

      Hello Joseph, Frank Indiviglio here. Thanks for your comment.

      I’ve had success in raising ribbed newt (Pleurodeles waltl) larvae on a diet of blackworms and chopped earthworms until about the time when the rear legs appear, after which I began to offer Reptomin Food Sticks. However, ribbed newt larvae are more likely than others to accept non-living food, so you may be able to switch them earlier than I did. Once accepted, Reptomin can form the basis of the diet, with live invertebrates, guppies and minnows added from time to time. Daphnia are a fine supplement as well.

      Salamander larvae also usually accept Freeze Dried Gammarus and canned shrimp. Canned shrimp are especially useful, and result in rapid weight gains.

      Good luck, please keep me posted.

      Best regards, Frank Indiviglio.

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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