Nutritional Values of Amphibian Foods

by Jennifer Macke

What are the most nutritious foods for carnivorous amphibians in captivity? The following are considered important factors:

Protein . A good staple diet should be relatively high in protein.

. A good staple diet should be relatively high in protein. Fat . Some fat is needed in the diet. As in human diets, some fats are better than others.

. Some fat is needed in the diet. As in human diets, some fats are better than others. Calcium . When considering the calcium content of a food, pay particular attention to the calcium-to-phosphorous ratio; the availability of the calcium is affected by phosphorous. Ideally, the Ca:Phos ratio should be >1. Foods that have a lower ratio should be gutloaded, supplemented, or balanced with other foods.

. When considering the calcium content of a food, pay particular attention to the calcium-to-phosphorous ratio; the availability of the calcium is affected by phosphorous. Ideally, the Ca:Phos ratio should be >1. Foods that have a lower ratio should be gutloaded, supplemented, or balanced with other foods. Vitamin D3 . Vitamin D3 is required for the absorption of calcium. Live foods generally contain some vitamin D3, and it is included in most calcium supplements. There have been reports that some commercial supplements may contain an excessive amount of vitamin D3, so do your homework about the brand you are buying. Vitamin D3 can be obtained through exposure to UV light, but most amphibians do not require UV.

. Vitamin D3 is required for the absorption of calcium. Live foods generally contain some vitamin D3, and it is included in most calcium supplements. There have been reports that some commercial supplements may contain an excessive amount of vitamin D3, so do your homework about the brand you are buying. Vitamin D3 can be obtained through exposure to UV light, but most amphibians do not require UV. Vitamin A . Like mammals, amphibians are unable synthesize vitamin A and must obtain it from their diet. It is present in most live foods. It is required for proper development and physiology, but excessive amounts are very toxic.

. Like mammals, amphibians are unable synthesize vitamin A and must obtain it from their diet. It is present in most live foods. It is required for proper development and physiology, but excessive amounts are very toxic. Carotenoids . Carotenoids are forms of vitamin A, but amphibians are not necessarily able to interconvert among the chemical forms. Carotenoids are necessary for the formation of some orange and red skin pigments.

. Carotenoids are forms of vitamin A, but amphibians are not necessarily able to interconvert among the chemical forms. Carotenoids are necessary for the formation of some orange and red skin pigments. Energy (calories). All foods listed below have a caloric content in the range of 4 - 7 kcal/g of dry weight. The exact amount is not generally critical. Foods higher in fat generally contain more calories per gram.

The table below shows the nutritional values of foods that are commonly used.

Food Protein

(% dry wt) Fat

(% dry wt) Calcium

(% dry wt) Phosphorous

(% dry wt) Ca:Phos

Ratio Ref. Blackworms 47.8 20.1 0.11 0.85 0.12 1 Bloodworms 52.8 9.7 0.38 0.90 0.42 1 Crickets, adult 64.9 13.8 0.14 0.99 0.14 1 Crickets, pinheada NA NA 1.29 0.79 1.63 2 Cockroach, American 53.9 28.4 0.20 0.50 0.40 1 Earthworms 62.2 17.7 1.72 0.90 1.91 1 Nightcrawlers 60.7 4.4 1.52 0.96 1.58 1 Fruit flies 63.9 19.5 0.10 1.05 0.09 1 Fruit fly larvae 40.3 29.4 0.59 2.30 0.25 1 Maggots 56.8 20.0 0.41 1.13 0.36 1 Mealworms 52.7 32.8 0.11 0.77 0.14 1 Mosquito larvae 42.2 16.1 0.79 1.07 0.73 1 Tubifex worms 46.1 15.1 0.19 0.73 0.26 1 Daphnia 55.2 6.6 0.10 1.17 0.08 1 Waxworms 42.4 46.4 0.11 0.62 0.17 1 Phoenix wormsb 45.3 32.4 2.33 1.53 1.52 5 Leeches 85.3 4.3 0.16 0.94 0.17 7 Rangen soft moist salmon pellets 44 18 NA NA NA 3 Shrimp, raw 83.3 8.3 0.22 0.85 0.26 4 Squid, raw 84.2 5.3 0.47 2.03 0.23 4 Salmon, raw 63.5 34.2 0.039 0.75 0.05 4 Codfish, raw 93.4 4.56 0.084 1.07 0.08 4 Anchovy, raw, wholec 74.0 18.5 0.544 0.644 0.84 4 Beef heart, raw 76.9 20.0 0.030 0.92 0.03 4 Beef liver, rawd 69.0 13.8 0.017 1.33 0.01 4 Beef sirloin, raw 79.4 16.1 0.081 0.756 0.11 4 Chicken breast, raw 92.0 4.0 0.044 0.784 0.06 4 Chicken, whole 1-day-old 64.9 22.4 1.69 1.22 1.39 4 Mouse, pinkiee 64.2 17.0 1.17 NA NA 6 Mouse, whole adulte 55.8 23.6 2.98 1.72 1.73 6 Frog, Green 71.2 10.2 4.80 1.87 2.29 6 Toad, Southern 61.0 14.0 2.94 1.79 1.64 6 Quail, whole 71.5 31.9 3.43 NA NA 6

Footnotes

NA: Data not available.

aFor pinhead crickets, the calcium and phosphorous values shown are from Reference 2. Note that Reference 1 reported values for pinheads being similar to those of adult crickets. We know of no explanation for the large discrepancy in the Ca:Phos ratio reported by the two different studies.

bPhoenix worms are larvae of the soldier fly, Hemetia illucens.

cAnchovies are not a commonly-used food for amphibians, but are used in some commercial fish foods. Anchovies are included in this table as an example of a fish that has been analyzed whole (bones included). Note that calcium content is much higher for whole fish than for fish filets. Other whole fish are likely to be similar.

dLiver is no longer recommended as a food for amphibians, as it contains excessively high levels of vitamin A, which can interfere with absorption of vitamin D and, hence, calcium. Other varieties of liver, such as chicken liver, have nearly identical levels of nutrients, vitamins, and minerals to those given for beef liver.

eValues for rat are very similar to values for mouse.

References

Additional information on amphibian foods and nutrition

CC article: Foods for Captive Caudates

CC article: Microfoods for Caudate Larvae

CC article: Worms: The Ideal Food for Caudates

Amphibian Ark: Husbandry Documents

Caudata.org article: Daphnia: An Aquarist's Guide

Melissa Kaplan: Nutrients of Foods Commonly Fed to Carnivorous and Omnivorous Reptiles

Browne RK. 2009. AArk Science and Research. Amphibian diet and nutrition (PDF)

Browne RK, et al. 2009. AArk Science and Research. UV-B, Vitamin D3, and amphibian health and behaviour (PDF)

McWilliams, 2008. Nutrition Recommendations for some Captive Amphibian Species (Anura and Caudata) (PDF)

Oonincx, DGAB and Dierenfeld, ES. 2011. An Investigation Into the Chemical Composition of Alternative Invertebrate Prey (PDF)

IACUC Learning Module Xenopus Nutrition

© 2007 Caudata Culture

Updated July 2013, Jennifer Macke.