# How many flies at mealtime?



## Auhsoj27 (Jun 3, 2005)

How many flies are you guys dumping in the tank for each frog? Obviously this will differ depending on age/size of the frog, but I'm looking for some generalities.

10?
50?
100?

The way some people talk about feeding their frogs, I'd think they're covering the tank floor with flies! Right now I'm only putting in 10-15 two or three times a day per froglet. Should I be upping my numbers?


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## Ed (Sep 19, 2004)

There were some discussions on this in the past. 

Here is some of the pertinent details 

There are some calculations that can give you the minimal caloric needs of a frog. (ill or rapidly growing frogs can have a caloric need up to 8 times as much). Assuming we are speaking about a large froglet let us use the values for a 1 gram frog (from Amphibian Medicine and Captive Husbandry) (I am using a figure for 25 C as this will increase metabolic need even more) is 0.02 kcal/day. A gross energy value for fruitflies (including undigestiable parts (but we don't know the amount of chitin that is digested as in insectivores it can range as high as 85% and if this is determined at some point it can significantly reduce the amount to be fed) is 5.12 kcals/gram fruit flies (from Feeding captive insectivorous animals: nutritional aspects of insects as food; 1997, Publication of the AZA Nutrtional Adisory Group Handbook). 
If you work the math then a 1 gram frog at 25 C needs is 0.0039 grams of fruit flies a day to deal with the basic metabolic needs. 

I had a little extra time one day so I warmed up the Ohaus TS120 and let it acclimate and tared it. I then dumped enough fruit flies on it to get a usable weight (0.125 grams). I took these ffs and froze them, and then counted them. It took 166 ffs to make 0.125 grams. This comes out to be 7.53 E-4 grams per fly. Using the previous calculation from above we had come up with 0.0039 grams/ffs/day. 
A quick calculation results in 5.2 ffs per day to sustain basal metabolic rates at 25 C (77 F). So an actively growing 1 gram frog can require as many as 42 ffs a day but the number is likely anywhere from 1/2 to 2/3 this amount as I was estimating high (8 times SMR requirements) on maximal amount. When pouring ffs from a container it is pretty easy to pour two to three times as many ffs. As the frogs are hard wired to take advantage of this time of plenty (even though it occurs daily), it is easy to overfeed your frogs. 

Ed


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## Blort (Feb 5, 2005)

Ed,

Great information. Just for a ballpark, can you give a size or species estimate of a frog that would weigh 1 gram. Also, I assume that you are talking about winged, but flightless melanogaster. Is that correct?

Thanks,

Marcos

PS. If this isn't in the food FAQ, it might be worth adding


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## JoshKaptur (Feb 17, 2004)

Thanks for the headache Ed :lol: 

My even more scientific approach, shared by many, is to dump a bunch in, and if there are no flies next time I feed, to dump more in. If there are lots of flies next time, I dump less. If there are just one or two flies (blow into the tank and they will move around so you can see them) then I know I'm feeding just about right.


Josh


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## Ed (Sep 19, 2004)

Hi Josh,

Your method works well too. The point to remember if you try to feed out an exact number of flies, this is difficult as the enclosures we typically use are complex and usually not 100% ff escape proof (or the flies move into a region where the frogs can't access them). I personally use a combination of the two. If I am observing a frog to see how well it is doing, I will count the tongue flicks and captured prey as this gives an idea of how well the frog is doing. (For example if there are a lot of tongue flicks without capturing prey then the frog's diet should be examined as it may (and I stress may) be insufficient in something say such as vitamin A and have short tongue syndrome). This way I can check to insure that they are getting the minimal metabolic requirements but try and keep them from getting grossly obese...

Marcos,

My scales are down and until they are repaired (and I have some froglets again) its hard for me to give you a good estimate but if I remember correctly an adult female tinct (like a patricia) would not uncommonly weigh between 5 and 7 grams. 
Newly metamorphed golden mantellas (Mantella aurantiaca) can be as small as 0.19 grams... 

Ed


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## melissa68 (Feb 16, 2004)

Awesome information Ed.


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## Skibadee (Mar 22, 2007)

http://www.doylesdartden.com/fruitfly.html
this link gives you a suggestion on feeding near the bottom of the page


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## Curt61 (Jan 16, 2007)

Hey, I just toss flies in, mine arn't fat and they arn't skinny so I can't be messing up to bad. (I tried counting how many I put in and it is a pain)



Just my 2 cents, Curt.


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