Tadpoles eating habits?

Question

Our family took a trip to a local berry farm a couple of months ago and while walking through the back roads we found a puddle in the dirt road that was filled with tad poles. My daughter spent a while watching them and really enjoyed watching them scurry and float along. When I was her age I spent hours outside watching the tadpoles in the creek that split my parents land. Young people learn a lot about life when they watch and care for it. We captured eight of them and brought them home. I have a few questions about them and one I really haven't found an answer for... We now have six tad poles and no bodies to be found. We have one little guy who is growing like crazy and is at least 2 times bigger than the 2nd biggest guy. I WAS just feeding them grass and though they ate it and loved it I switched them to basic gold fish food so that they can all eat and get the nutrients they need. We still have 2 of them that are still too little and don't seem to have grown at all in the past 2 months. Here are my questions

Is the big guy picking off the smaller ones?

Will switching to a fish food help?

Will we need to take out the big one or what?

How do we find out what kind of frog they will be?

For those of you who are just going to write about the frog population being reduced globally, please read this. My family is moving across the country soon and keeping the tadpoles/ baby frogs would be crazy... so this is just for educational reasons. Around halloween we are going back to the same farm to pick our pumpkins and we will take them with us and release them where we can around where we found them. Please do not respond if you are looking for a place to jump on your soapbox. It isn't nesessary here. Thank you.

Answer 1

No soapbox here.  I'm glad to know you care about the little guys.

Sounds like you're having fun.  I did the same thing when I was young.

Make sure they're in an adequately sized aquarium that's filtered and aerated.  

The best thing to feed them is "Algae" flake food.  Your better pet stores should have this.  It is the healthiest food to give them since it is exactly what they'd be eating in the wild.  Another good food is Rabbit Pellets, but be careful not to feed too much 'cause it can fowl the water.  And, this is in addition to the Algae.  

The big one will NOT hurt the little ones.  You just may have two different species there.  At this stage it is almost impossible for me to tell you what species they are.  It's most exciting to wait and see as they become adults.  

Since you found them in a puddle, they could be Toads or Frogs.  Possibly Tree Frogs.  Some species of tadpoles can get very large, the main body being the size of a quarter, while others are very small with a body size smaller than a split pea.

If you have any further questions, do not hesitate to email me.

Answer 2

They normally feed mostly on algae. An easy to use feed in captivity is frozen spinach. Just scrape some off the block.

As far as identification, the easiest book to get is by Conant and Collins, in the Peterson series of field guides. Reptiles and Amphibians [of] Eastern/Central North America. Be sure to get the third edition. The first two, by Conant alone, don't have anything on tadpole ID.  The guide is not complete. You might have to go to Wright and Wright's Handbook of Frogs and Toads but your local bookstore would not be likely to have it.

Answer 3

I am not an expert on amphibians or tadpoles, but I do recall reading that tadpoles can be cannabilistic feeders. So I did a little searching and found the link below. It states that tadpoles typically do not become cannabilistic unless their water holes are drying out. So it sounds as if you should be okay keeping your big tadpole with the smaller ones. Perhaps that tadpole is a different species from the others or from an older batch of eggs.

I have no idea what the best food for tadpoles is but they are omnivores so feeding them a mixed diet of animal and plant matter sounds like a good strategy. The second link is to a care sheet for tadpoles.