Toad Tadpole Life Cycle
Off to a New Start: When we left off on our toad tadpole trek, all the likely ponds were under an extra 14 feet of water. We couldn't get close. In fact, when the water dropped enough to approach the ponds on the previous page, the police kicked me out of the area. In fact, they questioned my ability to read. "What do you think those barriers said?" They asked. Well, to make a long story short, I left.
Help from a Swimming Pool: One of our customers brought in 200 of these little rascals. They came from her swimming pool. She said they creeped her out. If she'd just use the pool at night and leave the lights off, these little guys are totally harmless. (Be sure to wear a swimming cap.)
Look Crowded? You can put 200 tadpoles in a 10-gallon tank, but you really crowd them. We do 90% water changes every other day. Plus, we spread them out in several tanks.
Not sure what these little creepers are. They remind me of
hellgrammites, but I've never seen a little one before. They have
what looks like juice extractors on their snouts. Hellgrammite or
not, they do look like predators.
Brad, Ames, IA, May 18, 2012
A: Thanks for the info. I've never run across dragonfly
nymphs that young. I'm adding your info to my TT II page.
Jeff, Canada, May 21, 2012
*Note: I will be attaching pictures I find online to illustrate my points; however, since these aren’t my photos, I would ask that you refrain from posting them on your website.
First up, let me make a point to say that this site is one of my valued resources that I use to research pet keeping, and I regularly check back for updates. My compliments to your work.
However, I did notice a particular reply to your most recent page, the toad tadpole page, and one person’s unfortunately misgiving answer to your question: “Hellgrammites?” Brad told you they were dragonfly nymphs; they are not dragonfly nymphs. Dragonfly nymphs, as all other members of Odonata, do not undergo complete metamorphosis; however, their larval forms are both similar and dissimilar to their adult forms. A dragonfly nymph has three distinct body parts that all insects share; they have a flat, wide abdomen, internal gills, and, most characteristically, a “mask”, an extension of the jaw that operates by shooting out extremely quickly – something of an example of convergent evolution between the dragonfly and chameleon. So, the larvae in your photos are not dragonfly larvae. But what are they? I’ll run through some of the members of the aquatic larvae club.
Damselfly nymphs are slender, with a wide head; however, their features look similar to the dragonfly nymph (they are, after all, closely related). They are distinguished by the two external gills that extend from the end of their abdomen. Clearly, then, what you have is not a damselfly nymph.
This also immediately rules out mayflies, which have three gill filaments, as well as bristles along their sides.
Caddisflies, as you may well know, are casebearers; they construct casings of sediments/prey carcasses/debris, held together with that unique invertebrate substance, silk.
Dobsonfly nymphs, “hellgrammites”, are far more similar to what you have; however, that is not a hellgrammite. Hellgrammites have shorter mandibles than the creature you have; more importantly, each of their flanks present a row of filaments, which are entirely absent from your larva.
True bugs are completely out of the question; the prominent mandibles rule out the entire family of Hemiptera, which do not possess mandibles.
This leaves just one family uncovered: the Coleopterans, the beetles. So, is that a diving beetle larvae? Not quite; diving beetle grub, or water tigers, have a much wider, and square-shaped, head, as well as a more cylindrical body shape.
So what is it? After some searching, I am convinced that what you have is, in fact, the grub of a water scavenger beetle, belonging to the family Hydrophilidae. As you’ll see from the photos, they are nearly identical.
I would also like to point out one other mistake in Brad’s information: dragonflies, and damselflies, are predatory in both the larval and adult stages. In fact, adult dragonflies are one of the most important insect predators around streams. I think Brad may have confused it with Mayflies, which have generally too short an adult stage to require feeding.
A: Thanks for the addendum, Jeff. I'll add it to my
newest toad tadpole page. LA
Last Words. Adult toads make excellent, easy-to-care-for pets. Baby toads not so much. LA
Other Tadpole Info --
3600 Sixth Avenue
Corner of Sixth & Euclid Avenues
Des Moines, IA 50313