Macroinvertebrates: Tiny Creatures that Make Ponds Amazing

Think about the kind of creatures you might find living in a pond….

Some easy ones come to mind right away: fish, frogs, turtles, and maybe some waterfowl like geese or ducks! However, there’s a whole world of teeny tiny animals teeming just below the water’s surface, animals that might have gone their whole lives without being seen by a person. Let’s explore some of these tiny wonders! 

I have some specimens that I found while exploring one of our ponds at Sunset Hill Farm. At Sunset Hill Farm we have multiple water sources that can provide great ways to monitor some of these small animals and see them up close. Many of the creatures we find are called macroinvertebrates, which means they don’t have a spine and are small but can still be seen with the naked eye. Periodically we like to go and check out what kind of creatures we have living in our ponds. Some species can tell us a lot about the health of our pond. All of the creatures below were caught (and later released) at Sunset Hill Farm.

Dragonfly Nymph

The first creepy crawly I’d like to share with you is a Dragonfly Nymph. You know the dragonflies that you see flying around near ponds and marshes? Well, this little guy is a baby dragonfly. Did you know that dragonflies actually spend the first part of their lives as nymphs, living completely underwater? Dragonfly nymphs can be as small as your pinky nail and can grow as large as your thumb before they are ready to shed their skin and come above water as the cool adults we all know and love. Dragonfly nymphs are excellent hunters, just like their parents! They have an amazing hinged jaw with two spears on it that they use to hunt minnows and tadpoles, their main source of food. They lie in wait at the bottom of the pond for a minnow to swim above them, then they flip out their spear-jaw and stab them in the belly, catching them for lunch.  However, dragonfly nymphs are not harmful to humans and will often crawl all over your hand after you catch one. 

Water Tiger

The next super cool creature I want to introduce you to is the Water Tiger. While the Water Tiger may look big and scary, it is also the baby stage of an even bigger bug--a Predaceous Water Beetle. This little guy is one of the big bad predators living in the pond. If you look carefully, you can see the massive pincers on the front of its head; this is how it catches its prey, and it might even bite you if you bother it! Their usual prey is tadpoles, but they will go after any other kind of pond creature that they think they can catch. Water Tigers will sit perfectly still near some water plants and wait for prey to pass by. Then… they strike!

Freshwater Snail

One of our most abundant water creatures living in the pond is the Freshwater Snail. We have many different types of snails and mollusks living in our pond at Sunset Hill Farm. The snail pictured here has a conical, pointed shell while others that you might find have sort of a spherical (or cinnamon-roll) style shell. Snails are not only adorable, they are important players in the ecosystem of a pond. Snails are detritivores, which means they take up the role of garbage disposal! They eat algae and other decaying plant matter and turn it into energy, helping to break down unwanted plant matter. Many snails are also filter feeders, meaning they strain material from the water and consume it. This helps to clarify the water and rid it of unwanted particles. Next time you see a clean beautiful pond, thank a snail! 

Tadpole

Can anyone guess what this super slimy creature is? If you guessed a Tadpole, you are correct! A tadpole is a baby frog, but it sure doesn’t look anything like an adult frog. Tadpoles look more like a fish; with their strong powerful tails. They even breathe through gills found on the sides of their bodies. Tadpoles can be many different sizes depending on what type of frog they will later transform into. The one pictured is probably a baby bull-frog, one of the biggest frogs in our area. I held it briefly in my hand so you could see just how large it is (however, tadpoles should not be taken out of water very long—they need water to be able to breathe!).

Leaf with hundreds of frog eggs (the jelly-blob)

Tadpoles mostly eat plants, but they are the favorite foods of many pond-dwelling creatures such as fish, turtles, herons, dragonfly nymphs and water tigers! Because tadpoles are such a yummy snack, a mama frog has to lay thousands and thousands of eggs to make sure that some of her young will survive to adulthood. In the picture, you can see a small jelly-blob on the leaf. That blob contains hundreds of frog eggs! However, tadpoles are great at hiding, their bodies are a dark grey color to help them blend into the mud at the bottom of the pond and their strong tails also help them make a speedy getaway! 

Pretty cool, right? These are just a few of the hundreds of tiny creatures living just beneath the water’s surface. Next time you visit a pond, make sure you pay attention to the obvious creatures like turtles and birds and frogs. But, also think about the amazing world just beneath the surface and all of the interesting creatures that call it home!