Bug-eyed & Brilliant: Meet the Tiny Water Creatures of Coyote Creek

If you ever find yourself wandering near Malaguerra Avenue in Morgan Hill, pause for a moment and look beyond the trail—because tucked along this stretch of Coyote Creek is an entire world teeming with miniature life. Our group gathered near the Coyote Creek Visitor Center, trays in hand and curiosity piqued, ready to explore what the water had to reveal. These trays are a standard part of biomonitoring, helping us safely examine aquatic organisms without disturbing their natural habitat too much.

First Sightings

At first glance, the water may look still, maybe even empty—but give it a second glance. Beneath the surface, among the pebbles and leaf litter, live the unsung guardians of our watershed: aquatic macroinvertebrates. These tiny, spineless creatures might be small, but they play a huge role in telling us how healthy our creek really is. Scientists and conservationists use their presence or absence as “bioindicators”—living clues that reflect the condition of the surrounding environment.

Water boatman swimming

The first dip of the net was all it took to be transported into a different world. Just beneath the clear water, a Water Boatman (Family: Corixidae) kicked through the tray like a champion swimmer. Small, oval-shaped, and built for speed, these insects use their long hind legs like oars. They can even trap air under their bellies, acting like little scuba tanks as they dive! They are excellent examples of adaptation, using surface tension and specialized limbs to thrive in both still and moving water.

Nearby, a much larger creature lurked—the Dragonfly Larva (Suborder: Anisoptera). With its bulky frame and impressive mandibles, this aquatic predator is a silent assassin. Long before it ever takes flight,

Dragonfly larva

the dragonfly begins its life underwater, hunting smaller invertebrates with lightning-fast precision. Dragonfly larvae use a unique extendable jaw to snatch prey—a trait that makes them both fascinating and formidable.

In the same tray, we spotted Mayfly Larvae (Order: Ephemeroptera)—delicate and almost feathery, with their signature three “tails” trailing behind. These little guys are one of the best signs that the creek is healthy, since they’re super sensitive to pollution. They also serve as a crucial food source for fish, birds, and other predators. The presence of mayflies often signals clean, oxygen-rich water, making them a top-tier indicator species in water quality assessments.

Mayfly larvae

In another corner of the tray, we discovered a slender, almost alien-like Damselfly Larva (Suborder: Zygoptera). Unlike their bulkier dragonfly cousins, damselfly larvae have thinner bodies and three delicate gill "plumes" fanning out from the end of their tails. These feathery appendages not only help them breathe but also give them an otherworldly elegance as they move. Though graceful, they're no less fierce—damselfly larvae are skilled ambush predators, lying in wait to snap up unsuspecting prey with their extendable jaws.

Damselfly larva

There's More

But not everything we found was cause for celebration. Nestled among the native species were two invasive troublemakers: the Asian clam and the New Zealand mud snail (Potamopyrgus antipodarum). Both are incredibly small, but their impact is anything but. Once introduced—often unknowingly, by the soles of boots or tire treads—they multiply rapidly and outcompete native species for food and space. The mud snail, for example, reproduces through cloning and can form dense colonies that choke out entire streambeds. Because native predators rarely eat them, their populations can grow unchecked, throwing local food webs out of balance. They're a reminder that even something tiny can disrupt a delicate balance if it doesn’t belong.

←Asian Clams

New Zealand Mud Snail→

Even beyond the trays, the water’s edge buzzed with life. We saw ripple bugs (Family: Gerridae) clustering and gliding across the surface like synchronized swimmers, creating mesmerizing little circles that danced in the sun. These bugs, also known as water striders, can “walk” on water thanks to tiny hairs on their legs that repel water and distribute their weight evenly. At one point, I spotted honey bees pausing for a drink along the shallow shoreline—just a quick hydration break before heading back to their hives. And under a flat rock, we discovered an isopod (Family: Asellidae)—a cousin of the terrestrial rolly-polly, doing its part to recycle decaying matter in the aquatic environment. Every movement, every shimmer in the water, felt like another clue in the story of this ecosystem.

Honey Bee

What made this experience unforgettable wasn’t just the variety of species—it was how deeply interconnected everything was. These water creatures aren’t just background characters. They are vital. They feed the birds, fertilize the plants, cycle nutrients, and tell us if our creek is thriving or in trouble. Many of these organisms only survive in specific conditions, so their disappearance could be an early warning sign of environmental stress—like a “canary in the coal mine” for aquatic ecosystems. Watching a dragonfly larva crouch silently at the edge of a tray while a scud scurried past was like seeing a real-life nature documentary play out in miniature.

It’s easy to walk past a stream and never think twice about what’s beneath the surface. But if you take the time to look closer—really closer—you’ll find that these bugs and larvae, these snails and swimmers, are just as important as the biggest animals or tallest trees. They are quiet builders of balance, and they deserve to be seen.