Water Boatmen: All You Need to Know – Discover These Fascinating Aquatic Insects

Water boatmen are fascinating aquatic insects that glide effortlessly through freshwater habitats, using their specialized legs as oars. You may have encountered these intriguing creatures near ponds, lakes, or slow-moving streams and wondered what they were. In this article, we’ll dive right into the world of water boatmen to give you all the information you need to better understand these unique insects.

You’ll be amazed by their intriguing biology and how they contribute to the ecosystem. Despite their small size, water boatmen play a crucial role in their aquatic environments. As you learn more, you’ll appreciate the balance that exists in nature and discover the importance of maintaining healthy ecosystems.

As we begin your journey into the world of water boatmen, we’ll explore their key characteristics, habitats, and role in the food chain. Understanding these aspects will not only help you identify them when you come across them, but also widen your knowledge about how different organisms work together in a dynamic environment. So, let’s dive in and get to know these amazing insects!

Identification of Water Boatmen

You might be curious about water boatmen and how to identify them. These fascinating insects belong to the family Corixidae and are a part of the order Heteroptera. Here are some pointers to recognize them easily:

Water boatmen have a distinctive appearance. Their bodies are slender, oval, and streamlined, which helps them swim efficiently in the water. You can tell they are water boatmen by their long, oar-like hind legs covered in fine hairs. These specialized legs not only allow them to swim but also help them cling to surfaces underwater.

When it comes to coloration, water boatmen generally have a brown or grayish hue with dark, parallel crosslines on their flattened backs, which can sometimes be mistaken for backswimmers. However, water boatmen are usually flatter and have a different feeding behavior compared to backswimmers.

Here are some key characteristics of water boatmen in bullet points:

  • Slender, elongated body
  • Oar-like hind legs with fine hairs
  • Brown or grayish hue
  • Dark, parallel crosslines on their flattened backs

When considering the size of these insects, water boatmen are relatively small. The lesser water boatman is a common species of this insect, and its adult size varies depending on the particular species within the Corixidae family.

In conclusion, identifying water boatmen involves observing their appearance, coloration, size, and characteristics that set them apart from other aquatic insects. With this information, you’re now better equipped to recognize these intriguing creatures on your next outdoor adventure.

Natural Habitat of Water Boatmen

Water boatmen are fascinating insects that live in various aquatic habitats. You can find them in freshwater environments like ponds, streams, and lakes. These intriguing creatures can also thrive in stagnant water, such as backyard swimming pools.

Not only do water boatmen inhabit freshwater areas, but they can also adapt to brackish water and even some saltwater zones. This versatility enables them to survive in diverse locales, from the high-altitude Himalayas to North America’s Death Valley.

When searching for water boatmen, keep an eye out for their distinct characteristics:

  • Slender, oval, and streamlined bodies
  • Long, oarlike hind legs with fine hairs
  • Flattened back with narrow, dark crosslines

In addition to these features, remember that water boatmen are herbivores primarily consuming plant microorganisms and algae. They play an essential role in the ecosystem by helping maintain the balance of microorganisms and serving as a food source for birds, fish, and other aquatic creatures.

To sum it up, water boatmen are versatile insects that inhabit a wide range of aquatic habitats, from freshwater environments like ponds and streams to stagnant pools and even some brackish or saltwater locations. So next time you spot one of these interesting critters near your home or while exploring nature, take a moment to appreciate their adaptability and role in the ecosystem.

Physical Attributes of Water Boatmen

Water boatmen are fascinating aquatic insects with unique physical attributes that help them navigate their underwater environment.

Morphology: Their elongated bodies have a flattened appearance, which aids them in swimming efficiently. You’ll notice that they come in various sizes, ranging from 3 to 12 millimeters in length. These insects have a dark color, often appearing brown or black, which provides camouflage in their natural habitat.

Front legs: Water boatmen have two pairs of short front legs. Their primary purpose is to help the insect crawl on submerged surfaces and grasp onto food, making them crucial for their survival.

Hind legs: One of the most remarkable features of water boatmen is their long, oar-like hind legs. These legs, covered in tiny hairs, are adapted for swimming and act like paddles. They enable the water boatmen to move swiftly through the water and make quick turns, ultimately improving their agility in their aquatic surroundings.

Mouthparts: You might be curious about how water boatmen eat and drink. They have needle-like mouthparts known as stylets, which they use to pierce plants and suck fluids. This adaptation allows them to nourish themselves without having to surface in search of food.

Air bubble: Another interesting attribute is their ability to carry an air bubble under their abdomens, making these insects capable of breathing underwater. The air bubble acts like an oxygen tank, allowing them to stay submerged for extended periods and easily move around in their underwater domain.

By understanding the physical attributes of water boatmen, you can better appreciate their adaptability and remarkable features that make them exceptional in their watery environment.

Water Boatmen’s Life Cycle

Water boatmen are fascinating aquatic insects that play a significant role in freshwater ecosystems. In this section, we will discuss their intriguing life cycle.

When it comes to reproduction, adult water boatmen lay their eggs on submerged plants or other objects found beneath the water surface. After a short period, usually a few weeks, the eggs hatch into nymphs.

The life cycle of water boatmen consists of several stages. The nymphs undergo incomplete metamorphosis, where they transition through multiple instar stages before reaching adulthood. The nymphal stages resemble the adult form but are smaller and lack wings. In their development process, nymphs shed their exoskeletons multiple times to accommodate their growing bodies.

As nymphs grow and develop, they progressively transform into adults. The entire life cycle typically takes a few months to complete, depending on factors such as temperature and food availability. During the warmer months, you may witness water boatmen actively swimming and feeding in various aquatic habitats, contributing to the overall health and balance of the ecosystem.

Some key features of water boatmen include:

  • Incomplete metamorphosis, transitioning from nymphs to adults
  • Hatching from eggs laid under the water surface
  • Developing through multiple instar stages
  • Active during warmer months
  • Important role in aquatic ecosystems

So, the next time you come across these fascinating creatures, you’ll have a better understanding of their incredible life cycle and the important role they play in maintaining the health of freshwater ecosystems.

Diet and Feeding Habits

Water boatmen are known for their diverse diet that mainly includes:

  • Algae
  • Vegetation
  • Detritus
  • Organic matter
  • Mosquito larvae
  • Protozoa
  • Worms

These insects have a unique way of feeding. They use their strong front legs to grasp onto their food sources, such as algae and vegetation. Their mouthparts, called stylets, are adapted to pierce and suck the nutrients from their meal.

For example, when consuming mosquito larvae, they inject digestive enzymes into their prey to liquefy the internal tissues and then suck out the resulting nutrient-rich soup.

One of the benefits of their diet is that water boatmen help control mosquito populations by preying on their larvae. This can be especially useful in areas where mosquitoes are a nuisance or carry diseases.

In addition to their natural feeding behavior, water boatmen may also occasionally consume dead insects and other organic matter. This makes them detritivores, meaning they help clean the aquatic environment by consuming decomposing materials.

Here’s a simple comparison table of their primary and secondary food sources:

Primary Food Sources Secondary Food Sources
Algae Dead insects
Vegetation Decomposing organic matter
Mosquito larvae

In conclusion, water boatmen play a vital role in the ecosystem by controlling the population of certain pests, such as mosquitoes, and contributing to the decomposition process in aquatic environments.

Behavioral Characteristics

Water boatmen are fascinating little insects with unique behaviors that set them apart from other aquatic bugs. In this section, we’ll explore their swimming, flying, and stridulation abilities, as well as their mating season habits.

Swimming and Flying

Water boatmen are known for their remarkable swimming skills. They use their long, oarlike hind legs, which are covered in fine hairs, to propel themselves through the water. While swimming, these insects usually keep their heads pointing downwards as they search for food at the bottom source. But did you know that water boatmen can also fly? When they want to relocate, they are fully capable of taking to the air, making them quite versatile creatures.

Stridulation: Chirping and Squeaking Sounds

These water bugs are also famous for their unique communication method called stridulation. Water boatmen create chirping or squeaking sounds by rubbing parts of their body together. This behavior is not only fascinating but also serves a purpose in attracting mates or helping them stay connected in their aquatic environment.

Mating Season Behavior

During the mating season, water boatmen display some interesting behaviors. The males produce distinct chirping sounds to attract females, which they achieve by rubbing their front legs against their heads source. Once a female has been attracted, the pair engages in mating, with the male clasping onto the female’s back. After mating, the female goes on to lay her eggs on submerged vegetation and aquatic materials.

In conclusion, water boatmen exhibit unique behavioral characteristics that make them intriguing aquatic insects. From their swimming and flying abilities to their peculiar sound-making and mating behaviors, these tiny creatures are both fascinating and important members of aquatic ecosystems.

Water Boatmen in the Ecosystem

Water boatmen are fascinating aquatic invertebrates that play an essential role in the ecosystem. They are typically found in freshwater habitats such as ponds, lakes, and streams. Here’s how they fit into the ecosystem:

Water Boatmen and Plants

These bugs primarily feed on aquatic plants and algae, using their specially adapted mouthparts. They don’t pierce or suck the plant matter, but consume it whole. This makes water boatmen crucial in controlling the growth of aquatic plants and maintaining the balance in the ecosystem.

Interactions with Fish and Invertebrates

Water boatmen can serve as prey for fish, especially when other food sources are scarce. They also coexist with other aquatic invertebrates, such as backswimmers. However, backswimmers are predators, and their diets are more diverse than water boatmen, often feeding on small fish fry and tadpoles.

Predators and Natural Threats

While water boatmen have natural predators like fish, aquatic birds, amphibians, and some predatory insects, they can thrive in various environments. They use their oar-shaped hind legs to swim away from predators, making them elusive and versatile in navigating their surroundings.

In conclusion, water boatmen are an essential part of the ecosystem, interacting with aquatic plants, fish, and other invertebrates. Their roles as herbivores and prey contribute to a balanced aquatic environment. So next time you encounter one of these fascinating bugs, remember the incredible role they play beneath the water’s surface.

Important Considerations


Water Boatmen, also known as corixids, are not considered poisonous or dangerous to humans. They feed mainly on algae and other small aquatic organisms.


These insects have unique adaptations to help them survive in water. For instance, they use a thin, silvery air bubble trapped against their body to function like a “diving bell” for breathing underwater. They swim using their oar-like hind legs covered with fine hairs as paddles.

Water Quality and Pool Chemistry

Now, let’s talk about water quality. Maintaining good water quality is essential for both humans and aquatic life, including Water Boatmen. In natural bodies of water, proper oxygen and carbon dioxide levels should be maintained to ensure a healthy environment for these insects and other creatures.

For pool chemistry, maintaining balanced levels of chemicals, such as chlorine and pH, plays a crucial role in keeping water safe for swimming and preventing the growth of unwanted aquatic life, like Water Boatmen.

Addressing Concerns

In case you encounter Water Boatmen in a swimming pool or other water feature, you can:

  • Maintain proper pool chemistry: Keep your pool clean and well-balanced by monitoring the pH, sanitizer, and alkalinity levels.
  • Use pool nets: A pool net can help you remove any Water Boatmen from the water surface. Remember, it’s easier to remove them when they are swimming near the top.

In conclusion, understanding Water Boatmen and their behavior, as well as maintaining good water quality and pool chemistry, are important considerations for ensuring a safe and enjoyable aquatic environment.

Water Boatmen and Humans

Water boatmen are unique bugs that play a special role in freshwater ecosystems. They are slender, oval, and streamlined, allowing them to swim efficiently with their long, oarlike hind legs.

These insects are not harmful to humans and can even make for interesting sightings in your local pond or stream. In fact, fly-fishers might find them particularly fascinating because they help add diversity to the overall insect population. This, in turn, attracts more fish to the area, improving the experience for fly-fishers.

Water boatmen feed on algae and decaying organic matter. They can help maintain the overall health of a water body by keeping the nutrient levels in check. In addition to this, they serve as a food source for various predatory animals, such as fish and amphibians. This makes them an important part of the food chain in aquatic ecosystems.

To summarize:

  • Water boatmen are unique and fascinating insects found in freshwater environments.
  • They are not harmful to humans and can help improve the fly-fishing experience.
  • They play a vital role in the ecosystem, both as scavengers and prey for other animals.

Remember, when you’re near a body of freshwater, keep an eye out for these intriguing bugs and appreciate their role in maintaining our natural environments.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Backswimmer from The Netherlands


facinating instead of creepy bug
Sat, Apr 11, 2009 at 3:25 AM
Hey Bugman,
today I was in my garden, enjoying the first spring sun. When I walked near our pond, I came across this creature of wich I send the photo’s. When I tried to grab it, he kept falling on his back..but got up immidiatly with his 2 long legs. Was pretty cool to see, after like the 5th time he fell on his back, he just flew away.. I’ve never seen a bug like this, but I hope you can help me identify it.
Greetingz Joël ps. excuse my bad English, I’m a Dutchguy.
The Netherlands Budel-Schoot, near water.

Water Boatman

Dear Joël the Dutchguy,
Your fascinating insect is a Water Boatman in the family Notonectidae  The reason it was rather clumsy on land is that it is an aquatic insect that also flies quite well in the event its water habitat dries up or becomes otherwise unlivable.  Water Boatman swim up-side-down, with their bellies up.  The long oarlike legs propel them quickly through the water in a somewhat bobbing fashion.  Water Boatman are predators with piercing/sucking mouthparts.  You are lucky you were not bitten as the bite of a Water Boatman is quite painful, but otherwise harmless.  You can read more about North American Water Boatmen on BugGuide.

Update:  June 27, 2016
We just received a comment indicating that this is a Backswimmer and not a Water Boatman.  Backswimmers, according to BugGuide, are called Water Wasps or Water Bees and they do have a painful bite.

Letter 2 – Backswimmer, NOT Water Boatman are Edible


Insect found swimming in the pool
May 17, 2010
I’ve never seen a bug like this before and was curious if you knew what it was.
I found it swimming in my pool (I just shocked the pool yesterday, so it might have some chlorine resistance…). It was swimming underwater and was moving pretty well, using its larger legs to swim while the smaller ones were pressed against its body (it almost looked like a tiny frog at first, by the way that it moved, except that the legs were hinging near the center of its body instead of the back).
When I fished it out of the water, it didn’t seem overly mobile on land, although it was able to slowly scoot itself about. Its body was about 2 cm long.
A first time bug hunter, Jason
Folsom, CA (foothills near Sacramento)

Water Boatman

Hi Jason,
This is a Water Boatman in the family Corixidae, but we are uncertain of the species.  BugGuide has numerous genera but many look alike to us.  Clumsy on land, Water Boatmen are excellent swimmers and fliers.

Correction:  Backswimmer
Boatman Pic actually Notonecta?
September 28, 2010
Hello, Friends of the Bugs,
While trying to ID a bug that had landed on our deck here in Edmonds,WA, I discovered that you have the same picture on your site under two different headings/labels.  It comes up under “Water Boatman are Edible” when “Boatman” is typed into the search box.  Your answer to that post was to say it was Corixidae.  The picture matches “my” bug exactly, and I had also come to the tentative conclusion after initially looking in Bug Guide, of Corixidae, but wasn’t convinced.  However, on BugGuide I happened to see another pic that also matched, was mislabeled as Corixidae, and someone had posted that it was Notonecta.  Looking further online, I agree 100%.
If I type Notonecta or Backswimmer into your search box, it comes up with a post titled “Backswimmer” which appears to be the exact picture, this time correctly IDd as Notonecta.  I thought you’d like to know so a note can be added (or however you want to deal with it, if at all) to the Boatman one, correcting the ID.  It might be confusing to some, such as myself, who might not accidently happen upon the correct ID and be thinking it is a Boatman.  I think many folks, like myself, might initially do a search for Boatman upon finding one of these bugs, since I was not familiar with the existence of Backswimmers.  But now I know, and I would have really wondered how a waterbug got on my 2nd story deck, except you explained they can fly well.  The 7/22/10 pic of a Backswimmer swimming (on its back, of course) highlighting the abdominal hairs is especially nice.
I did not bother to submit all the pics I took because I found the ID, as you already have several pictures, including one from 2005. I only attached one for reference.  Later, the Backswimmer had flown away.  Thanks again for such a great site.
Cheers, Dee Warnock

Hi Dee,
Thanks for bringing this to our attention.  We did not realize that Baffled in Santa Cruz submitted the exact same image as Jason.

Letter 3 – Dead Water Boatmen in Convenience Store


Subject: Bugs found in convenience stores
Location: Edmonton alberta
August 9, 2017 5:24 pm
I work in different convenience stores and i come across these bug quite a lot. I know the pictures are not that great but i have to try and be discret while taking them. The bugs are about 10 mm long. I have never seen one alive! They are always dead at the bottom of the candy boxes.
Signature: Catherine

Alleged Dead Water Boatmen in Candy Box

Dear Catherine,
We can’t be certain, but these sure look like Water Boatmen to us.  See this BugGuide posting for comparison.  According to BugGuide:  “Adults fly to lights, sometimes in great numbers.”  Are you near a pond or other body of water?  Are these boxes stored near powerful lights that might be attracting them?  Water Boatmen are aquatic insects, but they are able to fly from pond to pond.

Dead Water Boatmen in Candy Box

Thanks for getting back to me!!

The body look similar but the legs seems wrong.
Next time i come across them, i will take a better picture! And count the legs!!!
Talk in a bit!

Update:  August 15, 2017
I was able to take better pictures today!!

Water Boatman

Hi Catherine,
Thanks for taking better images.  They confirm our original identification that these are Water Boatmen, aquatic true bugs that also fly and are sometimes attracted to lights in great numbers.  See the images on this BugGuide posting for comparison.

Water Boatman

Letter 4 – Water Boatmen: Plague of Biblical Proportions in Iowa


Subject:  Bugs swarming at night
Geographic location of the bug:  Central Iowa
Date: 08/08/2018
Time: 08:47 AM EDT
Your letter to the bugman:  Hi bug man, we live on a farm in central Iowa. The following bug has been swarming our lights at night and leaving heaping piles of dead bugs on the ground in the morning. What are these things?!
How you want your letter signed:  Becky H

Plague of Water Boatmen

Goodness Gracious Becky.
You have a plague of biblical proportions on your hands.  Even after cropping your image to a vertical, there appears to be hundreds of thousands of Water Boatmen present.  These are Water Boatmen in the family Corixidae, and your individuals look like the one in this BugGuide image from the genus
Trichocorixa.  Your submission is definite proof of the BugGuide claim:  “Adults fly to lights, sometimes in great numbers.”  Water Boatmen are aquatic True Bugs and according to BugGuide:  “Common in ponds. Also found in birdbaths. A few species live in streams, and others are found in brackish pools along the seashore above the high tidemark.”  Their food is listed as: “Algae, detritus, other aquatic organisms (mosquito larvae, brine shrimp).”  If this is the first time you have ever experienced this situation, we can only conclude that for some reason, conditions are ripe for a population explosion.  Perhaps fertilizer runoff to a nearby pond is causing an algae bloom, providing a food source for millions of Water Boatmen.  Since they can also fly, if a pond dries out, the Water Boatmen can migrate to another aquatic habitat.

Water Boatmen

Thank you for the information!  I told my husband they looked like the water bugs in our 1.4 acre pond that is right by our house!  We also live 1/4 mile from whitebreast creek.  I’m going to attach a video from this morning… biblical proportions is right!

Thanks again,
Water Boatman
Thanks Becky,
We don’t load many videos to our site, but yours is quite amazing and tells the story way better than the still image.  Glad we could assist in the ID.  Hopefully this situation will not last very much longer.

Awesome, thank you so much!


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

5 thoughts on “Water Boatmen: All You Need to Know – Discover These Fascinating Aquatic Insects”

  1. Water Boatman: edible

    Both the eggs and the adults of Water Boatmen and Backswimmers are edible, and consumed in several parts of the world. The most notable example of this is in Mexico, where the eggs were “farmed” when bundles of straw were laid in the lake (the famous one at Mexico City, which in the last half-century or so has gotten badly polluted, such that these insects aren’t found in great numbers any more — so I’ve read). Back in the Aztec days, the eggs were a food reserved for royalty.

    SmallStock Food Strategies

  2. These guys are said to be delicious!
    Haven’t tried them yet, but they were on the gourmet list for the Aztecs: both the eggs and the adults.
    I think they’d be hard to farm, but there must be some places where they’re greatly abundant.
    Some day I’ll have a plate of some…..


  3. All this information is correct if you substitute “backswimmer” with “water boatmen”… water boatmen are harmless and feed on algae; but ya this picture is a backswimmer and can sting/prick you


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