Notonectidae

Some bugs swim on their backs.

People call them backswimmers. They live in ponds and lakes. They can even live in pools.

These bugs hunt for food. They eat small fish and tadpoles. They use long legs to swim. These legs have tiny hairs on them.

Backswimmers can fly well. This helps them find new homes. They can be green or brown. Some are even yellow.

They have sharp mouths for eating. A bite can hurt a person. They are very interesting bugs to see!

Backswimmers are a family of water bugs.

They are called backswimmers because they swim upside down. They live in still water like ponds and lakes. You might even find them in garden pools. There are about 350 species of these bugs. Most are found in two groups. Some are larger than others.

These bugs are predators. This means they hunt other living things. They eat small fish and tadpoles. They use long hind legs to swim. These legs have a fringe of hair.

They have a sharp mouth called a proboscis. This is a tube used for feeding. A bite from this mouth can hurt a person.

Some types of backswimmers have a special way to dive. They use a substance called haemoglobin in their bellies. This helps them use extra oxygen. They use air bubbles to stay under the water. The bubbles change size as the bug uses oxygen. This helps them control how they float. Most backswimmers can fly well. Flying helps them find new homes.

Backswimmers are a special family of water bugs.

They belong to a group called Notonectidae. These insects live all over the world. You can find them in still water like lakes and ponds. They also live in marshes and garden ponds. Some can even be found in swimming pools. They are called backswimmers because they swim upside down. This means they swim on their backs. This way of moving is very different from other bugs.

These bugs are predators that hunt for food. They use their long hind legs to move through the water. These legs have a fringe of hair on them. This hair helps them paddle vigorously. They hunt things like tadpoles and small fish. They have a sharp mouth called a proboscis. This mouth is a tube used for feeding. A stab from this mouth can be painful to a human.

They are very good at catching their prey.

There are about 350 different species of backswimmers. They are split into two groups called subfamilies. One group is called Notonectinae. The other group is called Anisopinae. The Notonectinae group has seven genera. The Anisopinae group has four genera. Members of the first group are often larger. They look a bit like water boatmen. However, you can tell them apart by their color and legs.

Some bugs use a very smart way to dive. The genera Anisops and Buenoa stay underwater in a unique way. They use haemoglobin in their abdomen to hold extra oxygen. This is different from using oxygen in the water. They use air bubbles to help them float or sink. These bubbles are called buoyancy. The bubbles change size as the bug uses the oxygen. This helps the bug control how it moves in the water.

Backswimmers are very good at moving around. Even though they live in water, they can fly well. This flying helps them find new places to live.

You might see the species Notonecta glauca in Europe. In the United Kingdom, people call it the greater water boatman. Another type is N. maculata. It has forewings that look like mottled brick. These bugs are a big part of the freshwater world. They show us how life works in many different ways.

Notonectidae is a large family of aquatic insects. They belong to the order Hemiptera. Most people know them as backswimmers. This name comes from their unique swimming style. They swim upside down, or in an inverted position. These insects are found all over the world. They are cosmopolitan, which means they live in many different regions. They live in still freshwater environments. This includes lakes, ponds, and marshes. You might even find them in garden ponds or swimming pools.

Backswimmers are active predators in their habitats. They hunt for food using a specialized body design. Their hind legs are long and fringed with hair. They use these legs to paddle vigorously through the water. This movement allows them to chase prey. They can catch animals as large as tadpoles or small fish. To eat, they use a sharp, tubular mouthpart called a proboscis. This structure acts like a needle. If a backswimmer stabs a human, it can cause a painful bite.

There are approximately 350 different species within this family. Scientists divide them into two main subfamilies. The first subfamily is called Notonectinae. It contains seven different genera. The second subfamily is called Anisopinae. This group contains four genera. Generally, the members of Notonectinae are larger than those in Anisopinae. The most famous genus is Notonecta. These insects have streamlined, deep bodies. They can be green, brown, or yellowish in color.

It is easy to confuse backswimmers with Corixidae, known as water boatmen. However, you can tell them apart by looking closely. Backswimmers have a convex dorsum, which is the top side of their body. This part is lightly colored and lacks cross striations. Their front legs, or tarsi, are not scoop-shaped like those of water boatmen. Their hind legs are specifically fringed for swimming.

Some backswimmers have very special ways of staying underwater. The genera Anisops and Buenoa use a unique system for buoyancy. Most aquatic insects cling to objects to stay submerged. These two genera do not do that. Instead, they use extra oxygen stored in their abdomen. They use a substance called haemoglobin to hold this oxygen. This is different from using oxygen dissolved in the water. They carry air bubbles that help them float or sink.

This air bubble system is a precise biological mechanism. The size of the bubbles changes constantly. As the insect breathes, it uses the oxygen for respiration. At the same time, nitrogen dissolves into the insect's blood. These two processes change the concentration of oxygen in the bubble. This allows the insect to regulate the size of the bubble. By controlling the bubble, they can control their buoyancy. This helps them move through the water column effectively.

History and geography help us understand where these insects live. In Europe, the species Notonecta glauca is very common. In the United Kingdom, people call it the greater water boatman. Another species, N. maculata, is also found in that region. You can identify it by its mottled, brick-colored forewings. Although these insects spend most of their time in water, they are not stuck there. They can fly very well. This ability allows them to disperse easily to new habitats.

Backswimmers are important parts of freshwater ecosystems. They connect different levels of the food web. By hunting small fish and tadpoles, they act as regulators. Their ability to fly connects land and water environments. This makes them a fascinating subject for studying how animals adapt to different worlds. Their specialized breathing and swimming show how life finds clever ways to survive.