Freshwater snail

Small snails live in fresh water.

They live in many places. They live in big lakes and small rivers. Most snails have a hard shell.

Some snails use gills to breathe. Other snails must go to the top to breathe air. Many snails eat green plants. Some snails eat bits of old food. People in some lands even eat them. These snails are very interesting to see.

Freshwater snails are small animals that live in fresh water.

You can find them in many places. They live in big lakes and long rivers. They even live in tiny pools.

Most of these snails have a hard shell. Some snails use gills to breathe underwater. Other snails must go to the surface to breathe air. A few snails have both gills and a lung.

Most snails eat algae, which are tiny green plants. Some snails eat bits of old food. Many people around the world eat these snails. In the past, the Maya people ate them too.

Some snails are very special. The snail *Physa acuta* can make new snails all by itself. This is called self-fertilization. This snail can also mate with other snails.

Snails can also host tiny worms called parasites. These worms live inside the snail. Some of these worms can make people sick. Doctors call these snail-borne illnesses neglected tropical diseases.

Freshwater snails are small mollusks that live in many types of fresh water.

They can be found in almost any habitat on Earth. Some live in tiny, short-lived pools or small springs. Others live in huge lakes or very large rivers. Most of these snails have a hard shell to protect them. However, a few special types do not have a shell at all. There are thousands of known species of these snails. Scientists believe at least 33 to 38 different lineages have moved into fresh water.

These snails have different ways to breathe and eat. Some groups use gills to take oxygen from the water. Other groups must swim to the surface to breathe air. Some snails, like those in the Ampullariidae family, are amphibious. This means they have both gills and a lung.

When it comes to food, most snails eat algae. Many others are detritivores, which means they eat bits of dead matter. Some even use filter feeding to get their food. This variety helps them live in many different places.

People have a long history with these small creatures. In Guatemala, researchers found that the Maya people ate snails. This happened during the Classic Period, between AD 250 and AD 900. Today, many different species are used in Asian cuisine. You can also find many snails in pet stores.

People often keep them in aquaria with tropical fish. In the United States, people often keep ramshorn snails or apple snails. These snails are very common in home fish tanks.

There are many different groups of freshwater snails. A 2008 review found about 4,000 living species. There are also 5,182 known species of fossil snails.

Some snails, like the Viviparidae, are called mystery snails. Others, like the Planorbidae, are called ramshorn snails. The Hydrobiidae family is very large and has about 1,250 species. Some snails are very small, while others are quite large. This makes the world of snails very diverse.

Snails also play a role in how diseases spread. Some snails carry parasitic worms called flukes.

These worms can cause a disease called schistosomiasis. This disease kills between 10,000 and 200,000 people every year. Because of this, these illnesses are called neglected tropical diseases. One snail, *Physa acuta*, has a very interesting way of making babies. It can use sexual reproduction or self-fertilization to create new snails. This helps the snail survive in many environments.

Freshwater snails are gastropod mollusks that inhabit various freshwater environments.

These organisms live in habitats ranging from small seeps and ephemeral pools to massive lakes and major rivers. While most freshwater gastropods possess a protective shell, a few rare exceptions exist without one. Scientists have identified at least 33 to 38 independent lineages that have successfully colonized freshwater ecosystems. A 2008 taxonomic review estimated there are approximately 4,000 living species. Additionally, researchers have identified 5,182 species of fossil freshwater gastropods. This diversity makes them a significant part of global aquatic biology.

These snails utilize different biological mechanisms to breathe and eat. Some groups respire using gills to extract oxygen from the water. Other groups must travel to the water's surface to breathe air. Certain amphibious families, such as Ampullariidae, possess both gills and a lung.

Their diets are equally varied. Most species feed on algae, but many are detritivores that consume dead organic matter. Some snails even function as filter feeders. These specialized methods allow them to thrive in many different ecological niches.

Taxonomists categorize these snails into several major groups. The Neritimorpha are primitive snails that use gills and have a shell lid called an operculum. The Caenogastropoda is a large group of gilled snails. Within this group, the Ampullariidae family includes large tropical apple snails. The Viviparidae family contains medium to large snails known as mystery snails.

Other families include the Pleuroceridae, which are abundant in eastern North America, and the Thiaridae, known as trumpet snails. The Hydrobiidae family is particularly large, containing about 1,250 freshwater species.

Another major group is the Heterobranchia, which includes the Pulmonata. These are air-breathing snails, often called basommatophorans. These snails are characterized by having eyes at the base of their tentacles rather than at the tips. Most basommatophorans have thin, translucent, and colorless shells. They also lack an operculum. Within this group, the Planorbidae are known as ramshorn snails, while the Physidae are known as pouch snails. This group also contains the Lymnaeidae, which are common in temperate and northern regions.

Some species exhibit unique reproductive strategies to ensure survival. The snail Physa acuta, a member of the Physidae family, is a self-fertile organism. It can undergo both sexual reproduction and self-fertilization. Researchers have studied how these methods affect the accumulation of mutations. Inbreeding through self-fertilization can lead to the expression of harmful recessive mutations in offspring. However, outbreeding allows females to choose mates with smaller mutation loads. Studies by Noel et al. concluded that both methods allow the species to efficiently eliminate harmful mutations.

Freshwater snails also have a significant relationship with human history and culture. In Guatemala, archaeological evidence shows that the Maya people ate freshwater snails during the Classic Period, between AD 250 and AD 900. Today, many species are common in Asian cuisine. They are also popular in the aquarium hobby.

In the United States, people often keep ramshorn snails, bladder snails, or apple snails in tanks with tropical fish. This shows how these creatures move from wild ecosystems into human homes.

However, snails can also be vectors for serious diseases. They serve as intermediate hosts for various parasites, particularly trematodes, which are also called flukes.

For example, certain snails host the parasites that cause schistosomiasis. This disease is estimated to kill between 10,000 and 200,000 people annually. Because of these impacts, snail-borne infections are classified as neglected tropical diseases. This includes other conditions like fascioliasis and paragonimiasis. Understanding snail biology is therefore vital for managing global public health.