Animals that live in a lake include bacteria, insects, fish, birds, amphibians, reptiles and mammals too. They are part of a whole ecosystem of life – a mostly hidden world that exists around, on and in the waters of a lake. Today we’ll find out what animals that live in a lake you might have living in your local lake hole!
- Types of animals that live in a lake
- Tiny animals that live in a lake
- Invertebrate animals that live in a lake
- Fish that live in a lake
- Birds that live in a lake
- Reptile animals that live in a lake
- Amphibian animals that live in a lake
- Mammals that live in a lake
Learning about the animals that live in a lake highlights how important lakes are. A lake can provide so much for its residents and visitors, including food, water, shelter, comfort, community. Speaking of residents and visitors, what types of animals live in a lake? In this article, meet the different types of animals you are likely to encounter at your local lake as well as in lakes around the world.
Types of Animals That Live In A Lake
Lakes, like the animals that live in them, come in all shapes and sizes. Lake water is typically still or slow moving. Lakes can be shallow or deep, wide or narrow. Intriguingly, while most lakes are freshwater lakes, saline (saltwater or marine) lakes also exist.
Your typical lake ecosystem will include two main types of inhabitants: abiotic or non-living matter and biotic or living organisms. Within the biotic group, a healthy lake will have several major categories of organisms. Lake animals are generally categorized based on where they live and how they function in the lake ecosystem, which includes the lake food web or food chain.
A lake ecosystem has several different zones that can support different types of abiotic animal life. The littoral zone is the shoreline zone. The limnetic zone is the open water zone. Depending on the lake’s size and depth, this zone might be sub-divided into two additional zones, the upper euphotic and lower profundal. Finally, the benthic zone is on the lake floor.
Every lake ecosystem also goes through three distinct life stages, whether that lake is naturally occurring or human-made. A lake’s life stage will determine to a large extent which species are able to call it home. Oligotrophic lakes, with their deeper, clearer water and lower levels of biologic activity, are young in every way and thus are still growing into their ecosystems. These young lakes typically have clearer water but less variety of organic life.
A mesotrophic lake has reached adulthood and is going to feature the most diverse assortment of organisms.
A eutrophic lake is a late-life lake that is in the process of transitioning into a different type of ecosystem altogether. Over time, eutrophic lakes often become filled-in dry land, wetlands, bogs or marshes. So now that you know a bit more about types of lake animals, lake zones and lake life cycles, let’s turn our full attention to learning about the animals that live in a lake!
Categories of Animals That Live In A Lake
When you visit a lake, you might easily be able to spot some lake residents such as insects, birds, fish and small animals. But did you know there are hundreds of millions of other animals that live in the lake too? You won’t be able to see them unless you bring along a microscope, but these incredibly tiny animals are vitally important to sustaining life in and around the lake.
A wide variety of plants also call lakes home. Plants can be found in all of the major lake zones as well as on the near-lake shoreline zone. And even more animals will make their homes near lakes, visiting the lake to get water, find food or find temporary shelter.
The four major categories of animals that live in a lake include:
- Primary producers (tiny plants and animals, aquatic plants)
- Vertebrates (fully aquatic, land/aquatic and shoreline dwellers)
Now it is time to meet the animals that live in a lake!
Bacteria That Live In A Lake
Bacteria living in a lake are so tiny they are easily overlooked. But the weird fact is, if a lake didn’t have any bacteria, nothing else would want to live there.
The simplest definition of bacteria is a single-celled organism that occurs in one of four shapes: rod, cone, sphere or spiral. Bacteria are essential to help decompose and recycle organic material and keep the lake ecosystem healthy.
- Proteobacteria. These bacteria are the most common types of lake bacteria and help with breaking down ammonia.
- Alphaproteobacteria and gammaproteobacterial. These bacteria help to increase the amount of oxygen dissolved in the lake water.
- Cyanobacteria. These bacteria are responsible for maintaining active photosynthesis throughout the lake ecosystem.
- Actinobacteria. These bacteria help to break down organic matter as it decomposes. They also convert nitrogen into other useful components.
- Bacteroidetes. These bacteria like to live at the bottom of the lake and assist with breaking down larger organic molecules during the decomposition process.
Primary Producers That Live In A Lake
The term primary producers isn’t one most people are familiar with. Yet primary producers are essential to maintaining the lake ecosystem and its food web. Depending on their roles and sunlight requirements, primary producers mainly inhabit the upper limnetic and benthic zones of the lake ecosystem.
In both salt and freshwater lakes, the primary producers include phytoplankton and periphyton. The term “phytoplankton” means “plant wanderer.” The term “periphyton” means “around plants.” So here we are talking about aquatic plant species and the plant-based microorganisms that like to live near them.
- Phytoplankton. Blue-green algae and green algae are two of the most common periphyton species.
- Periphyton. Algae combined with bacteria, various microbes and lake detritus.
- Aquatic plants. Water lilies, cattails, bulrushes, water lettuce, water hyacinth, moss and lichens are all great examples of lake aquatic plants.
Invertebrates That Live In A Lake
The term invertebrates describes animals that do not have any kind of backbone or spinal structure inside their bodies. However, invertebrates often have an exoskeleton or shell of some sort that surrounds their body and provides protection. Invertebrate lake animals are an essential part of the greater lake food chain and ecosystem.
- Zooplankton. Zooplankton are single-celled animals. They can be temporary (one part of an animal’s lifecycle) or permanent. The four major categories of zooplankton include rotifers, protozoa and two types of micro-crustaceans, copepods and cladocerans.
- Sponges. Spongilla lacustris is the most common freshwater lake sponge. Saline lakes are home to golf-ball sponges like Tethya aurantium (orange puffball sponge) as well as many Porifera sponge species.
- Worms. Three main species of worms live in lakes: planaria (flatworms), nematoda (roundworms) and annelida (leeches).
- Mollusks. Mollusks have soft bodies that are not segmented. They may or may not have a shell. The three main types of mollusks are bivalves, gastropods and cephalopods. Bivalve mollusks like snails, mussels and clams are the most common lake species.
- Arthropods. Arthropods have a segmented body, a hard exterior shell and multiple legs. Lake arthropods include millipedes, spiders, mites, fleas, midges, beetles, brine shrimp, lobster, crayfish, water striders, mosquitoes and others.
Vertebrate Animals That Live In A Lake
Thus far, we’ve been examining the smallest animals that live in a lake. Some are so small you can’t even see them without extreme magnification! Now we turn our attention to the vertebrates – lake animals that have some type of backbone or spinal column within their bodies.
With the exception of fish, most of the lake vertebrate animals you are about to meet will divide their time between the water and the land.
Fish That Live In A Lake
An amazing diversity of fish species live in saline and freshwater lakes. Many make great eating! Bass, perch, catfish, smelt, sturgeon, gar, minnow, goldfish, eel, carp, crappie and tuna are just some of the many fish species that call lakes home.
Birds That Live In A Lake
Birds will often visit a lake to drink water and hunt aquatic prey or insects. They may also take shelter on the water or along the shoreline zone of a lake.
Herons, egrets, cormorants, ducks, geese, swans, grebes, loons, killdeer, a variety of gulls, turns, stilts, sandpipers, willets, curlews, kingfishers and many other local and migratory bird species live in or near lakes or visit lakes from time to time.
Amphibian Animals That Live In A Lake
Ectothermic (cold blooded) animals like amphibians move in and out of the water for temperature regulation, to find food and to lay their eggs.
Salamanders, frogs and toads are the most common lake dwelling amphibian species.
Reptile Animals That Live In A Lake
Turtles and crocodilians might be the first thing that comes to mind when you think of lakeside reptiles, but there are plenty more besides!
The most frequently seen lake reptile species include turtles, snakes, iguanas, geckos, crocodiles, water dragons and basilisks.
Mammalian Animals That Live In A Lake
While some lake mammals will live most or all of their lives in or on the waters of the lake, many lake mammals will also divide their time between the water and the land.
Common lake mammals include beavers, mice, rats, rabbits, beaver, river otters, muskrats, raccoons, nutria, water shrews and water voles.
What Are Your Favorite Animals That Live In A Lake?
Now you have met some of the many animals, seen and unseen, that call marine and freshwater lakes home. Do you have a favorite lake animal or animal species? Post your favorites in the comments!
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- Hoverman, J. “Ponds and Lakes: A Journey Through the Life Aquatic,” Nature, 2012.
- Logan, A. “Love your lake? Here’s what you need to know about its ecosystem,” The Lilly Center for Lakes & Streams, 2021.