Are Clams Producers or Consumers? (Are They Herbivores?)

Clams are a type of bivalve mollusk that lives in freshwater or saltwater. Clams are filter feeders, meaning they strain small food particles from the water around them using their gills.

Clams are predominantly primary consumers because they mostly eat plant material, such as phytoplankton and pant detritus floating around in the water. However, they cannot control what food particles they filter and they will also ingest zooplankton, which effectively makes them secondary consumers.

This means that clams are mostly herbivores, eating algae and other plant matter. However, they will also consume small animals like plankton and detritus if it is available in their environment. As primary consumers, clams play an important role in the aquatic food chain by providing a source of food for larger predators.

Clams are found in both saltwater and freshwater and their diets are quite similar. Some species live buried in sand or mud, while others are found partially buried in the sand.

Are Clams Carnivores, Herbivores or Omnivores?

Clams are typically considered to be herbivores, since their diet consists primarily of phytoplankton and other tiny plant-like organisms. However, it is possible for them to consume small amounts of animal matter as well.

Therefore, one can also argue that some clams are omnivores because they also eat zooplankton which essentially consists of small animals.

Although some clams look like it, they are not carnivores but peaceful herbivores!

However, most clams are primarily herbivores because they eat plant debris and algae.

What are clams and why are they important for Ecosystems?

Clams belong to the class Bivalvia, which contains more than 10,000 species (including mussels and oysters). There are more than 1,500 living species of clam.

Being bivalves means that they have two shells. They range from about 0.5 to 120 cm in length (excluding their siphons)!

The clam’s body is divided into three major parts: the foot, the siphon, and the mantle. The foot extends from the mantle and is used for locomotion. The siphon is used for respiration and withdraws water into the animal. The mantle is the soft-bodied muscular organ that secretes the shell.

A good example of a widespread freshwater clam is the Corbicula fluminea also known as the Asian Clam.
Other common freshwater clams include: Anodonta, Sphaerium, Pisidium, and Sinonovacula. Some saltwater clams are edible (quahogs, hard-shelled clams) while others are too tough to eat (soft-shelled clams).

Large Asian Clams.

For most of their early evolutionary history, clams were small, burrowing creatures that often lived in saltwater. However, some species later adapted to freshwater.

See more about how clams eat and digest their food in this video!

The clam’s body is divided into three major parts: the foot, the siphon, and the mantle. The foot extends from the mantle and is used for locomotion. The siphon is used for respiration and withdraws water into the animal. The mantle is the soft-bodied muscular organ that secretes the shell.

Clams are important animals in the ecosystem. As a primary consumer, they help to convert algae and plankton into food that can be used by other animals. They also play a role in breaking down detritus, which helps to recycle nutrients back into the ecosystem.

Without clams, there would be an increase in detritus and a decrease in available food for other animals. This could lead to a decline in species diversity and an overall decrease in ecosystem health.

Are Clams Producers, Consumers, or Decomposers?

Clams are consumers because they eat other living organisms. Clams are herbivores, which means that they eat plants and algae. Only plants as well as some bacteria and protozoa are producers.

What Type of Consumer is a Clam?

Clams are primary and secondary consumers because, because they may eat plants and animals. Generally, herbivores are primary consumers, omnivores are secondary consumers and carnivores are tertiary consumers.

Are Clams Decomposers?

To some extent yes because clams can be considered detritivores. Clams are not the last ones to eat dead or decaying matter and are therefore not true decomposers.

However, they do filter out dead organic matter from the water, which means that they are helping the decomposition of organic matter.

The bacteria in the gut of the clam play a very important role in their digestion and these microorganisms may be considered true decomposers.

Learn more about the different types of decomposers in the ocean here!

Where are Clams in the Food Chain?

Clams are mostly located on the second trophic level in the energy pyramid because they are mainly primary consumers.

Clams, oysters and mussels belong predominantly on the 2nd trophic level of the energy pyramid.

However, they eat plants, algae, bacteria, and some amounts of microscopic crustaceans (zooplankton) which places them at the 2nd and, to a lesser extent, the 3rd trophic level.

Are Clams Autotrophs or Heterotrophs?

Clams are heterotrophs because they eat other living organisms. Practically no animals are truly autotrophic because animals do not get their energy from inorganic sources like plants and some bacteria do.

However, clams sometimes have a symbiotic relationship with algae, which provides them with food and shelter. A bit like is seen between fungi and cyanobacteria in lichens.

In return, the clam helps to aerate the water around the algae and provide nutrients for it to grow. This relationship is important for maintaining healthy coral reef ecosystems.

This does, however, not make clams truly autotrophic as they still need the presence of an external organism to provide them with energy. Other animals like some species of salamanders and snails use this strategy of semi-autotrophy as well!

What Animals Prey on Clams?

Clams are food for a variety of animals found in marine and freshwater environments including birds, fish, crabs, and starfish.

Some birds, such as oystercatchers, also eat clams. In fact, the most prolific predator of clams is actually a bird! The great blue heron has been known to eat up to four hundred clams in a single day!

Clams themselves are not very nutritious and are mostly made up of water. However, they do contain some minerals and protein which helps to make them a good food source for many animals.

What Decomposers Eat Clams When They Die?

Many decomposers and scavengers may eat a clam when it dies.

When the clam is dead, it is likely that smaller detritivores of the ocean like worms, crabs, slugs and some fish will smell it and begin to feed on it. A dead clam will be eaten by scavengers like crabs and bacteria in a matter of weeks.

After days and weeks have passed, little actual flesh is left and only the tough parts of the shell.


In this post I have looked into the diet of the clam. Clams are a type of mollusk, and giant clams are one of the largest molluscs in the world.

Clams have been around for a very long time, and are often found in the sediment of the ocean floor.

The clam diet consists of algae and detritus, which are the remains of dead organisms that have been broken down by other organisms.

Clams are a very important part of the food chain as they are the first animal to feed on the algae and detritus, which helps to keep the water clean!  

Therefore, the presence of clams is a good indicator of the health of the ocean or a lake, as they are sensitive to pollution.

If you would like more interesting facts about mollusks, check out my other post on the diet of mussels and what saltwater clams, more specifically, eat in a fish tank!