The crustacean known as the shrimp is closely related to lobsters and crabs, but it has plenty of variety within its more immediate family line. There are over 2,000 documented shrimp species in the wild. They can be found in every ocean and sea, as well as in many freshwater sources. They’re also sometimes referred to as the “cockroaches of the sea.” It’s a nickname they’ve earned due to their reputation for eating anything within reach. But what do shrimp eat? While there are plenty of omnivores throughout the animal kingdom, few stretch the definition of the word as thoroughly as the shrimp. Keep reading to find out exactly what shrimp eat.
A Shrimp’s Diet
In general, shrimp are what’s known as “opportunistic omnivores.” A shrimp’s diet consists of everything from plant matter to worms to other shrimp. They also don’t discriminate between living and dead matter. They’re just as likely to feast on the remains of a fish as they are to make a meal of plankton. As a result, the diet of a shrimp is wholly dependent on its environment. Since shrimp typically occupy the sea, lake, or river floor, their diet consists of what all the other creatures have left behind.
Shrimp eat zooplankton, which are microscopic organisms that drift in the ocean.
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In most environments, however, the bulk of a shrimp’s diet is made up of algae and plankton. There are two types of plankton: phytoplankton and zooplankton. Phytoplankton includes microscopic plants, which can take the form of diatoms, microalgae, or cyanobacteria. Zooplankton are microscopic organisms floating in the ocean that must eat other organisms to survive.
Although there is some variation based on habitat, some of the food shrimp eat includes:
- Bacteria
- Phytoplankton (algae, cyanobacteria, diatoms)
- Zooplankton
- Small fish and invertebrates
- Dead and decaying animal matter (clams, fish, snails, crabs)
What Do Shrimp Eat in a Tank vs. in the Wild?
Ghost shrimp and cherry shrimp are some of the most popular types of shrimp kept in aquariums. The sea or lake floor may be a veritable buffet of delicacies for shrimp species. However, most aquarium owners don’t want to line the floor of their habitat with decaying fish.
Ghost shrimp or cherry shrimp that live in colonies or share an aquarium with other fish can often survive on biofilm and leftover food. However, tanks with fewer inhabitants may require a more specialized diet. Algae wafers and shrimp pellets are the most popular choices for aquarium owners, but cherry shrimp and ghost shrimp also enjoy blanched vegetables.
Cherry shrimp are one of the most popular types of shrimp to put in a tank.
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How Do Shrimp Forage for Food?
The actual methods that shrimp use to forage for food can vary from species to species. Brine shrimp are filter feeders, which means that they strain potential food matter from water while swimming through it. Most shrimp species are nearly blind and instead rely on an awareness of their surroundings that combines smell and taste. This chemosensory input allows them to sense chemicals from potential prey in the wild. They also use their legs and tentacles to feel along the sandy floor and uproot potential prey burrowed underneath it.
Other shrimp employ more creative approaches to gathering food. Coral reefs are habitats that are abundant in marine life. Cleaner shrimp have found a unique niche in the coral reef ecosystem by cleaning bacteria and detritus off the bodies of larger fish. It’s a symbiotic relationship, and these ocean shrimp will often set up cleaning stations throughout the coral reef where fish can congregate. Cleaner shrimp are most often found working singly or in pairs, cleaning larger fish such as parrotfish, snappers, and blue tang. In this symbiotic relationship, the shrimp meet their nutritional needs while the fish are cleaned of potentially harmful bacteria and dead skin.
Even when they aren’t actively cleaning the local fish, shrimp always fulfill an important role within their habitats. As scavengers, they prevent dead organic matter and detritus from building up in their environments. Shrimp also keep algae and plankton populations at manageable levels. Their ubiquity throughout the world’s oceanic and freshwater habitats is a reflection of the valuable role they can play in practically any aquatic ecosystem.
