The humble shrimp is living proof that the age-old scientific adage about nature abhorring a vacuum wasn’t tested thoroughly enough, and that there are some exceptions to the rule.

And right at the top of that list of anomalies is the little crustacean that could, the shrimp. They are one of nature’s perfect living vacuum cleaners, and much like their not-so-distant land-based cousin the cockroach, shrimp will eat almost anything. 

Anything And Everything 

When we say that shrimp like to eat anything, what we mean is that as a species they’re omnivorous. They exist entirely on a diet made up of other fish and insects, decaying vegetable matter, and algae.

the shrimp’s diet has evolved over millions of years to make it the perfect bottom feeder that’ll hoover up all of the detritus and decaying matter that settles on the bottom of the ocean or the gravel in your fish tank without harming (for the most part) any other creatures.

They’re not fussy eaters, and they’ll mostly eat whatever they can get their pincers on.

It’s their omnivorous nature that makes shrimp so appealing to aquarists and fish keepers the world over, as they can let shrimp run free in their tanks, safe in the knowledge that they’ll help to keep their tanks clean and preserve the integrity of their miniature ecosystems at the same time. 

Hitching A Ride

No two species of shrimp are the same, and some, like the saltwater Cleaner Shrimp, have evolved to accommodate the strangest diets.

Like the rest of their genus, Saltwater Cleaner Shrimp feast mainly on dead and decaying protein and vegetable matter, but it’s the way that they do it that makes them unique. 

Cleaner Shrimp wait for other fish to swim past, then wiggle their antennae and if a curious fish decides to stop, the shrimp then leaps on the back of that fish and begins to “clean” it by eating the dead skin, scales, and any parasites that their new dining table may have acquired while swimming around in the ocean depths.  

These uninhibited shrimp have also been known to climb inside the jaws of apex predators and act as a defacto underwater dentist by eating the decaying and rotting flesh that has gathered between their teeth.

It’s a dirty, thankless job but driven by its insatiable appetite the Cleaner Shrimp doesn’t hesitate to face down certain death in pursuit of its next meal. 

Scavenging The Depths

As we’ve already said, no species of shrimp are the same and while the Cleaner Shrimp is the bold and courageous black sheep of the crustacean family, most shrimp are content to scavenge for whatever food they can find on the bottom of rivers or oceans. 

Due in no small part to their timid, non-aggressive nature and their fastidious approach to cleaning the algae and biofilms that can collect on tanks, shrimp are seen as being a valuable addition to freshwater aquariums.

They won’t attack or disturb any of the other residents of their new home and are content to be left to their devices and suck up any waste that they come into contact with. 

And if you’re worried about adding shrimp to your tank in case they start eating the plants that are a crucial part of its ecosystem, don’t be.

For some reason known only to their omnivorous selves and the scientists who’ve made it their life’s work to study these crustaceans, shrimp don’t seem to be particularly enamored by living plants and would rather wait until they’ve perished before consuming them.

Cannibal Holocaust

Remember when we said that shrimp were omnivorous and would eat literally any animal or vegetable protein that they could lay their pincers on and fit in their mouths?

Well, it turns out that eating anything includes each other, and like almost every other crustacean, shrimp regularly eat each other. 

But the scariest part about their cannibalistic tendencies is that they only indulge in them during a certain phase of their life cycle. 

Like other ocean and water-based crustaceans, most notably crabs and lobsters, during their lifetime, shrimp outgrow their hard exoskeletons and need to “shed” their shells before they can start to grow another.

When they do abandon their hard exoskeletons and leave them behind, until their new “shell” grows, shrimp are soft and defenseless, which makes them perfect prey for other shrimp.  

How other shrimp know when to pounce on their shell-less brothers and sisters is a question for the ages and nature, but somehow they either sense or know exactly when to make their move, and they do.

And it isn’t uncommon to see one shrimp attack another and begin to gradually consume it. 

Feeding Shrimp 

Given everything that you’ve just read, it’d be natural to assume that if you were going to add some shrimp to your tank, that you could just let them loose and leave them to do what they do best and never have to think about them again.  

For the most part, that’s absolutely true, but some tanks are too clean and too perfect to satisfy all of a shrimp, or multiple shrimps dietary requirements (especially if you don’t want them to eat each other), and occasionally you’ll need to intervene and feed them with one of any number of specially formulated shrimp foods. 

But if you decide to add these crazy crustaceans to your tank, that’s all you’ll ever need to do to help them to live long, happy, and somewhat odd, lives.