The Benefits of Rotifers in a Saltwater Aquarium

Rotifers are a bit like the unlikely hero of the reefing scene. Small, unassuming, and a little alien-looking, these bad boys are a force to be reckoned with when introduced into a reef environment.

Rotifers, named after the scientific classification Rotifera, meaning “wheeled animal”, is easily recognizable in part by the unique cilia crowning their head. When in motion, the cilia resembles two spinning wheels, hence the name.

The basic anatomy of a Rotifer is quite simple. They have three main sections: The head, the trunk, and the tail-like foot. The head is where the strong jaws, called trophi, are located. Down further, at the base of the trunk, is the long foot. Although it’s typically referred to as a foot, it’s a lot more like a barb or a tail. The “foot” can be used to latch onto hard surfaces.

While there are many species of Rotifers out there, most commonly used in aquariums is the Brachionus plicatilis. This specific type of Rotifer is by far the best suited for aquarium life. The majority of the other species of Rotifers are actually naturally freshwater creatures. That, as you should know, is an unfavorable feature for a saltwater reef habitat.

Rotifers, as mentioned before, are tiny but mighty. At around only one-tenth of a millimeter, you won’t be seeing them, so much as seeing the results of incorporating them into your aquarium. Rotifers are pretty much the all-around support team for your aquarium.


Marine RotiferWhat do they do?

Rotifers may not look like much, but they really do pack a punch. As a delicious food for the smallest inhabitants of your aquarium, from baby fish to your colonies of copepods, they’re irreplaceable staples to keep on hand. Similar to the gut microbiome of humans, the health of your Rotifers can determine the health of your entire aquarium.

Rotifers are a particularly good food source due to the wide range of fish that enjoy them; practically anything that can fit them in their mouth will eat them, including young and baby fish and Corals.

In fact, Rotifers are the best food source for baby fish and larvae, like young clownfish. The problem with most foods is that they’re simply too big to even fit in the mouths of baby fish. Since Rotifers are so outrageously small and easy to digest, they’re a nutritious food source for newly hatched fish.

As for Corals, Rotifers are the quintessential food source for them. The right rotifers can give your Coral a major boost in size and growth. Since they’re so rich in crude fat and protein, Rotifers are especially attractive to most corals, as well.

The spot where many reefers fall short, though, is the diet they feed their Rotifers. No two Rotifers will have the same nutritional value, but you can be sure that a Rotifer fed a diet of pea flour and yeast will not have the same nutritional value as a Rotifer fattened up on a diet of phytoplankton and other living foods.

You see, Rotifers are a bit like delivery vehicles for nutrients. On their own, they aren’t “technically” very nutritious at all, sort of like a happy meal. If you feed them nothing but nutrient poor foods and dead supplements, they’ll take on the nutrition of what they’re eating.

Feed them something bursting with nutrients and energy like, say, Green Phytoplankton, and both their growth and nutritional value will be through the roof. That’s when you start to see the enhanced growth and vitality of your reef habitat.

It couldn’t hurt to give them some nice, healthy supplements to give them a little boost. Fatty acid supplements are perfect for making them even more nutritious. When fish eat properly fed and nourished Rotifers, they seem to grow faster and be more resistant to fatigue than those who eat nutrient-poor Rotifers.

That point cannot be stressed enough. Your Rotifers are only as good as the food you feed them.

However, Rotifers aren’t just for feeding. Just like Copepods, Rotifers thrive on detritus, or the nasty stuff floating in your tank water. A large colony of them will be super-effective at clearing all the gunk out of the water. Naturally, this makes Rotifers excellent at maintaining the integrity of your tank.



If you thought Tisbe Pods and Tiger Pods were easy to colonize, wait until you try to colonize Rotifers. A little bit like rabbits, Rotifers are easier to colonize than they are to crash. Even an absolute beginner could have a thriving colony in just a few days,

The magic lies in how fast Rotifers actually reproduce. In one day, a female Rotifer could give birth to about seven babies. Just over a day later, all those babies could have babies, and so on and so on. In only a week, one Rotifer could easily become over 100,000.

“But”, you may be wondering, “how does a single Rotifer reproduce? I took health class in middle school. I know that’s not how it works.” Well, Rotifers don’t reproduce the same way as humans. They reproduce using a process called Parthenogenesis, which is basically asexual reproduction.

It might be helpful to not think of them as “male” and “female”, but more like two separate versions of the same thing.

When water conditions are good and food is plentiful, “female” rotifers give birth to other “females” without fertilization, meaning they can give birth on their own.

But when conditions are bad, something really interesting happens. The females give birth to males in response to harsh conditions. Then the males fertilize the females, who in turn give birth to a type of “super egg” that essentially hibernates until conditions are favorable, which could be up to twenty years. Then, like a spring sparrow, the Rotifers emerge from their eggs in order to repopulate the favorable water.


Wrapping Up

Rotifers are a great addition to any reef, thanks to their versatility and rich nutrition content. They’re great for beginners, reproduce quickly and efficiently, and are generally just an agreeable creature to raise.

Whether you’re raising Clownfishes or Seahorses, Coral or Clam Shrimp, Rotifers can and should be the backbone food for your entire habitat. From supporting growth to enriching overall diet, quality Rotifers should be your insurance for a healthy reef.

You can Buy Live Rotifers Here


Jett Murdock
Jett Murdock

Jett Murdock is the resident reef writer here at When he isn’t writing about all things reef related, he freelances over at He’s a seasoned writer with 3+ years of experience writing everything from product descriptions to essays.

One thought on “The Benefits of Rotifers in a Saltwater Aquarium

  1. Vanessa says:

    Hi, I am new to the reef/saltwater tank hobby. I was told that if I supplement my tanks with rotifers and copepods, I don’t need a protein skimmer. Can you confirm this for me, please? Thank you!

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