Pineapple Sponges – Are They Reef Aquarium Safe?

There is nothing more beautiful than a reef aquarium that mimics the look of a natural ocean reef. Pineapple sponges are stunning, fluffy-looking marine creatures that thrive in low-light areas of aquariums. But should you be worried if pineapple sponges start multiplying in your reef aquarium?

Pineapple sponges are not considered harmful, and therefore are safe in reef aquariums. Many hobbyists love seeing them naturally grow in reef aquariums as they provide a surface area for beneficial bacteria to grow, which purifies water contaminants in the aquarium water, making your fish healthier and happier.

What Are Pineapple Sponges?

Pineapple sponges are nothing but harmless marine invertebrates that will not overtake corals unless your reef aquarium has a nutrient issue. 

Pineapple sponges also known as Sycpha or Sycon, are sponge-like marine organisms typically found in colonies around 1.8 m deep. Unlike other sponge species, pineapple sponges prefer to place themselves in areas with enough water flow to bring nutrients. As pineapple sponges are sessile, they must anchor themselves in the right location from day one.  

All pineapple sponges have a unique tubular shape that can grow up to 4 inches long, and usually has a hairy surface resembling yellowish to cream-colored cotton candy, in the shape of a pineapple. However, some pineapple species may look slightly different, as dozens of species exist around the world. 

Pineapple sponges tend to grow in aquariums that are overflowing with food and excess nutrients, as they are super-eaters. Like other sponges, pineapple sponges are filter feeders. Using their specialized cells, pineapple sponges can separate tiny food particles from the aquarium water. So, if you have lots of food residue inside your reef aquarium, you are more likely to see an outbreak of these funky-looking sponges. 

How Do Pineapple Sponges Multiply?

Pineapple sponges have fascinating reproduction, as they can reproduce both sexually and asexually. But due to their rapid asexual reproductive capabilities, pineapple sponges can sometimes cause issues in reef aquariums. 

Asexual reproduction occurs via budding and regeneration, which means one small sponge grows at the base of the mother sponge and eventually grows into another full-size pineapple sponge. If given the right environmental conditions, a pineapple sponge can regenerate ANY part of its body. 

This means if your reef aquarium is suitable for sponge growth, pineapples will use this to grow into more and more colonies, and this is the reason why pineapple sponges are often seen as aquarium pests.

Are Pineapple Sponges Good Or Bad For Reef Aquariums?

Pineapple sponges are both good and bad for aquariums, but the most important thing is that there are more good points than bad ones. 

Pineapple sponges thrive in reef aquariums with excess nutrient availability and good water quality. So, if your reef aquarium is experiencing a spike in nutrients, be prepared, as the number of pineapple sponges is also likely to spike. 

However, this doesn’t mean it is a bad thing that pineapple sponges are growing. It just means your reef aquarium is suitable for healthy sponge growth, and as they do not sting, they shouldn’t be problematic. 

The only time you should be worried about sponges appearing is if you have both corals and fish inside your reef aquarium and if the sponges are bright pink or blue, as those are the harmful types! If you remember from earlier, pineapple sponges are white or yellow, so there is no matter of concern here. In fact, a healthy pineapple sponge is beneficial for coral skeleton formation!

But, if your pineapple sponges are consuming almost all the food in your reef tank, they can reduce food security for your fish. 

If pineapple sponges seem to be taking over your reef aquarium, do not fear as some fish species, turtles, and the sea lemon nudibranch are all known to feast on pineapple sponges. 

Also, as your reef aquarium becomes more established, pineapple sponges tend to die off on their own when algae start smothering their surface. 

Why Do Pineapple Sponges Take Over Reef Aquariums?

If you are constantly fighting an outbreak of pineapple sponges, you may be encouraging them to grow without realizing it. 

First, check if you are overfeeding your reef aquarium. Pineapple sponges will appreciate any leftovers! 

If overfeeding isn’t the issue, check the nutrient levels inside your reef aquarium, particularly phosphorous, which is associated with excess silicates. Perform frequent small water changes with deionized or reverse osmosis water to discourage the pineapple sponges to reproduce.

Can You Remove Pineapple Sponges From Reef Aquariums?

Yes, if your pineapple sponges are becoming problematic, you can remove them. But, if you have the odd one or two pineapple sponges, they will not pose a threat, and therefore, there is no need to consider removing them at this stage. 

However, if they are causing issues for your corals and/or fish, you need to know how to control or remove them. 

Removing pineapple sponges is a bit challenging as they are reproductive masters. But, if you want to control the population, this is super easy. 

Physically Removing Pineapple Sponges

Pineapple sponges are large enough to remove with tweezers. With a good grip around the base of the pineapple sponge, pull the sponge from the rocky surface. If the pineapple sponge has encrusted on the aquarium glass, it is much easier to use a scalpel. 

NOTE: Ensure you have scraped any sponge left behind, otherwise the pineapple sponge can recolonize.

Introducing Natural Predators

Angelfish are avid sponge eaters and one of the most popular fish for any reef aquarium. They are graceful and create stunning display tanks, which is why they are one of our favorite fish at Reef Tank Advisor! 

Angelfish do, however, grow pretty big, so they require a large aquarium to feel at home. While they are generally peaceful in reef aquariums, they are known to nip or even eat smaller fish. It’s not because angelfish are aggressive, but they will take any opportunity to eat a fish that fits inside their mouth. 

Nudibranchs are one of the cutest marine species, and even better, they won’t hang back at grazing on algae, corals, AND sponges! Nudibranchs are reef predators, but most species cannot be kept inside reef aquariums. The good news is, the sea lemon nudibranch is aquarium safe and craves pineapple sponges. 

Other reef critters that may nibble on pineapple sponges that are also REEF-SAFE include emerald crabs and sea urchins.

NOTE: Before adding sponge predators, check the compatibility with the rest of your tank inhabitants. You want to avoid adding a fish or other predator that may disrupt the rest of your reef aquarium, for the sake of a sponge species that isn’t problematic.

Summary

Many reef aquarium hobbyists obsess over the fear of pineapple sponges taking over their display tank. While they may not be the most attractive aquatic creature inside aquariums, they are however reef safe and are not a threat to reef aquariums. 

Despite the pineapple sponge being reef aquarium safe, many people dislike them. As long as you do not overfeed your fish, pineapple sponges should not take over. As many hobbyists say, “if you limit the pineapple sponges’ resources, you will generally limit the aquarium pest”.

    by
  • Darby Bonner

    As a marine biologist, scuba diving instructor, and experienced aquarium hobbyist, I am obsessed with everything from corals to cruising pelagics like sharks, and everything else in between.

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