While investigating the mantis shrimp, we found mixed emotions about these marine animals. There are people who think they are great pets for aquariums and others who think they are the worst thing that could ever happen to an aquarium. To learn more about them, let’s look at their traits and nature. Then you can decide for yourself if you want to keep one or not.
Can Mantis Shrimp Live in Freshwater? Everything You Need To Know
Mantis shrimp are marine crustaceans that have captivated aquarists with their incredible hunting abilities and dazzling colors. Their ability to smash through shells with lightning-fast punches makes them both fascinating and notorious in saltwater tanks.
But what about freshwater – can these predators adapt?
I’ve done extensive research to uncover the truth about mantis shrimp and freshwater, Keep reading to learn everything you need to know about
- Mantis shrimp anatomy and habitat
- Challenges of keeping mantis shrimp in freshwater
- Examples of freshwater-adapted mantis shrimp species
- Tips for successfully keeping mantis shrimp in freshwater aquariums
Let’s dive in!
An Introduction to Mantis Shrimp
While often called a “shrimp”, mantis shrimp are actually stomatopods – an ancient order of crustaceans that split off from true shrimp and crabs over 340 million years ago.
There are over 450 mantis shrimp species found in subtropical and tropical marine waters around the world. They live in burrows on sandy or muddy substrate near shorelines.
Mantis shrimp are divided into “spearers” and “smashers” based on their hunting tactics. Spearers impale soft-bodied prey on spiked forelimbs. Smashers bludgeon crabs, snails and bivalves with club-like appendages.
Both types pack incredible punching power for their small size. The peacock mantis shrimp (Odontodactylus scyllarus) accelerates its club to speeds of over 50 mph underwater! This creates cavitation bubbles that boil water and stun prey with shockwaves.
With their formidable weaponry and aggressive territoriality, mantis shrimp are infamously destructive in marine aquariums. They’ll readily eat or smash any fish, coral or inverts they can catch!
Challenges of Keeping Mantis Shrimp in Freshwater
Given their marine adaptations, most mantis shrimp species do poorly in freshwater environments. Here are some key challenges they face:
Osmoregulation Difficulties
Like other crustaceans, mantis shrimp rely on highly concentrated body fluids to maintain water balance. Sudden exposure to low-salt freshwater causes their cells to bloat and burst from osmotic shock.
While some crustaceans can adapt their ion transport systems to varying salinities, most mantis shrimp cannot. They lack specialized gill ionocytes for active ion exchange found in euryhaline (salt-tolerant) species.
Vulnerability to Toxins
Mantis shrimp rely on active ion transport to excrete ammonia as their main nitrogenous waste. However, low salt levels impair ion transport and ammonia excretion.
Ammonia rapidly accumulates to toxic levels in their hemolymph. High ambient ammonia in freshwater poses an added challenge.
Greater Disease Risk
The marine Vibrio bacteria common in mantis shrimp digestive systems can reach pathogenic levels in low-salt conditions. Freshwater also lacks beneficial marine microbes that protect against fungal infections.
Marker enzymes like superoxide dismutase needed to neutralize free radicals are adapted for marine environments. Without these defenses, cell damage from oxidation is increased in freshwater.
Lack of Burrowing Substrate
Most mantis shrimp species rely on specific sandy or muddy substrates to construct protective burrows. Coarse gravel or absence of burrowing materials causes stress.
Examples of Freshwater Mantis Shrimp Species
Despite the above challenges, a handful of mantis shrimp species can survive in freshwater and low-salt brackish habitats. These include:
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Lysiosquillina sulcata – lives in estuaries and tidal mangrove swamps from India to Taiwan. Up to 4 inches long.
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Lysiosquillina maculata – found in muddy estuaries and rivers from Indonesia to the Philippines. Grows over 12 inches long.
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Gonodactylaceus graphurus – inhabits low-salinity mangrove swamps in northern Australia. Reaches 4 inches in length.
These species have adapted ion transport systems, anti-oxidant defenses and burrowing behaviors for periodic exposure to low-salinity environments. However, they will still require very specific care.
Tips for Keeping Mantis Shrimp in Freshwater Aquariums
If you’re up for a challenge, here are some tips for successfully keeping more freshwater-tolerant mantis shrimp species:
- Choose the Right Species
Select species known to inhabit brackish environments like L. sulcata. Avoid most marine species.
- Use At Least a 30 Gallon Tank
Bigger is better – large tanks dilute toxins and provide ample burrowing space.
- Maintain Low-Salt Conditions
Keep salinity around 1.005-1.010 using marine salt. Slowly acclimate shrimp over several hours.
- Provide Deep Sand Substrate
Use at least 6 inches of fine silica sand for burrowing. Avoid sharp substrates.
- Use Additional Buffers
Add alkalinity and calcium to stabilize pH between 7.5-8.5.
- Supplement Their Diet
Feed calcium-rich foods like krill, mollusks and vitamin supplements.
- Use High Filtration
Heavily filter to remove ammonia and nitrates. Target <20 ppm nitrates.
- Perform Frequent Water Changes
Aim for 25% weekly water changes to replenish minerals and reduce nitrates.
- Quarantine New Shrimp
Isolate and observe new shrimp for 1-2 weeks before adding to main tank.
- Monitor Water Parameters
Test for ammonia, nitrites, nitrates, pH, GH and KH weekly. Address any changes.
- Have an Escape Plan!
These shrimp can break tanks and escape – have a backup tank ready just in case!
Even with pristine water conditions, success keeping mantis shrimp in freshwater long-term is not guaranteed. Be prepared for losses, especially with sensitive larvae and juveniles.
With their demanding care requirements, marine mantis shrimp species remain better left to saltwater systems. But the challenge of keeping these predators in low-salt environments continues to intrigue seasoned aquarists.
Common Sign of a Mantis Shrimp
Before looking any further, many aquarium owners think that a mantis shrimp is to blame when fish, crustaceans, and invertebrates start to disappear without a trace. That being said, this is a strong indication that a mantis shrimp might be in your tank. However, it’s not always the case. There are other marine animals that can contribute to this same problem. If fish are going missing, you should think about a mantis shrimp as a possible culprit, but look into other options carefully before you go crazy trying to find one.
Popping Noises: Mantis Shrimp vs. Pistol Shrimp
Some people say that if you hear popping, clicking, or snapping sounds coming from your tank, you have a mantis shrimp. Others say this is not so, that you have a pistol shrimp and not a mantis shrimp.
Of course, if you already have a pistol shrimp, you should think that’s what’s making the noise. That not withstanding, pistol shrimp are unlikely candidates for attacking or killing fish. But they will poke holes in the shells of hermit crabs, snails, and other mollusks to get to the animals inside and kill and eat them.
Because these animals naturally dig holes or tubes in sand, rubble, or mud, look for holes or tunnels in the substrate. These are usually accompanied by a mound of sand or substrate rubble piled up outside the hole. If you find a hole like this, turn down the lights in the tank and wait to see what comes out. This is also true for pistol shrimp.
Mantis Shrimp Care & Where to Buy Mantis Shrimp
Are mantis shrimp a pest?
Temp. The Mantis shrimp is frequently considered an aquarium pest, as they are frequent hitchhikers on live rock and will kill aquarium stock. They are becoming increasingly popular as a Saltwater pet and keeping a mantis is one of the cheapest types of saltwater aquariums.
Can a mantis shrimp show up in a tank?
A mantis shrimp could even unexpectedly show up in your tank because it hid (too successfully) on a live rock —they are masters at hiding! The mantis shrimp is no wimp; some species can reach up to a length of about 12 inches.
Can mantis shrimp be moved?
Mantis shrimp can be moved to the aquarium inadvertently through live stone and, when set up. These hitchhikers are usually very resilient and can survive unnoticed for a long time.
Where do mantis shrimp live?
Mantis shrimp are usually found in shallow subtropical or tropical waters, with some types or species occasionally found in sub-Antarctic waters. They are found along shores, usually living in an abandoned burrow to maneuver in, and bent capture prey when spotted.