Last update: November 8, 2023

15 Best Red Claw Crab Tank Mates – FishLab

Red claw crabs are an intensely aggressive species and notorious for their hunting skills. They love slightly brackish water with a wide variety of prey from which to choose.

So, if you’re going to attempt a community tank with them, this article contains the 15 Best red claw crab tank mates. These include cherry barbs, figure 8 puffer fish, x-ray tetras, flagfish, African mono fish, silver moony fish and dragon gobies, to name a few.

Whatever species you decide to house with a red claw crab is going to be risky. Because this crustacean requires access to dry land and a tank’s bottom, choosing roommates should not be a light consideration.

15 Best Red Claw Crab Tank Mates – What You Need to Know

Red claw crab tank mates are a delicate operation, so you first have to understand some things about them. Keep the following points in mind when looking at other fish breeds.


While red claw crabs are prime hunters, they are also shy. They actually prefer to be alone, hanging out at the bottom of the tank and swimming to drier land on occasion. In most cases, they scurry away from anything they perceive as a threat, like a predator or another of their own kind.

Because they are always on the defensive, their claws are at the ready. If they are hungry, agitated, threatened or offended, they will attack their perceived enemy. However, it’s essential to note that the males tend to be more territorial than the females, who are much more peaceful.


Red claw crabs are quite small. They have a max leg length of four inches while their bodies, called the carapace, never get larger than two inches. There isn’t much difference between males and females in this regard.


Every fish is competition to red claw crabs, even their own species. However, they will be aggressive to small, slow-swimming fish.

Parameters ; Tank Setup

These crabs do not require too many plants and decorations. In fact, they are rather destructive to these accoutrements. However, it’s imperative they have soft substrate and a dry-land area they can climb to frequently.

Also, there should be places where the crab can hide and for their periodic molting. So, you’ll want some foliage where they can establish a shelter. The following indicates water parameters and conditions red claw crabs prefer:

  • Tank Size: At least 10 gallons, but definitely more for a community aquarium
  • Temperature: 75°F to 80°F (24°C to 27°C)
  • pH Balance: 7.5 to 8.5
  • Salinity/Specific Gravity: 1.005 (about one to two tablespoons per gallon of water or 1/6 salinity of natural sea water)
  • Filtration: Marine filtration
  • Hardness: dKH 8+

15 Best Red Claw Crab Tank Mates

1. Cherry Barbs

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  • Scientific Name: Puntius titteya
  • Adult Size: Up to two inches
  • Compatible with: Gouramis, Otocinclus, Loaches, Mollies, Tetras, Platies
  • Care Level: Easy/Beginner
  • Origin: Sri Lanka

Cherry barbs may come as a surprise roommate for red claw crabs. But, many experienced aquarists swear by it. Because they are shoaling fish, it’s not likely the crab with bother them. They’re very peaceful and stay in the middle of the tank. If a red claw wants to attack, they’ll quickly learn that cherry barbs are far too fast.

2. Figure 8 Puffer Fish

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  • Scientific Name: Tetraodon biocellatus
  • Adult Size: Up to three inches 
  • Compatible with: Mollies and Bumblebee Gobies
  • Care Level: Difficult/Advanced
  • Origin: Southeast Asia

Although a risky roommate for red claw crabs, it can work if there is enough food for both species. Also, you can only keep one of these in a tank. However, once a figure 8 puffs itself up with water, surely the red claw crab will think twice about instigating a battle.

3. Flagfish

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  • Scientific Name: Jordanella floridae
  • Adult Size: Up to 2½ inches
  • Compatible with: Tetras, Swordtails, Large Shrimp
  • Care Level: Easy/Beginner
  • Origin: Florida, United States

Called the Florida Flagfish or American Flagfish, these fast and active swimmers are adept at avoiding predators. They are incredibly hardy, capable of handling a wide water parameter range. But, they stay mostly at the top of the tank with a lowered water level in groups of six or more.

4. African Mono Fish

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  • Scientific Name: Monodactylus sebae
  • Adult Size: 10 to 12 inches
  • Compatible with: Most semi-aggressive fish; Puffers, Scats, Dragon Gobies, Archerfish
  • Care Level: Medium/Intermediate
  • Origin: Coastal West Africa (Canary Islands to Angola)

These large fish with diamond-shaped bodies make an interesting addition to any aquarium. They tend to reside in the middle to upper regions of the tank. So, their chances of coming to blows with a red claw crab is minimal. But, you want to ensure they have plenty of food like zooplankton and shrimp.

5. Banded Archerfish

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  • Scientific Name: Toxotes jaculatrix
  • Adult Size: Up to 12 inches
  • Compatible with: Danios, Rasboras, Tetras, Gouramis and Barbs
  • Care Level: Advanced/Difficult
  • Origin: Entire area around India, Australia and the Philippines

Because banded archerfish hang out at the water’s surface and are agile swimmers, they make an ideal tank mate for red claw crabs. They are interesting hunters and spit water onto foliage outside their aquatic abode. This forces their meal to fall into and float on the water’s surface.

6. Golden Wonder Killifish

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  • Scientific Name: Aplocheilus lineatus
  • Adult Size: Up to four inches
  • Compatible with: Banjo Catfish, most Cory Catfish, Large Tetras, Otocinclus
  • Care Level: Easy/Beginner
  • Origin: Africa, Sri Lanka ; India

These brightly colored yellow fish are incredibly peaceful and are an acceptable tank mate for red claw crabs. They love similar water conditions and spend most of their time at the top of the tank. But, they can become aggressive if there isn’t enough food.

7. Mollies

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  • Scientific Name: Poecilia sphenops, P. latipinna, P. velifera and etc.
  • Adult Size: Up to 4½ inches
  • Compatible with: Discus, Cichlids, Severums, Guppies
  • Care Level: Easy/Beginner
  • Origin:  Throughout Central America

Any subspecies of molly fish will do well in a tank with a red claw crab. They hang out at the top of the water column and won’t usually bother the crab. However, it’s not uncommon for a molly fish to succumb to an attack.

8. Otocinclus

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  • Scientific Name: Otocinclus vestitus
  • Adult Size: Up to two inches
  • Compatible with: Corty Catfish, Neon Tetras, Boraras, Rasboras, Dwarf Gouramis
  • Care Level: Medium/Intermediate
  • Origin: South America

Also called “otos,” these are small catfish with sucker mouths to slurp up algae that builds up all over the tank. While these are too small for comfort in terms of a red claw crab, keeping them in schools of six or more will avert an attack. Likewise, they are fast, active swimmers and usually evade aggression from predators.

9. X-Ray Tetras

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  • Scientific Name: Pristella maxillari
  • Adult Size: Up to two inches
  • Compatible with: Neon Tetras, Molly Fish, Swordtails, Harlequin Rasboras
  • Care Level: Easy/Beginner
  • Origin: South America

X-ray tetras are excellent tank mates for just about any community setup. However, they can fall prey to red claw crabs if they enter the territory. But, they do spend most of their time as far up to the top of the water column as they can. Even still, they’re hardy, easy to care for and interactions with the crab will be rare.

10. Pacific Blue Eye Rainbowfish

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  • Scientific Name: Pseudomugil signifer
  • Adult Size: Around 2½ inches
  • Compatible with: Any peaceful species
  • Care Level: Easy/Beginner
  • Origin: Australia

What makes the Pacific blue eye rainbowfish ideal for a tank with red claw crabs is the fact that it can tolerate a huge salinity range. They’re fast swimmers and do not often stray from the topmost portions of the aquarium. While they won’t be completely safe from the crab, there is strength in numbers of at least four or more.

11. Silver Moony Fish

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  • Scientific Name: Monodactylus argenteus
  • Adult Size: Between 4½ and 10½ inches
  • Compatible with: Gobies, Larger Mollies, Scats, Banded Archerfish
  • Care Level: Difficult/Advanced
  • Origin: Persian Gulf, Red Sea, Pacific Ocean, Indian Ocean

Also known as Silver Batfish or Sea Angels, this is another type of mono fish. They’re curious, peaceful and do best in groups of at least five of their own species. However, they do like to eat detritus, so they may enter the red claw crab’s territory. However, their size alone may deter the crustacean from attacking.

12. Guppies

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  • Scientific Name: Poecilia reticulata
  • Adult Size: Between ½ and 2½ inches
  • Compatible with: Any other peaceful species
  • Care Level: Easy/Beginner
  • Origin: South America ; the Caribbean

Guppies are cousins to molly fish are a very common recommendation to house with a red claw crab. However, they are very small and there are many horror stories of fish keepers coming home to see their ultimate demise. Therefore, keep them in a large enough tank with plenty of food for the crab.

13. Dragon Goby

  • Scientific Name: Gobioides broussonnetii
  • Adult Size: Between 12 and 24 inches
  • Compatible with: Glassfish, Guppies and Swordtails
  • Care Level: Medium/Intermediate
  • Origin: North, Central ; South America

Dragon gobies are enormous, sea monster-looking fish. While they do spend a lot of time on the bottom, the red claw crab won’t bother them in the least. Likewise, these gobies are too big to care about what crabs do. You just have to ensure you have a huge tank to give everyone their own territory.

14. Golden Topminnow

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  • Scientific Name: Fundulus chrysotus
  • Adult Size: Between 1½ and 3 inches
  • Compatible with: Danios, Tetras, Rainbowfish
  • Care Level: Easy/Beginner
  • Origin: Southeastern United States

Because golden topminnows are hardy and stay mostly toward the top of the tank, they make an adequate roommate for red claw crabs. However, they can become dinner if a crab is hungry or devious enough to nab them.

15. Red Claw Crabs

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  • Scientific Name: Perisesarma bidens
  • Adult Size: Up to four inches
  • Compatible with: One female red claw crab
  • Care Level: Difficult/Advanced
  • Origin: Eastern Pacific Ocean

Because of how intensely territorial and combative red claw crabs are, it’s not advisable to make them part of a community tank. However, of all the species mentioned so far on this list, housing one male and one female is best. But, only do this if you wish to breed these crabs.


Even though these are the 15 best red claw crab tank mates, none is desirable in full. There is going to be a major downside no matter what species you select. So, if you really want a community aquascape with these crabs, prepare yourself to have a big tank that will require frequent attention.

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

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