Maybe you selected a crayfish because it’s pretty in a small dish. Within weeks, you’ll be having broken equipment and dead pets. Why? Everything else about keeping them depend on their size, from tank volume to social dynamics. Before you put water into the glass, know the growth potential of whatever species you plan to keep. Otherwise, you’re setting yourself up for failure.
You can see from the chart above how dwarf crayfish differ from their larger cousins (like the signal crayfish). Size alone doesn’t mean an animal will fit in your tank. You also has to consider space required for normal behavior including hiding and burrowing. For example, a dwarf orange crayfish only reaches about two inches, which allows it to easily fit in a ten-gallon tank. But a Giant Papuan or a Louisiana Red Swamp crayfish wouldn’t survive in that same tank. They reach more than seven or eight inches long and require at least fifty gallons to adequately move around and breathe.
What You Need to Know Before Getting Crayfish
The sizes given above are the max size of adults. They do not reflect size of juveniles. Most people who start keeping dwarf crayfish purchase very small juveniles (hatchlings), which grow up to three times bigger in just one year. An inch long juvenile might seem harmless, but it’s got the genetics to be so much bigger then that. As young ones, they molt often and grows rapidly for the first year-and-a-half or so. After that, they begin slowing down considerably as they become mature adults. Avoiding having to upgrade your tanks due to their size will save you money… and your pets don’t like stress either.
Because crayfish are omnivores/scavengers, feeding them complicate their care requirements. Since they’ll consume most anything available in their surroundings, it ensures they rarely starve. While this makes for a very flexible pet, it also means lots of waste. Food that isn’t eaten decomposes rapidly and will raise ammonia levels that is intolerable for these sensitive inverts. To properly manage the bioload from multiple crayfish, you require heavy filtration capable of processing twice as much water as your total tank volume. If you wish to maintain healthy crayfish, regular water changes aren’t negotiable.
One very important aspect of crayfish ownership are molting. When your crayfish sheds, it appears alarming. Don’t worry, it’s normal. After they lose their shell, they’re soft and vulnerable for several days. During this time, they hide in full cover, as much as possible to protect themselves from physical harm and predators. Do NOT mess with them during this period. Often times, they’ll eat their previous exoskeleton to reabsorb calcium into the new one. A shed skin isn’t trash, it’s part of the cycle; leave it be.
Selecting compatible tank mates takes into account not only their territories but also how they move around the tank. Crayfish can’t get up to the top of the tank so danios (and other fast surface swimmers) are generally okay. Bottom feeders like corydoras may fight for space, which can cause injury or at least stress. Shy shrimp and active crayfish don’t mix, the crayfish see the shrimps as dinner. By nature most crayfish are solitary, so having more than one male in the same tank mean one is going to suffer injury or death. For a community tank, select species that are naturaly compatible and stay in different parts of water column.
Keeping crayfish boils down to understanding what they are, and how big they really get. This isn’t an exercise in fitting more of them in smaller spaces. This is creating an environment for crayfish to be what they are. When you create a habitat suitable for the ultimate size they will reach, you have developed a self-sustaining system. And that care and feeding results in an ongoing hobby that you’ll appreciate as it evolves with time.
