Building a productive aquaponics system takes more than hooking a fish tank up to a set of grow beds — picking the right species for the plants you’re growing matters just as much, and there’s no shortage of options. Tilapia is usually the first fish that comes to mind, but yabbies are worth a closer look; they offer some surprising advantages.

Know Your Yabbies

The common yabby is a freshwater crustacean native to Australia. Even though it’s classified as vulnerable, wild populations remain healthy and seem to be growing. Yabby coloring varies quite a bit — you’ll see everything from black to greenish-brown to beige, and water quality has a real influence on which shade they end up.

Yabbies also need somewhere to hide, so build that into your system design from the start. And because they’re natural climbers — they’ll scale plants and pipework without hesitation — you’ll want to keep your water level on the low side, or you may find a few missing from your backyard setup.

Yabbies Temperature Range

One advantage yabbies hold over the similar-looking marron crayfish is a wider comfort zone for temperature, which makes them easier to manage overall. They do best between 60°F and 85°F; go much cooler than that and they’ll turn sluggish. Warmer water, on the other hand, tends to push them toward breeding. Beyond temperature, keep an eye on ammonia (stay under 0.25 ppm) and pH, which should sit between 6 and 7.

Yabbies Growth Rate

A single female can produce anywhere from 30 to 500 eggs per clutch. She carries them attached beneath her tail, and they hatch in about 40 days. The newly hatched young cling to their mother for roughly three weeks before striking out on their own — at which point she’s ready to breed again.

You can slow down breeding by keeping the water toward the cooler end of their range. Also be aware that yabbies will cannibalize each other, so many keepers end up running four separate tanks: one for females, one for males, one for pregnant females, and one for juveniles. Males and females should only be together in the breeding tank, and the males need to come out as soon as the female lays her eggs. Once the babies leave their mother, move them into the juvenile tank and return her to the female tank — this setup limits cannibalism and gives you control over how many offspring you end up with.

Can You Combine Yabbies With Other Fish?

This question matters whether you’re raising yabbies to breed them or simply to feed your plants. Generally speaking, the answer is no — yabbies will eat anything smaller than themselves and get eaten by anything larger, which makes them a poor match for mixed-species tanks.

Benefits Of Using Yabbies In Aquaponics

Like any fish or crustacean in your system, yabbies provide a steady stream of nutrients that feed your plants. But there’s another perk that might tip the scale in their favor: yabbies get by on relatively little water. In fact, give them too much and they may simply climb out over the top of the tank. That works in your favor, though, since it keeps the system simple and largely self-maintaining.

Difference Between Crayfish And Yabbies

Yabbies tend to be more aggressive than crayfish, even though the two look quite similar — a yabby is technically a type of crayfish, though not every crayfish is a yabby. Australia is home to around 140 crayfish species, so mixing them up is easy to do, and it matters because collection rules in the wild differ from species to species.

Both yabbies and crayfish have hard exoskeletons that they must molt periodically to keep growing. Honestly, the most reliable way to tell them apart is to pick one up: crayfish have spiny backs, while yabbies feel smooth. In their natural habitats, yabbies tend to favor dams, while crayfish gravitate toward the moving water of rivers.

Yabbies FAQ

What Do Yabbies Eat?

Yabbies scavenge for food and will eat nearly anything — vegetables, aquatic plants, even fish that have died. You can also feed them formulated pellets, just be sure they finish what’s there before adding more, since yabbies are notoriously messy eaters and overfeeding quickly fouls the tank.

How Big Do Yabbies Get?

Yabbies grow at a fast clip. They can live as long as 7 years and reach up to 8 inches, depending on how much room they have. Growth requires shedding their exoskeleton, which leaves them especially vulnerable to attack during that window — though if they happen to lose a limb, it typically grows back within a few months.

Are Yabbies For Eating?

Yes. They’re a popular food source in Australia and a nice bonus of running a yabbie aquaponics setup. Preparation is similar to crayfish — boil them and serve plain or with a sauce of your choice. Before cooking, hold them in clean, fresh water for a few days to rinse out any tank-related flavor and produce sweeter-tasting meat.

How Long Do Yabbies Live?

Yabbies can live up to 7 years.

Where To Buy Yabbies?

You can find yabbies at most fish stores or aquaponics suppliers. Catching your own at the edge of a still lake is another option, as is buying from a private seller — just confirm you’re actually getting yabbies before you commit.