The Yabby is a freshwater crustacean native to Australia. At first view, yabbies look very similar to lobster, only much smaller -- a lobster can reach sizes of up to 3.25 feet as adults, while the yabby's adult size is around 4.7 inches. Yabbies are not a protected species and can be kept as pets.
A World of Colors
Yabbies come in a wide variety of colors. According to ABC's Creature Features, yabbies can be brown -- a common color -- or they can be different shades of green and pale blue. The difference in colors is due to the environment, not to genetics or variations among species. Yabbies living in clean, clear water will be bluer or greenish to match their surroundings, while those living in muddy or dirty waters are a brownish or darker color.
Yabbies molt. Molting is a process by which a crustacean sheds its shell. As the shell falls out, the yabby expands its size -- by absorbing lots of water -- and then grows a new shell of the "proper" size. The moulting process is not a one-time thing. Yabbies molt numerous times during their lifetimes. The latest shell will always match the existing water conditions. That means that if the surrounding water has become dirtier or cleaner, the new shell will be browner or bluer to match.
When it comes time to reproduce, yabbies do it in impressive numbers. A female can lay anywhere from 100 to 1,000 eggs at once. She carries those eggs under her curved tail for up to 40 days, waiting for them to hatch. Only then she releases the new babies into the world.
Eat This, Eat That
Yabbies are detritivores. The word detritivore basically means scavenger -- and that's exactly what yabbies are. They'll eat anything and everything they find, including dead animals, dead plants, decomposing algae and anything else they find at the bottom of the river.
An All-Season Crustacean
Yabbies are happier -- and reproduce better -- in temperatures of between 68 and 77 degrees Fahrenheit. However, these adaptable creatures can survive in very cold or very hot waters with a bit of adaptation. In fact, yabbies can survive in waters as cold as 34 degrees Fahrenheit and as warm as 95 degrees Fahrenheit. When temperatures drop under 61 degrees Fahrenheit, however, yabbies go into semi-hibernation.