BACKGROUND Yabbies are crustaceans. They have three stages in their life cycle: egg - juvenile - adult. Yabbies have large claws used for defence, fighting, holding food and digging. They breathe by using their gills to absorb oxygen from the water. They draw water under the back of their exoskeleton (hard shell), over their gills and out through a hole near their head. They are generally green or brown in colour. Yabbies live in streams, lakes, dams and ponds in southeastern Australia. In the water, yabbies like to hide under rocks, mud and branches. Predators such as humans, fish, turtles, birds and water rats eat Yabbies. BEHAVIOUR
They are very adaptable and dependent on environmental conditions. They are very active and breed when conditions are right. Temperature, weather conditions (drought, flood) water quantity and quality determine the number of healthy yabbies in a water source.
Yabbies are aggressive and when several are together in a small space they will fight.
Size (adult): Approximately at 1-year 6cm, 2 years 10cms and 3 years 12cms.
Life span: Average life span 3 years.
Sexual maturity: Usually when they are 10-20gms they can begin to breed.
Gestation period: 1-2 months.
Number of offspring: 200-1,000 eggs.
SPACE You will need an aquarium 60cm x 30cm x 30cm. There should be a gravel base. MOVEMENT They have four pairs of walking legs and a long thick tail. To move through the water quickly, they flap their tail. A flip with the tail will propel them backwards rapidly. WATER Whilst they do not need water maintained as fish do they still need clean water. Change 1⁄4 of the water every 2 weeks.
TEMPERATURE Yabbies should be kept at 12-22 degrees. FILTRATION A filtration system will assist to keep water clean. VENTILATION Ensure no sprays or fumes are used around the aquarium. A mesh top will assist with ventilation.
SHELTER The aquarium should provide an area for refuge from lights, action and other yabbies. This can be created with plants, rocks and rocky overhangs. If breeding occurs there needs to be lots of spots for the babies to hide. Removing the male may assist with their survival but be advised mothers may also eat them. They could be placed in a separate aquarium.
CLEANING Regular daily removal of food waste is required. To clean the whole tank, remove and place the yabbies in a secure container. Rinse the tank carefully and fill again with gravel and items. Do not use chemicals. Rinse gravel through thoroughly. FEEDING Yabbies eat algae, dead and decaying plants, and sometimes small fish insects or animals. They can be fed finely chopped vegetables and goldfish pellets. They only need a small amount of food each second/third day – 1 pellet and 1⁄4 teaspoon of vegetable matter (e.g. carrot).