Tasmanian Freshwater Lobster

The Tasmanian giant freshwater lobster, also called the giant freshwater crayfish or Astacopsis gouldi, is the largest freshwater invertebrate in the entire world. They can grow up to 5 kilograms (about 11 pounds) and over 80 cm long, and can live up to 60 years. These giant invertebrates are endemic to Tasmania and live in rivers and creeks that flow into the Bass Strait, though recent local extinctions have shrunk the number of rivers they live in. In these rivers, adults live in still, deep, cool water under rocks, logs, and overhanging banks. Like many aquatic animals, they prefer clean streams.

Problems facing the Tasmanian giant freshwater crayfish include poaching and habitat loss, and these problems are exacerbated by the large lobsters slow reproductive rate. Although it is hard to count aquatic animals, research shows that there are about 100,000 lobsters left. Almost none of those are full grown, as the larger lobsters were mostly wiped out in the last century. In 1998, a ban was placed on the fishing of these lobsters. However, because of their slow reproduction rate and the fact that it takes up to 14 years for lobsters to reach sexual maturity have prevented the population from returning to its usual numbers. Larger lobsters that can reproduce are easily caught, making them threatened by illegal fishing, and young Tasmanian giant freshwater lobsters are threatened by habitat loss. This is caused by agricultural expansion, forestry operations and a decline in water quality. A recent increase in sedimentation blocks the crevices young lobsters need to hide from predators.