Beddomeia tumida The Critically Endangered Freshwater Snail of Australia

Beddomeia tumida

The Endangered Hydrobiid Snail (Great Lake): A Look at the Life and Habitat of This Rare Snail

The Hydrobiid Snail (Great Lake) Beddomeia tumida, a unique and critically endangered species of freshwater snail found only in Tasmania, Australia. These small, unassuming creatures may not seem like much at first glance, but they play an important role in their ecosystem and are worth our attention and protection.

Beddomeia tumida is a member of the Beddomeia genus, which contains several species of snails found in Australia and New Guinea. The species gets its scientific name from its discoverer, Thomas Beddome, and the Latin word “tumidus,” which means swollen or distended. This refers to the snail’s distinctive swollen shell, which can reach up to is a tiny 3-4 mm millimeters in diameter.

In terms of physical characteristics, Beddomeia tumida is a small snail with a brown shell that is covered in a layer of slime. It has a head with two tentacles, which it uses to sense its environment and locate food. The snail also has a muscular foot that it uses to move around and attach itself to surfaces. B. tumida is a very small, hard to find species which can be difficult to tell apart from other species of Beddomeia and the related genus Phrantela. The accurate identification of Beddomeia to species level normally requires a specialist scientist.


Beddomeia tumida is found in a very specific and limited habitat: the Great Lake, in north-central Tasmania. It favours submergent weed beds and rocks on the lake bed. This area of Tasmania is home to a diverse array of plants and animals, and the snail plays an important role in the ecosystem by helping to break down organic matter and recycle nutrients. However, this habitat is under threat from human activities such as land development and water extraction, which can disrupt the delicate balance of the ecosystem.


In terms of distribution, Beddomeia tumida is found only in a small part of Australia, and it is considered critically endangered. This means that it is at high risk of extinction due to its limited habitat and the threats facing it. No comprehensive surveys have recovered additional specimens to allow for estimates of the population size at any site, making it one of the most endangered snail species in the world.


Beddomeia tumida feeds on a variety of native water plants and algae, and it is an important component of the food chain in its ecosystem. Hydrobiid snails are often prey to native and exotic fish in Tasmania. The introduction of trout into Great Lake is likely to have an impact upon the population.


In terms of reproduction not much is know, except Beddomeia tumida the snails lay small clusters of eggs on the undersides of rocks or other objects in the water. The period of egg incubation is unknown; however, unlike other aquatic molluscs with a free-swimming larval stage (Bryant & Jackson 1999) Beddomeia tumida eggs develop into fully formed juvenile snails prior to emergence – this makes dispersal a problem for the species. Other species of Beddomeia are capable of breeding throughout the year, with no evidence of a seasonal reproduction (Richards 2010). Some Beddomeia species are known to live for over 5 years and develop slowly, reaching sexual maturity only after 2-3 years.


Beddomeia tumida is a fairly solitary creature, and it is not known to engage in complex social behaviors. However, it does communicate with other snails through chemical signals, and it can also produce a defensive slime when it is threatened.

Conservation Status

As mentioned, Beddomeia tumida is critically endangered, which means that it is at high risk of extinction. The main threats facing the species are habitat loss and degradation due to human activities, such as land development and water extraction, agricultural clearing and forestry. B. tumida may also be impacted by competition with and displacement by the exotic snail Potamopyrgus antipodarum (New Zealand hydrobiid). Climate change is also a concern, as it can alter the conditions in the snail’s habitat and make it more difficult for the species to survive.

Fortunately, there are efforts underway to protect and conserve Beddomeia tumida. The Australian government has listed the species as critically endangered and has put measures in place to protect its habitat.

Beddomeia tumida is a unique and fascinating species of freshwater snail that is found only in Tasmania. It is critically endangered and facing a number of threats, but there are efforts underway to protect andconserve it. It is important that we recognize the value of these small but vital creatures and work to protect them, as they play a vital role in the ecosystem and are an important part of our natural heritage. Beddomeia tumida may not be a household name or cute like other species, but it is an important and deserving species that deserves our attention and care. Let’s do our part to ensure that Beddomeia tumida and other species like it continue to thrive and enrich our world for generations to come.