Wamberal Lagoon Catchment Aquatic Survey Final Report (PDF ...

5.3. Mollusca
5.3.1. Hyriidae
Freshwater mussels were not identified from the Wamberal catchment. Despite our
best efforts we were unable to confirm the presence of any freshwater bi valves. We
expect the small catchment and intermittent flow rates of feeder creeks is unsuitable
for these species.
5.3.2. Planorbidae
Freshwater Snails Glyptophysa gibbosa were common at most sites and the shear numbers
available were very exciting. These snails are a common native Australian species
recorded widely from the eastern states. They can be distinguished from the similar
planorbid species, Isidorella newcombi by possessing a columellar twist on the aperture.
The shells of G. gibbosa are generally also more elongate than those of I. newcombi.
Snails were most common within the bulrush and reed systems in the drains and the size
of the specimens collected represent the largest ever recorded by the ACP & AABS from
all sites across Australia to date (30mm long). Conditions for the snails must be exceptional
for the numbers and size of the specimens.
Additionally, no exotic freshwater snails were found within the system which was also
a very good sign.
Figure 28. Freshwater Snails Glyptophysa gibbosa
Wamberal Lagoon Catchment Report Australian Aquatic Biological P/L 26