Complete list of species
Plants | Algae | Fish
Crustaceans | Birds

Crustaceans

	Ostracods
	Osticythere baragwanathi Ostracods are tiny crustaceans, usually about 1 mm in length, enclosed within a bean-shaped covering that can completely enclose the body. Ostracods inhabit almost all types of aquatic environments and most live on the seabed. There are a number of Ostracod species which also inhabit Lake Illawarra. Osticythere baragwanathi, for instance, is characteristic of a lagoon environment such as Lake Illawarra where large fluctuations in salinity and disscolved oxygen occur. It is one of the most common ostracods on the eastern coast of Australia.
	Decapods
	Blue Swimmer Crab Portunus pelagicus Blue swimmers can be distinguished from other large crabs by the long spine projecting from each side of the shell and its bluish colour. They settle as juveniles in very shallow sandy habitats among the seagrasses in the lake and grow rapidly to maturity after only one year. Adult blue swimmers are caught within the lake and must be greater than 6 cm long from the notch between the eyes to the back of the carapace to be of legal size. A maximum of 20 crabs can be kept.
	Eastern King Prawn Penaeus plebejns King prawns grow to a maximum length of 30 cm and migrate from coastal waters into estuaries as larvae. They then grow rapidly over the next 9-12 months before migrating into offshore waters where they spawn. Whilst in Lake Illawarra the prawns are sought after by people keen to catch a feed for dinner. They are caught in the night on very dark nights with the aid of a light, when the prawns emerge from the sand and migrate towards the sea. They are then scooped up in hand-held nets. Prawns are an important commercial species in Lake Illawarra as well.
	Molluscs
	Spisula trigonella Small cockles, off-white in colour. Average length 2-2.5 cm. Very abundant in muddy and sandy-mud bottom of the whole lake. Largely distributed in the estuarine environment of Australia.
	Sydney Cockle or Mud Ark Anadara trapezia Large cockles, whitish in colour with dark brown edging. Average length 7-8 cm. Very abundant in the mud, sandy mud and seagrass beds of the lake.
	Gastropods
	Batillaria australis Whelk-like mollusc. External grey-brown and interior purple-brown in colour. Very common and found in seagrass beds, mud and sand flats of the whole lake.
	Bembecium melanostomum Snail-like mollusc with length usually greater than width. Colour yellow or green-brown and up to 2.5 cm long. Very abundant on seagrasses and the concrete retaining wall of the entrance tidal channel, especially on the eastern side of Windang Bridge. It is still abundant on the seagrasses of the back channel, but very rare on the seagrasses along Windang Peninsula.
	Nassarius burchardi Snail-like mollusc, grey-brown in colour and up to 1.5 cm long. Very abundant on the seagrasses and on the mud and sand flats of the lake. It lives in the main body of the lake as well as the entrance channel.
	Salinator fragilis Snail-like mollusc, pale yellow-gray in colour. Up to 1.5 cm long. Widely distributed in the mudflats, salt marshes and mangroves of the lake.
	Jelly-fish
	Common Jelly-fish Catostylus mosaicus Is the most conspicuous jelly-fish in NSW coastal lakes. They are up to 30 cm across. The bell has four pyramidal mouth arms about one and half times the length of the bell radius and numerous small sensory organs in the bell margin. They are usually translucent in colour. The species is very abundant in the lake in late summer and autumn month.