The Department of Fisheries has initiated surveys of the Swan River, near Eden Hill and Caversham, for feral pearl cichlids, after a member of the public found several of the unwanted species in the river last week.

full story at - http://www.news.com.au/perthnow/story/0,21598,25234587-2761,00.html

info regarding these species  

http://www.gcca.net/fom/Geophagus_brasiliensis.htm