Cockrone Lagoon Aquatic Biological Survey-Final Report (PDF File ...

Australian Aquatic Biological Pty Ltd
5.2. Fish Species
5.2.1. Poeciliidae
Gambusia holbrooki are an introduced species that is a major pest and is having devastating
repercussions on our native species. They are live bearers protecting their eggs and young and an
exceptionally robust species, surviving in conditions that will kill most native species. They eat
the eggs and larvae of our native species, and the same food and survive in both fresh and marine
environments. They are an exceptionally robust species surviving in water conditions that are
unsuitable for our native species.
Exceptionally small numbers of mosquito sh Gambusia holbrooki were captured. This was very
disappointing, if the aquatic conditions are not even suitable for mosquito sh then there is no
hope or future for native species. Most of the upper catchments were devoid of mosquito sh with
specimens not appearing till lower down closer to the Lagoon proper.
Other pest and exotic sh species like swordtails, guppies, mollies, carp & goldsh were all absent
from the catchment. Much of eastern NSW is impacted by these pest species and their absence in the
catchment was fantastic news and very encouraging for the future health of the local environment
and prosperity of the native aquatic fauna.
Figure 7. Mosquito fish or plague minnow Gambusia holbrooki
WPT003 Forest pond off Bounty Hill Road
Cockrone Lagoon Catchment Aquatic Biodiversity Report 15