Tree Water Spider

Size about 25mm including legs. This was a fast and extremely alert spider. When I came close, it ran to the middle of its web and faced me head-on out in the open. It is certainly not a coward. Not sure if it is an introduced species to Australia, probably not. It was found in the undergrowth of some woodland, beautiful habitat. The web was on the ground near some tree trunks, quite a visible funnel actually, not extremely dense and relatively flat with lots of dried leaves incorporated. The animal shows a beautiful pattern on its thorax and abdomen, a bright stripe through the middle up to its eyes, a dark middorsal patch up to about the middle. Legs are banded in various brown-cream tones. The fangs are large with proudly shown venom injectors. Taxonomically, it belongs to the family of water spiders, which is odd. ALA shows a few representations. Like the one on http://www.arachne.com.au mine was found near Wynnum in Brisbane. Update 12/5/2017: This species is definitely quite common. I found it again, in wet habitat, near mangroves. This time, it was on a tree and not near the ground at all. It showed a remarkably similar behaviour. It sat in a very large/wide cocoon-shaped but open web.