Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Infraorder: Entelegynae
Superfamily: Lycosoidea
Family: Pisauridae
Genus: Dolomedes
Species: D. dondalei
Binominal name: Dolomedes dondalei
Common name: Fishing spider

Dolomedes dondalei is a New Zealand native Pisaurid spider and a member of fishing spiders in the genera Dolomedes. Dolomedes dondalei is the largest of the three species of Dolomedes native to New Zealand. Pisaurid spiders don’t spin webs or use silk to catch prey – they are ambush hunters.
Dolomedes dondalei habitat is the fringes of shallow freshwater streams, rivers, lakes, ponds, swamps and fens. These semi-aquatic spiders can swim, dive and walk on it due to the waters surface tension. They can breathe underwater by trapping air on the hairs of their body, they use the ability to run under the water as an escape mechanism
Dolomedes dondalei is an unusual spider as it is capable of catching little fish. They predate fish up to twice their size by using powerful neurotoxins to kill and digestive enzymes that liquefy flesh. It’s a slow process and it can take many hours for a spider to consume a fish.
Dolomedes dondalei will wait poised on a rock or on vegetation overhanging a body of water usually anchoring its hind legs to a stone or plant and its front legs resting on the surface of the water feeling for vibrations from below. It has highly developed mechanosensory systems and when it feels vibrations from a nearby fish, it will leap into the water grabbing and subdue it with its neurotoxin venom before dragging the fish back to shore. It is thought that vision plays a relatively minor role in prey detection.

Click photos to enlarge.
Fishing spider Dolomedes dondalei.jpg

Fishing spider Dolomedes dondalei .jpg

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/