Spiders are a pretty diverse group and while many species of spiders prefer to use webs to catch insects, scientists have observed a number of spiders who prefer to catch fish for prey. These fish eating spiders have been seen to be quite effective fishermen often landing fishes over twice their size.

A study on these fish eating spiders was recently conducted by researchers from the University of Basel in Switzerland and the University of Western Australia. According to the researchers' findings, fish-eating spiders are actually pretty common and can be found on all continents with the sole exception of Antarctica. Moreover, the choice of prey can also be pretty varied. Scientists have documented certain spiders preying on captive dwarf fishes in aquariums in the United States and even pint sized catfish in the rivers of Ecuador.

"The fact that so many species of spiders go on hunt fish, is a new discovery," said Martin Nyffeler, a researcher from the University of Basel in Switzerland.  "Our results suggest that the occasional fish prey plays an important role in the diet of spiders."

While scientists have known for a while that there are spiders that live on fish, the new study shows that there are actually many species of spiders that prefer to prey on fish. Moreover, the new study proves that these types of spiders are widely distributed throughout the world.  To complete their research, Nyffeler and University of Western Australia researcher Brad Pusey went through numerous studies to confirm their suspicions. The researchers also combed through independent reports from various countries. All in all, the pair investigated a total of 89 reports of spiders preying on fish. The researchers published their findings in the online journal PLOS ONE.

Previous studies have confirmed that a small number of spiders belonging to the Pisauridae family preyed on fish. However, the new study shows that at the minimum, 18 species of spiders have been confirmed to prey on fishes as well. These reports were taken from individuals who have seen the spiders catching fish in the wild. Aside from the field reports, the scientists also confirmed 6 more species of spiders that prefer to prey on fish. Unlike the field reports, the six additional species of spiders were observed catching fish in laboratory settings.

Fishes are a great source of nutrition and the spiders that prey on them often reap handsome rewards. Unlike the insects that other spiders prey on, a large percentage of a fish's body weight lies in its muscle mass, which the spiders can digest and turn into energy.