Chillin’ Spider

This laid-back fishing spider (Dolomedes triton), was resting on a floating birch branch at the pond edge at the Jan Janzen Nature Centre. I had to add a tele-extender to my macro lens to get it within range, and, while holding on to a boardwalk railing, and leaning precariously over the water, I just managed to get close enough for a one-handed macro photograph. Nearby, a larger female was not as accommodating–she hid away underwater beneath the same branch, just to annoy me.

A Basking Fishing spider,  Dolomedes triton.

A Basking Fishing spider, Dolomedes triton.

When hunting, Dolomedes spiders usually rest on the water surface, with at least one leg in contact with a stable object. They sense ripples in the water as other spiders sense prey with their webs. Fishing spiders are opportunists, feeding mostly on insects on the water surface, but the most common food item seems to be water striders (Family Gerridae)*. Dolomedes triton and other water spiders were recently featured in a study (Nyffeler M, Pusey BJ (2014) Fish Predation by Semi-Aquatic Spiders: A Global Pattern. PLoS ONE 9(6)) which examined scientific literature as well as perusing the Internet to come up with a word wide list of spiders that were capable of catching fish. Below are some images from North America:

Figure 2. Fish caught by spiders – examples from North America. A – Dolomedes triton caught mosquitofish (Gambusia) in backyard pond near Tampa, Florida (photo by Stacy Cyrus, DavesGarden website; report # 24). B – Dolomedes triton feeding on fish (probably mosquitofish Gambusia holbrooki) in garden pond near Lady Lake, Florida (photo by Machele White, Lady Lake, Florida; report # 20). C – Dolomedes triton feeding on small fish (presumably least killifish Heterandria formosa) on Tsala Apopka Lake, Florida (photo by Claire Sunquist-Blunden, Ocala, Florida; report # 19). D – Dolomedes triton feeding on fish (probably mosquitofish Gambusia holbrooki) in garden pond near Lady Lake, Florida (same incidence as in Fig. 2B; report # 20). E – Dolomedes triton devouring fish (probably mosquitofish Gambusia holbrooki) on edge of small, slow-moving stream near Fayetteville, North Carolina (photo by Patrick Randall, Fort Bragg, North Carolina, USA; report # 30). F – Dolomedes okefinokensis feeding on small fish (probably mosquitofish Gambusia holbrooki) in swamp in Big Cypress National Preserve, Florida (photo by Misti Little, Stagecoach, Texas; report # 28). doi:10.1371/journal.pone.0099459.g002

Figure 2. Fish caught by spiders – examples from North America.
A – Dolomedes triton caught mosquitofish (Gambusia) in backyard pond near Tampa, Florida (photo by Stacy Cyrus, DavesGarden website; report # 24). B – Dolomedes triton feeding on fish (probably mosquitofish Gambusia holbrooki) in garden pond near Lady Lake, Florida (photo by Machele White, Lady Lake, Florida; report # 20). C – Dolomedes triton feeding on small fish (presumably least killifish Heterandria formosa) on Tsala Apopka Lake, Florida (photo by Claire Sunquist-Blunden, Ocala, Florida; report # 19). D – Dolomedes triton feeding on fish (probably mosquitofish Gambusia holbrooki) in garden pond near Lady Lake, Florida (same incidence as in Fig. 2B; report # 20). E – Dolomedes triton devouring fish (probably mosquitofish Gambusia holbrooki) on edge of small, slow-moving stream near Fayetteville, North Carolina (photo by Patrick Randall, Fort Bragg, North Carolina, USA; report # 30). F – Dolomedes okefinokensis feeding on small fish (probably mosquitofish Gambusia holbrooki) in swamp in Big Cypress National Preserve, Florida (photo by Misti Little, Stagecoach, Texas; report # 28).
doi:10.1371/journal.pone.0099459.g002

This entry was posted in Alberta, Arachnid, Araneae, Bugs, Camera, Canada, Edmonton, Equipment, Flash, Gerridae, Habitat, Hemiptera, macro, photography, Pisauridae, Research Blogging, Science, Season, Summer and tagged , , , , .

2 Comments

  1. Charles Bird 23 June, 2014 at 3:26 PM #

    Well done Adrian! Your photograph is particularly good.

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