WATER STRIDERS AND WATER SPIDERS

      Common water striders and six-spotted fishing spiders, though not related, have some characteristics in common because of the habitats of ponds and slow streams they share.  Habitats force wildlife into particular physical traits, and behaviors, so each creature can use its habitat to full advantage.  Both these aquatic species are up to an inch long, dark on top, which camouflages them, and feed on tiny invertebrates on and in water.  And both kinds of common, invertebrate predators inhabit much of the United States.  

      Water striders and fishing spiders are both attractive in somber ways.  And they have intriguing life histories that make them even more appealing to spot and quietly study by a lovely pond or sparkling, little waterway, both of which are surrounded by lovely, lush vegetation.  

     Water striders "skate" on top of the water's surface without breaking through.  Each strider is long and thin, and has six long legs that spread that insect's tiny weight across such a large expanse of water as to allow it to stride or skate over its surface with ease.  Striders' long bodies are suspended in the air, as if on stilts. 

     Each pair of striders' legs have a distinct function beyond holding the insects above the water.  The front legs are a bit shorter than the others and are used to grab land invertebrates that fall onto the water and float helplessly.  Front legs also seize mosquitoes emerging from ponds.  The middle pair of legs are longer than the rest and used as oars or ski poles to push each strider over the water's surface.  And the rear legs balance and brace striders, holding up their abdomens and helping distribute their weight on the water.

     Water striders are dark on top to be invisible to birds above them.  But they are white or silvery underneath to be invisible to fish below them.

     Female striders lay eggs on objects at the water's shallow edges.  And striders overwinter under fallen leaves on the shores of those shallows. 

     Fishing spiders are mostly brown, with beige markings on their upper abdomens, which blends them into their surroundings quite well.  These spiders don't spin webs, but perch on lily pads and mats of algae and duckweed on the water's surface to wait for prey.  Each spider places one or two feet on the water, from their floating perch, to feel for vibrations that might indicate nearby prey.  These spiders feed on tiny invertebrates, fish and tadpoles that blunder near their perch.  

     Female fishing spiders carry off-white egg sacs with them and protect their newly-hatched young until they disperse on their own.   

     Water striders and water spiders are camouflaged, aquatic invertebrates that are interesting to see living on the surfaces of ponds and slow streams.  Once spotted, they are unmistakable because they occupy unique niches through each summer.        

     

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