Friday Beetle Blogging: Amphizoa trout-stream beetle

Amphizoa insolens - trout stream beetle

California

Amphizoa are among the more enigmatic insects I've photographed. These dime-sized beetles are found only in the mountains of China and western North America, a disjunct distribution paralleled by a number of interesting taxa, including the giant redwoods. All six species are predaceous and aquatic, living in debris and under stones in fast-running creeks. Because adults have a morphology suggestive of the terrestrial ground beetles, some researchers have proposed that Amphizoa represents an evolutionary transition between terrestrial and aquatic habitats.

photo details: Canon 100mm f2.8 macro lens on a Canon D60

f/13, 1/125 sec, ISO 100, twin flash bounced off white board

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It is even more interesting with those taxa that are found only in eastern North America & eastern Asia. One of them is the slug family Philomycidae.