VELIIDAE (family) (Water Treader)

One of several, similar families which are all commonly called 'water treaders'. 

ADULTS: similar to the family Gerridae, but usually distinguished by: 'shoulders' very wide; lack elongated middle and hind legs; small or even tiny (1-6mm); very fast movement. Usually dark coloured and in large numbers. They are found in a range of habitats: on ponds and rivers, near lakes, in salt water, or on mud flats.