Paddles and spurs on the legs of the pygmy mole cricket create faster aquatic jumps by increasing the cricket's surface area.

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The pygmy mole cricket is adept at jumping quickly from water. When the cricket prepares to jump from rest on the water surface, it extends its hind legs so rapidly that they break the water surface. During this movement, a varying number of paddles and spurs flare out from each leg, increasing the cricket's surface area in contact with the water. When the leg is fully extended, the spurs and paddles are retracted to reduce drag. This pattern creates a laminar flow beneath the cricket, pushing down the water directly beneath it in streamline, parallel layers that launch the cricket upward.

The leg pads and spurs contain resilin, an incredibly elastic protein, suggesting that these structures are spring-loaded. The cricket's jumping mechanism emphasizes speed over control.

This strategy was contributed by Rachel Major

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"Their [pygmy mole cricket's] powerful hind legs are moved so quickly that they penetrate the surface and as they move through the water, unique arrays of spring-loaded paddles and spurs fan out to increase surface area. This enables these insects to propel a large volume of water downwards in a laminar flow, so that they are launched upwards into the air." (Burrows and Sutton, 2012:1)

"The extension resulted in flaring of tibial paddles and spurs which increased the surface area by 2.4 times and moved the insect upwards." (Burrows and Sutton, 2012:1)

"The distal hind tibia has a medial row of three, and a lateral row of four paddle-like processes 300–400 μm long and 70–110 μm wide... All paddles are normally folded flat, but flare laterally under water when the tibia is extended by the insect or experimenter. After forcible extension, paddles return rapidly to their folded positions... All paddles and spurs have concave inner surfaces like oars. Illumination with ultraviolet light revealed patches of bright blue fluorescence at the articulation of each paddle...and spur, indicating the elastic protein resilin... This suggests that folding of the paddles and spurs, and hence reduction of drag, is effected by springs." (Burrows and Sutton, 2012:2)

Journal article
Pygmy mole crickets jump from waterCurrent BiologyDecember 4, 2012
Malcolm Burrows, Gregory Patrick Sutton

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