Roger L. Caldwell

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Mantis shrimp are renowned for their unusual method of breaking shells with brief, powerful strikes of their raptorial appendages. Due to the extreme speeds of these strikes underwater, cavitation occurs between their appendages and hard-shelled prey. Here we examine the magnitude and relative contribution of the impact and cavitation forces generated by(More)
Stomatopods (mantis shrimp) are well known for the feeding appendages they use to smash shells and impale fish. Here we show that the peacock mantis shrimp (Odontodactylus scyllarus) generates an extremely fast strike that requires major energy storage and release, which we explain in terms of a saddle-shaped exoskeletal spring mechanism. High-speed images(More)
Mantis shrimp (Stomatopoda) generate extremely rapid and forceful predatory strikes through a suite of structural modifications of their raptorial appendages. Here we examine the key morphological and kinematic components of the raptorial strike that amplify the power output of the underlying muscle contractions. Morphological analyses of joint mechanics(More)
It has been estimated that air pollution damage to crops, ornamentals and forests amounts to over $500 million nationally per year. Of this approximately 25 per cent occurs in southern California. Included in this figure is non -visible damage which is represented as reduced growth and yields; for example, citrus yields in southern California may be reduced(More)
Several behavioural circadian rhythms have been described in Oncopeltus fasciatus, including daily cycles of mating, feeding, oviposition, flight, and general locomotor activity (Caldwell & Dingle, 1967; Dingle, 1968; Caldwell & Rankin, 1971). This insect is known to be migrant, and the temporal segregation of daily activities brought about by this temporal(More)