Alpheus heterochaelis, the bigclaw snapping shrimp, belongs to the snapping shrimp or pistol shrimp family (Alpheidae), whose members possess a single, large chela (claw) that has been modified such that it is capable of producing a distinct snapping or popping sound. The acoustic claw snap of Alpheus heterochaelis is important as a means of stuning/killing prey, in defense, and as part of a theat display in agonistic intraspecific encounters as well (Herberholz and Schmitz 1998)Individuals are typically dark translucent green with orange and blue tipped uropods. The rostrum is small and the carapace edge is smooth and spineless and large snapping claw is strongly notched on both the upper and lower margins at the base of the fingers. The snapping claw can be either the left or right claw, and it attains a length nearly half that of the body. The opposite paired claw remains an unmodified pincer. The snapping claws of male A. heterochaelis are larger and broader than those of females of equal size (Nolan and Salmon 1970, Herberholz and Schmitz 1998).A. heterochaelis is the largest and most colorful of the snapping shrimps of the southeastern United States (Rupert and Fox 1988).Sound-production in Alpheus heterochaelis had long been believed to be the result of either rapid closure of the oversized pistol claw or of the separation of two smooth disk areas at the base of each of the fingers of the large claw. The true basis for snapping shrimp sound production was described in 2000 by Versluis et al. The authors explain that the very rapid claw closure emits a high-velocity (25m/s) jet of water whose speed exceeds cavitation conditions to create a small (expanding from miscroscopic to around 3.5mm at maximum size), extremely short-lived cavitation bubble. High-speed imaging revealed that the characteristic popping sound was actually produced by the rapid (<300 ¦#181;s after formation), violent collapse of the cavitation bubble.Lohse et al. (2001) studied this phenomenon further and found that as the snapping claw cavition bubble collapses a very short, intense flash of light is emitted. The authors conclude from this observation that the collapsing bubbles experiences extremely high internal pressures and temperatures exceeding 5,000°C.Curiously, auditory organs have not been identified in A. heterochaelis and may be absent. Mechanoreception and chemosensory reception may therefore be the most important means for individuals to analyze signals from conspecifics (Herberholz and Schmitz 1998). This subject is taken up in more detail below.