Meeting Abstract
Snapping shrimp are a cosmopolitan group of marine crustaceans consisting of hundreds of tropical and temperate species, many of which are recognizable by a large, specialized claw. Snap production results from rapid claw closure, during which a cavitation bubble pops. The short-duration snap is one of the loudest bioacoustic sounds in the marine environment, and their colonies create a pervasive and continuous crackling in many coastal habitats. Despite the contribution of snapping to marine soundscapes, relatively few studies have investigated related acoustic patterns or the underlying behavioral ecology. Recent field recordings have shown tremendous spatiotemporal complexity in snapping shrimp sound production, including variable diurnal rhythms, but the environmental drivers are unclear. In this study, the effect of light on snapping shrimp behavior and snap production was investigated for Alpheus heterochaelis. Snap rates were compared for individual shrimp in isolated chambers under different light treatments (constant light, constant dark, ambient day-night cycle). Shrimp showed high individual variability in snap rate but overall higher snap rates in complete darkness. In further experiments to observe behavior under different light conditions, 2-h video recordings of individuals in isolated chambers in a light or dark treatment were made. Shrimp behaviors were categorized: exploration, excavation, fixed position (cleaning, feeding), and snapping. Results showed that exploration and excavation behaviors differed between the light and dark treatments but fixed position and snap behaviors did not.
