benthic infaunal species through bioturbation 

 (biological disturbance of the sediments). Other 

 mobile epibenthic invertebrates which are basi- 

 cally subtidal but which may occur at the very 

 low end of the intertidal zone include the dwarf 

 olive (Olivella), which is presumed to be a herb- 

 ivore and detritivore; the heart urchin (Moira), 

 which is a deposit feeder; ihe slonecrdh (Menippe), 

 spider crabs (Libinia spp.); and stomatopods or 

 mantis shrimp (Squilla). Mantis shrimp are vora- 

 cious predators which live in permanent burrows 

 extending fairly deep into the sediments. They 



lurk in these burrows until they spot a potential 

 prey item, whereupon they quickly emerge and 

 snap up the prey with their powerful chelae, 

 capable even of inflicting a substantial wound on 

 the hand of an unsuspecting biologist. Mantis 

 shrimp are extremely common in subtidal sandy 

 areas in North Carolina's sounds, but, because of 

 the depth at which they burrow into the sedi- 

 ments and their mobility, their density is ordinarily 

 grossly underestimated by typical benthic grab 

 sampling. 



29 



