UC San Diego Library – Scripps Digital Collection

UCDWR No. U146. A relationship has been established between crackling ambientnoise a~d the habits and distribution of snapping shrimp* in Americanwaters, and unusually high noise levels at the higher frequencies canbe expected in the areas where these animals are known to .live. There- ·fore, it is considered important to know their geographic distributionin the inaccessible areas of the Pacific ln order that the generalsound conditions in coastal waters and areas of shoal water can beantlcipated as an aid in the use of Sonar cqutpm.ent.These an~~s live under rocks and shells on the bottom, or incoral. Evon when bottoo. condi tiona are favorable, they do not oftenlive at depths greater than 30 fathons. The report covers a survey or ·all biological literature dealing with the distribution of the noiseproducinggenera Crangon (Alphous) and Synalpheus of the Pacific Ocean,the east and west coasts of North .America and sone contiguous areas.Three charts are presented giving the geographic distribution. Theseindlcate that the animals occur virtuelly throughout the whole tropicaland subtropical areas of the Pacific with the northern and souhhernmargins delimited approximately by the 52~ surface winter isotherm.In examining the charts, it nust be renembered that the absence of apositive indication nny menn only· that no observation has been made.Tn.e noise-producing anll:lals undoubtedly have a wide . distribution withinthe limits indicated. Within this area, their distribution is probablylimited only by unfavorable water depths and bottom characters. Referenceis :oade to recent survey work which verifies that serious shrimp crackledoes occur in the central and southwest Pacific areas.