Distribution of Migrating Juvenile Pink Shrimp, Penaeus duorarum duorarum Burkenroad, in Buttonwood Canal, Everglades National Park, Florida

Abstract

Abstract The vertical and horizontal distribution of migrating juvenile pink shrimp, Penaeus d. duorarum Burkenroad, in Buttonwood Canal, Everglades National Park, Florida, was studied by sampling with 13 small, conical nets. Samples were taken during darkness on the ebb tide, and were scheduled thrice monthly for 13 months to coincide with the full moon, new moon, and either the last- or first-quarter moon. Juvenile pink shrimp responded positively to moonlight by moving to the surface of the canal during the ebb tide. They probably stayed on the bottom or along the sides of the canal during flood tides. Changes in lateral distribution also were attributable to moonlight. More shrimp were caught on the western side of the canal than on the eastern side during the full- and last-quarter-moon phases because the eastern side of the canal is in shadow for the early part of the ebb tide on these moon phases. On new and first-quarter moons the shrimp were usually distributed evenly across the center of the canal.