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Behavioral responses of blue crab Callinectes sapidus postlarvae to turbulence:implications for selective tidal stream transport

1999; Inter-Research; Volume: 179; Linguagem: Inglês

10.3354/meps179135

1616-1599

JM Welch, RB Forward, PA Howd,

Fish Ecology and Management Studies

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 179:135-143 (1999) - doi:10.3354/meps179135 Behavioral responses of blue crab Callinectes sapidus postlarvae to turbulence: implications for selective tidal stream transport James M. Welch*, Richard B. Forward Jr, Peter A. Howd** Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516, USA *Present address: Harbor Branch Oceanographic Institution, 5600 US Hwy 1 North, Ft. Pierce, Florida 34946, USA. E-mail: jim.welch@duke.edu **Present address: Department of Marine Sciences, University of South Florida, 140 7th Avenue South, St. Petersburg, Florida 33701-5016, USA ABSTRACT: Postlarvae (megalopae) of the blue crab Callinectes sapidus move up estuaries using selective tidal stream transport, in which they are in the water column on flood tides and at or near the bottom at other times. They have no endogenous tidal rhythm in activity, so this behavior must be driven by reactions to exogenous environmental cues. Previous work indicated that rates of increase of salinity cue megalopae to ascend into the water column at the beginning of flood tide. However, this ascent due to salinity changes is a short-term response which cannot explain the duration of transport during flood tide or the descent at the end of flood tide. The present study examined turbulence in flow as a cue to regulate swimming behavior during selective tidal stream transport. Laboratory flow tank experiments show that megalopae react to increases in turbulent kinetic energy (TKE) by ascending in the water column and react to decreases in TKE by descending. Above a threshold TKE, megalopae are stimulated to swim regardless of changes in TKE. Reactions to turbulence were similar whether TKE was generated by variations in flow speed or bottom roughness. A model for the joint regulation of selective tidal stream transport by salinity and turbulence is proposed, in which increases in salinity cue the ascent in the water column at the beginning of flood tide, TKE cues swimming throughout the flood tide, and decreases in TKE cue the descent in the water column at the end of flood tide. KEY WORDS: Turbulence · Callinectes sapidus · Blue crab · Selective tidal stream transport · Megalopae · Postlarvae · Currents Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 179. Publication date: April 15, 1999 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1999 Inter-Research.