Marine Biology

, Volume 124, Issue 2, pp 313–324

Spring abundance and distribution of the ctenophore Pleurobrachia pileus in the Seine estuary: advective transport and diel vertical migration

  • Z. Wang
  • E. Thiébaut
  • J. C. Dauvin
Article

DOI: 10.1007/BF00347135

Cite this article as:
Wang, Z., Thiébaut, E. & Dauvin, J.C. Marine Biology (1995) 124: 313. doi:10.1007/BF00347135

Abstract

Several sets of plankton and hyperbenthos samples were collected from the Seine estuary in late May-early June of 1991, 1992 and 1994, and the abundance, size-frequency, horizontal and vertical distribution, and short-term fluctuations of Pleurobrachia pileus (O.F. Müller, 1776) were determined. In the Seine estuary, P. pileus was more abundant than reported for any other European shallow waters. Its depth-averaged density was 33 individuals m-3 in 1991 and 32 individuals m-3 in 1992, with a maximum density of 808 individuals m-3. The ctenophores displayed passive tidal advection and active diel vertical migration. In the outer estuary, high abundances were observed around low tide, and diel vertical migration was very pronounced. However, many individuals remained aggregated near the bottom at all times. In spring, the distribution of P. pileus coincided with the 33 and 150‰ S isohalines, with high abundances on the marine side of the estuary. It is suggested that aggregation of ctenophores near the bottom and diel vertical migration play an important role in the retention of P. pileus in the estuary. Two schemes of P. pileus life cycle in the Bay of Seine are proposed.

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Z. Wang
    • 1
  • E. Thiébaut
    • 2
  • J. C. Dauvin
    • 1
  1. 1.Laboratoire de Biologie des Invertébrés Marine et Malacologie, URA CNRS 699Muséum National d'Histoire NaturelleParis Cedex 05France
  2. 2.Observatoire Océanologique de RoscoffUPR 4601 et Université P. & M. CurieRoscoff CedexFrance
  3. 3.Department of OceanographyUniversity of SouthamptonSouthamptonEngland