Biodiversity & Conservation

, Volume 6, Issue 11, pp 1507–1522

Biogeographic and bathymetric ranges of Atlantic deep-sea echinoderms and ascidians: the role of larval dispersal

  • Craig M. Young
  • Mary A. Sewell
  • Paul A. Tyler
  • Anna Metaxas

DOI: 10.1023/A:1018314403123

Cite this article as:
Young, C.M., Sewell, M.A., Tyler, P.A. et al. Biodiversity and Conservation (1997) 6: 1507. doi:10.1023/A:1018314403123


Dispersal plays an important role in the establishment and maintenance of biodiversity and, for most deep-sea benthic marine invertebrates, it occurs mainly during the larval stages. Therefore, the mode of reproduction (and thus dispersal ability) will affect greatly the biogeographic and bathymetric distributions of deep-sea organisms. We tested the hypothesis that, for bathyal and abyssal echinoderms and ascidians of the Atlantic Ocean, species with planktotrophic larval development have broader biogeographic and bathymetric ranges than species with lecithotrophic development. In comparing two groups with lecithotrophic development, we found that ascidians, which probably have a shorter larval period and therefore less dispersal potential, were present in fewer geographic regions than elasipod holothurians, which are likely to have longer larval periods. For asteroids and echinoids, both the geographic and bathymetric ranges were greater for lecithotrophic than for planktotrophic species. For these two classes, the relationships of egg diameter with geographic and bathymetric range were either linearly increasing or non-monotonic. We conclude that lecithotrophic development does not necessarily constrain dispersal in the deep sea, probably because species with planktotrophic development may be confined to regions of high detrital input from the sea surface. Our data suggest that more information is necessary on lengths of larval period for different species to accurately assess dispersal in the deep sea.

bathymetric range biodiversity biogeographic range developmental mode larval dispersal lecithotrophy vs. planktotrophy 

Copyright information

© Chapman and Hall 1997

Authors and Affiliations

  • Craig M. Young
    • 1
  • Mary A. Sewell
    • 2
  • Paul A. Tyler
    • 3
  • Anna Metaxas
    • 4
  1. 1.Department of Larval EcologyHarbor Branch Oceanographic InstitutionFt PierceUSA
  2. 2.Department of Biological SciencesUniversity of Southern CaliforniaLos AngelesUSA
  3. 3.Department of OceanographyUniversity of SouthamptonSouthamptonUK
  4. 4.Department of BiologyDalhousie UniversityHalifaxCanada

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