Epizoic associations among the White Sea hydroids
D. Orlov

The epizoic hydrozoan fauna established on other hydroids comprises twenty four species from nine families in the White Sea. Epizoic hydroids and their hosts are considered as multilevel epizoic complexes, with the hydroid host as the first level, hydroids colonizing a host, as the second level, and species established on other epizoic colonies, as the higher levels. The colonial structure of epizoic hydroids is so varied and flexible that the morphology of some species differs from their accepted descriptions. This colonial plasticity is varied in accordance with a host´s structure, and is an evident adaptation to an epizoic mode of life. Epizoic hydroids, rising above the bottom, not only colonize a new substrate and escape compexitively superior benthic organisms, but also feed on plankton in tidal currents and local water movements caused by the host´s hydranths. The hydranth sizes of hydroids combined in one epizoic complex, are different possibly to reduce competition for food. Epizoic hydrozoan complexes capture planktonic organisms of a wide size range, thus becoming integrated modules in epibenthic food webs.

Contents of this volume Sci. Mar. 61(1) : 17-26 Back PDF
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