Does the amphipod fauna associated with epiphytes on kelp (Laminaria hyperborea) change with depth?

Abstract

The present study showed a differential composition of amphipod fauna on red algae with different morphology. The stipes of Laminaria hyperborea are covered with epiphytes, of which red algae constitute a main group. A rich invertebrate fauna dominated by gastropods and amphipods is associated with the epiphytes. The algae may function as a habitat providing refuge against wave action and predation, or as food. The study was carried out on the southwest coast of Norway. Common epiphytic red algae of different morphology with associated amphipods were sampled at three different depths at three localities with kelp forest (L. hyperborea). Although the total amphipod densities increased with habitat size, the distribution of amphipods on the selected epiphytes differed. Ptilota gunneri is repeatedly feather-branched with a complex branching pattern and has high densities of small amphipods, dominated by Jassa falcata and species from the familiy Stenothoidae. The filamentous epiphyte Polysiphonia elongata had low densities with dominance of Caprellidea species. Densities of amphipods associated with P. elongata increased with depth. The amphipod distribution was patchy on Delesseria sanguinea and P. gunneri in relation to station and depth.

Keywords:

• Amphipods
• epiphytes
• kelp fauna
• kelp forest
• red algae

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark

Acknowledgements

This study was funded by the Norwegian Institute of Water Research and the University of Bergen. We are grateful to Stein Fredriksen and Hartvig Christie for help during fieldwork, and to Magnus Reeve for comments on the manuscript.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,University of Copenhagen, Denmark