Evolution of annelid diversity at whale-falls and other marine ephemeral habitats
When whales die and sink to the sea-floor, they provide a sudden, enormous food supply to organisms in the vicinity. At first, larger mobile scavengers remove the flesh, but also when only the bones remain, the whale-fall can still sustain macrofauna communities for several years. Some organisms have adapted so well to this kind of food source that they would have problems living elsewhere, e.g. species within the polychaete genus Osedax which have developed a root system which can bore into the bones to reach nutrients. Other organisms are not so specialized on the bones, but rather on the sulphur-oxidizing filamentous bacterial mats covering the bones. Polychaetes from several families have been observed grazing the bacterial mats, and some of the species reported from whale-falls have also been found in other ephemeral, chemosynthetic habitats like e.g. hydrothermal vents, cold seeps and beneath fish farms, where filamentous mat-forming bacteria also occur. In this thesis, nine new species from two polychaete families are described from whale-falls and fish farms in Scandinavian waters, and from whale-falls and sunken wood off the Californian coast. Their phylogeny is investigated using molecular data. The genetic data are further used to separate morphologically cryptic species from ephemeral habitats in different ocean basins.
Parts of work
I. Dahlgren TG, Wiklund H, Källström B, Lundälv T, Smith CR, Glover AG. 2006. A shallow-water whale-fall experiment in the north Atlantic. Les Cahiers de Biologie Marine 47(4): 385-389.II. Wiklund H, Glover AG, Johannessen PJ, Dahlgren TG. 2009. Cryptic speciation at organic-rich marine habitats: a new bacteriovore annelid from whale-fall and fish farms in the North East Atlantic. Zoological Journal of the Linnean Society 155: 774-785.::doi:: 10.1111/j.1096-3642.2008.00469.xIII. Wiklund H, Glover AG, Dahlgren TG. In press. Three new species of Ophryotrocha (Annelida: Dorvilleidae) from a whale-fall in the North East Atlantic. Zootaxa.IV. Wiklund H, Altamira I, Glover AG, Smith CR, Baco-Taylor A, Dahlgren TG. Manuscript. Five new species of Ophryotrocha (Annelida: Dorvilleidae) from whale-fall and sunken wood habitats off California.
Doctor of Philosophy
University of Gothenburg. Faculty of Science
Department of Zoology ; Zoologiska institutionen
Fredagen den 25 september 2009, kl. 10.00, Föreläsningssalen, Zoologiska Institutionen, Medicinaregatan 18.
Date of defence