Vertebrata lanosa on Ascophyllum nodosum: Effects on reproductive and vegetative structures

GAUNA, M.C.; PARODI, E.R.; CÁCERES, E.J.; GARBARY, D.

Rhodos

Congreso; Fifth European Phycological Congress; 2011

Federations of European Phycological Societies (FEPS) Council

The nature of the symbiosis between Ascophyllum nodosum and Vertebrata lanosa, remains largely unresolved. To address this issue we conducted field observations on both vegetative and reproductive parameters of epiphyted and non-epiphyted fronds of A. nodosum. The main aim of this study was to evaluate the effects of the presence V. lanosa on vegetative and reproductive structures of A. nodosum. The samples were collected from Tor Bay Provincial Park, Guysborough County, Nova Scotia. Between April to July 2008, were haphazardly collected 80 non-epiphytized and 81 epiphytized A. nodosum fronds during low tides in the mid-intertidal zone where V. lanosa was common. A second sampling was made in late July 2011 collecting over 200 fronds of both A. nodosum’s populations. We detected significative differences in several analyzed variables: frond length (FL); dry mass (DM), number of primary branches (NPB); number of broken branches (NBB); length of segments added in 2007 and 2006 (LSA07)(LSA06); dry mass segmented formed in 2007, 2005 and 2004 (DMS07) (DMS05) (DMS04); number of receptacles added on segments formed in 2007 (NR07) and dry mass receptacles on segments of 2007 (DMR07). All of them were higher on epiphyted A. nodosum fronds. Also, we observed significative and positive correlations between number V. lanosa clumps and A. nodosum dry mass.