Naslov
Caulerpa racemosa: Adaptive varieties studied by fatty acid composition (Northern Adriatic Sea, Vrsar, Croatia)

Autori
Blažina, Maria ; Iveša, Ljiljana ; Najdek, Mirjana

Izvornik
European journal of phycology (0967-0262) 44 (2009), 2; 183-189

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Caulerpa racemosa ; exposed ; fatty acids ; northern Adriatic Sea ; sheltered ; propagation state

Sažetak
Total lipids and fatty acid composition were monitored seasonally in exposed and sheltered Caulerpa racemosa settlements along the coast of St. Juraj isle (Vrsar, Croatia). The underlying sediment in the exposed area was characterized by a lower content of total lipids (0.63± ; ; 0.18 mg/g d.w.) and coarser grain sizes (Md=1319.5 µ ; ; m) in comparison to sediment of the sheltered area (0.89± ; ; 0.06 mg/g d.w. ; Md 378.9 µ ; ; m). Despite the proximities of both populations studied, and, hence, both experiencing similar exposure to seasonal fluctuations, the alga responses were different. Total lipid changes and fatty acid composition of the related settlements indicated the differences in thalli condition during summer of 2004 and to some extent different strategies in cold adaptation during winter 2005. In August 2004, the bad condition of thalli at the sheltered site expressed by low unsaturation (UNS/SAT 0.45) resulted from its sexual propagation state, in contrast to the advanced condition of vegetative propagation state at the exposed site (UNS/SAT: 1.1). The poor thalli condition was related to its slower development at the sheltered habitat, having correspondingly lower biomass. Furthermore, at this site little to no difference in total lipids was observed with season. During the winter period (min. temp. 7.7 °C) both settlements altered their fatty acid composition by increasing unsaturation (UNS/SAT up to 1.8), but a pronounced winter peak in total lipids occurred at the exposed site. Under similar environmental conditions, the C. racemosa in this study developed different strategies in cold adaptation and propagation state as a consequence of apparently varying impact of the hydrodynamism at these two proximate sites. This study suggests the mode in which exposure impacts the growth cycle of C. racemosa in temperate regions.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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