The seasonal and interannual proximate and sterol composition were assessed in two red (Gelidium robustum, Gelidiaceae and Gracilariopsis sjoestedtii, Gracilariaceae), two brown (Ecklonia arborea, Lessoniaceae and Macrocystis pyrifera, Laminariaceae), and two green (Ulva lactuca and Ulva clathrata, Ulvaceae) macroalgae species and the seagrass Phyllospadix torreyi (Zosteraceae) sampled over 3 years in a subtropical climate in Baja California Sur, Mexico. Each macroalga had a particular sterol composition that was typical of their taxonomic group. The red algae had cholesterol as the major sterol; 92% on average in G. robustum and 90% in G. sjoestedtii, followed by t‐dehydrosterol and brassicasterol. In the brown algae the major sterol was fucosterol, which accounted for approx. 90% and 92% of total sterols for M. pyrifera and E. arborea, respectively, followed by campesterol (7% and 5%) and isofucosterol (1.5% and 1.3%). The green algae had isofucosterol as the major sterol, with 92% on average for U. lactuca and 87% for U. clathrata, followed by cholesterol, fucosterol, and brassicasterol or norcholesterol. The seagrass P. torreyi had β‐sitosterol as the major sterol (39 to 89%, depending on the season), followed by campesterol (4 to 7%), stigmasterol (3 to 6%), and isofucosterol (1.7 to 3.5%). Four (cholesterol, campesterol, fucosterol, and isofucosterol) of the 14 sterols identified in macroalgae and the seagrass could be used to differentiate between classes (Florideophyceae – red, Phaeophyceae – brown, Ulvophyceae – green, and Monocots – seagrass) both seasonally and interannually. The seasonal and interannual sterol composition of macroalgae and seagrass was quite stable, with the exception of red G. sjoestedtii sampled in August and green macroalga U. lactuca and seagrass P. torreyi both sampled in May 2002. Seasonal and interannual variations of proximate and sterol composition are discussed in relation to their reproductive state and environmental parameters.

中文翻译：

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下加利福尼亚半岛（墨西哥）太平洋沿岸大型植物甾醇的季节性和年际变化

季节性和年际近端和甾醇组成在两种红色（粗石花、石斛科和江蓠科，江蓠科）、两种棕色（Ecklonia arborea、Lessoniaceae 和 Macrocystis pyrifera、Laminariaceae）和两种绿色（Ulva lactucauca 和 Ulva lactucae ) 大型藻类物种和海草 Phyllospadix torreyi (Zosteraceae) 在墨西哥南下加利福尼亚州的亚热带气候中采样超过 3 年。每个大型藻类都有特定的甾醇成分，这是它们分类群的典型特征。红藻的主要甾醇是胆固醇；G.robustum 中平均为 92%，G.sjoestedtii 中为 90%，其次是 t-脱氢甾醇和芸苔甾醇。在褐藻中，主要的甾醇是岩藻甾醇，约占。M. pyrifera 和 E. arborea 总甾醇的 90% 和 92%，其次是菜油甾醇（7% 和 5%）和异岩藻甾醇（1.5% 和 1.3%）。绿藻以异岩藻甾醇为主要甾醇，平均为 92% 的 U. lactuca 和 87% 的 U. clathrata，其次是胆固醇、岩藻甾醇和芸苔甾醇或正胆固醇。海草 P. torreyi 以 β-谷甾醇为主要甾醇（39% 至 89%，视季节而定），其次是菜油甾醇（4% 至 7%）、豆甾醇（3% 至 6%）和异岩藻甾醇（1.7% 至 3.5%） ）。在大型藻类和海草中鉴定出的 14 种甾醇中的四种（胆固醇、菜油甾醇、岩藻甾醇和异岩藻甾醇）可用于季节性和年际区分类别（花藻科 - 红色、褐藻科 - 棕色、叶藻科 - 绿色和单子叶植物 - 海草） . 大型藻类和海草的季节性和年际甾醇组成相当稳定，