The Marine Macroalgae of the Genus Ulva: Chemistry, Biological Activities and Potential Applications

The genus Ulva (Phylum Chlorophyta, Class Ulvophyceae, Order Ulvales, Family Ulvaceae) was first identified by Linnaeus in 1753 [1]. Since then many taxonomists and phycologists have been involved in the identification of Ulva species [2] which are notoriously difficult to classify due to the morphological plasticity expressed by many members as well as the few reliable characters available for differentiating taxa [2,3]. Its morphology resembles bright green sheets [4], heavily influenced by environmental conditions, age of the thallus, and life style, making difficult the delineation of species by morphological features alone [2]. There is an important relationship between morphological features of Ulva and salinity and nutrient concentrations in these freshwater habitats; however, the most essential physical factor positively correlated with mats development was water depth [3,5].