Bryopsis is a genus of marine green algae in the family Bryopsidaceae.[1] It is frequently a pest in aquariums,[2] where it is commonly referred to as hair algae.[citation needed]
Bryopsis/ˌbɹaɪˈɑpsɪs/ is a genus of macroscopic, siphonous marine green algae that is made up of units of single tubular filaments. Species in this genus can form dense tufts up to 40 cm in height (Fong et al., 2019; Giovagnetti et al., 2018). Each cell is made of up an erect thallus that is often branched into pinnules (Green, 1960). Approximately 60 species have been identified in this genus since its initial discovery in 1809 (J. V. . Lamouroux, 1809). The ecological success of Bryopsis has also been attributed to its associations with endophytic bacteria that reside in the cytoplasm of their cells (Hollants, Leliaert, Verbruggen, Willems, & De Clerck, 2013). Species in this genus are known to be pests in aquariums and associated with green tides due to macroalgal blooms (Han, Li, Wei, Wang, & Zhang, 2020; Song et al., 2019). However, Bryopsis also contains unique chemical properties, most notably, Kahalalide F (KF), a depsipeptide that is being studied for its antitumor properties in human cancer cells and also has important ecological significance in protecting the algae against herbivory. The removal of algal blooms for the extraction of KF may be a pragmatic approach to eradicating Bryopsis from green tides and aiding the economic burden of producing KF experimentally for clinical trials.
Jean Vincent Felix Lamouroux was the first person to differentiate green, red and brown algae. In 1809, he discovered five new marine algal genera and he cited his findings in the Journal de Botanique. Among them were the first five species in the genus Bryopsis (B. pennata, B. hypnoides, B. arbuscula, B. cupressina and B. muscosa) (J. V. . Lamouroux, 1809). He described this genus as being green, with feather-like fronds (M. Lamouroux, 1809). Lamouroux differentiated these species by their size, arrangement and densities of pinnules on the main axes of the thallus (Krellwitz et al., 2001). In 1823, Bory de Saint Vincent brought forth the family of green algae Bryopsidaceae which included the genus Bryopsis, (Bryopsidales, Ulvophyceae and Chlorophyta) (Woolcott, Knöller, & King, 2000). Later, 4 other genera (Bryopsidella, Derbesia, Pedobesia and Trichosolen) were also placed in this family. Since Lamouroux’s initial discovery, there have been over 60 Bryopsis species described worldwide (Krellwitz et al., 2001). The discovery of the variety of life history patterns has been formative in understanding the relationship between Bryopsis and other genera in the order. The life history varies between species of Bryopsis and even within single species of this genus. The differentiation of new genera, such as Bryopsidella, which was previously reported as Bryposis halymeniae and Derbesia neglecta, resulted from the identification of its unique life history. This resulted in taxonomic reorganization at the family level (Morabito et al., 2010). Continuous morphological variations and their inherently simple thallus structure has made it difficult to differentiate species within this genus (Krellwitz et al., 2001). Therefore, the use of molecular datasets is an important tool in differentiating species. Currently, research using the chloroplast genome of Bryopsis as an identifier for species level studies is being done. The entire chloroplast genome of B. plumosa, B. maxima and B. hypnoides has been sequenced (Krellwitz et al., 2001; Lü et al., 2011).
The word Bryopsis comes from Greek origins. Bry- comes from the Greek words bryos and byron, meaning moss, blossom and bloom. Ópsis or Ypsis is the Greek word for appearance or sight (M. Lamouroux, 1809). -opsis is synonymous to “likeness” and used in naming living organisms with organic structures that resemble other pre-existing structures that have already been named.