Monterey Bay Aquarium Research Institute
Marine Botany

Delesseria decipiens Taxonomy


Ecology | Morphology | Glossary | Acknowledgments

Delesseria blade

Division: Rhodophyta

Class: Florideophyceae

Order: Ceramiales

Family: Delesseriaceae

Genus: Delesseria

Species: decipiens

Herbarium specimen of Delesseria decipiens

Division Rhodophyta -
      The Division Rhodophyta includes over 4,100 species of algae commonly know as the red algae. The major defining characteristics of the division include: possession of chlorophyll a and possibly chlorophyll d and the presence of phycobiliproteins, phycocyanin and phycoerythrin, a red pigment which is primarily responsible for the algae's unique color. Reproductive characteristics include the absence of flagellated sperm (spermatia) and the possession of carpogonia on the female gametophytes. Other defining characteristics include the arrangement of the thylakoids in the chloroplasts, which are not stacked but scattered individually in the chloroplasts, and the use of floridean starch a s a storage product.
     Delesseria displays all of these characteristics, as well as other characteristics common among red alga, such as pit plugs and a brilliant red color.

Class Florideophyceae-
     The Class Florideophyceae is a diverse group of red alga containing species as seemingly different as the coralline algae and Botryocladia, the sea grapes. These algae are all united, however, by morphological similarities such as filamentous or pseudoparenchymatous construction, apical cell division, the formation of pit connections, and dioecious gametophytes. In addition, members of the class Florideophyceae also have carpogonia located on a trichogyne, as well as carpospores that form on gonimoblast filaments.

Order Ceramiales-
     The order Ceramiales is the largest order in the red algae, and is grouped primarily by the morphology of the algae's reproductive structures. A major characteristic of the order is that the auxiliary cell in the female gametophyte is derived from a supporting cell only after fertilization. The carposporophyte is in turn derived from this auxiliary cell and is surrounded by a distinct pericarp. Algae of the order Ceramiales generally have isomorphic life histories.

Genus Delesseria-
     First described by J.V. Lamouroux in 1813 and named for French naturalist Baron Delessert, the genus Delesseria includes species from a variety of places around the Delesseria underwaterworld including Delesseria sanguinea from the west coast of Europe and Delesseria lancifolia from the Falkland Islands and Antarctica. Of these, most scientific research has been done on D. sanguinea, including studies of seasonal growth patterns and sensitivity to UV light. Recent genetic analysis has questioned the classification of the genus, suggesting that D. decipiens and D. sanguinea are more closely related to the genus Membranoptera then to many of the other species currently in the Delesseria genus. The blades of Delesseria species are generally thin, flat and monostomatic while the conspicuous midrib is often polystromatic. Intercalary divisions occur in Delesseria except in the primary axial cell row. 

Delesseria sanguinea
Image © M.D. Guiry

The location of reproductive structures is also an important characteristic of the genus. Cystocarps are located on fertile leaflets branching from the midrib in the female gametophyte, and have a single carpogonial branch on a supporting cell. Spermatangia on the male gametophyte are located all over the thallus of the alga. Finally, tetraspores are located on blades of the last two orders of branching along the midrib.

Species decipiens
      Delesseria decipiens
is an intertidal to subtidal species of Delesseria that grows annually on the west coast of North America (distribution). It was first collected in 1859 from the Strait of Juan de Fuca near present day Washington State, and was described by J. Agardh in 1872.


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© Hannah Griego 2003