Codium
What is Codium?
Where is Codium commonly found?
What are the structural characteristics of Codium?
What is the ecological and economic importance of Codium?
Codium, genus of about 140 species of marine green algae (family Codiaceae) usually found in deep pools along rocky coasts, to a depth of at least 40 meters (132 feet). The genus is cosmopolitan in distribution, occurring in all marine habitats except the Arctic and Southern oceans. The largest number of species are found in the waters around Australia, California-Mexico, Japan, and South Africa.
Structure
Species of this genus vary widely in form and shape. Their thallus, which is the vegetative body of an alga, is a single giant cell with multiple nuclei. Depending on the species, the thallus can be spherical, flattened, fingerlike and unbranched, or branched. Essentially filamentous, the branches are often woven together to form a velvety pseudothallus that can exceed 30 cm (11.8 inches) in length. Some species are dichotomously branching—their thallus is split in two—and they are somewhat erect, whereas other species may spread out on hard surfaces like a mat. Most species are usually dioecious, which means that male and female gametes are produced on different thalli. However, some species are monoecious, producing gametes from the same thallus. The male gametes are small, contain one or two chloroplasts, and have two threadlike flagella, whereas the female gametes are larger and have many chloroplasts. Some species may also reproduce asexually by fragmentation of the thallus and gamete-producing structures or by parthenogenesis.
- Related Topics:
- dead man’s fingers
- Kingdom: Plantae
- Phylum: Chlorophyta
- Class: Ulvophyceae
- Order: Bryopsidales
- Family: Codiaceae
- Genus: Codium
Ecological and economic importance
Codium is the favorite food of some sea slugs. It is commonly eaten by people in China, Japan, and South Korea. Codium species are also a source of commercially important biochemicals under study for their potential to modulate immunity, suppress inflammation, and prevent cancer. Some species of this genus have become invasive and form algal blooms. The invasive Codium fragile subspecies tomentosoides, for example, has serious negative effects on the global aquaculture industry, particularly oyster farming. The alga grows on hard surfaces such as oyster shells and in strong waves can lift the oysters out and away from the beds into unfavorable waters; this has earned them the nickname “oyster thief.”