The video that I present to you shows a Red Alga that has parasitized a Soft Coral (Paramuricea clavata). Parasitism and mutualism, or symbiosis, are very frequent phenomena in the marine world between similar species and different species. There is not always a mutual convenience; in this case the Red Alga has parasitized the Soft Coral to draw its own advantage, because in doing so it can make the most of the sea currents that carry elements useful for its nourishment. Surely the area of the Soft Coral that houses the algae will be damaged and the polyps will die by atrophy even if they are not the feeding element for the algae. alga rossa su paramuricea
Algae an informal term for a large, diverse group of photosynthetic eukaryotic organism that are not necessarily closely related, and is thus polyphyletic. Included organisms range from unicellular microalgae, such as Chlorella and the diatoms, tomulticellular forms, such as the giant kelp, a large brown alga which may grow up to 50 m in length. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomata, xilem and phloem, which are found in land plants. The largest and most complex marine algae are called seaweeds. Algae exhibit a wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction.
Algae lack the various structures that characterize land plants, such as the phyllids (leaf-like structures) of bryophytes, rhizoids, in nonvascular plants, the roots, leaves, and other organs found in tracheophytes (vascular plants). Most are photrophic, although some are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some unicellular species of green algae, many golden algae, euglenids, dinoflagellates, and other algae have become hetrotrophs (also called colorless or apochlorotic algae), sometimes parasitic, relying entirely on external energy sources and have limited or no photosynthetic apparatus. Some other heterotrophic organisms, such as the apicomplexans, are also derived from cells whose ancestors possessed plastids, but are not traditionally considered as algae. Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a by-product of photosynthesis. alga rossa su paramuricea