Opsin three domains of life: Archaea, Bacteria, and Eukaryota. In Eukaryota, type I opsins are found mainly in unicellular organisms such as green algae, and in fungi. In most complex multicellular eukaryotes, type I opsins have been replaced with other light-sensitive molecules such as cryptochrome and phytochrome in plants, and type II opsins in Metazoa (animals). Microbial opsins are often known by the rhodopsin form of the molecule, i.e., rhodopsin (in the broad sense) = opsin + chromophore. Among the many kinds of microbial opsins are the proton pumps bacteriorhodopsin (BR) and xanthorhodopsin (xR), the chloride pump halorhodopsin (HR) the photosensors
Marine fungi asexual fungi. Many species of marine fungi are known only from spores and it is likely a large number of species have yet to be discovered. It is impracticable to culture many of these fungi, but their nature can be investigated by examining seawater samples and undertaking rDNA analysis of the fungal material found. Different marine habitats support very different fungal communities. Fungi can be found in niches ranging from ocean depths and coastal waters to mangrove swamps and estuaries with low salinity levels. Marine fungi can be saprobic or parasitic on animals, saprobic or parasitic on algae, saprobic on