An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. Algal bloom commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.
Oscillatoria is a genus of filamentous cyanobacterium which is often found in freshwater environments, such as hot springs, and appears blue-green. Its name refers to the oscillating motion of its filaments as they slide against each other to position the colony facing a light source. Oscillatoria reproduces by fragmentation, facilitated by dead cells which separate a filament into separate sections, or hormogonia, which then grow. Oscillatoria uses photosynthesis to survive and reproduce. Each filament of oscillatoria consists of trichome which is made up of rows of cells. The tip of the trichome oscillates like a pendulum. In reproduction, it takes place by vegetative means only. Usually the filament breaks into a number of fragments called hormogonia. Each hormogonium consist of one or more cells and grow into a filament by cell division in one direction.
Gracilaria is a genus of red algae (Rhodophyta) notable for its economic importance as an agarophyte, as well as its use as a food for humans and various species of shellfish. Various species within the genus are cultivated among Asia, South America, Africa and Oceania.
Porphyra is a genus of coldwater seaweeds that grow in cold, shallow seawater. More specifically, it belongs to red algae phylum of laver species, comprising approximately 70 species. It grows in the intertidal zone, typically between the upper intertidal zone and the splash zone in cold waters of temperate oceans. In East Asia, it is used to produce the sea vegetable products nori and gim. There are considered to be 60 to 70 species of Porphyra worldwide and seven around Britain and Ireland where it has been traditionally used to produce edible sea vegetables on the Irish Sea coast. The species Porphyra purpurea has one of the largest plastid genomes known, with 251 genes.
Atractophora hypnoides is a rare red alga (Rhodophyta) found in the British Isles, France and some Atlantic Islands and is the only species of the genus found in the British Isles. It is attached to the rock or other algae by a small basal disc and is much branched with downgrowing filaments which enclose the main branch or axis forming a cortex. Short filaments of limited growth radiate in whorls from the axis and frequently convert into hairs. The spreading filaments grow irregularly in a diffuse manner. Microscope examination is required for identification.
Bryopsis is a genus of marine green algae in the family Bryopsidaceae. It is frequently a pest in aquariums, where it is commonly referred to as hair algae.
Vaucheria is a genus of Xanthophyceae or yellow-green algae known as water felt. It is one of only two genera in the family Vaucheriaceae. The type species of the genus is Vaucheria disperma.
Bangia is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. Bangia has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants are attached by down-growing rhizoids, usually in dense purple-black to rust-colored clumps. The chloroplasts of Bangia, like others in the division Rhodophyta, contain chlorophyll a and sometimes chlorophyll d, as well as accessory pigments such as phycobilin pigments and xanthophylls. Depending on the relative proportions of these pigments and the light conditions, the overall color of the plant can range from green to red to purple to grey; however, the red pigment, phycoerythrin, is usually dominant.
Laurencia is a genus of red algae that grow in temperate and tropical shore areas, in littoral to sublittoral habitats, at depths up to 65 m (213 ft).
Ectocarpus is a genus of filamentous brown alga that is a model organism for the genomics of multicellularity. Among possible model organisms in the brown algae, Ectocarpus was selected for the relatively small size of its mature thallus and the speed with which it completes its life cycle. The type species for the genus is Ectocarpus siliculosus (Dillwyn) Lyngbye. The life history is an isomorphic to slightly kiheteromorphic alternation of generations, but asexual strains also exist.
Soranthera ulvoidea, sometimes called the studded sea balloon, is a species of brown algae in the family Chordariaceae. It is the only species in the monotypic genus Soranthera. The generic name Soranthera is from the Greek soros (heap) and antheros (blooming). The specific epithet ulvoidea refers to certain resemblances the algae has with Ulva. The name in Japanese is 千島袋のり / ちしまふろくのり literally meaning "Kuril Islands bag nori".
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
Aglaothamnion is a genus of algae belonging to the family Callithamniaceae.
Mesotaenium is a genus of algae belonging to the family Mesotaeniaceae.
The Gelidiellaceae is a small family of red algae containing 5 genera of agarophytes.
Naccariaceae is a family of red algae in the order Bonnemaisoniales, with 3 monotypic genera. Which are found in both the Pacific and Atlantic Oceans.
Wrangelia is a genus of red algae in the family Wrangeliaceae.
Callithamnion is a genus of algae belonging to the family Callithamniaceae.
Liagoraceae is a family of red algae (Rhodophyta) in the order Nemaliales. The type genus is LiagoraJ.V.Lamouroux.
