The genus Ceratium is restricted to a small number of freshwater dinoflagellate species. Previously the genus contained also a large number of marine dinoflagellate species. However, these marine species have now been assigned to a new genus called Tripos. Ceratium dinoflagellates are characterized by their armored plates, two flagella, and horns. They are found worldwide and are of concern due to their blooms.
Chaetoceros is a genus of diatoms in the family Chaetocerotaceae, first described by the German naturalist C. G. Ehrenberg in 1844. Species of this genus are mostly found in marine habitats, but a few species exist in freshwater. It is arguably the common and most diverse genus of marine planktonic diatoms, with over 200 accepted species. It is the type genus of its family.
Attheya is a genus of small single celled diatoms. Some of these species were earlier regarded to belong to Chaetoceros, or to Gonioceros, the taxonomic status of some of these species are still debated.
Bacteriastrum is a genus of diatoms in family Chaetocerotaceae. There are more than 30 described species in genus Bacteriastrum, but many of these are not currently accepted, and new species are still added to the genus. The type species for the genus is Bacteriastrum furcatum Shadbolt.
Grethe Berit Rytter Hasle was a Norwegian planktologist. Among the first female professors of natural science at the University of Oslo, she specialized in the study of phytoplankton.
Pseudo-nitzschia is a marine planktonic diatom genus that accounts for 4.4% of pennate diatoms found worldwide. Some species are capable of producing the neurotoxin domoic acid (DA), which is responsible for the neurological disorder in humans known as amnesic shellfish poisoning (ASP). Currently, 58 species are known, 28 of which have been shown to produce DA. It was originally hypothesized that only dinoflagellates could produce harmful algal toxins, but a deadly bloom of Pseudo-nitzschia occurred in 1987 in the bays of Prince Edward Island, Canada, and led to an outbreak of ASP. Over 100 people were affected by this outbreak after consuming contaminated mussels; three people died. Since this event, no additional deaths have been attributed to ASP, though the prevalence of toxic diatoms and DA has increased worldwide. This anomaly is likely due to increased awareness of harmful algal blooms (HABs) and their implications for human and ecosystem health.
Odontella aurita is a diatom and the type species of genus Odontella. The easiest way to identify this species is by recognizing the very distinct shape of the cells belonging to this genus. Odontella aurita is cultivated industrially for human consumption due to its ability to produce up to 28% of its total lipids as eicosapentaenoic acid (EPA), a long-chain polyunsaturated fatty acid (PUFA). PUFAs such as EPA are known to provide a variety of health benefits in humans, and are commonly obtained by fish oil. However, with the increasing concern of over-exploited fisheries, microalgae are a promising source of PUFAs as they can be grown year-round and their fatty acid profile and content are easily manipulated by growth conditions.
Odontella is a genus of marine diatoms. It contains the following species:
Skeletonema dohrnii is a diatom. Together with S. marinoi, this species has flattened extremities of the processes of the fultoportulae, which interlock with those of succeeding valves without forming knuckles. It is a species of the genus Skeletonema that can be found in many waters across the globe. In the coastal waters of South Korea, their cell diameters are about 3 to 6 micrometers.
Skeletonema grethae is a species of diatom. Together with S. pseudocostatum, S. tropicum, and S. japonicum, it possesses external processes of its fultoportulae that have narrow tips which connect with those of sibling cells via fork-, knot-, or knuckle-like unions.
Skeletonema japonicum is a diatom. Together with S. pseudocostatum, S. tropicum, and S. grethae, it possesses external processes of its fultoportulae that have narrow tips which connect with those of sibling cells via fork-, knot-, or knuckle-like unions.
Eucampia zodiacus is a common marine centric diatom species. It is known to be cosmopolitan except in polar regions. E. zodiacus is a harmful diatom that has become known as the predominant organisms causing the bleaching of aqua-cultured nori seaweed.
Thalassiosira is a genus of centric diatoms, comprising over 100 marine and freshwater species. It is a diverse group of photosynthetic eukaryotes that make up a vital part of marine and freshwater ecosystems, in which they are key primary producers and essential for carbon cycling
Torodinium (ˌtɔɹoʊˈdɪniəm) is a genus of unarmored dinoflagellates and comprises two species, Torodinium robustum and the type species Torodinium teredo. The establishment of Torodinium, as well as the characterization of the majority of its morphology, occurred in 1921 and further advances since have been slow. Lack of research is largely due to its extremely fragile and easily deformed nature, which also renders fossil records implausible. The genus was originally characterized by torsion of the sulcus and a posterior cingulum. Since then, new distinctive features have been discovered including an extremely reduced hyposome, a longitudinally ribbed episome, and a canal on the dextro-lateral side. Further investigation into the function of many anatomical features is still necessary for this genus.
Cyclotella is a genus of diatoms often found in oligotrophic environments, both marine and fresh water. It is in the family Stephanodiscaceae and the order Thalassiosirales. The genus was first discovered in the mid-1800s and since then has become an umbrella genus for nearly 100 different species, the most well-studied and the best known being Cyclotella meneghiniana. Despite being among the most dominant genera in low-productivity environments, it is relatively understudied.
Chaetoceros coarctatus is a marine, unicellular species of planktonic diatom in the genus Chaetoceros, first described by Lauder in January 1864 using samples from the Hong Kong harbor. Like many diatoms, it is preyed upon by ctenophores. During warming periods of the Mediterranean Sea, this non-native species, first introduced through the Suez Canal, expands its range. Cell chains showcase pairs of posterior and anterior terminal setae, as well as intercalary setae, for anti-predatory mechanical protection and floating benefits. These silica appendages have spines, curved tips, and are longer those on other members of the Chaetoceros genus for higher survival benefits.
Leptocylindrus is a genus of diatoms belonging to the family Leptocylindraceae. They are long, cylindrical diatoms that are made up of multiple cells in a line. These cells have chloroplast to allow it to produce energy through photosynthesis by taking in sunlight and carbon dioxide to create sugars. the cells are attached at the cell walls called valves, the cell wall is slightly concave on one side and convex on the other so that the other cell wall attached will fit together.
Greta Albrecht Fryxell was a marine scientist known for her work on the biology and taxonomy of diatoms. In 1996, she was elected a fellow of the American Association for the Advancement of Science.
Linda Karen Medlin is a molecular biologist known for her work on diatoms. She is an elected member of the Norwegian Academy of Science and Letters.
Skeletonema costatum is a cosmopolitan centric diatom that belongs to the genus Skeletonema. It was first described by R. K. Greville, who originally named it Melosira costata, in 1866. It was later renamed by Cleve in 1873 and was more narrowly defined by Zingone et al. and Sarno et al. Skeletonemacostatum is the most well known species of the genus Skeletonema and is often one of the dominant species responsible for red tide events.
