How Pollution Transforms Marine Ecosystems With Dinoflagellates

Dinoflagellates are a diverse group of unicellular flagellated algae, with some species being photosynthetic and others being heterotrophic. They are a common source of bioluminescence at the surface of the ocean, and are the most common causative agents of harmful algal blooms. They are also responsible for some amazing light shows, including the sparkling, phosphorescent wakes sometimes left by boats or people in the water on a warm, still night.

Dinoflagellates are not only important marine primary producers and grazers, but also the major causative agents of harmful algal blooms. It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Consumption of seafood contaminated by algal toxins results in various seafood poisoning syndromes: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP) and azaspiracid shellfish poisoning (ASP). Most of these poisonings are caused by neurotoxins which present themselves with highly specific effects on the nervous system of animals, including humans, by interfering with nerve impulse transmission.

Dinoflagellates are a group of over 2000 species of eukaryotic algae, with a wide range of ornate shapes and sizes

Dinoflagellates are a group of over 2,000 species of eukaryotic algae, with a wide range of ornate shapes and sizes. They are neither plant nor animal, but unicellular protists, and are mostly marine plankton. They are small, ranging from 15 to 40 microns in size, although the largest, Noctiluca, can be up to 2 mm in diameter. They are motile, swimming through the use of two flagella. Many are thecate, having an internal skeleton of cellulose-like plates, while "naked" cells lack these plates. Dinoflagellates have condensed chromosomes and a large amount of DNA, with some species' genomes being up to 50 times larger than the human genome.

Not all dinoflagellates are photosynthetic. While many are, providing a food source for other organisms, approximately half of all species are heterotrophic, eating other plankton and even each other. Some species are parasites, and some are symbiotic, living in the cells of their hosts, such as corals. Dinoflagellates usually reproduce asexually, with daughter cells forming by simple mitosis and division of the cell.

Dinoflagellates are the most common sources of bioluminescence in the ocean, and they can also produce harmful blooms known as red tides. These occur when a dinoflagellate population increases to such huge numbers that it discolours the water, and they can be caused by nutrient and hydrographic conditions. Some red tides are toxic, with the dinoflagellates producing neurotoxins that can accumulate in shellfish and be harmful to humans.

They are the most common sources of bioluminescence at the surface of the ocean

Dinoflagellates are a diverse group of unicellular flagellated algae belonging to the phylum Pyrrophyta. They are the most common sources of bioluminescence at the surface of the ocean. They are small, ranging from 15 to 40 microns in size, but the largest, Noctiluca, may be as large as 2 mm in diameter. They are motile, swimming by means of two flagella. Many are thecate, having an internal skeleton of cellulose-like plates. The peripheral part of the cell has a series of membranes called the amphiesma. In "armored" species, polysaccharide deposited between the membranes forms rigid plates called thecae. "Naked" cells lack thecae.

Dinoflagellates usually reproduce asexually, with daughter cells forming by simple mitosis and division of the cell. The daughter cells will be genetically identical to that of the original cell. The thecal plates may either be divided, or completely shed and then reformed.

Dinoflagellates are responsible for some amazing light shows including the sparkling, phosphorescent wakes sometimes left by boats or people in the water on a warm, still night. Noctiluca is an example which sometimes occurs in swarms around the British Isles and produces myriads of tiny flashes of light when stimulated by agitation of the water. This can be seen to dramatic effect when scuba diving.

They are the major causative agents of harmful algal blooms

Dinoflagellates are a diverse group of unicellular flagellated algae, with some species being photosynthetic and others being heterotrophic. They are a major causative agent of harmful algal blooms, which can be toxic and have adverse effects on human health and marine ecosystems.

Dinoflagellates are a very large and diverse group of eukaryotic algae in the marine ecosystem, with over 2000 species. They are a major causative agent of harmful algal blooms, which can be toxic and have adverse effects on human health and marine ecosystems.

Dinoflagellates are not only important marine primary producers and grazers, but also the major causative agents of harmful algal blooms. It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents.

Dinoflagellates are a common component of the marine plankton, where they are best known for the roles they play in biogeochemical cycling, toxin production, and bioluminescence. Autotrophic and heterotrophic species contribute to cycling of key elements such as C, N and P. Toxin-producing species can significantly alter food webs and impact both human and ecosystem health via the bioaccumulation and transfer of toxins through the food chain.

They are either photosynthetic or heterotrophic

Dinoflagellates are a group of diverse aquatic organisms that can be either photosynthetic or heterotrophic. Photosynthetic dinoflagellates are primary producers that use pigments like chlorophylls a and c to manufacture their food using energy from sunlight. They are an important source of nutrition for many other organisms and play a crucial role in coral reefs. Heterotrophic dinoflagellates, on the other hand, feed on other plankton or prey and sometimes even on each other. They can be further classified as phagotrophic, which trap and engulf prey, and myzocytotic, which pierce prey and suck out their contents.

Photosynthetic dinoflagellates are encased in interlocking plates of cellulose and have a unique nucleus structure, with chromosomes attached to the nuclear membrane. This structure, called a dinokaryon, is not found in other eukaryotes. They have two flagella, one longitudinal and one transverse, that contribute to their characteristic spinning motion.

Heterotrophic dinoflagellates, on the other hand, do not have a unique structure like photosynthetic dinoflagellates. They have varied feeding strategies and prey preferences, and their abundance is influenced by the availability of prey. They are an important component of planktonic communities, with approximately 50% of dinoflagellate species being heterotrophic.

Dinoflagellates play essential roles in marine food webs and are a diverse group of organisms that can be either photosynthetic or heterotrophic, each with their unique characteristics and functions in the ecosystem.

They are responsible for some amazing light shows

Dinoflagellates are the most common sources of bioluminescence in the ocean. They are single-celled organisms and are common members of the plankton—tiny marine plants, animals or bacteria that float on or near the ocean’s surface. They range in size from about 30 µm to 1 mm, and are found in all the world’s oceans.

Bioluminescence is the biological production of light or bioluminescence is a widespread phenomenon in nature. Bioluminescence is particularly predominant in the marine environment, in members of planktonic bacteria and protozoa, many invertebrates, and vertebrates with specialised light-producing organs that harbour symbiotic bioluminescent bacteria.

Bioluminescence in dinoflagellates is caused by a chemical reaction that happens inside the dinoflagellate. A chemical called luciferin is responsible for the glow. Luciferin is similar to the green chlorophyll in the leaves of plants. Luciferin reacts with oxygen to produce blue-coloured light in the ocean. It happens in the presence of an enzyme called luciferase. When the water where dinoflagellates live is disturbed, it triggers a chemical reaction, and they all start to emit blue light.

Each tiny flash of light is very short, lasting just 0.5 microseconds. But because there are so many blinking on and off at the same time, it brightens the whole surface of the water.

The reason why dinoflagellates give off bright flashes of light is not clearly understood by scientists, but it is probably the organism’s way of defending itself. When a predator swimming close by creates a disturbance in the water, the dinoflagellate reacts by emitting light. One hypothesis is that the flash is enough to scare off the predator and make it stay away.

In coastal regions, the primary source of flow-agitated bioluminescence is dinoflagellates. Occasionally they become very abundant, resulting in red tides, so called because the large number of organisms discolours the water. If the dinoflagellates are luminescent, there can be spectacular displays of bioluminescence at night.

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