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Plankton

Plankton

Awareness is growing regarding the importance of the oceans and the variety of life they support. Research in many branches of oceanography is discovering the vast unknown of the marine world, and has expanded interest in the understanding of the marine environment and the role each member plays in a complex community.

The free-floating organisms known as plankton, from the Greek "wandering," are the drifters of the ocean. Although most of these organisms are motile (moving), they cannot swim or move against currents, but they can move vertically in the water column.

Many marine plankton are found in the deep waters of the outer ocean, or pelagic waters, whereas others are found in the shallow waters known as the neritic zone. Many of the neritic plankton are known as meroplankton, and spend only a brief period of their life cycle in the planktonic category. Many pelagic forms, such as the holoplankton, are planktonic during their entire lifespan.

The size of plankton can also determine its general name.

  • Picoplankton: Smaller than 2 μm ; includes bacteria, prochlorophytes, and viruses
  • Nanoplankton: 2 to 20 μm; includes diatoms, coccoliths, and silicoflagellates
  • Microplankton: 20 to 200 μm; includes large diatoms, dinoflagellates, and small zooplankton, such as ciliates
  • Macroplankton: 200 to 2,000 μm; includes large zooplankton, copepods, and invertebrate larvae
  • Megaplankton: Larger than 2,000 μm; includes fish larvae and gelatinous zooplankton

Phytoplankton

Many kinds of marine and fresh-water organisms utilize inorganic carbon (as carbon dioxide) and fix it into organic compounds by photosynthesis . The principal taxa of microscopic planktonic producers, primary producers , are found over most of the world's oceans, lakes, rivers, and estuaries, and comprise the base of the food web . Phytoplankton consist primarily of diatoms, dinoflagellates, coccolithophorids, silicoflagellates, bacteria, and viruses. All of the organisms discussed below are key players in the microbial food web.

Diatoms.

Diatoms have cell walls of silica and pectin, and float in the water column or attach to surfaces as single cells or chains. They are one of the major contributors to primary production in coastal waters, and occur everywhere in the ocean, but are most abundant in colder, nutrient-rich, nearshore waters. Cell division occurs by fission, which is accompanied by a reduction in cell size. They are one of the principal groups that fix carbon through photosynthesis, and this production is prominent during seasonal blooms of short duration.

Dinoflagellates.

Dinoflagellates occur as single cells, either naked or within a cellulose cell wall, and many species use flagella to move. These organisms are sometimes classified as protozoa and algae because of their ability to photosynthesize and also absorb nutrients by being parasitic, or by ingesting organic particles. They are second to diatoms in contributing to primary production, and are widespread in the oceans, but are most abundant in nutrient-poor waters offshore. Reproduction is by cell division. Some species are bioluminescent (emitting a pale blue glow seen at night). Dinoflagellates often are the cause of red and brown tides, so named because the algal pigments give the water a colored tint.

Coccolithophorids.

Coccolithophorids are single-celled organisms. Many are flagellated, and are protected by ornate calcareous plates, called coccoliths, embedded in a gelatinous sheath that surrounds the cell. These organisms may form cysts that produce spores to produce new individuals. They are most abundant in warm, open-ocean waters, and are sometimes found nearshore.* Coccolithophores can photosynthesize (autotrophic) and may also absorb organic matter (heterotrophic).

Silicoflagellates.

Silicoflagellates occur as single flagellated cells and typically secrete a silicious outer skeleton. Like coccoliths, these organisms are both autotrophic and heterotrophic , and are most abundant in cold, nutrient-rich waters.

Bacteria.

Bacteria are prokaryotes with cell walls made of chitin , and occur as single coccoid cells or long filaments. They often are restricted to waters with low oxygen, and are important in the metabolism of aquatic ecosystems. To support their metabolism, they obtain nutrients by the uptake of organic matter and the release of exoenzymes to lyse (distintegrate or dissolve) particulate organic matter, and attack diatoms, dinoflagellates, and flagellates. Blue-green algae, or cyanobacteria, are photosynthetic. Bacterial activity in marine waters is strongly affected by availability of nutrients and organic matter. Their productivity increases as phytoplankton productivity increases.

Viruses.

Viruses play an important role in marine food webs. They infect a wide range of hosts, including bacteria and phytoplankton. They can potentially reduce phytoplankton and bacterial production by viral lysing of their cells and the releasing of dissolved organic carbon. This dissolved carbon can than be utilized by other phytoplankton cells.

Prochlorophytes.

Prochlorophytes are a recently discovered group of extremely abundant producers that are barely visible by microscopy. They are most abundant at the lower layers of the illuminated region of the water column, and are now considered to be another major player in primary production.

Nanoflagellates.

Nanoflagellates are both autotrophic and heterotrophic. They feed on viruses, bacteria, and some picoplankton and nanoplankton. Nanoflagellates are major consumers of bacteria; some experiments show that they may be able control their abundances when larger predators, such as dinoflagellates, are not present. However, this is less likely to occur in nature.

Protozoans.

Nanoplanktonic and microplanktonic protozoan groups are mainly ciliates and heterotrophic dinoflagellates. They consume bacteria, nanoplankton, and microplankton. While these groups engulf their prey, they also release nutrients that stimulate the growth of these same prey.

Zooplankton

Zooplankton are planktonic free-floating animals in fresh and marine aquatic systems, and are the major consumers of the organisms in the microbial food web. These organisms possess a wide range of feeding strategies, from the nematocysts (stinging cells) of cnidarians (e.g., jellyfish) to the complicated mouthparts of copepods. Some are carnivorous (animal-eaters), some are herbivorous (plant-eaters), and some are omnivorous (eaters of plants and animals).

These animals can move by means of cilia, flagella, jointed appendages, jet propulsion, or tailed larvae (as in tunicates to larval fish). Reproduction varies from asexual, to fission and fragmentation, to sexual reproduction where some gametes are released into the water and fertilized, yet others are retained and fertilized internally.

Zooplankton include many phylum, and not all can be discussed here. Some live their entire life cycle in the water (holoplankton), whereas only the larval stages of fish and other benthic organisms (such as starfish) live in the water column for a short time (meroplankton). All are considered zooplankton. An overview of the major zooplankton phyla follows.

Protozoa.

Discussed previously, this group includes ciliates, dinoflagellates, foraminifera, and radiolarian.

Coelenterata (Cnidaria).

Typically known as jellyfish, the major groups are Hydrozoa, Scyphozoa, and Anthozoa. The hydrozoans medusae are the prominent members in zooplankton, and the most common forms are aurelia, pelagia, and siphonophores. These gelatinous animals are major consumers of smaller zooplankton and some of the microbial food web.

Ctenophora.

Best known as comb jellies, these possess eight "comb" rows of fused cilia. When they are abundant, these animals can consume phytoplankton and zooplankton, and can clear the water of food for other zooplankton.

Chaetognatha.

Known as the arrow worm, this is a common member of deep-water plankton. Smaller species are found in coastal waters, whereas larger species are abundant offshore in blue water. They are predacious carnivores that grasp their prey and paralyze them before ingesting them.

Annelida.

This includes many species of marine polychaetes. Many of these organisms can be seen on the surface at night, shedding gametes for sexual reproduction. Their larvae are abundant in the zooplankton community.

Mollusca.

This includes marine gastropod larvae, pteropods, and cephalopods (commonly known as squid and octopus).* Mollusks are consumers of larger zooplankton.

Echinodermata.

This includes starfish, brittle stars, and sea cucumber. All these animals are meroplankton. Their larvae are a major presence in the zooplankton community.

Arthropoda.

These are the major members of zooplankton and include copepods, shrimp, crabs, lobsters, amphipods, crustaceans, and euphausids, or krill, which are the major source of nutrition for some whales.* The most studied of crustacea are the copepods. These animals are found in all parts of the world's oceans, lakes, and estuaries and are considered the major consumers of most of the organisms in the microbial loop. Because they are holoplankton, spending their entire life in water, they can consume a wide range of food particles, from nanoplankton to microplankton, as they mature. Copepods are responsible for much of the carbon energy transferred from phytoplankton to larger zooplankton.

Chordata.

Known as the urochordates (tunicates), this includes ascidians (or sea squirts) and are found on the coast, whereas larvaceans, oikopleura, thaliaceans, salps, and doliolids are pelagic and spend their entire life cycle in the water column. Tunicates are now realized to be major consumers of phytoplankton and smaller zooplankton, and can contribute to the entire food-web dynamics as much or even more than copepods.

Larvaceans have retained their notochord and tail as adults and produce a mucus net, or "house," around their bodies to capture food particles. The house is either ingested or abandoned.

The salps and doliolids are free-swimming tunicates with a cylindrical or barrel-shaped body with up to eight muscle bands to aid in swimming by jet propulsion and feeding with an internal mucus net. These animals have a complicated life cycle that includes a sexual stage and one or two asexual stages. They are known for their ability to create "blooms," or a rapid increase in their abundance, exceeding 1,000 animals in a cubic meter of water in a short period of time. With this rapid increase in population and their ability to filter feed a wide range of food sizes, they can outcompete copepods during these bloom events. Their role in the food web is being studied more intensely because of their production of large, fast-sinking fecal pellets that can transfer organic matter produced by primary producers to fish and benthic organisms.

see also Algal Blooms, Harmful; Algal Blooms in the Ocean; Cephalopods; Crustaceans; Ecology, Fresh-Water; Ecology, Marine; El NiÑo and La NiÑa; Lakes: Biological Processes; Life in Water; Microbes in the Ocean; Ocean Biogeochemistry.

Deidre M. Gibson

Bibliography

Barnes, R. S. K., and K. H. Mann. Fundamentals of Aquatic Ecosystems. Oxford, U.K.: Blackwell Scientific Publications, 1980.

Parsons, T. R., M. Takahashi, and B. Hargrave. Biological Oceanographic Processes, 3rd ed. Oxford, U.K.: Pergamon Press, 1984.

Smith, Deboyd L. A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae. Dubuque, IA: Kendall/Hunt, 1977.

Valiela, Ivan. Marine Ecological Processes, 2nd ed. New York: Springer Verlag, 1995.

* See "Algal Blooms in the Ocean" for a photograph of a coccolithophore bloom near the coast.

* See "Cephalopods" for a photograph of an octopus's suction-cupped tentacles, and the Nautilus.

* See "Crustaceans" for photographs of crustaceans, and "Ecology, Marine" for a photograph of a krill swarm.

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Plankton

Plankton

Plankton (from the Greek word planktos, which means "wandering") are communities of mostly microscopic organisms that inhabit watery environments, from oceans to muddy regions. Some plankton drift passively or swim weakly near the surfaces of oceans, ponds, and lakes, while others exist as bottom-dwellers, attaching to rocks or creeping on the ground through sand and silt.

Plankton are classified under the kingdom Protista. During the genesis of protists, a true nucleus, as well as the other components of eukaryotic cells (mitochondria, chloroplasts, endoplasmic reticulum, Golgi bodies, 9 2 flagella and cilia , the functions mitosis and meiosis ) arose. Thus these organisms are considered to be ancestral to plants, fungi and animals. While the majority of plankton are unicellular and therefore considered to be simple eukaryotic organisms, at the cellular level they are extremely complex. Plankton should be considered an organism in itself and not be compared to a single cell from a multicellular organism.

Despite their small size, plankton are the very basis for life in the earth's various ecosystems . An ecosystem is comprised of all the organisms living in a community and all abiotic factors with which the organisms interact.

The two main processes within an ecosystem are energy flow and chemical cycling. Energy enters most systems in the form of sunlight and is converted to chemical energy by autotrophs . The chemical energy is then passed to heterotrophs in organic compounds of food, and finally dissipates into the system as heat. Trophic levels are based on an organism's main source of nutrition. Autotrophs, also called primary producers, are generally photosynthetic organisms that use light energy to synthesize sugars and other organic compounds. Heterotrophs, or consumers, are supported by these photosynthetic organisms. The primary consumers are herbivores, who gain sustenance directly from autotrophs. Secondary consumers feed on the herbivores and tertiary consumers feed on the secondary ones. Those organisms that feed off of dead organisms are known as detritovores. An understanding of this pyramid within an ecosystem explains why the extent of photosynthetic activity determines the energy supply of the entire ecosystem.

Algae, as freshwater and marine phytoplankton and intertidal seaweeds, are responsible for nearly half of all photosynthetic production of organic material, rendering them extremely significant in the aquatic food webs where they support countless suspension-feeding and predatory animals. All algae, except prokaryotic cyanobacteria (formerly called blue-green algae), belong to the kingdom Protista. Algae all contain chlorophyll A, a primary pigment in cyanobacteria and plants, but differ in accessory pigments, which trap wavelengths of light to which chlorophyll A is not as sensitive. These accessory pigments include other chlorophylls (green), carotenoids (yellow-orange), xanthophylls (brown), and phycobilins (red and blue).

These differences in pigments point to different roles and effects of algae on the ecosystem. An overabundance of dinoflagellates (algae containing phycobilins) results in the blooming of red tides. When shellfish such as oysters feed on the dinoflagellates, they concentrate the algae along with toxic compounds released by the dinoflagellate cells. Because these toxins are dangerous to humans, collection of shellfish is restricted during red tides to reduce the risk of paralytic shellfish poisoning. Seaweed is the large marine algae that inhabits intertidal and subtidal zones of coastal waters. Coastal people, especially in Asia, harvest seaweed for food since it is high in iodine and other essential minerals. The brown alga laminaria is used in soups and the red alga porphyra is used to wrap sushi.

With so much dependent on the existence of plankton, the fight against water pollution aims to prevent not only the destruction of plankton, but of other species as well.

see also Food Web; Zooplankton.

Danielle Schnur

Bibliography

Campbell, Neil A. Biology, 3rd ed. Berkeley, CA: Benjamin/Cummings Publishing Company, Inc, 1993.

Odum, Howard T. Systems Ecology: An Introduction. New York: Wiley, 1984.

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Plankton

Plankton

Plankton are microscopic plants and small animals that live in the surface waters of oceans, lakes, and rivers and drift with the currents. They include bacteria, fungi, algae, protozoa, invertebrates, and some vertebrates.

Phytoplankton are photosynthetic, meaning that they use sunlight to convert carbon dioxide and water into organic molecules such as glucose to use as food. Phytoplankton include microscopic algae, blue-green bacteria, and some true bacteria. These organisms exist in waters where light is able to penetrate. Phytoplankton form the base of nearly all aquatic food chains, directly or indirectly supplying the energy needed by most aquatic protozoa and animals.

Words to Know

Algae: Single-celled or multicellular plants or plantlike organisms that contain chlorophyll.

Bacteria: Single-celled microorganisms that live in soil, water, plants, and animals, and some of which are agents of disease.

Consumer: Organisms that cannot make their own food and consume other organisms to obtain the nutrients they need for growth.

Ecosystem: A community of organismsplants, animals, and microorganismstogether with their environment.

Food chain: A series of organisms, each dependent on the organism at the level below it for food.

Food web: An interconnected set of all the food chains in the same ecosystem.

Fungi: Kingdom of various single-celled or multicellular organisms, including mushrooms, molds, yeasts, and mildews, that do not contain chlorophyll.

Invertebrates: Animals that lack backbones.

Photosynthesis: Chemical process by which plants containing chlorophyll use sunlight to manufacture their own food by converting carbon dioxide and water to carbohydrates, releasing oxygen as a by-product.

Primary producer: Organisms such as plants, algae, and certain bacteria that make organic molecules from inorganic substances.

Protozoa: Single-celled animal-like microscopic organisms that must live in the presence of water.

Vertebrates: Animals with backbones.

Zooplankton are small grazing animals that live in surface waters and feed on phytoplankton. The amount of zooplankton present in a given area depends on the amount of the microscopic algae present. Zooplankton are a diverse group mostly made up of crustaceans (animals with external skeletons) such as water fleas and shrimps but also include jellyfish, protozoa, and insects. Some species of zooplankton are predators, feeding on other species of zooplankton, and some spend part of their lives as parasites of larger animals, such as fish.

Zooplankton are very important in open-water marine and freshwater food webs. They are eaten by relatively small fish that are then eaten by larger fish. Zooplankton are an important link in the transfer of energy from the algae (the primary producers) to the ecologically and economically important fish community (the consumers).

Species of zooplankton react differently to factors that place stress on aquatic ecosystems. Toxic chemicals, acidity of the water, decreased oxygen, or changes in temperature may kill some zooplankton while others survive. As a result, the health of a body of water or a change in its physical or chemical makeup can be determined in part by the species of zooplankton that are present.

[See also Crustaceans; Protozoa ]

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Plankton

Plankton

Plankton are small aquatic organisms that live in both freshwater and marine environments. The word "plankton" is derived from the Greek word planktos, which means "drifting." In general, plankton have little or no means of locomotion and their distribution is determined largely by water currents and mixing. However, some plankton can swim through less turbulent waters using flagella and other appendages .

There are several broad categories of plankton. Phytoplankton are small plantlike plankton and are commonly referred to as algae. Phytoplankton are primary producers (they use energy from the sun to make organic food molecules). Bacterioplankton are very small (only seen through a microscope) and include bacteria, fungi, and viruses. Some bacterioplankton play important roles as primary producers and others as decomposers. Zooplankton are planktonic invertebrate animals (for example, the water-flea Daphnia ). Some zooplankton consume phytoplankton, whereas others are predatory and consume smaller zooplankton. Ichthyoplankton are planktonic fish eggs and larvae. The ichthyoplankton are highly vulnerable to predation by invertebrate and vertebrate predators.

Plankton are important because they form the base of aquatic food webs . That is, plankton are a critical food resource for other aquatic organisms (such as fish) that live in freshwater and marine environments. Plankton are important to humans because they support recreational and commercial fisheries. Some humans consume plankton directly in the form of dietary supplements. For example, the phytoplankton species Spirulina has been marketed as a source of vitamins and protein .

Plankton are also important in processes that control the distribution and movement of energy and essential nutrients such as carbon, nitrogen, and phosphorus. A significant amount of the total global carbon is stored in the ocean. Some researchers have proposed that it is possible to increase the uptake of carbon dioxide generated by human combustion of fossil fuels by increasing production of ocean plankton through fertilization . Researchers debate whether this proposal is practical at a large scale.

see also Algae; Biogeochemical Cycles; Ecosystem; Estuaries; Ocean Ecosystems: Hard Bottoms; Ocean Ecosystems: Open Ocean; Ocean Ecosystems: Soft Bottoms

Janet M. Fischer

Bibliography

Hutchinson, G. Evelyn. A Treatise on Limnology, vol. 2. New York: John Wiley & Sons, Inc., 1967.

Smith, DeBoyd L. A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae. Dubuque, IA: Kendall/Hunt Publishing Company, 1996.

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plankton

plankton Aquatic organisms that drift with water movements, generally having no locomotive organs. The phytoplankton (plants) comprise mainly diatoms, which carry out photosynthesis and form the basis of the aquatic food-chains. The zooplankton (animals) which feed on the diatoms may sometimes show weak locomotory powers. They include protozoans, small crustaceans, and, in early summer, the larval stages of many larger organisms. Plankton are sometimes divided into net plankton (more than 25 μm diameter) and nannoplankton, which are too small to be caught in a plankton net. The word is derived from the Greek plagktos, meaning ‘wandering’.

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plankton

plankton Aquatic organisms that drift with water movements, generally having no locomotive organs. The phytoplankton (plants) comprise mainly diatoms, which carry out photosynthesis and form the basis of aquatic food-chains. The zooplankton (animals), which feed on the diatoms, may sometimes show weak locomotory powers. They include protozoans, small crustaceans, and in early summer the larval stages of many larger organisms. Plankton are sometimes divided into net plankton (more than 25 μm diameter) and nannoplankton, which are too small to be caught in a plankton net. The word is derived from the Greek plagktos, meaning ‘wandering’.

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"plankton." A Dictionary of Plant Sciences. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

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plankton

plankton Aquatic organisms that drift with water movements, generally having no locomotive organs. The phytoplankton (plants) comprise mainly diatoms, which carry out photosynthesis and form the basis of the aquatic food chains. The zooplankton (animals) which feed on the diatoms may sometimes show weak locomotory powers. They include protozoans, small Crustacea, and in early summer the larval stages of many larger organisms. Plankton are sometimes divided into net plankton (more than 25 μm diameter) and nanno plankton, which are too small to be caught in a plankton net. The word is derived from the Greek plagktos, ’wandering’.

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plankton

plankton (adj, planktonic) Minute aquatic organisms that drift with water movements, generally having no locomotive organs. The phytoplankton (plants) comprise mainly diatoms, which carry out photosynthesis and form the basis of the aquatic food-chains. The zooplankton (animals) which feed on the diatoms may sometimes show weak locomotory powers. They include protozoans, small crustaceans (Crustacea), and in early summer the larval stages of many larger organisms. Plankton are sometimes divided into netplankton (more than 25 μm diameter) and nanoplankton, which are too small to be caught in a plankton net (see NANO-; and NANOFOSSIL).

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plankton

plank·ton / ˈplangktən/ • n. the small and microscopic organisms drifting or floating in the sea or fresh water, consisting chiefly of diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals. Many animals are adapted to feed on plankton, esp. by filtering the water.Compare with nekton. DERIVATIVES: plank·tic / -tik/ adj. plank·ton·ic / -ˈtänik/ adj.

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plankton

plankton All the floating or drifting life of the ocean, especially that near the surface. The organisms are very small and move with the currents. There are two main kinds: phytoplankton, floating plants such as diatoms and dinoflagellates; and zooplankton, floating animals such as radiolarians, plus the larvae and eggs of larger marine animals. They are a vital part of the food chain.

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plankton

plankton Minute pelagic organisms that drift or float passively with the current in a sea or lake. Plankton includes many microscopic organisms, such as algae, protozoans, various animal larvae, and some worms. It forms an important food source for many other members of the aquatic community and is divided into zooplankton and phytoplankton. Compare benthos; nekton; neuston.

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plankton

plankton Minute organisms, both plant (phytoplankton) and animal (zooplankton), drifting in the sea, which serve as the basic foodstuffs of marine life; the basis of the marine food chain.

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"plankton." A Dictionary of Food and Nutrition. . Encyclopedia.com. (August 17, 2017). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/plankton

"plankton." A Dictionary of Food and Nutrition. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/plankton

plankton

plankton XIX. — G. — Gr. plagktón, n. of plagktós wandering, drifting, f. base of plázein strike, cause to wander.

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"plankton." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

"plankton." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (August 17, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/plankton-1

"plankton." The Concise Oxford Dictionary of English Etymology. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/plankton-1

plankton

plankton: see marine biology.

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"plankton." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

"plankton." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (August 17, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/plankton

"plankton." The Columbia Encyclopedia, 6th ed.. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/plankton

plankton

planktonbaton, batten, fatten, flatten, harmattan, Manhattan, Mountbatten, paten, patten, pattern, platen, Saturn, slattern •Shackleton • Appleton •Hampton, Northampton, Rockhampton, Southampton, Wolverhampton •Canton, lantern, Scranton •Langton, plankton •Clapton •Aston, pastern •Gladstone •Caxton, Paxton •capstan • Ashton • phytoplankton •Akhenaten, Akhetaten, Aten, Barton, carton, Dumbarton, hearten, Parton, smarten, spartan, tartan •Grafton •Carlton, Charlton •Charleston • kindergarten •Aldermaston •Breton, jetton, Sowetan, threaten, Tibetan •lectern •Elton, melton, Skelton •Denton, Fenton, Kenton, Lenten, Trenton •Repton •Avestan, Midwestern, northwestern, Preston, southwestern, western •sexton •Clayton, Deighton, Leighton, Paton, phaeton, Satan, straighten, straiten •Paignton • Maidstone •beaten, Beaton, Beeton, Cretan, Keaton, neaten, Nuneaton, overeaten, sweeten, uneaten, wheaten •chieftain •eastern, northeastern, southeastern •browbeaten • weatherbeaten •bitten, bittern, Britain, Briton, Britten, handwritten, hardbitten, kitten, Lytton, mitten, smitten, underwritten, witan, written •Clifton •Milton, Shilton, Stilton, Wilton •Middleton • singleton • simpleton •Clinton, Linton, Minton, Quinton, Winton •cistern, Liston, piston, Wystan •brimstone • Winston • Kingston •Addington • Eddington •Workington •Arlington, Darlington •skeleton •Ellington, wellington •exoskeleton •cosmopolitan, megalopolitan, metropolitan, Neapolitan •Burlington • Hamilton • badminton •lamington • Germiston • Penistone •Bonington • Orpington • Samaritan •Carrington, Harrington •sacristan • Festschriften •Sherrington • typewritten •Warrington • puritan • Fredericton •Lexington • Occitan • Washington •Whittington • Huntington •Galveston • Livingstone •Kensington •Blyton, brighten, Brighton, Crichton, enlighten, frighten, heighten, lighten, righten, tighten, titan, triton, whiten •begotten, cotton, forgotten, ill-gotten, misbegotten, rotten •Compton, Crompton •wanton • Longton •Boston, postern •boughten, chorten, foreshorten, Laughton, Morton, Naughton, Orton, quartan, quartern, shorten, tauten, torten, Wharton •Alton, Dalton, Galton, saltern, Walton •Taunton • Allston • Launceston •croton, Dakotan, Minnesotan, oaten, verboten •Bolton, Doulton, molten •Folkestone • Royston •Luton, newton, rambutan, Teuton •Houston • Fulton •button, glutton, Hutton, mutton •sultan •doubleton, subaltern •fronton • Augustan • Dunstan •tungsten • quieten • Pinkerton •charlatan • Wollaston • Palmerston •Edmonton • automaton • Sheraton •Geraldton • Chatterton • Betterton •Chesterton • Athelstan •burton, curtain, uncertain •Hurston

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"plankton." Oxford Dictionary of Rhymes. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

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"plankton." Oxford Dictionary of Rhymes. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/plankton