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Original-"Picoplankton"

Classification[edit]

In general, plankton can be categorized on the basis of physiological, taxonomic, or dimensional characteristics. Subsequently, a generic classification of a plankton includes:

However, there is a simpler scheme that categorizes plankton based on a logarithmic size scale:

  • Macroplankton (200-2000 μm)
  • Micro-plankton (20-200 μm)
  • Nanoplankton (2-20 μm)

This was even further expanded to include picoplankton (0.2-2 μm) and fem-toplankton (0.02-0.2 μm), as well as net plankton, ultraplankton. Now that picoplankton have been characterized, they have their own further subdivisions such as prokaryotic and eukaryotic phototrophs and heterotrophs that are spread throughout the world in various types of lakes and tropic states. In order to differentiate between autotrophic picoplankton and heterotrophic picoplankton, the autotrophs could have photosynthetic pigments and the ability to show autofluorescence, which would allow for their enumeration under epifluorescence microscopy. This is how minute eukaryotes first became known.[1] Overall, picoplankton play an essential role in oligotrophic dimicitc lakes because they are able to produce and then accordingly recycle dissolved organic matter (DOM) in a very efficient manner under circumstance when competition of other phytoplankters is disturbed by factors such as limiting nutrients and predators. Picoplankton are responsible for the most primary productivity in oligotrophic gyres, and are distinguished from nanoplankton and microplankton.[2] Because they are small, they have a greater surface to volume ratio, enabling them to obtain the scarce nutrients in these ecosystems. Furthermore, some species can also be mixotrophic. The smallest of cells (200 nm) are on the order of nanometers, not picometers. The SI prefix pico- is used quite loosely here, as nanoplankton and microplankton are only 10 and 100 times larger, respectively, although it is somewhat more accurate when considering the volume rather than the length.

Edit-"Picoplankton"

Classification[edit]

In general, plankton can be categorized on the basis of physiological, taxonomic, or dimensional characteristics. Subsequently, a generic classification of a plankton includes:

However, there is a simpler scheme that categorizes plankton based on a logarithmic size scale:

  • Macroplankton (200-2000 μm)
  • Micro-plankton (20-200 μm)
  • Nanoplankton (2-20 μm)

This was even further expanded to include picoplankton (0.2-2 μm) and fem-toplankton (0.02-0.2 μm), as well as net plankton, ultraplankton. Now that picoplankton have been characterized, they have their own further subdivisions such as prokaryotic and eukaryotic phototrophs and heterotrophs that are spread throughout the world in various types of lakes and tropic states. In order to differentiate between autotrophic picoplankton and heterotrophic picoplankton, the autotrophs could have photosynthetic pigments and the ability to show autofluorescence, which would allow for their enumeration under epifluorescence microscopy. This is how minute eukaryotes first became known.[3] Overall, picoplankton play an essential role in oligotrophic dimicitc lakes because they are able to produce and then accordingly recycle dissolved organic matter (DOM) in a very efficient manner under circumstance when competition of other phytoplankters is disturbed by factors such as limiting nutrients and predators. Picoplankton are responsible for the most primary productivity in oligotrophic gyres, and are distinguished from nanoplankton and microplankton.[4] Because they are small, they have a greater surface to volume ratio, enabling them to obtain the scarce nutrients in these ecosystems. Furthermore, some species can also be mixotrophic. The smallest of cells (200 nm) are on the order of nanometers, not picometers. The SI prefix pico- is used quite loosely here, as nanoplankton and microplankton are only 10 and 100 times larger, respectively, although it is somewhat more accurate when considering the volume rather than the length.

Role in Marine and Freshwater ecosystems[edit]

Picoplankton contribute greatly to the biomass and primary production in both marine and freshwater lake ecosystems. In the ocean, the concentration of picoplankton is 105- 107 cells per millilitre of ocean water [5]. Algal picoplankton is responsible for up to 90 percent of the total carbon production daily and annually in oligotrophic marine ecosystems[6]. The amount of total carbon production by picoplankton in oligotrophic freshwater systems is also high, making up 70 percent of total annual carbon production[6]. Marine picoplankton make up a higher percentage of biomass and carbon production in zones that are oligotrophic, like the open ocean, versus regions near the shore that are more nutrient rich[6][7]. Their biomass and carbon production percentage also increases as the depth into the euphotic zone increases. This is due to their use of photopigments and efficiency at using blue-green light at these depths[6]. Picoplankton population densities do not fluctuate throughout the year except in a few cases of smaller lakes where their biomass increases as the temperature of the lake water increases[7].

Picoplankton also play an important role in the microbial loop of these systems by aiding in providing energy to higher trophic levels[6] They are grazed by a various number of bacteria such as flagellates, ciliates, rotifers and copepods. Flagellates are their main predator due to their ability to swim towards picoplankton in order to consume them[7].

References[edit]

  1. ^ C. Callieri and J. G. Stockner, Freshwater autotrophic picoplankton: a review, J. Limnol., 2002, 61, 1–14 [1]
  2. ^ Vershinin, Alexander. "Phytoplankton in the Black Sea". Russian Federal Children Center Orlyonok.
  3. ^ C. Callieri and J. G. Stockner, Freshwater autotrophic picoplankton: a review, J. Limnol., 2002, 61, 1–14 [2]
  4. ^ Vershinin, Alexander. "Phytoplankton in the Black Sea". Russian Federal Children Center Orlyonok.
  5. ^ Schmidt, T. M.; DeLong, E. F.; Pace, N. R. (1991-07-01). "Analysis of a marine picoplankton community by 16S rRNA gene cloning and sequencing". Journal of Bacteriology. 173 (14): 4371–4378. doi:10.1128/jb.173.14.4371-4378.1991. ISSN 0021-9193. PMID 2066334.
  6. ^ a b c d e Stockner, John G.; Antia, Naval J. (April 14, 1986). "Algal Picoplankton from Marine and Freshwater Ecosystems: A Multidisciplinary Perspective". Canadian Journal of Fisheries and Aquatic Sciences. 43 (12): 2472–2503. doi:10.1139/f86-307.
  7. ^ a b c Fogg, G.E. (April 28, 1995). "Some comments on picoplankton and its importance in the pelagic ecosystem" (PDF). Aquat microb Ecol. 9: 33–39.

Gsavage1 (talk) 21:12, 8 October 2017 (UTC) Gsavage1 (talk) 06:20, 18 November 2017 (UTC)