Nekton

Nekton

Nekton refers to the aggregate of actively swimming aquatic organisms in a body of water (usually oceans or lakes) able to move independently of water currents.

Nekton are contrasted with plankton which refers to the aggregate of passively floating, drifting, or somewhat motile organisms occurring in a body of water, primarily comprising tiny algae and bacteria, small eggs and larvae of marine organisms, and protozoa and other minute predators.

As a guideline, nekton are larger and tend to swim largely at biologically high Reynolds numbers (>10^3 and up beyond 10^9), where inertial flows are the rule, and eddies (vortices) are easily shed. Plankton, on the other hand, are small and, if they swim at all, do so at biologically low Reynolds numbers (0.001 to 10), where the viscous behavior of water dominates, and reversible flows are the rule. Organisms such as jellyfish and others are considered plankton when they are very small and swim at low Reynolds numbers, and considered nekton as they grow large enough to swim at high Reynolds numbers. Many animals considered classic examples of nekton (e.g., Mola mola, squid, marlin) start out life as tiny members of the plankton and gradually transition to nekton as they grow.

Contents

Oceanic nekton

Oceanic nekton comprises animals largely from three clades

Etymology

The term nekton was coined in 1890 by Ernst Haeckel; it is rooted in the Greek adjective νηκτός nēktós ("the swimming") derived from the verb νήχειν nḗkhein ("to swim"). The study of swimming organisms (biofluidynamics, biomechanics, functional morphology of fluid locomotion, locomotor physiology) is called nektology. One who studies swimming in all its forms is called a nektologist.

See also

  • plankton (the organisms that float or drift within the water)
  • neuston (the organisms that float on the water)
  • benthos (the organisms at the bottom of a body of water)

External links

  • Stefan Nehring and Ute Albrecht (1997): „hell und das redundante Benthon: Neologismen in der deutschsprachigen Limnologie“. In: Lauterbornia H. 31: 17-30, Dinkelscherben, Dezember 1997 E-Text (PDF-Datei)

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Look at other dictionaries:

  • nekton — 1893, from Ger. nekton (van Heusen, 1890), from Gk. nekton, neuter of nektos swimming, from nekhein to swim (see NATATORIUM (Cf. natatorium)) …   Etymology dictionary

  • nekton — [nek′tän΄, nek′tən] n. [Ger < Gr nēkton, neut. of nēktos, swimming < nēchein, to swim: see NATANT] the larger, aquatic, free swimming animal life having movements that are largely independent of currents and waves, including squids, fishes …   English World dictionary

  • nekton — ekton n. The aggregate of actively swimming animals in a body of water ranging from microscopic organisms to whales. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • Nekton — Nekton, im Gegensatz zum Plankton, d.h. den passiv treibenden Organismen an der Oberfläche des Meeres oder größerer Wasserflächen, die Gesamtheit der aktiv an der Wasseroberfläche schwimmenden Organismen. Vgl. Haeckel, Plankton Studien (Jena… …   Meyers Großes Konversations-Lexikon

  • Nekton — Nekton, im Pelagial des Meeres und der Süßgewässer im Gegensatz zum ⇒ Plankton sich aktiv auch gegen die Wasserströmung fortbewegende Tiere, v.a. Fische, aber auch z.B. Cephalopoden, Robben, Wale …   Deutsch wörterbuch der biologie

  • nekton — nèktōn m <G nektóna> DEFINICIJA zool. životinje koje se aktivno kreću u vodi, plivaju za razliku od planktona koji je nošen gibanjem vode ETIMOLOGIJA grč. nēkhtós: koji pliva ≃ nḗkhein: plivati …   Hrvatski jezični portal

  • Nekton — Marines Nekton: Ein Schwarm Atlantischer Heringe (Clupea harengus) auf Wanderung zu den Laichplätzen in der Ostsee. Die hohe Geschwindigkeit kann über mehrere Tausend Kilometer durchgehalten werden. Einige Wissenschaftler sind der Meinung, dass… …   Deutsch Wikipedia

  • nekton — nektonic, adj. /nek ton, teuhn/, n. the aggregate of actively swimming aquatic organisms in a body of water, able to move independently of water currents. [1890 95; < G, n. use of neut. of nektós swimming (verbid of néchein to swim; see… …   Universalium

  • nekton — noun Etymology: German Nekton, from Greek nēkton, neuter of nēktos swimming, from nēchein to swim more at natant Date: 1893 free swimming aquatic animals essentially independent of wave and current action • nektonic adjective …   New Collegiate Dictionary

  • Nekton — nektonas statusas T sritis ekologija ir aplinkotyra apibrėžtis Aktyviai plaukiojančių ir srovės jėgą įveikiančių vandens gyvūnų visuma (pvz., žuvys, banginiai, delfinai, galvakojai moliuskai). atitikmenys: angl. nekton vok. Nekton, n rus. нектон …   Ekologijos terminų aiškinamasis žodynas

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