351
zooplankton samplers
a clear zonation from lichens high on the coast, and barnacles ( --7 Thoracica and
--7Cirripedia) and different algal zones lower down. Zonation is also present
along sandy or muddy coasts, in estuaries, and in the open sea. In the tidal or
littoral zone, the part of the shoreline that is alternately exposed to air and
wetted by submersion, splash or spray, can be discerned: the intertidal or
eulittoral zone between high and low water; the supralittoral (syn. supratidal or
surf zone), the splash zone or spray zone above the highwater line; and a sublittoral (or subtidal) zone below low water and usually down to the shelf edge
(ca. 200 m), sometimes divided into inner sublittoral (= inner shelf) and
outer sublittoral (= outer shelf). The name surf zone is also used to denote
the near-shore zone where both sea and swell waves peak up and break into
surf, and change from waves of oscillation to waves of translation. The bottom of the ocean below the sublittoral zone is divided into a bathyal zone,
roughly from the outer shelf down to ca. 2000 m (the 4 °C isotherm), an
abyssal zone from roughly 2000 to 6000 m and a hadal zone from 6000 m down
to the greatest depths, comprising all the deep trenches and characterized by
a distinct fauna. The pelagic environment of the water column can be equally divided into an epipelagic zone (O-roughly 200 m), more or less equivalent
to the photic (= lighted) zone; a meso pelagic (ca. 200-ca. 2000 m), a bathypelagic (ca. 2000-ca. 6000 m), with the deepest part called hadal zone and an
abyssopelagic zone (> ca. 6000 m) forming together the aphotic zone. Not all
authors agree on exact limits for the different depth zones, but the sequence
as given here is generally accepted. Gradients in environmental factors effect
the observed zonation in organisms. In the littoral zone particularly irradiation, exposure time, desiccation, grazing, and predation determine the
zonation. Temperature is the main factor for zonation in deep water. The
salinity gradient is the dominant ecological factor in zonation in estuaries.
--7hypsographic curve.
zoobenthos --7benthos.
zoogeography --7biogeography.
zooid individual polyp in a colony. Often more than one type of polyps occur
(polymorphism); they can be modified for feeding (gastrozooids), defense
(dactylozooids), asexual reproduction, etc. --7zoid.
Zoomastigophora (syn. Zooflagellata) --7Mastigophora.
zooneuston animals living near or at the water surface of seas and lakes.
zooplankton animals in the plankton. In marine zooplankton most animal phyla
are represented, and both herbivores and predators occur; herbivores feed on
phytoplankton and are in turn eaten by zooplankton predators. Fecal pellets pro-
zooplankton samplers
a clear zonation from lichens high on the coast, and barnacles ( --7 Thoracica and
--7Cirripedia) and different algal zones lower down. Zonation is also present
along sandy or muddy coasts, in estuaries, and in the open sea. In the tidal or
littoral zone, the part of the shoreline that is alternately exposed to air and
wetted by submersion, splash or spray, can be discerned: the intertidal or
eulittoral zone between high and low water; the supralittoral (syn. supratidal or
surf zone), the splash zone or spray zone above the highwater line; and a sublittoral (or subtidal) zone below low water and usually down to the shelf edge
(ca. 200 m), sometimes divided into inner sublittoral (= inner shelf) and
outer sublittoral (= outer shelf). The name surf zone is also used to denote
the near-shore zone where both sea and swell waves peak up and break into
surf, and change from waves of oscillation to waves of translation. The bottom of the ocean below the sublittoral zone is divided into a bathyal zone,
roughly from the outer shelf down to ca. 2000 m (the 4 °C isotherm), an
abyssal zone from roughly 2000 to 6000 m and a hadal zone from 6000 m down
to the greatest depths, comprising all the deep trenches and characterized by
a distinct fauna. The pelagic environment of the water column can be equally divided into an epipelagic zone (O-roughly 200 m), more or less equivalent
to the photic (= lighted) zone; a meso pelagic (ca. 200-ca. 2000 m), a bathypelagic (ca. 2000-ca. 6000 m), with the deepest part called hadal zone and an
abyssopelagic zone (> ca. 6000 m) forming together the aphotic zone. Not all
authors agree on exact limits for the different depth zones, but the sequence
as given here is generally accepted. Gradients in environmental factors effect
the observed zonation in organisms. In the littoral zone particularly irradiation, exposure time, desiccation, grazing, and predation determine the
zonation. Temperature is the main factor for zonation in deep water. The
salinity gradient is the dominant ecological factor in zonation in estuaries.
--7hypsographic curve.
zoobenthos --7benthos.
zoogeography --7biogeography.
zooid individual polyp in a colony. Often more than one type of polyps occur
(polymorphism); they can be modified for feeding (gastrozooids), defense
(dactylozooids), asexual reproduction, etc. --7zoid.
Zoomastigophora (syn. Zooflagellata) --7Mastigophora.
zooneuston animals living near or at the water surface of seas and lakes.
zooplankton animals in the plankton. In marine zooplankton most animal phyla
are represented, and both herbivores and predators occur; herbivores feed on
phytoplankton and are in turn eaten by zooplankton predators. Fecal pellets pro-