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schooling
sample. Material to be studied with the SEM ought to meet two conditions:
the sample should be dehydrated to avoid implosion in the low-pressure
environment of the electron-specimen collision. As a consequence organisms cannot be studied in vivo. Secondly, nonconductive material should be
coated with a thin conductive (gold or carbon) layer to avoid image-disturbing electric charging.
Scaphopoda (tooth or tusk shells) class of the phylum Mollusca. Burrowing
marine mollusks with a typical conical or cylindrical, gently curved shell,
which is open at both ends. There are no gills. The animals live head down
in the sediment and feed by numerous contractile filaments on microscopic organisms. They have a pointed foot to burrow, and a radula is present.
Example: Dentaiium.
scattering the changing of the direction of propagation or phase of a wave, due
to small-scale variation of the properties of the medium. Scattering occurs
in optics, acoustics and in water waves. As a criterion for the scattering properties of the medium the so-called WKB (Wentzel, Kramers, Brillouin) approximation is used, stating that the scattering can be neglected if the properties
vary at length scales much larger than the wavelength.
scattering layer a concentration of marine organisms in a well-defined depth
interval that scatter sound waves from an echosounder. The sound scattering is largely due to the gas-filled swim bladders (~gas bladder) of mesopelagic fish, e.g., lanternfish (Myctophidae) and Stomiatidae. In the open
ocean, these layers are very common and are called deep scattering layers
(DSL). Up to five or more layers can be found down to a depth of about 1000
m. They can be more or less stationary, but others undergo daily vertical
movements (vertical migration). In general, deep scattering layers are closer to
the surface at night than during the day, due to vertical migration of the
organisms.
scavengers animals feeding on dead animals.
schooling the behavior of forming aggregations with a definite mutual attraction between individuals. Grouping of individuals into aggregations is common throughout the animal kingdom. They may be more or less permanent
groupings often closely knit and well coordinated or temporary aggregations dispersing in relation to fluctuating environmental conditions. The
first type reaches its highest development in the sea in the schooling of fish,
Crustacea, Cephalopoda and mammals such as porpoises. The advantage in
forming such well-coordinated groups is probably to be found in an extended perception of the environment, including in some cases a protection
against predators.
schooling
sample. Material to be studied with the SEM ought to meet two conditions:
the sample should be dehydrated to avoid implosion in the low-pressure
environment of the electron-specimen collision. As a consequence organisms cannot be studied in vivo. Secondly, nonconductive material should be
coated with a thin conductive (gold or carbon) layer to avoid image-disturbing electric charging.
Scaphopoda (tooth or tusk shells) class of the phylum Mollusca. Burrowing
marine mollusks with a typical conical or cylindrical, gently curved shell,
which is open at both ends. There are no gills. The animals live head down
in the sediment and feed by numerous contractile filaments on microscopic organisms. They have a pointed foot to burrow, and a radula is present.
Example: Dentaiium.
scattering the changing of the direction of propagation or phase of a wave, due
to small-scale variation of the properties of the medium. Scattering occurs
in optics, acoustics and in water waves. As a criterion for the scattering properties of the medium the so-called WKB (Wentzel, Kramers, Brillouin) approximation is used, stating that the scattering can be neglected if the properties
vary at length scales much larger than the wavelength.
scattering layer a concentration of marine organisms in a well-defined depth
interval that scatter sound waves from an echosounder. The sound scattering is largely due to the gas-filled swim bladders (~gas bladder) of mesopelagic fish, e.g., lanternfish (Myctophidae) and Stomiatidae. In the open
ocean, these layers are very common and are called deep scattering layers
(DSL). Up to five or more layers can be found down to a depth of about 1000
m. They can be more or less stationary, but others undergo daily vertical
movements (vertical migration). In general, deep scattering layers are closer to
the surface at night than during the day, due to vertical migration of the
organisms.
scavengers animals feeding on dead animals.
schooling the behavior of forming aggregations with a definite mutual attraction between individuals. Grouping of individuals into aggregations is common throughout the animal kingdom. They may be more or less permanent
groupings often closely knit and well coordinated or temporary aggregations dispersing in relation to fluctuating environmental conditions. The
first type reaches its highest development in the sea in the schooling of fish,
Crustacea, Cephalopoda and mammals such as porpoises. The advantage in
forming such well-coordinated groups is probably to be found in an extended perception of the environment, including in some cases a protection
against predators.