3
Actinopoda
sound propagation depends on the variation of sound velocity with temperature, pressure and, to a lesser degree, salinity. The distribution of temperature and salinity in the sea may, under given circumstances, result in
refraction of sound and propagation patterns that may either concentrate
sound energy in certain zones ("sound channels") or that may leave other
areas outside the area where the sound can penetrate (shadow zone).
Acoustic signals may be obscured by background noise (ambient noise); this
can be noise produced by organisms, noise from rain or waves, and the noise
produced by ships. --7echosounding and --7sonar.
acoustic tags --7tagging.
Actiniaria (sea anemones) order of subclass Zoantharia, class Anthozoa (phylum
Cnidaria). Sessile and solitary, usually with basal disk, no skeleton. Cylindrical
polyp with a muscular body wall, and (many) tentacles.
relract, Ot muscl. 01 meSlln'lery
mesenteriallilament - ... nr- -<-- ~--.... ...
com prete mesentery
ICant"'l !1"'1N!nl---- - ¥ .. df'-7~
Actiniaria. (From Barnes 1987 after Hyman 1940)
Actinopoda phylum of the kingdom Protoctista. Heterotrophic unicellular organisms
with long slender stiff podia (axopods) that radiate from the center of the cell.
This phylum is split into four classes: the Polycystina, Phaeodaria (together
formerly known as the Radiolaria), Heliozoa and Acantharia. All of these classes are
Actinopoda
sound propagation depends on the variation of sound velocity with temperature, pressure and, to a lesser degree, salinity. The distribution of temperature and salinity in the sea may, under given circumstances, result in
refraction of sound and propagation patterns that may either concentrate
sound energy in certain zones ("sound channels") or that may leave other
areas outside the area where the sound can penetrate (shadow zone).
Acoustic signals may be obscured by background noise (ambient noise); this
can be noise produced by organisms, noise from rain or waves, and the noise
produced by ships. --7echosounding and --7sonar.
acoustic tags --7tagging.
Actiniaria (sea anemones) order of subclass Zoantharia, class Anthozoa (phylum
Cnidaria). Sessile and solitary, usually with basal disk, no skeleton. Cylindrical
polyp with a muscular body wall, and (many) tentacles.
relract, Ot muscl. 01 meSlln'lery
mesenteriallilament - ... nr- -<-- ~--.... ...
com prete mesentery
ICant"'l !1"'1N!nl---- - ¥ .. df'-7~
Actiniaria. (From Barnes 1987 after Hyman 1940)
Actinopoda phylum of the kingdom Protoctista. Heterotrophic unicellular organisms
with long slender stiff podia (axopods) that radiate from the center of the cell.
This phylum is split into four classes: the Polycystina, Phaeodaria (together
formerly known as the Radiolaria), Heliozoa and Acantharia. All of these classes are