51
Cheilostomata
are exclusively marine, free-living predators and form an important part of
the oceanic plankton. Some species are characteristic for certain water
masses and are as such indicators of plankton communities. Example: Sagitta.
Challenger Deep-Sea Expedition (1872-1876) the first global survey of the deep
ocean, directed by Charles Wyville Thomson. The 2300 tons corvette
Challenger with auxiliary steam power covered nearly 70 000 miles in this period. Over 500 deep soundings, 133 dredgings and various other operations were
executed at 362 oceanographic stations. As a result, 715 new biological genera
and about 4500 new species were described. Utilizing steel hydrographic wire,
a record deep-sea sounding of 8180 m in the Mariana Trench was recorded. W.
Dittmar analyzed very accurately 77 seawater samples collected by Buchanan
from which the concept of the "constant composition of seawater" was
derived, which is the concept underlying salinity being a cornerstone measure
for marine sciences. The initial results of the expedition were published in The
Voyage of H.M.S. Challenger (1884), edited by Sir John Murray, who in this and
later publications laid the foundation for the field of marine geology. The
expedition marks the beginning of modern oceanography, and its reports are
still a major source of information on life in the deep ocean.
channel (1) relatively narrow sea or stretch of water, wider and larger than a
strait, connecting two larger bodies of water. Also used for the English
Channel between England and France; (2) deeper part of bottom below moving water (in a bay, estuary or strait) through which the main current flows.
Charophyceae class of the green algae or Chlorophyta; candleworths and related
species. Algae that approach the higher plants in level of organization.
Charophyceae contain the pigment chlorophyll-b and lutein. They store carbohydrate as starch inside the plastids. The flagellar apparatus of their zoids,
including the parts inside the protoplast, resembles in fine structure the corresponding organelles in mosses and ferns. During cell division, the primary
cell wall develops in the same way as in higher plants, different from all
other organisms. Though this class chiefly comprises freshwater plants, the
genus Chara also lives in brackish marine environments, for instance in
sheltered shallow bays of the Baltic.
chart datum a reference level for chart depths. The chart datum needs not to be
mean sea level or horizontal plane, but is usually connected with the local tide,
e.g., the mean lower low water level at spring tides.
Cheilostomata order of the class Gymnolaemata (phylum Bryozoa). Colonies composed of zooids are generally flattened and have calcified body walls. The
aperture of the zooids is closed by an operculum. In many species modified
zooids (vibracula, avicularia) occur. Example: Bugula.
Cheilostomata
are exclusively marine, free-living predators and form an important part of
the oceanic plankton. Some species are characteristic for certain water
masses and are as such indicators of plankton communities. Example: Sagitta.
Challenger Deep-Sea Expedition (1872-1876) the first global survey of the deep
ocean, directed by Charles Wyville Thomson. The 2300 tons corvette
Challenger with auxiliary steam power covered nearly 70 000 miles in this period. Over 500 deep soundings, 133 dredgings and various other operations were
executed at 362 oceanographic stations. As a result, 715 new biological genera
and about 4500 new species were described. Utilizing steel hydrographic wire,
a record deep-sea sounding of 8180 m in the Mariana Trench was recorded. W.
Dittmar analyzed very accurately 77 seawater samples collected by Buchanan
from which the concept of the "constant composition of seawater" was
derived, which is the concept underlying salinity being a cornerstone measure
for marine sciences. The initial results of the expedition were published in The
Voyage of H.M.S. Challenger (1884), edited by Sir John Murray, who in this and
later publications laid the foundation for the field of marine geology. The
expedition marks the beginning of modern oceanography, and its reports are
still a major source of information on life in the deep ocean.
channel (1) relatively narrow sea or stretch of water, wider and larger than a
strait, connecting two larger bodies of water. Also used for the English
Channel between England and France; (2) deeper part of bottom below moving water (in a bay, estuary or strait) through which the main current flows.
Charophyceae class of the green algae or Chlorophyta; candleworths and related
species. Algae that approach the higher plants in level of organization.
Charophyceae contain the pigment chlorophyll-b and lutein. They store carbohydrate as starch inside the plastids. The flagellar apparatus of their zoids,
including the parts inside the protoplast, resembles in fine structure the corresponding organelles in mosses and ferns. During cell division, the primary
cell wall develops in the same way as in higher plants, different from all
other organisms. Though this class chiefly comprises freshwater plants, the
genus Chara also lives in brackish marine environments, for instance in
sheltered shallow bays of the Baltic.
chart datum a reference level for chart depths. The chart datum needs not to be
mean sea level or horizontal plane, but is usually connected with the local tide,
e.g., the mean lower low water level at spring tides.
Cheilostomata order of the class Gymnolaemata (phylum Bryozoa). Colonies composed of zooids are generally flattened and have calcified body walls. The
aperture of the zooids is closed by an operculum. In many species modified
zooids (vibracula, avicularia) occur. Example: Bugula.