To the aggregate of such forms, both animal and vegetable, the term plankton has been applied, and the investigation of the vegetable plankton, both freshwater and marine, has been pursued in recent times with energy and success.
The organisms constituting this plankton are mostly unicellular, often aggregated together in colonies, and the remarkable structure which they exhibit has added a new chapter to the story of adaptation to environment.
Besides collecting plankton the biologist was now able to put down one or other of his dredges at more frequent intervals, always taking care, however, not to exhaust his store of preserving material, which was limited.
During the drift of the 'Endurance' samples of plankton were taken almost daily during an Antarctic summer and winter.
Clark, who was using his trawl as often as possible, reported that there was a marked absence of plankton in the sea, and we assumed that the seals and the penguins had gone in search of their accustomed food.
When the proper balance of plankton and algae was achieved, the air jets that gave the ship its spin would also purify the ship's air, giving it back in a natural manner the oxygen it was now fed from tanks.
The vats of plankton and algae concentrates were not so important as to orientation, but should be fed into their rim-river homes as soon as possible, although this could not be done until the rim spin was well under control.
A longer step takes us to the Crustacea, represented in the pelagic plankton by queer little shrimplike forms that in countless hosts of individuals play a part in the ocean comparable to that of insects on land.
The plankton of the shallow waters near continental shores, however, presents a decidedly different assemblage from the pelagic plankton.
An important part of the pelagic plankton consists of certain small mollusks; and "as regards abundance of individuals few groups of pelagic animals can compare with the winged snails, or Pteropoda.
Lieutenant Gjertsen and Kutschin collected plankton all the time; the latter smiled all over his face whenever he chanced to get one or two "tadpoles" in his tow-net.
At no fewer than sixty stations they took a number of temperatures, samples of water, and specimens of the plankton in this little-known region, to a depth of 2,000 fathoms and more.
The plankton organisms are a mingling of European and arctic species.
It is probable that if the whole plankton could be annihilated, it would be replaced by ordinary migration within a few years.
Some of these species of plankton organisms are almost universal in the Scottish lochs, while others are quite local.
All of these, according to Dr Lund, belong to the general plankton association of the European plain, or are even cosmopolitan.
The plankton animals which are dominant or common, both over Scotland and the rest of Europe, are:-- Diaptomus gracilis.
When the drum was beaten, the air vibrations drove plankton into the native's mouth, and he ate and hummed.
This is, of course, due to the terrific expense of importing both natives and plankton to other planets than Wellington V for concerts.
This was a large drumlike construction with a small hole in its side through which airborne plankton could enter.
For there is great diversity in this respect, most of the Mediterranean, for instance, having a scantyPlankton as compared with the North Sea.
Hunger and Love Hunger is often very much in evidence in the open sea, especially in areas where the Plankton is poor.
The animal plankton comprises a mass of microscopic creatures belonging to the Protozoa, Radiolaria, and Globeriginæ.
It is necessary to make a distinction between the "neritic" plankton of shallow water near the coast and the "oceanic" plankton of the open sea.
The large feathered bristles that decorate the limbs or tail of many plankton Copepoda have no doubt the same function in assisting flotation.
In many plankton species, however, this simple eye becomes much enlarged and complicated in various ways.
The Crustacea of the plankton never carry the heavy armour found in bottom-living species.
As in the case of many marine plankton Crustacea, this transparency is probably due to the thinness of the shell and to the general watery condition of the body, giving the necessary buoyancy to enable the animal to remain constantly afloat.
There are a few Crustacea living habitually on the high seas which cannot be reckoned as belonging either to the true plankton or to the necton, since they depend on outside help for keeping themselves afloat.
Bullen that the fluctuations in the yield of the Mackerel fishery from year to year follow very closely the fluctuations in the abundance of the Copepod plankton on the fishing-grounds.
Certain species of Cladocera belong to the plankton of lakes and large ponds, and show modifications which adapt them for a floating life.
The plankton of lakes and ponds includes species of Diaptomus (Fig.
Thus, the thick-shelled Ostracoda of the bottom are represented in the plankton chiefly by the family Halocypridae (Fig.
Illustration: Men aboard the research vessel Shimada pulling in plankton nets during sampling operations at sea.
The distribution of residual radioactivity in the sea a month after the close of a nuclear testing program could be determined by counting radioactivity in plankton samples.
Significantly, it was found thatplankton immediately take up large amounts of radioactivity.
Illustration: Autoradiograph of a plankton sample collected from a Pacific lagoon a week after a 1952 test.
Aquatic biologists emptying plankton traps to study concentrations of radioactivity in microscopic organisms in the Columbia River downstream from the Hanford atomic plant in Washington State.
An ingenious plankton trap is placed in a river as part of a long-range study of radionuclide uptake by aquatic organisms.
He proceeded to draw divisions between the bottom organisms without power of motion, benthon, the nekton motile life in mid-water, and the plankton or floating life.
Physically plankton life must depend on this salinity and also on temperature, pressure, light, and movement.
The armour-plates are often exquisitely sculptured, and may be produced into spines or perpendicular plates to give greater surface extension, as we find in other plankton organisms.
By autumn, plankton concentrations diminish as light and nutrient levels decrease.
Both fish and plankton are consumed by humpback whales as well as by other predators.
Mallotus villosus and Pacific sand lance, Ammodytes hexapterus), feed on the plankton when it becomes available.
The quantity of organic carbon released is considerable, although it is not known what fish or invertebrate populations are supported by this plankton as soon as it is released.
In areas where ice is present throughout the year, the planktonbloom supports a population of under-ice invertebrates.
The most important benefit that sea ice provides to seabirds is the planktonbloom that occurs in the ice in the spring.
The ship was not slowed down to enable marine biological observations to be taken on this part of the expedition, but something like forty samples of plankton were taken with a full-speed net.
Diatoms were so abundant in parts of the Ross Sea, that a large plankton net (18 meshes to an inch) became choked in a few minutes with them and other members of the Phytoplankton.
General information with regard to such animals is useful, however, as showing the relative abundance of planktonon which the whales feed in the ocean.
The plankton nets can be lowered when the ship is running at full speed, and a great many such hauls were made during the expedition.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "plankton" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: algae; cetacean; dolphin; fish; fry; kipper; plankton; porpoise; salmon; shark; sponge; whale
