Animal and Vegetable Organisms Found in Water
Description and Illustrations of Microscopic and Macroscopic Life Found in Water by St. Louis Department— Teeming Animal and Vegetable Life in Many Forms
FOR the following instructive description and illustrations FIRE AND WATER ENGINEERING is indebted to the water department of St. Louis, Mo., being taken from the annual report of Water Commissioner Edward E. Wall:
The presence of objectionable organic matter in our clear water basins at Baden, Bissell’s Point and Compton Hill became a matter of great concern immediately after the opening of the Filter Plant on May 15, 1915. Since that date these basins have been out of service at various times, due to the great number of organisms, both microscopic and macroscopic, present in the water. At these times the basins must be emptied, cleaned and then filled. In from three to four weeks after filling, the basins are again in the same foul condition. There is only one way of preventing the objectionable matter from entering and multiplying in the basins, and that is by covering the basins at Baden and Bissell’s Point. With these basins covered, we feel that Compton Hill Reservoir will remain free from growths due to its location. Until the basins are covered we will experience the same trouble, year after year, from objectionable organic matter.
A great variety of classes and species of organisms have been found in the basins, a few of which are shown on the following pages. The organisms shown in Fig. 1 belong to the vegetable kingdom and those in Fig. 2 to the animal kingdom.
The Diatomaceae, to which group the organisms Synedra and Cyclotella belong, comprise a group of minute vegetable forms of a low order. The early writers considered them to belong to the animal kingdom because of the power of movement that some of them possess. Later, when they had become generally recognized as plants, they were considered as a class or order of the Algae. There is no class of unicellular organisms in which the outlines vary more than in those of the Diatoms. From the straight line to the circle almost all the geometrical figures may be found.
Diatoms multiply by a process of halving or splitting, the Greek word for which gives rise to the name Diatom. As many as 3,600 Synedra per cubic centimeter have been found in our clear water, so that a person drinking a glass full of water would consume over 600,000 of these organisms. Cyclotella has never been found in any great number..
The organisms Coelosphaerium, Coelastrum, Scenedesmus and Pediastrum belong to the class of Algae, the first named being blue-green in color and the others green. The fresh water Algae are among the most widely distributed of plants. They are found in all natural bodies of water and they abound wherever there is moisture. They are of great importance because Crustacea, which form the basis of food for fishes, live on them. They grow in great number and rise to the surface causing “waterbloom.” When they decay they impart a decided taste to the water. The species mentioned are microscopic in size.
Protozoa, the class to which Paramoecium belongs, is the lowest form of animal life. They are found in fresh and salt water and in the infusions of meat or plants. They are also found in parasites on or within animals. By chopping up hay and allowing it to remain in water for a short time a great number of Paramoecium can be produced.
Daphnia, Bosmina, Cyclops and Cypris belong to the class of Crustacea; Daphnia and Bosmina to the order Cladocera; Cyclops to the order Copepoda and Cypris to the order Ostracada. Crustacea, except the Cray fishes and river-crabs, are rarely found in running water; but in all standing fresh water, from the smallest pond to the inland seas, they are abundant and characteristic and form an important item in the food of fresh-water fishes.
The Cladocera, the most common form of which is the water-flea, Daphnia, may breed in spring in such numbers as to render a reservoir water turbid. Dr. Kemna at Antwerp tells of ten tons being screened from one reservoir in a single season.
Daphnia bear two kinds of eggs, the so-called summer eggs, with relatively little yolk, which develop rapidly without fertilization, and the so-called winter eggs, containing much yolk, which require to be fertilized and then develop slowly. The summer eggs, sometimes as many as 40 or 50, are nourished by a fluid excreted by the mother and the young develop directly and hatch in the form of the mother. They have broods of summer eggs in rapid succession, and the young are able to reproduce when a few days old. All summer eggs produce females, so the rate of multiplication is very great.
The winter-eggs are fertilized in the same part of the female in which the summer eggs develop, but after fertilization they are thrown off from the body of the mother, either with or without a protecting membrane. The winter eggs may be dried or frozen without injury. The sides and floor of a dried-up pond are often covered with winter eggs, which develop quickly when placed in water. This mud containing a large number of eggs may be carried by the wind, on the legs of birds and by other means to considerable distances.
Daphnia and Bosmina have only one eye made up of a number of lenses. The lenses in the eye are constantly moving so as to cover the entire field of vision.
Daphnia has been found in great number in our basins and several times during the past four years it has been necessary to empty basins to get rid of them or to treat the water with copper sulphate to kill them.
On a bright, calm day a few inches of water at the surface of a basin may be deserted by the organisms. A little deeper may be found young forms and still deeper, six or ten feet below the surface, the adult animals. On rainy days and at night, if the water is not rough, most of the Daphnia present will be found near the surface.
Cyclops is the most common crustacean inhabitant of drinking water. Hardly any body of water is without its presence, although running waters have a less abundant population than lakes. Frequently standing pools swarm with them. At times large swarms of Cyclops will attack a good-sized fish and by their combined efforts literally tear the fish to pieces. The ultimate food of fish is composed very largely of this organism.
(Continued on page 1211)
(Continued from page 1209)
An old Cyclops may produce 40 or 50 eggs at one time, and may give birth to eight or ten broods living five to six months. As the young begin to reproduce at an early age, the rate of multiplication is astonishing. The descendants of one Cyclops may number in one year 4,500,000,000, provided that all the young reached maturity and produced a full number of offspring.
The eggs are not hatched in the form of the mother as is the case with the Daphnia. The eggs are dropped and from the egg the nauplius is hatched which ultimately becomes a Cyclops.
The color of the Cypris depends upon the general color of its surroundings. Cypris live in algae-rich habitats and are notably green. The eggs of Cypris are provided with small limy shells, and commonly develop in from 5 to 14 days. The eggs are orange-red and are laid in packets on the leaves and stems of water plants. These eggs are hatched as in the case of Cyclops. The eggs have remarkable vitality, an instance of which is on record. Samples of dried mud sent to England from Jerusalem produced Cypris after a lapse of 24 to 30 years.
Cypris are always found where the light is strongest. They are never found in the shaded portion of a pond or lake.
Work was recently started on the new 1,500,000-gallon reservoir for the municipal water system of Big Spring, Texas This and other plans which are being pushed to completion will greatly increase the water supply of the city.