Part 5

Goat fish have two growths under the mouth which look like the chin whiskers of goats.

Porcupine fish, whose skins are covered with sharp spines and which can fill their sac-like bodies with water or inflate them with air until they form a ball about twice their normal size. When the bodies are puffed up the sharp spines are erected to protect the creatures against their enemies. The inflation is a defense measure which takes place almost automatically when the fish is alarmed.

Trigger fish are creatures with rigid spines which “lock” automatically when the animals are in danger so that they cannot be bent. They can be unlocked, presumably by a nerve reflex, only by the fish themselves or by some scientist who knows the precise spinal process to touch.

Squirrel fish are brilliantly colored little creatures with large deep-brown eyes which look like the eyes of a squirrel.

Scorpion fish have bodies covered with venomous spines whose poison is reputed to be sometimes fatal even to man.

Flying half-beaks are fish with long, slender upper jaws and practically no lower jaws. They make long glides over the water and may represent an ancestral form of flying fish.

The elephant fish is so-called because of its very rough thick skin and apparent extreme clumsiness of its body, both characteristics of the elephant. Elephantichthys might be likened to a thick leather bag about eight inches long stuffed loosely with vital organs. It has a cartilaginous rather than a bony skeleton. It flattens out when laid on a flat surface out of water. It is almost mollusk likee in the softness of its body. Its skin is approximately a quarter of an inch long.

The aptocyclus, or “rattling fish”, is a close relative of Elephantichthys in Arctic waters. It also seems to be a haphazard conglomeration of vital organs stuffed in a bag. The fish actually rattle inside when the skin is not filled with water. All fish of this family live at the bottom of fairly shallow water, firmly attached to flat stones by disk-like suckers. Although they have the power of locomotion they seldom use it, remaining stationary on the bottom and waiting for their food to come to them.

Most fish have a tail fin, usually forked, with which they propel themselves, but the rat fish has a body tapering down to a long, pointed extension that looks like a rodent’s tail. They are dwellers in deep waters all over the world. Some are quite fantastic. One, Macruroides inflaticeps, consists essentially of a head and a tail without any apparent intermediate body; it looks like an enormous tadpole.

Pearl fish are minute animals that are sometimes found inside oysters and clams entirely encrusted with mother-of-pearl. They actually become large pearls shaped like fish. These small, nearly transparent creatures sometimes back into the open shell of an oyster or clam that snaps once the fish are inside. When this happens the creature perishes but sets up an irritation that leads to the pearl secretion over it.

Love Life Among the Spiders

There is love and courtship among spiders, as among birds and mammals, but with a unique—and fatal—difference. An observer thus describes a courtship scene in the Cambridge Natural History:

“When some inches from her he stood still. She eyed him eagerly, changing her position from time to time. He, raising his whole body on the other side, leaned so far over he was in danger of losing his balance which he only maintained by sidling rapidly toward the lower side. Again and again he circled from side to side, she gazing toward him in a softer mode and evidently admiring the grace of his antics. This was repeated until we had counted 107 circles made by the ardent little male. He approached nearer and nearer and when almost within reach whirled madly around and around her. She joined him in the giddy dance. Again he fell back and resumed his semi-circular motion. She, all excitement, lowered her head and raised her body so that it was almost vertical. Both drew nearer. She moved slowly under him, he crawling over her head. Thus the mating was accomplished.

“A few minutes later, however, the female had eaten her ardent lover.”

The Lace Weavers

For 300,000,000 years tiny animals have been weaving delicate lace. They weave constantly, rapidly and in lovely, open mesh patterns. They make a stiff stable lace. Their own limestone entombed bodies are the threads. Night and day, millenium after millenium, they weave and weave, for the curse of weaving is forever upon them. Through time they have covered hundreds of square miles with white and green veils. For the most part these are fragile and short-lived, but in a few cases they have been preserved untorn through the ages.

These lace weavers are the bryozoa, or moss animalcules—one of the oldest, most abundant and least known forms of animal life. They have much the same habits as the corals, but the two limestone secreting creatures are not even remotely related. The weavers are far higher in the scale of evolution than the island builders. Their family associations long have been in dispute. They have been associated with the rotifers and mollusks and even with some unknown ancestral form leading to the vertebrates. Now, however, it is believed that their nearest relatives are the nearly extinct brachiopods, or lampshells.

The two groups started at about the same time in the Cambrian geological period of half a billion years ago, but they followed different paths of development. Both might be considered proto-mollusks—very remotely kin to clams and oysters. For milleniums the brachiopods flourished in the primaeval seas. During the Permean period, about 300,000,000 years ago, they constituted one of the most abundant forms of animal life. Now they seem close to the end of the road. The weavers are as flourishing, and busy, as ever.

Like a coral polyp or the larva of a clam, the bryozoan starts life as an almost invisibly minute, free-swimming creature, usually less than a thirtieth of an inch long. After a few weeks it settles on some hard surface, usually a stone, and secretes its limestone shell. New individuals rise from the body of the founder of the colony at various angles, depending on the particular design of the tapestry being produced. Each of the buds, after achieving its coat, sends out new buds. This is the weaving process.

The outside of the stone coat often is marked with delicate and bizarre designs discernable under a microscope. These designs always are the same for members of a colony and quite similar for an entire species. They make it possible to identify species in geological formations and this eventually may be of considerable importance for oil geologists. After death a colony usually is broken up quickly by wave action. Sea bottom ooze often is filled with the remains. This ooze, over periods of milleniums, becomes compacted into rock.

The weaving process may be very rapid. A colony, starting with a single free-swimming larva, may cover as much as 100 sq. feet. Such colonies have been found on a single stone. They often are found on mollusk shells. At present the bryozoans are economically important chiefly as a menace to the oyster industry. Once they have covered an abandoned shell, oystermen believe, no other oyster will make use of it. About their only other importance to man comes from the fact that some fresh-water species may clog water pipes by their rapid growth.

Every bryozoan in a colony remains throughout its life a separate animal, shut off from its fellows by a wall of limestone and leading an independent existence. Nevertheless, in the species pattern it assumes, each colony acts as if it were a single organism.

Moreover, a phenomenon unique in nature, every individual appears to be two and in some species three animals in one. Each leads its own life and dies its own death at its own time. But all make up a single microscopic whole.

First is the zooecium, a limestone-encrusted box of tissue. This is the continuing individual. Inside the box is a little tentacled worm, the polypide. It contains all the vital organs—the brain and the nerve, circulatory and digestive systems. It breathes, hunts, eats and lives quite independently of the zooecium. This polypide usually is short-lived. It has no excretory system. Poisons pile up. It degenerates and dies. When it expires the cells of the zooecium wall assert themselves. From the dead cells of the polypide they extract what nutritive material is present. The “inside animal” becomes a brown speck-like body. Then the zooecium cells sprout a bud which becomes a new polypide. This lives its normal life span and suffers the same fate as its predecessor. Another brown body is the only evidence that it has lived. This process may be repeated ten or twelve times. Think of a man, or any other high animal, which could replace over and over again its entire internal system with another made out of its own skin which had eaten its own defunct brain and heart.

The relation of zooecium and polypide as it exists in one type of bryozoa, the so-called “sea mats”, was vividly described by the great British naturalist P. H. Gosse. These are not lace weavers. They form a colony which looks like a pale, yellow leaf, such as Gosse found in a microscopic study of a mass of sea weed in which he saw other animals like “exquisitely crimson leaves thinner than the thinnest tissue paper, with tall and elegant dark red feathers and purple filaments each as fine as a silk worm’s thread.”

“Each individual cell [zooecium] of the sea mat”, Gosse tell us, “is shaped like a child’s cradle. Suppose a coverlet of transparent skin were stretched over each cradle, leaving an opening just over the pillow. Suppose in every cradle there lies a baby with its little knees bent up to the chin in that zig-zag fashion in which children often lie.

“But—the child is moving. A slowly pushed open semi-circular slit of the coverlet and we see him gradually protruding his head and shoulders in an erect position, straightening his knees at the same time. He is raised half out of bed. His head bursts open and becomes a bell of tentacles. This baby is the tenant polypide.

“The chambers themselves show signs of life. Their front doors suddenly open, gape widely and shut with a snap. This opening and shutting is repeated over and over again. The polypide emerges from the cell slowly and withdraws like lightning at the slightest alarm.”