Meet Mighty Leviathan
“I NEED hardly mention his limbs,” reads an ancient description of Leviathan, “his strength, and the fitness of his armor. . . . Who can force open the doors of his mouth, close to his terrible teeth? . . . Should the sword reach him, it will not avail; nor will the spear, nor the dart, nor the javelin.”—Job 41:4-18, New American Bible.
What creature has a set of fear-inspiring teeth and hide so tough that ancient swords, spears, darts and javelins were almost powerless to penetrate it? The creature is a reptile, one of the largest in existence. Since the ancient description of Leviathan was committed to writing in the Middle East, the creature meant was doubtless the Nile crocodile. This crocodile may attain a length ranging from thirteen to sixteen feet (3.9 to 4.8 meters).
The real power of the crocodile resides in its triangular snout. What a sight greets the eye when the hinged lower jaw drops open, revealing perhaps a full set of sixty-six sharp teeth! When the jaws clamp shut, the pressure exerted is tremendous. In his book Nature Parade, F. W. Lane writes: “In experiments in France a 120-pound [54-kilo] crocodile exerted a pressure between its jaws of 1,540 pounds [698 kilos].”—Pp. 83, 84.
The toughness of the crocodile’s armor is indeed amazing. Naturalist R. L. Ditmars observes: “Against javelins and arrows the hide is undoubtedly invulnerable.” (Reptiles of the World, 22nd printing, p. 16) Although not bulletproof, the plates, if struck obliquely, will often cause the bullet to ricochet. (Library of Natural History, Vol. V, p. 2381) Just what is the makeup of the crocodile’s hide?
Tough horny scales imbedded in bony plates cover the upper parts of the back and the tail. The horny scales are arranged in rows. Most of them have a ridge or keel.
The underside consists of smooth horny scales. These usually have no bony plates beneath them. Especially toward the throat, however, there may be some small bony platelets.
The sides of the crocodile’s body are covered with small knobby scales. On account of these scales the sides can stretch or expand—a vital requirement for breathing and, in the case of the female, an essential for accommodating the expansion resulting from pregnancy.
Because of its valuable hide, the crocodile has been slaughtered ruthlessly by men seeking quick profits. For leather goods, only the undersurfaces are used. Whenever small bony platelets are present in the underside, the commercial value of the hide may be reduced.
Well-equipped for Its Existence
The crocodile is ideally equipped for its twofold existence on land and in water. The submarine-shaped body and powerful paddle tail enable it to swim rapidly. Situated on the highest part of the crocodile’s head, the eyes, ear openings and external nostril openings can be above water while the rest of the head is submerged. That is why the crocodile can both see and breathe even though nearly the entire body may be beneath the surface of the water.
When the crocodile is totally submerged, special muscles or valves close the external nostril openings. Likewise, scaly flaps close the reptile’s ears. The translucent inner eyelid (nictitating membrane) protects the surface of the crocodile’s eyeball from water and at the same time enables the reptile to have a measure of vision.
The internal nostril openings at the end of the crocodile’s long nasal passage open, not into the roof of the mouth, but into the throat. What prevents the respiratory system from being flooded when the crocodile opens its mouth under water? A special valve arrangement comes to the rescue. A flap projects from the roof of the mouth just in front of the interior nostril openings, and there is a corresponding fold on the tongue. When the crocodile is submerged, the lower fold is pressed snugly against the upper flap, thereby preventing the water from getting into the throat. Because of this, the crocodile can still breathe when the mouth is open beneath the water while the nostrils are above water.
A Vital Role Among Living Things
Scientific investigation of the feeding habits of crocodiles has brought to light that, despite their being predators, they are not especially destructive. Comparatively lazy creatures, adult crocodiles expend relatively little energy. Their food requirements are far less than what many people might imagine. One researcher, Hugh Cott, stated: “Bearing in mind the fact that crocodiles feed mainly upon fish only during part of their life-cycle and that eventually many other foods are also taken, we are left with the surprising conclusion that the overall daily fish consumption of an individual crocodile is less in bulk than that of a white-breasted cormorant (which consumes at least one kilogram of fish per day).”
Crocodiles often feed on fish that prey on other fish and on those fish that are less valuable to humans. Whenever crocodiles disappear from a certain area, various kinds of fish get out of hand and threaten the existence of other varieties. By eating large water beetles, dragonfly nymphs and crabs that feed on newly hatched fish, young crocodiles allow more fish to mature.
Studies of the American alligator, a close relative of the crocodile, indicate that these mighty reptiles contribute much to the preservation of plant and animal life.
For example, in the Everglades, situated in the southern section of Florida, alligators keep the bony-scaled spotted garfish in check. Without control on the gar population, these fish would eat up all the valuable bass and bream, as well as other game fish.
The alligator contributes toward the preservation of living things by digging basinlike holes in areas where the water table fluctuates greatly. In the Everglades, these “gator holes” constitute the deepest pools. During periods of drought they are the last to dry up and so provide a refuge for various fish, amphibians and reptiles. Once the drought passes, the creature life preserved in the “gator holes” can begin to multiply. These holes also supply food and water for birds and mammals.
Nutrients derived from the alligator’s droppings and remnants of its meals enrich the soil and contribute to the support luxuriant vegetation. On the banks formed by material dredged from “gator holes” plants can start to grow that differ from those of the immediate surrounding area.
Even the movement of the alligator through its habitat has a beneficial effect on the landscape. Being a large reptile, the alligator makes channels through the plant life and thereby retards the processes that transform a pond into a marsh.
Truly, mighty “Leviathan” is an impressive creature. Its protective armor and the strength of its jaws are awe-inspiring. This reptile is marvelously suited for its existence and contributes a valuable part in preserving the present balance of living things. While perhaps not especially attractive to many people, mighty Leviathan should make one aware that it is unwise to underestimate the value of any creature. Especially now, since man’s ruthless slaughter has exterminated this reptile in many areas, is its importance beginning to be discerned.