Marine species

“ About forty species, contained in four genera, compose this Family: they are all marine, and are found in both hemispheres, principally in the intertropical seas. A few inhabit the Mediterranean, and one is by no means uncommon around the British Isles, and on the northern shores of Europe. ”

“ Most marine animals have a wide range; and we have seen that with plants it is those which have the widest range, that oftenest present varieties; so that with shells and other marine animals, it is probably those which have had the widest range, far exceeding the limits of the known geological formations of Europe, which have oftenest given rise, first to local varieties and ultimately to new species; and this again would greatly lessen the chance of our being able to trace the stages of transition in any one geological formation. ”

“ Ten species have been distinguished in different seas and oceans. They usually attach themselves to some hollow part of the bodies of marine animals, preferably entering the respiratory cavities of star-fish. ”

“ Marine vegetation.—The marine vegetation is divisible into different systems, like those prevailing on the land; but they are much fewer, as we might have expected, the temperature of the ocean being more uniform than that of the atmosphere, and consequently the dispersion of species from one zone to another being less frequently checked by the intervention of uncongenial climates. The proportion also of land to sea throughout the globe being small, the migration of marine plants is not so often stopped by barriers of land, as is that of the terrestrial species by the ocean. ”

“ Turning to the sea, we find the same law. No two marine faunas are more distinct, with hardly a fish, shell, or crab in common, than those of the eastern and western shores of South and Central America ”

“ Among these the most numerous are the remains of marine animals, and in some instances shells and corals occur in such abundance as to form the principal part of extensive beds. Every part of the earth exhibits similar, or nearly similar formations; and not only are marine fossils met with in the interior of continents, and at great elevations above the sea, but a vast variety of plants, corals, shells, fish, reptiles, etc., are found, of species dissimilar to any at present on the land or in the waters. Besides rocks, we meet with earthy formations on the surface. ”

“ The fauna is made up of a modified marine and a modified fresh-water fauna, and always has its nearest relatives in the open sea, on the one hand, and in the rivers and connecting fresh-water lakes, on the other. Since the species contributed by the marine waters are so much more numerous than those contributed by the rivers, the greater number of the species in the brackish water will be related to marine forms. ”

“ They rest upon those not less remarkable beds of limestone, of which our capital is built, in the more or less compact texture of which the patience and sagacity of our naturalists, and of several ardent collectors, have already detected more than 800 species of shells, all of them marine, but the greater part unknown in the presently-existing sea. They also contain only bones of fishes, and of cetacea and other marine mammifera. ”

“ We know that a fish cannot live long in air, or a man under water. An oak growing in the ocean and a seaweed on the top of a hill, are incredible combinations of ideas. We find that each kind of animal is limited to a certain range of climate; each kind of plant to certain zones of latitude and elevation. Of the marine flora and fauna, each species is found only between such and such depths. Some blind creatures flourish in dark caves; the limpet where it is alternately covered and uncovered by the tide; the red-snow alga rarely elsewhere than in the arctic regions or among alpine peaks. ”

“ Let it be noted also that those tertiary species which have continued with little change down to our days are the marine animals of the lower grades, especially mollusca. Their low organization, moderate sensibility, and the simple conditions of an existence in a medium like the ocean, not subject to great variation and incapable of sudden change, may well account for their continuance ”

“ Although so few marine animals are common to the above-named three approximate faunas of Eastern and Western America and the eastern Pacific islands, yet many fishes range from the Pacific into the Indian Ocean, and many shells are common to the eastern islands of the Pacific and the eastern shores of Africa on almost exactly opposite meridians of longitude. ”

“ They are more numerous, particularly the marine kinds, in the colder seas both of the north and south, than in the tropical regions. Our own islands possess a very large number, almost one-third of the species marked as British belonging to this Order. ”

“ We also use as examples those species of marine birds whose abundance in the eastern Bering Sea and feeding habits give them the greatest potential for influence on, or being influenced by, fish abundance. ”

“ Westward of the shores of America, a wide space of open ocean extends, with not an island as a halting-place for emigrants; here we have a barrier of another kind, and as soon as this is passed we meet in the eastern islands of the Pacific with another and totally distinct fauna. So that three marine faunas range northward and southward in parallel lines not far from each other, under corresponding climate ”

“ It has long been a fact familiar to geologists, that, both on the east and west coasts of the central part of Scotland, there are lines of raised beaches, containing marine shells of the same species as those now inhabiting the neighbouring sea. ”

“ In the sea, the tropical plains with their tangled vegetation and plentiful animal life are represented by the still more uniform plain forming the submerged continental 13 shelf with its strange forests of flowerless plants, the seaweeds. These submarine jungles shelter hosts of animal species, many of which swarm in countless myriads. This life embraces all grades of invertebrates, such as the microscopic protozoa, sponges, radiate animals like the coral-polyps, starfishes, sea-urchins, etc., and crustaceans in vast variety, and, among vertebrates, includes fishes, reptiles, and mammals. ”

“ As this era begins, the sea bottoms, the extensive continental shelves, and the numerous shallow near-shore basins are covered with prolific vegetation. The more simple and primitive forms of animal life have already developed from preceding vegetable organisms, and the early animal organisms have gradually made their way along the extensive coast lines of the various land masses until the many inland seas are teeming with primitive marine life. ”

“ That there are animals in the northern and other seas with which we are unacquainted, is more than probable: discoveries of animals of new species are constantly being made, especially in the life of the deep sea. ”

“ Some of its beds consist of a range of certain species possessing a considerable similarity; while in others, animals of the most opposite habits, and inhabiting different regions of the globe, as well as different elements of nature, are strangely brought into contact, and confusedly blended in one heterogeneous mass. Shell-fish of the rivers and of the sea, corals, fishes of various kinds, insects, bones of different species of birds, remains of elephants, bears, and other quadrupeds, requiring for their existence different climates, are here united in an extraordinary assemblage. ”

“ The shallow-water, or littoral, fauna includes all marine animals which belong neither to the deep-sea nor to the surface fauna, and is the most important of all three.The shallow-water fauna. In addition to the great bulk of marine invertebrates, the littoral fauna may be taken to include the reef-building corals (whose distributional limitations under the influence of temperature-control have been already mentioned) and likewise seals and sea-cows among mammals, and turtles among reptiles. ”

“ A Animal life had its beginning in the waters, and to this day the waters are the chief habitat of animals, especially of the lower forms. If we divide the animal kingdom into great leading types, the lowest of these groups, the Protozoa, includes only aquatic forms; the next, that of the coral animals and their allies, is also aquatic. So are all the species of the Sea Urchins and Star Fishes. Of the remaining groups, the Mollusks, the Crustaceans, and the Worms are dominantly aquatic, only a small proportion being air-breathers. ”

“ The distribution either of animals possessing the power of flight, or of inhabitants of the ocean, is, of course, easily to be accounted for; the difficulty, if there is really any, must mainly be with strictly terrestrial animals of moderate or small powers of locomotion and with inhabitants of fresh water. Mr. Darwin himself observes, [1] "In regard to fish, I believe that the same species never occur in the fresh waters of distant continents." ”

“ Of Marine Fishes, some roam the wide ocean, some play around the coral islands of the tropics, others affect the mud, or the sands of the shallows; some linger near the estuaries of great rivers; others come in mighty armies around the coast at particular seasons, retiring again to the deep water in the offing; finally, some habitually keep near the surface, while others rarely rise from the vicinity of the bottom. ”

“ On the whole the fish-fauna is typically Neotropical, but with a small infusion of Nearctic forms. There are a considerable proportion of peculiar genera, and almost all the species are distinct from those of other countries. ”

“ The most prominent and remarkable result of the voyage was the final establishment of the fact that the distribution of living beings has no depth-limit, but that animals of all the marine invertebrate classes, and probably others also, exist over the whole of the flora of the ocean. ”

“ In the sea, whales, sharks, and teleost fishes of modern types rule in the stead of huge swimming reptiles. The lower vertebrates, the invertebrates of land and sea, and the plants of field and forest take on a modern aspect, and differ little more from those of to-day than the plants and animals of different countries now differ from one another. From the beginning of the Cenozoic era until now there is a steadily increasing number of species of animals and plants which have continued to exist to the present time. ”

“ Some families, like the cod, are prevailingly distributed in colder waters, and certain species have been taken in lakes above the line of perpetual snow. Temperature is one of the important factors in determining the distribution of fishes. Deep-sea forms, where the temperature is uniform, have a wide distribution. The geological history of any region, with the changes in the river systems, etc., it has brought about, is another important factor. See Deep-Sea Exploration; Distribution of Animals; Cave Animals; Evolution. ”

“ When some great class of stations is in excess in certain latitudes, as, for example, in wide savannahs, arid sands, lofty mountains, or inland seas, we find a corresponding development of species adapted for such circumstances. In North America, where there is a chain of vast inland lakes of fresh 696 water, we find an extraordinary abundance and variety of aquatic birds, fresh-water fish, testacea, and small amphibious reptiles, fitted for such a climate. ”

“ Scientific men are busily hunting for instances of variation of this sort. Take for example, an animal which lives sometimes in salt water, sometimes in water that is only brackish; there are cases in which small differences can be noticed, according to the difference in the habitat. Notice the marine shell-fish, for instance, near the estuary of a river: they are often less robust specimens than are found at a point free from the influence of fresh water. ”

“ The processes of natural selection have given to each kind of river or lake species of fishes adapted to the conditions of life which obtain there. There is no condition of water, of bottom, of depth, of speed of current, but finds some species with characters adjusted to it. These adjustments are, for the most part, of long standing; and the fauna of any single stream has as a rule been produced by immigration from other regions or from other streams. Each species has an ascertainable range of distribution, and within this range we may be reasonably certain to find it in any suitable waters. ”

“ The human mind enjoys impressive visions of unearthly creatures. Now then, the sea is precisely their best medium, the only setting suitable for the breeding and growing of such giants—next to which such land animals as elephants or rhinoceroses are mere dwarves. The liquid masses support the largest known species of mammals and perhaps conceal mollusks of incomparable size or crustaceans too frightful to contemplate, such as 100-meter lobsters or crabs weighing 200 metric tons! ”

“ Though subtle differences in ranges, color patterns, and dorsal fin shapes and positions may be helpful in narrowing the choices of living animals, the species will continue to be extremely difficult to distinguish from one another in the brief encounters typical at sea until additional data are collected. ”

“ They devoured even their own species. Living mostly in the open seas or fresh-water lagoons, they sometimes chased their prey far up the rivers, and sometimes basked in the sunshine on the sands of the shore. ”

“ Thus we perceive that these creatures, though they are regarded as being so low in the scale of creation, may nevertheless be regarded as agents of much importance in the terrestrial economy; for we perceive that they are capable of spreading over certain parts of the ocean those benign mantles of warmth which temper the winds, and modify, more or less, all the marine climates of the earth. ”