Ganoid fish

“ They were covered with true [56] scales (fig. 4, a,) and their free gills were protected by gill-covers; and so they must be regarded as real Ganoids but as the shagreen of the spotted dog-fish nearly approaches, in form and character, to ganoid scales, without being really such, the scales of this family, on the other hand, approached equally near, without changing their nature, to the shagreen of the Placoids, especially to that of the spiked dogfish, (Spinax Acanthias.) (Fig. 4, b.) We even find on their under surfaces what seems to be an approximation to the characteristic footstalk. ”

“ Passing on next to the Vertebrate Animals of the Cretaceous period, we find the Fishes represented as before by the Ganoids and the Placoids, to which, however, we can now add the first known examples of the great group of the Bony Fishes or Teleosteans, comprising the great majority of existing forms. The Ganoid fishes of the Cretaceous (Lepidotus, Pycnodus, &c.) present no features of special interest. Little, also, need be said about the Placoid fishes of this period. As in the Jurassic deposits, the remains of these consist partly of the teeth of genuine Sharks (Lamna, Odontaspis, &c.) ”

“ The Ganoid fishes, although intermediate between the Sharks and common bony fishes or Teliosts, have many affinities with the Amphibia: thus, the Amia and Lepidosteus, among the Ganoids, have the air-bladder filled with air-vesicles and resembling strongly the lung of the Amphibia. ”

“ When it cannot catch fish for itself, it watches for the gannets and sea-swallows after they have been out fishing all day, and darting down upon them, compels them in their fright to throw some of their prey out of their crops, when it is caught by the plunderer before it reaches the water. ”

“ Of the large group of Ganoids so abundant during all these geological ages but few forms are living to-day. These are the Ceratodus, lung fish of Australia; the Polypterus of the Nile, the Protopterus of Western Africa, the Dogfish and the three Garpike of North America. These few species are but the remnants of a once large and extensive group of fishes.
In the study of fishes we notice that some are highly specialized so far as their structures are concerned; the teeth of some become especially fitted for a peculiar kind of food, and as a result quite unfit for any other kind. ”

“ The commissioners who recently collected information on the Scottish herring-fisheries, assume that in Scotland alone the gannet (a sea-bird) will annually draw on the shoals to the extent of one thousand one hundred and ten million herrings! In addition to dog-fish, cod, gannets, and other sea-birds, the herring has many other enemies; porpoises, seals, coal-fish, and other predaceous fishes are constantly lying in wait to fall upon and devour them. A female herring, we know, yields over thirty thousand eggs; but at the shoaling-time myriads of those eggs are devoured by a variety of enemies ”

“ Before that time they are scarcely able to move, and thousands of them fall a prey, not only to the other fish, but to the larvae of aquatic insects which prey upon them very greedily. As I happen to know from my own observations, the larva of the stone fly (May fly of Lancashire) and those of all the larger ephemera (drakes) , to say nothing of the fresh-water shrimps, swarm in all the spawning beds, and no doubt destroy myriads of the ova. All these would be saved by proper precautions and well formed spawning-boxes, with good supplies of spring water to feed them. ”

“ I fancy sportsmen would want protection for them; and if they were not able to obtain it, they would do what is seriously proposed by many people with regard to the Salmon—they would do all they could to exterminate them, rather than continue to act as brood hens to hatch chickens for other men's eating.
Then take the annual close time and the pretended compensation it offers in the two months' rod-fishing (September and October) . After the nets have been withdrawn, what is it worth? Or, what is the value of black fish full of spawn? They cannot be sold; they are not fit to eat ”

“ There is such a plentiful supply of larvae, caddis, "stone-loach," fresh-water shrimps, crayfish, and other crustaceans, to say nothing of flies, minnows, and small fry, that a trout would very seldom attack a snake. A large lobworm, however, as every one knows, is a very attractive bait for any kind of fresh-water fish except pike.
Stoats with reddish-brown backs and yellow bellies may often be seen hunting the rabbits, and the little weasels may sometimes be drawn out of their holes in the walls if one makes a squeaking noise with the lips. ”

“ Wading up stream, the angler casts before him into every likely stream and eddy, allowing the line and bait to come down towards him in mid-water, and striking the moment he perceives a check. This is a very killing plan, and is adopted with a modification of tackle, to fish with beetles, larvae, palmers, and, in fact, almost any kind of insect ; for the trout is a very omnivorous fish, and will hardly refuse anything that is small enough. The lure is cast overhand, as in fly-fishing, and practice enables the angler to cast nearly twice the length of the rod. ”

“ Earlier in the year the trout feeds on the larvae of the May fly, which is itself very destructive to the spawn of the salmon, and hence, by a sort of house-that-Jack-built, the destruction of the mosquito, that feeds the trout that preys on the May fly that destroys the eggs that hatch the salmon that pampers the epicure, may occasion a scarcity of this latter fish in waters where he would otherwise be abundant. ”

“ The reason probably is that they have not been feeding on the fresh-water shrimps or crustaceans, owing to the abundance of olive duns and other flies that have been on the water. Last winter, being so mild, was very favourable for the hatching out of fly in the spring. A hard winter doubtless commits sad havoc among the caddis and larvae at the bottom of the river; the trout, not being able to get much fly, are then compelled to fall back on the crustaceans. The food in these limestone rivers is so plentiful that the fish are able to pick and choose from a very varied bill of fare. ”

“ It hides amongst the sea-weed at the bottom of the sea, and the fleshy shreds attached to its nose, floating about in the water, act as natural bait, and attract the unwary little fishes in its neighborhood, but the instant one of them makes a bite at the tempting morsel it is whisked away, and the poor fish is caught in the huge mouth of the fisherman fish, and crushed up by its sharp teeth. ”

“ Even in streams where a successful deposition of the ova has been accomplished, there never appears, as far as my observations have gone, any disposition in the parent-fish to return to the sea. Their instinct still prompts them to keep swimming up-stream, until you often find them with their noses worn quite off, their heads bruised and battered, fins and tail ragged and torn, bodies emaciated, thin, and flabby; the bright silvery tints dull and leaden in hue, a livid red streak extending along each side from head to tail, in which large ulcerous sores have eaten into the very vitals. ”

“ And a fourth was convicted of breaking down the stake nets in the estuary of a river—at the same time he had a net stretched entirely across the river above, both day and night. And so with many others, every one striving with all his might to kill the goose that laid the golden eggs.
This is not the way to improve the Salmon fisheries. To do this effectually the upper proprietors must have a strong interest in the preservation of the breeding of fish, and in order to give them this interest they ought to have an ample supply of fish when they are in the best condition ”

“ Others become poisonous by feeding on sea-centipedes—curious creatures which twine themselves round the coral, and resemble yards of black string with myriad tiny legs. There are certain fish which may be eaten with impunity on one isle, and are positively deadly if caught on other reefs. The natives themselves have sometimes died by rashly trusting to their experience of their own fishing-grounds, and so venturing to eat the identical fish caught elsewhere. ”

“ The Smolts and the Par ought to be protected as strictly as the Salmon; and there ought to be a penalty attached to the killing of them, or having them in possession, and conservators of rivers ought to have the power of inspecting all mills and manufactories driven by those rivers, to ascertain that they have no contrivances for taking the fry on their way to the sea, as it appears that in some rivers they are taken in large quantities. There ought also to be a penalty attached to the killing of Kelt fish, which in that state are not only tasteless and insipid, but actually unwholesome ”

“ For the gannet, whose breeding success has been studied in some detail (Brun 1974) , it was concluded that the differences in exposure (to severe weather) and in breeding experience were the most important factors responsible for annual fluctuation in breeding success. For such species as murres, razorbills, and puffins, food supply is an important limiting factor. If the spawning of the fish species that constitute their main food items fails 1 year for some reason, it may be very difficult for the seabirds to find an adequate alternative food supply and most of the chicks starve to death. ”

“ Here in the Ribble the Salmon fisheries are not quite so near extinction (though they are rapidly progressing in that direction) , for although we are very seldom allowed to see or catch fish in seasonable condition, a good many come up the river to spawn, though very few of them ever do so, and very few of those that do ever reach the sea again. The reason is obvious, no one here has any interest in preserving the spawning fish, and they are openly killed by the poachers, who never dream of being prosecuted for it. ”

“ Not only trout, but cat-fish, eels, and suckers, have met the same untimely fate, and now boys and men search vainly for their prey.
By fair fishing no stream or pond can be entirely exhausted; when trout have the privilege of biting or not, they will exhibit sufficient circumspection to perpetuate their species; but when they can be followed during the hours of darkness to their retreats, and exposed by the glare of the jack, are liable to death by the fatal spear, or in case they may be enveloped by the all-devouring net, they have no defence or escape, and must soon disappear entirely. ”

“ He remarked on the enormous length of time and the large extent to which fishing had been carried on for the commercial sponge, the red coral, trepangs, the lob- worm, and similar marketable forms of fish life, and he said it was very interesting and instructive to find that after ages of eager pursuit there is as yet no sign of the extinction of these species. For ages man has gathered the sedentary and creeping shellfishes, such as Mussels, Cockles, Periwinkles, for food and bait, often without the slightest restriction, as in the case of the Periwinkle and Limpet ”

“ The sharp eye of the Gannet detects the fish, and the bird, first raising itself to an elevation which experience or instinct has taught it to be sufficient to carry it down to the requisite depth, pounces on the fish, and in the effort penetrates the board to which the fish is attached. Being thus held fast by the beak, and unable to extricate itself, it is drowned. Gannets are frequently caught in the herring-nets, at various depths below the surface. Diving after the fish, they become entangled in the nets, and are thus captured in a trap not intended for them. ”

“ The best mode of taking them at this time, for they are small and fastidious, is with a salmon-rod and a tiny spearing on a Limerick hook; by making casts and drawing the bait along the surface of the water and through the frothy eddies, the young innocents are deceived, and thinking to prey upon their weaker brethren, become themselves a palatable viand for larger creatures. They break like trout, without throwing themselves out of water, but with a noisy snap, and if they miss the bait at first, will follow it resolutely. ”

“ Certain kinds of shellfish, for example oysters, mussels, cockles, live in the sand or attached to the stones or seaweed on the seashore, generally between high and low watermarks. They obtain their food from the water as it streams over their gills. They require adequate room for growth and development, and constant irrigation by water containing sufficient floating food. When mussel beds or oyster beds become overcrowded, the fish are ill-nourished, their health is impaired and their growth is arrested. ”

“ Sometimes a single ill-timed spate will destroy millions of eggs by tearing them from the gravel and laying them bare to a whole host of enemies. [2] These enemies are in the air, on the land, in the water, and nothing short of an enumeration of them can convey any idea of their numbers and wholesale methods of destruction. In addition to the yearling salmon and trout which for ever haunt the skirts of the spawning grounds, there are always a number of mature unfertile fish which for a part of the year live entirely upon the spawn. ”

“ The whole surface of the upper platform is closely covered with nests, placed about two feet asunder, and in such regular order that a person may see between the lines, which run north and south, as if looking along the furrows of a deeply ploughed field. The Labrador fishermen and others who annually visit this extraordinary resort of the Gannets, for the purpose of procuring their flesh to bait their cod-fish hooks, ascend armed with heavy short clubs, in parties of eight, ten, or more, and at once begin their work of destruction. ”