Rays and Skate.] 



MUSEUM OF ANIMATED NATURE. 



175 



SECTION PLECTOGNATHI. 



In the imperfect structure of their jaws, and the 

 slow ossification of the skeleton, these fish approach 

 the cartilaginous series. Their principal character 

 consists in the solid attachment of the maxillary 

 bone on the side of the intermaxillary, which forms 

 alone the jaw ; the palatal bones unite with the 

 skull by means of a suture, and consequently are 

 destitute of mobility. The gill-flaps and rays are 

 concealed under a thick skin, which gives exit to 

 the water only through a small orifice. There are 

 only trifling vestiges of ribs ; ventral fins are 

 wanting; the swimming-bladder is generally con- 

 siderable. 



Family GYMNODONTID^ (GLOBE-FISHES, 

 SUN-FISHES, DIODONS, &c.). 



The jaws, instead of being furnished with ordinary 

 teeth, are garnished with an ivory substance, divided 

 into series of laminae, the whole resetnbling a par- 

 rot's beak; this beak really consists of true teeth 

 united together, succeeding each other, in propor- 

 tion as the anterior teeth or laminae are worn by 

 . trituration. These fishes live on Crustacea and sea- 

 weed, and their flesh is generally musky, and even 

 unwholesome. Some, as the tetraodons and dio- 

 dons, are capable of inflating themselves into a 

 spherical form, and thus distended they float with 

 the back downwards, and make progress by the 

 aid of the pectoral fins. The sun fishes seem ca- 

 pable of floating, but not of distending themselves 

 with air. 



2496.— The Short Sun-fish 



(Orthagoriscus mola). In these flat discoid 

 fishes the dorsal and posterior fin below are 

 united to a deep caudal fin, of which they seem 

 to be two long wing-like points. The short 

 sun-fish is sometimes seen floating in our seas, 

 with little motion, appearing, as it lies on one 

 side, like a fish dead or dying. It attains to a great 

 size, upwards of four feet in length, and more than 

 three hundred pounds in weight. Mr. Neill says, 

 respecting one brought to him, — "The fisherman 

 informed him that when they observed it, it was 

 swimming along sideways, with its back fin fre- 

 quently above water ; it seemed to be a stupid dull 

 fish, and made little or no attempt to escape, but 

 allowed one of the sailors to put his hands under it 

 and lift it fairly into the boat. The sun-fish is gene- 

 rally mentioned as remarkable for its phospho- 

 rescence ; but this specimen did not exhibit that 

 phenomenon so distinctly as a haddock or herring." 

 The sun-fish, according to Mr. Couch, is migratory, 

 and, he suspects, keeps at the bottom feeding on 

 sea-weed ; but in calm weather it mounts to the 

 surface, and lies, perhaps asleep, with its head and 

 even its eyes above the water, floating with the 

 tide. Mr. Couch has known the sun-fish make 

 powerful but awkward efforts to escape when at- 

 tacked, bending and directing its motions in various 

 ways. (See Yarrell.) 



CHONDROPTERYGII (CARTILA- 

 GINOUS FISHES.) 



In these fishes with a cartilaginous skeleton, the 

 maxillary and intermaxillary bones are reduced to 

 a mere rudiment, and their functions are filled by 

 bones analogous to the palatal, and even sometimes 

 by the vomer. They are divided into two sections : 

 those with the branchiae free, covered with gill- 

 flaps ; and those with the branchise fixed by their 

 outer edge, the water escaping by five or more 

 branchial apertures pierced in the skin. To the first 

 division belongs the Sturgeon ; to the second, the 

 Sharks and Rays. 



Family STURIONID^ (STURGEONS). 

 2497. — ^Thk Beluga Sturgeon 

 (Acipemer huso). In the genus Acipenser the 

 body is elongated and angular, defended by indurated 

 plates and spines arranged in longitudinal rows; 

 snout pointed and conical ; mouth placed on the 

 under surface of the head, tubular, and without 

 teeth. 



The species of the genus Acipenser are very nu- 

 merous; seven species appear up the Danube, 

 different from the ordinary sturgeon (A Sturio), 

 which IS caught, often of large size (from six to 

 eight feet and upwards in length, and two or three 

 hundred pounds in weight), around our coast and 

 in our estuaries. Along the northern coasts of 

 Europe the common sturgeon is very abundant, and 

 extensive fisheries are established for its destruction 

 Caviar is made from the roe of the female ; isinglass 



from the thick air-bladder ; and the flesh, besides 

 being highly esteemed while fresh for the table, is 

 preserved by salting and pickling. 



In the Caspian Sea there is a huge species called 

 Le Hansen, Great Sturgeon, and by some Beluga* 

 Sturgeon, which often measures fifteen and some- 

 times twenty feet in length, and individuals weigh- 

 ing from one thousand to fifteen hundred pounds 

 weight are not unfrequently taken. An extensive 

 fishery is established for the purpose of capturing 

 these fish for the sake of the roe and the air-blad- 

 der, and as many as 103,500 are said to be taken 

 in the course of a year, aff'ording 30,000 pounds of 

 isinglass, and 414,000 pounds of caviar. The fishery 

 is kept up during the winter, holes being made in 

 the ice for the introduction of the ropes and lines. 

 The principal fishing, however, commences about 

 the end of March or beginning of April, when the 

 great sturgeons approach the shore in immense 

 swarms ; they are caught by means of lines, each 

 about nine feet long, with a baited hook, and fas- 

 tened to the number of 125 to a rope 262 feet in 

 length. 



This rope, with its lines, is called a nest, and thirty 

 of these nests tied together commonly belong to 

 one fishing-machine ; the two ends of this are se- 

 cured to two wooden anchors, and a stone of several 

 pounds weight divides each nest. The rope, stretched 

 out from point to point, floats heavily in the water, 

 and is visited twice a day, and the lines tied ; the 

 fish attached to the hooks are secured by a cord 

 passed through their gills, and drawn ashore. This 

 work lasts about a fortnight, when, on the retreat of 

 the great sturgeons to the deep water, a smaller 

 species takes their place ; it is termed the Sevruga 

 (A. helops, Pall.), and seldom exceeds four feet, 

 but sometimes attains to eight or ten, and is so nu- 

 merous, that a single vessel will in the course of a 

 fortnight capture 16,000 or 20,000. 



In the autumn there is a second fishery of the 

 great sturgeon, and, as we have said, it is kept up 

 on the ice during the winter. The value of the dif- 

 ferent sorts of sturgeons and their products, caught 

 in the Caspian in an ordinary year, is said to amount 

 to 300,000/. Of the skins of old and large fish a 

 sort of leather is made, and those of the young are 

 used in some parts of Russia and Tartary instead of 

 window-glass. But we must pass to our second 

 division. 



Family SQUALID^ (SHARKS, DOG-FISH, &c.). 

 2498. — The Small-spotted Dog-fish 



(Sq/llium Caniculd). In a sketch like the present 

 want of space precludes our entering into all the 

 structural details of the present family, or into the 

 grounds upon which the many genera are founded. 

 For daring, voracity, and rapidity, these fishes have 

 been long notorious. 



Of the sharks which frequent our seas the small- 

 spotted dog-fish is one of the most common, and few 

 I have visited the shore who have not observed its flat 

 oblong eggs with a long tendril from each corner, 

 called sea-purses, thrown upon the beach or cling- 

 ing to the ponds of sea-weed. It may be here 

 observed that many of the true sharks are ovovivi- 

 parous, producing their young alive, while others 

 produce eggs in the form of horny cases, with 

 two fissures, one at each end, for the admission of 

 sea-water and the exit of the young. 



Among the sharks the females exceed the males 

 in size ; they hunt in company, are very tenacious 

 of life, and their teeth are severe weapons, formed 

 for cutting and retaining their prey. 



On our southern coast especially the present spe- 

 cies (of small size) is very abundant, and annoying 

 to the fishermen, who often capture it in their nets, 

 and draw up a useless booty ; it is, moreover, in- 

 jurious to the interests of the fishermen from its 

 voracity, making terrible havoc amongst the shoals 

 which migrate towards the coast. The same obser- 

 vation applies to the other species of dog-fish and 

 sharks which frequent our seas. 



Of these the following are described by Mr. 

 Yarrell :— The Large-spotted Dog-fish (Scyllium ca- 

 tulus), le Rochier of the French ; the Black-mouthed 

 Dog-fish (Scyllium melanostomum), rare on our 

 coast, but well known in the Mediterranean ; the 

 White Shark (Carcharias vulgaris), le Requin of 

 the French, a large and dangerous fish, occasionally 

 met with on the British coast, more common in the 

 Mediterranean, and the dread of mariners in the 

 seas of warmer latitudes, where it will follow the 

 vessel for leagues, and is often taken by a baited 

 hook. The Fox-Shark, or Thresher (Carcharias 

 vulpes), remarkable for the length of the upper 

 portion of the tail-fin ; it measures from eight or 



* The true Beluga is a species of porpoise or dolphin (D, leucas, I 

 Gm.), in the northern seas, j 



ten to fifteen feet in length, and has received the 

 name of Thresher from its mode of defending itself 

 by violently lashing with its powerful tail. It is 

 not common near our shores, but is frequent in the 

 Mediterranean and the warmer seas. The blue 

 Shark (Carchaiias glaucus), a migratory visitor to 

 the coast of Cornwall, arriving about the middle or 

 latter part of June, and detested by the fishermen 

 for the devastation it commits among the shoals 

 of pilchards, &c., and the injury it does to the nets, 

 which it cuts to pieces with its teeth as an easy 

 means of extricating the fish entangled in the 

 meshes, swallowing both fish and string together. 

 The Porbeagle (Lamna Cornubica), a species more 

 common on the north and north-east coast of our 

 island, especially in autumn, than along our southern 

 shores. It appears to be gregarious, hunting its 

 prey in small troops. The Beaumaris Shark rLamna 

 Monensis), rare on our shores, two specimens only 

 having been taken on the Anglesey side of the 

 Menai. The Tope or Penny Dog (Galeus vulgaris), 

 a common species on the southern coast and along 

 the shores of Cornwall, attaining to six feet in length, 

 and noted for its rapacity. The Smooth Hound 

 (Muotelus laevis), a species in tolerable abundance 

 round our coast, and used in the Hebrides as food. 

 It is TEmissole of the French. Its food consists of 

 Crustacea, which its flat teeth, arranged like the 

 pieces of a mosaic pavement, are well adapted for 

 crushing. The Basking Shark (Selachus maximus), 

 so called from its habit of basking quietly on the 

 surface of the sea in sunny weather, when it is so 

 listless as often to allow of the close approach of a 

 boat : it is seen principally off our southern coast, 

 and one measuring thirty-six feet in length was 

 taken some years since near Brighton. The Picked 

 Dog-fish (Spinax Acanthias), a common species, 

 with a sharp spine before each dorsal fin, used as 

 eff'ective weapons of, defence. It is very annoying 

 to fishermen, and is gregarious in its habits. The 

 Greenland Shark (Scymnusborealis), a native of the 

 northern seas, but occa.sionally visiting the shores 

 of Scotland. It measures from ten to fifteen feet in 

 length, and is celebrated as being one of the deadly- 

 foes of the whale. 



Family RAIID^ (RAYS AND SKATE), 



2499.— The Thoknback . 



{Raia clavata). The Rays or Skate are of a de- 

 pressed figure, having the disc rhomboidal, the great 

 breadth of the body being produced by the singular 

 expansion of the pectoral fins. There is no distinct 

 head; the tail is long and slender, and furnished 

 with two dorsal or upper fins, and sometimes with 

 the vestige of a caudal. The mouth and branchial 

 orifices are on the under surface. The texture of 

 the skin varies; in some it is rasp-like, in others 

 studded with tubercles or spines, with which latter 

 the tail is always armed. These fishes, some of 

 which attain to enormous dimensions, are admirably 

 adapted by their form for existing at the bottom of 

 the water on beds of sand or mud. When disturbed 

 they slide along in an undulatory manner, and with 

 a slight motion of the pectoral fins. They defend 

 themselves by lashing violently with the tail. The 

 Rays are very voracious, feeding on fishes and Crus- 

 tacea together with shelled or naked mollusks. 

 Their teeth are flattened and lozenge-shaped, and 

 set in close array ; but in adult males the posterior 

 angles of the teeth become elongated (at least in 

 most species), forming a serried phalanx of points 

 directed backwards. So powerful are the jaws, that 

 they are capable of crushing the shell of a crab with 

 the greatest ease. At the base of each ventral fin 

 posteriorly and beneath is a cylindrical appendage, 

 peculiar only to the male. The females exceed the 

 males in size ; their eggs are corneous, and closely 

 resemble those of the dog-fish. 



The thornback is very common on our coasts, and 

 is taken in abundance for the table in spring and 

 summer, when it visits the shallows. Its flesh, how- 

 ever, is in the best condition in November. The 

 female is known under the term of " Maid." The 

 skin is covered with thorny tubercles, variable in 

 number. 



Fig. 2500 represents a fisherman of South Wales 

 with his coracle, or portable boat of hide or pitched 

 canvas stretched over slight ribs of wood. In this 

 frail bark he fearlessly ventures on the waters of the 

 Severn or the Wye : such were the boats of the 

 painted Britons in the time of Caesar. 



Fig. 2501 represents ancient Egyptians capturing 

 fish with a drag-net. Fig. 2502, Egyptians angling. 

 Both are taken from a tomb at Beni-Hassan: they 

 illustrate the mode in which fish were taken in the 

 Nile at a remote period. 



Figs. 2503, 2504, 2ii05, are dehneations of AraJ? 

 fishermen of the present day. 



END OF THE CLASS PISCES (FISHES). 



