230 



ICHTHYOLOGY. 



Chondrop. 



tervcu: ORDER I.— STURIOXES, OR CHONPROPTERYGII 

 Stur'iones. WITH FREE BRANCHIiE. 



The few genera of tliis order approach to ordinary fishes, 

 by their gills being attaclicd only at one extremity. They 

 have but one branchial ajierture, which is very o])en ; they 

 have but one operculum, and are without rays to the mem- 

 brane of the gills. 



Genus Acipenseu, Linn.; Sturgeon. The general 

 form of this genus resembles that of the sharks ; but they 

 are distinguished by longitudinal rows of bony plates or 

 bosses implanted on the skin ; the head is defended by 

 similar plates ; the mouth is small, and. as in sharks, placed 

 below the snout ; the palatal bones are lufited to the max- 

 illaries, and vestiges of the inter-maxillaries may be traced 

 in the lips, while the mouth is capable of some degree of 

 projection, by its position on a style with three articiilations. 

 Instead of teeth, the mouth is furnished with a sort of horny 

 process on the jaws. The nostrils and eyes are on the 

 sides of the head; the muzzle is furnished with vermiform 

 cirrhi. There is no vestige of an external ear, but the 

 labyrinth is perfect within the bones of the head. The 

 dorsal fin is behind the ventrals, and the anal immediately 

 below the dorsal. The caudal fin surrounds the extremity 

 of the s|)ine, and its upper lobe is longer than the lower. 

 Internally there exists the spiral intestinal valve, and the pan- 

 creas forming a single mass ; but we also find a very large 

 and strong swimming bladder, communicating by a wide 

 aperture with the gullet. They prey on the smaller fishes, 

 in pursuing which they can exert much speed ; but in the 

 rivers they frequent they are said to search for Vermes in 

 the oozy bottom, which they explore with their snout, like 

 swine. 



Sturgeons are marine fishes, but at certain seasons they 

 ascend in vast numbers particular rivers, where they are 

 the subject of extensive fisheries, jiarticularly in the large 

 rivers that disembogue themselves into the Black Sea and 

 Caspian, and the rivers of France and Prussia ; they abound 

 also in the large rivers of North America, where the spe- 

 cies appear to be peculiar to that continent. 



The European species are — 



Acipenser sturio, or common sturgeon. Its ordinary 

 length is seven or eight feet, but sometimes they are caught 

 exceeding sixteen feet. Snout pointed, and furnished with 

 cirrhi ; body gradually tapering, pentagonal, from the dis- 

 position of six longitudinal rows of hard, bony, radiated, and 

 mucronated tubercles. Its skin, except the flat belly, is 

 rough, from small plates of a similar form ; mouth a trans- 

 verse oval orifice ; lips cartilaginous ; tongue thick ; gill- 

 covers consisting of an oval radiated plate ; pectorals oval ; 

 dorsal near the tail. Its flesh is white and delicate, re- 

 sembling veal. Its roe forms common caviar. This fish 

 was highly prized by the ancients, and is still an esteemed 

 food. 



Acipenser rtdhenus, or sterlet, is the smallest of Euro- 

 pean sturgeons, rarely measuring more than three feet long. 

 It is very numerous in the Volga and Ural, and is uncommon 

 in the IJaltic. The lateral tubercles are very numerous, 

 and strongly carinated ; those of the under part of the body 

 are more flattened. The flesh resembles delicate veal, and 

 the roe forms the most highly prized caviar. See Plate 

 CCCVII. fig. 1. 



Acipenser huso, or isinglass sturgeon, is the largest of 

 the genus, sometimes attaining the length of from twenty 

 to thirty feet, and weighing from 1300 to between 2000 and 

 3000 lbs. Its skin is much less tuberculated than the com- 



mon sturgeon, and is covered with a viscid mucus ; the Chondrop- 

 snont and cirrhi are shorter. This species is chiefly found terygii. 

 in the Caspian and Euxine, or the rivers that flow into Sturiones. 

 those seas ; but the large sturgeons sometimes caught in ^'^"^^^"^ 

 the northern seas appear also to belong to the same species. 

 The best isinglass is formed of its air-bladder. 



The following species, which are found in the rivers of 

 North America, appear to be peculiar to that continent 

 (See Ainer. Trans, vol. i.) : Acipenser brevirostris, A. 

 o.rijrin/nchus, A. macvlosus, and A. rubicundus. The last 

 of these appears to be the American representative of the 

 A. riilhcniis, the preceding one of the A. sturio.^ 



Genus Polyodon, Lacep. ; Spatularia, Shaw. This 

 genus, which consists but of a single species, is at once re- 

 cognised by the enormous prolongation of its snout, which 

 has a dilated middle, something resembling the leaf of a 

 tree when viewed from above. The habit of the body re- 

 sembles the sturgeon ; but the spinal column is formed of 

 one piece, as in the lamprey. The upper jaw is formed of 

 the maxillary and palate bones \mitcd together, and the 

 pedicle of the mouth has two articulations ; the mouth is 

 small, and furnished with numerous minute teeth. The 

 spiracle is wide, and covered by a very large, soft opercu- 

 lum, extending to the middle of the body. The intestine 

 is provided with the spiral valve, so frequent among the 

 Chondropterygii ; but tlie pancreas exhibits the commence- 

 ment of a subdivision into lobules. The existence of an 

 air-bladder suificiently distinguishes it from the Scjuali. It 

 has only been found in the Mississippi, and does not exceed 

 a foot in length. 



Genus Chimera, Linn. This genus has a strong affi- 

 nity to the Squall in general shape, and in the position of 

 the fins, but the gills have only one aperture on each side ; 

 yet, on inspecting more accurately, we see that the rays 

 are attached by most of the edges, and that there are really 

 five holes opening into the bottom of a general cavity. A 

 rudiment of an operculum is found in the skin ; the jaws 

 are still less complex than in the Squali, for the upper jaw 

 is represented only by the vomer, and the palate bones 

 and tympana are merely rudimentary, attached to the sides 

 of the muzzle. Instead of teeth, the mouth is fiu-nished 

 with undivided hard plates, of which four are above and 

 two below. The snout resembles that of the shark, and 

 also has regular ranges of pores. The first dorsal fin is 

 armed with a strong spine, and is placed over the pectorals. 

 The males, as in the Squali, are distinguished by the carti- 

 laginous appendages of the ventral fins, divided into three 

 branches, and have two spiny plates before the base of the 

 ventrals. These fish have also on their front a fleshy ca- 

 runcle, garnished with a group of small prickles. The in- 

 testine of this genus is short, and has a spiral valve. The 

 female lays eggs of a large size and coriaceous consistence, 

 flattened, and hairy. The only species is Chimcera borea- 

 lis, or northern chimera. It is found in the Northern Ocean, 

 where it is believed to feed on the numerous Mollusca and 

 Crustacea of that sea. It is rarely taken, because it keeps 

 much in deep water ; but it has been occasionally caught 

 among our northern islands, and is sometimes seen of 

 the length of three or four feet. Its head is the thickest 

 part of the body, whence it tapers imiformly to the tail. 

 It is most common on the coasts of Norway, where its eggs 

 are eaten, and the oil of its liver is used as a stimulant em- 

 brocation. It also occurs in the iMediterranean. 



Genus Cali,oiuiynchus, Gronovius. Cuvier separates 

 this from the last genus, to which it was united by Linnae- 

 us. It is distinguished by its snout terminating in a fleshy, 



' In a quarto work published some time ago at Berlin (Geltreiic Darstclhing, &c.). containing figures and description of the various 

 animals of use in Therapeutics, tliere is a MoiwgrajiU of the Sturgeons by Messrs Brandt and Rulzeburgh. See Anmles dcs Science} 

 A'at. for Feb. 1831, p. 223. 



