CHAP. 36. (20.)—CLASSIFICATION OF FISHES, ACCORDING TO THE SHAPE OF THE BODY.
Some sea-fish are flat, such, for instance, as the rhombus,[2448] the sole,[2449] and the sea-sparrow;[2450] which last only differs from the rhombus in the lateral position of the body. The rhombus lies with the right side upwards,[2451] while in the sea-sparrow the left side is uppermost. Some sea-fish, again, are long, as the muræna and the conger.
CHAP. 37.—THE FINS OF FISH, AND THEIR MODE OF SWIMMING.
Hence it is that there is a difference,[2452] also, in the fins of fish, which have been given them to serve in place of feet, none having more than four,[2453] some two[2454] only, and others none.[2455] It is in Lake Fucinus[2456] only that there is a fish found that has eight fins[2457] for swimming. Those fishes which are long and slimy, have only two at most, such, for instance, as eels and congers: others, again, have none, such as the muræna, which is also without gills.[2458] All these fish[2459] make their way in the sea by an undulatory motion of the body, just as serpents do on land; on dry land, also, they are able to crawl along, and hence those of this nature are more long-lived than the others. Some of the flat-fish, also, have no fins, the pastinacæ,[2460] for instance—for these swim broad-wise—those, also, which are known as the “soft” fish, such as the polypi, for their feet[2461] serve them in stead of fins.
CHAP. 38. (21.)—EELS.
Eels live eight[2462] years; they are able to survive out of water as much as six days,[2463] when a north-east wind blows; but when the south wind prevails, not so many. In winter,[2464] they cannot live if they are in very shallow water, nor yet if the water is troubled. Hence it is that they are taken more especially about the rising of the Vergiliæ,[2465] when the rivers are mostly in a turbid state. These animals seek their food at night; they are the only fish the bodies of which, when dead, do not float[2466] upon the surface.
(22.) There is a lake called Benacus,[2467] in the territory of Verona, in Italy, through which the river Mincius flows.[2468] At the part of it whence this river issues, once a year, and mostly in the month of October, the lake is troubled, evidently by the constellations[2469] of autumn, and the eels are heaped together[2470] by the waves, and rolled on by them in such astonishing multitudes, that single masses of them, containing more than a thousand in number, are often taken in the chambers[2471] which are formed in the bed of the river for that purpose.
CHAP. 39. (23.)—THE MURÆNA.
The muræna brings forth every month, while all the other fishes spawn only at stated periods: the eggs of this fish increase with the greatest rapidity.[2472] It is a vulgar[2473] belief that the muræna comes on shore, and is there impregnated by intercourse with serpents. Aristotle[2474] calls the male, which impregnates the female, by the name of “zmyrus;” and says that there is a difference between them, the muræna being spotted[2475] and weakly, while the zmyrus is all of one colour and hardy, and has teeth which project beyond the mouth. In northern Gaul all the murænæ have on the right jaw seven spots,[2476] which bear a resemblance to the constellation of the Septentriones,[2477] and are of a gold colour, shining as long as the animal is alive, but disappearing as soon as it is dead. Vedius Pollio,[2478] a Roman of equestrian rank, and one of the friends of the late Emperor Augustus, found a method of exercising his cruelty by means of this animal, for he caused such slaves as had been condemned by him, to be thrown into preserves filled with murænæ; not that the land animals would not have fully sufficed for this purpose, but because he could not see a man so aptly torn to pieces all at once by any other kind of animal. It is said that these fish are driven to madness by the taste of vinegar. Their skin is exceedingly thin; while that of the eel, on the other hand, is much thicker. Verrius informs us that formerly the children of the Roman citizens, while wearing the prætexta,[2479] were flogged with eel-skins, and that, for this reason, no pecuniary penalty[2480] could by law be inflicted upon them.