The St. Johns herald., 1891-04-30
WHENCE FISHES coLoRs COME.
WI;y They Are the Most Decorative of
 Animals in This World.

yEI;y They Are the Most Decorative of
 Animals in This World.
 ''There are lots of funny things to be told about fish scales,'' said a naturalist the other day to writer for the Wash ington Star. ''The surface of the scales ordinarily is covered with thin, silver coating, which derives its brilliant me tallic luster from the presence of many crystals composed of lime and a sub- stance known as 'guanin.' This coat ing is easily rubbed off, and in one sort of European carp, called the bleak, the crystals are so numerous that me tallic pigment is derived from theTa, known in the arts as argentine, which is used to iInpart luster to the glass globules sold under the name of Roman pearls When the silver coating is ab- sent the scales of fish are lusterless and transparent, as in the case of the smelt, the abdominal cavity of which, however, has brilliant, silvery lining composed of the same substance.
 Every one knows from observation that the fishes of the world are the most gorgeous of animals in point of color ing. The colors they exhibit are often due to a simple arrangement of pig | inent cells, but the brilliant and change able hues, which constitute the great est beauty of these creatures, are de rived from two causes very wide apart. An illustration of one of these may be observed in the scales of the herring. shad or macberel, being a true irides- cence, similar to that seen in the pearl. and due to the refraction of the rays ot light as they glance off the surfaces ot the thin plates of which the scales arc composed. More frequently, however. the coloration is dependent on the ar engagement of the pigment cells that arC in the lower layers of the outer skin C. the fish.
 ''In fish, when the black pigmen' predominates, the color is somber, as i: the adult tautog. A slight admixtur. of yellow gives the bronze-like hue t. the eel, and little more of the same if you please, results in the brightc green of the black bass and the blu. fish. Red pigments intermixed wit, black give the dingy brown of th carp and some of the catfishes. Whc the yellow and red outnumber the blac cells there result the tawny coloT's C the sunfshes, the cusks and of som varieties of the cod. Red pigment eel iii the lower strata of the outer ski alone cause the brilliant scarlet of th red snapper and the roseish, and yvhe these are interspersed with black tb deeper colcrs of the mangrove snappe and the ruddy variety of the sea rave result. When the pigment cells gathc into separate groups according to colo bands, stripes, spots aud shadings, in1 nite in their variety, are found.
 ''In fish, as in other animals, albinoe occur. Very curious are the albin haddocks occasionally taken on or coasts. The same phenomenon is als observed in founders, carp and eels. I the depths of the sea, where light scanty, many fishes appear to renal. permanently albinoes.
 Fishes very commonly change thei colors to harmonize with the bottomsc which they live, for the sake of concca rent. This is accomplished by U special secretion of the proper pi' mcntS. On certain lodges along t. New England shore the rocks are col cred with dense growths of scarlet an crimson seaweed, and the fishes whic frequent their neighborhood becon tinted accordingly. It has been su: rested, by the way, that the pink Of u salmon's flesh is due to the absorptio, of the coloring matter of the crust ceans they feed upon. Probably tl' brilliant coloration of many kinds fishes is designed by nature to attrac the opposite sex, as the beauty of pcacocl1's tail is intended for the san purpose. Fear or other emotions wi often change the colors of fishes ral idly.
 Ut is in tropical seas that the mos brilliantly colored and beautiful fshe of the world are to be found. Warmf and light are favorable to brillianc and variety of hues always. The fshC of the polar regions and those living considerable depth are usually son Der, and when you get down to th dark abysses of the ocean they arc black"