. American fish-culture [microform] : embracing all the details of artificial breeding and rearing of trout, the culture of salmon, shad and other fishes. Fish culture; Fishes; Oyster-culture; Pisciculture; Poissons; Ostréiculture. CULTURE OP THE SHAD. igj " Within eighty-two hours after hatching, great develop, ment has taken place. The tail, though not forked, haB taken on its triangular form, and is up of fine, radiat- ing fibres. The embryonic dorsal and ventral are reduced in breadth, whereby the anal opening is brought close to the body, the base muscles of the true dorsal may
. American fish-culture [microform] : embracing all the details of artificial breeding and rearing of trout, the culture of salmon, shad and other fishes. Fish culture; Fishes; Oyster-culture; Pisciculture; Poissons; Ostréiculture. CULTURE OP THE SHAD. igj " Within eighty-two hours after hatching, great develop, ment has taken place. The tail, though not forked, haB taken on its triangular form, and is up of fine, radiat- ing fibres. The embryonic dorsal and ventral are reduced in breadth, whereby the anal opening is brought close to the body, the base muscles of the true dorsal may also be seen as it begins to form. Along the body the trans- verse muscles show themselves distinctly both above and below the lateral line. The pectoral fins have now their fibres complete, and resemble two little flat brushes. The mouth is pushing forward towards its normal place. It seems to have, in the under lip, a notch, perhaps the point of future union of the mamillaries. The yolk-sac no longor plays an important part, and is reduced to very small dimensions. But the most striking change is the develop, ment of gills, four on a side, and each in its gill-pouch. Ihe gills themselves can be distinguished, like little bows along which run their veins and arteries. These, together with the size and position of the eyes, give the under sur- face of the head rather the look of that of a skate embryo than of a shad. - Such is a hasty sketch of three periods of embryonic life m this Alosa. Of the young, at three months, outlines have already been given.* It should be added, that their jaws ure, at this age, rrmed with fine, sharp, slightly curved teeth, nearly continuous along the upper maxillary and intermaxillary pieces, with a few at the point of the * See plate at the commencement of this \. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectfishes, bookyear1868
