. British and Irish Salmonidae. Salmon. PRESH-WATEB TEOUT—PINS, SCALES, AND CJEOA OF. 199 this fin is most deTeloped in those taken from running waters.* Ventrals inserted beneath the middle or last third of the base of the dorsal fin. Caudal forked in the very young, emarginate in those of a medium size, becoming square in large examples, or even rounded, as shown in figure 46. While Yarrell (edition 3, p. 281) figured a Thames trout 28 in. long, and 11 lb. weight, in which the hind edge of this fin was slightly rounded. It would also appear that as a general rule the tail fins of trout inhab
. British and Irish Salmonidae. Salmon. PRESH-WATEB TEOUT—PINS, SCALES, AND CJEOA OF. 199 this fin is most deTeloped in those taken from running waters.* Ventrals inserted beneath the middle or last third of the base of the dorsal fin. Caudal forked in the very young, emarginate in those of a medium size, becoming square in large examples, or even rounded, as shown in figure 46. While Yarrell (edition 3, p. 281) figured a Thames trout 28 in. long, and 11 lb. weight, in which the hind edge of this fin was slightly rounded. It would also appear that as a general rule the tail fins of trout inhabiting rapid streams are usually more deeply emarginated than in specimens living in more stagnant Fig. 46. Tail fins of brook toout. 1, male, 5-6 in. long, from peat burn. 2, male, 6-2 in. long, from peat burn. 3, female, 6'7 in. long, from same place. 4, male, 8 in. long, Colesbourne. 5, male, 9-6 in. long, Colesbourne. 6, female, 10-6 in. long, Lossie river. 7, female, 12 in. long, Elgin. Tails of brook trout from New Zealand: 8, female, ^ natural size: 9, male, 20| in, long, ^ natural size: 10, male, 32^ in. long, J natural size. Scales.—From 12 to 15 rows are present between the hind edge of the adipose dorsal fin, in a line passing downwards and forwards to the lateral-line : while about 26 or 27 rows are present between the lateral-line and the base of the ventral fin. As regards the appearance of the scales I have had examples from ten races of fresh-water and sea trout photographed under the microscope for comparison one with another, and likewise examined many more, but the variations were found to be so great, even in those from the same specimens, that nothing would be gained by figuring them. The concentric lines in some of those from the sea trout, sewin, and Lochieven seemed in a few examples to be coarser than in the generality of brook trout. GcBcal appendages.—The number present vary considerably as has been already referred to (p. 188 ante), and
Size: 1610px × 1553px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookpublisherlondo, bookyear1887
