AGE OF A FISH.
: THE WAY TO TELE IT. i Could you tell the age of a fish if j asked to do so? | It has been found that the age of a I fish may he read from its scales, j These increase in size by annular growths, two rings being formed each ! year. The “otoliths,” or ear stones, j which lie in two sacs on either side i of the base of the cranial cavity, af- : ford another means of determination. Like the scales, the otoliths ini' crease by two rings annually. Each - spring a white ring is formed, and ; each autumn a black one. Thus the 1 number of either white or black rings ■ in an otolith gives the age of the fish | in years. In the case of flatfish the latter : method has been found more reliable, I whereas in the case of the cod the j scales give a better result. ‘ Although varying much in size arid ; shape in different species, the otoliths ! show a remarkable constancy in the ; same species; hence they are of con--1 siderable value in the diagnosis of a species.
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Bibliographic details
Thames Star, Volume LVII, Issue 15885, 25 July 1923, Page 3
Word Count
189AGE OF A FISH. Thames Star, Volume LVII, Issue 15885, 25 July 1923, Page 3
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