THE TARPON 67 



There are stones in the ears of most fish which are called 

 otoliths. Their function is not well understood. They show 

 concentric rings which confirm the age indicated by the scales. 

 I have examined those of the tarpon but they did not throw any 

 light on the problem. 



The annual growing period of a scale is represented by 

 evenly spaced rings while the narrow compressed and broken 

 rings indicate the cessation of the growth in the winter. Each 

 group of growths represents a year of the fish's life and its 

 age can be determined by counting the number thus shown. 



All this sounds very simple but when this theory is applied 

 to the tarpon, many difficulties arise to confuse the observer. 

 In the first place there is possibly a checking of the growth 

 during the spawning season and the rings may also indicate 

 the cessation of growth due to that condition. The tarpon is 

 a warm water fish, living in the midst of plenty. It has not been 

 observed to hibernate and may grow steadily throughout the 

 year. If there is any cessation of growth during the spaw- 

 ning period, the rings do not appear to reflect it. A few years 

 ago, I collected a series of ten scales from fifteen fish which 

 were labelled with the length, weight and sex as each fish 

 was caught. I sent sets of these scales to five noted 

 ichthyologists with the request that they determine the ages 

 of the fish from the samples so taken. In due time I received 

 the reports but none of them checked; on the contrary, they 

 widely differed. The letter from the Federal Grovernment 

 expert is quoted to show the difficulty which confronts the 

 student : 



**The tarpon scales sent in by Mr. Babcock have been 

 studied carefully. While the scale of this species appears 

 rather promising as a means of determining age, consider- 

 able data, scales from many fish, and careful study, are 

 required to arrive at results in any way near correct. Ac- 

 cording to my judgment the scales at hand were analyzed 

 as follows: 



