56 
BULLETIN OF THE BUREAU OF FISHERIES 
with others of much shorter duration, offer sufficient evidence, however, to show 
that it is not practicable to make selections of fast growing terrapins at 1 year or 
less of age. Furthermore, it seems very probable that such selections can not be 
made even at 2 or possibly at 3 years of age. The data on this last point still are 
quite meager. The fact that some animals (as is plainly shown by the accompanying 
tables) grow very slowly and require a much longer time than others to reach maturity 
and a size sufficiently large to make them valuable on the market, however, is well 
established, and these extremely slow growing individuals appear to furnish the 
chief obstacle to terrapin farming as an enterprise. 
Comparatively few females 11 (as shown by the tables presented herewith) 
reached sexual maturity and a length of 5% inches at the age of 5 years. A some- 
what larger percentage reached it at 6 years of age. However, 9.8 per cent of the 
females of the winter-fed lot of the 1910 brood were still under that size at the age 
of 15 years. Among the hibernating lot of the same brood, 19.5 per cent were under 
5^2 inches in length at the same age. Although marketable at a smaller size, a 
terrapin is not considered a “count” and does not bring a fancy price until it has 
reached a length of 6 inches or more. According to this classification only 28.5 
per cent of the winter-fed lot of the 1910 brood and 25.2 per cent of the hibernating 
lot of the same brood would have passed as counts at the age of 15 years. 
In the 1911 brood 12.9 per cent of the animals (no males included) of the winter- 
fed lot were less than inches in length at 14 years of age, and in the hibernating 
lot of the same brood 15.2 per cent were under this size at 14 years of age. The 
percentage of counts was somewhat greater than in the 1910 brood, for 41 per cent 
of the fed lot and 45.8 per cent of the hibernating lot could have been classed as 
counts at 14 years of age. Younger broods have made even slower growth. 
The growth curves presented herewith show that, in general, the average rate 
of growth is fairly rapid until the terrapins reach an age of 5 or 6 years. Thereafter 
it becomes much slower, and after the eighth to the tenth year it is extremely slow. 
The almost negligible growth of the older animals, as, for example, those of the 1910 
brood, after attaining an age of about 8 years suggests that some of the animals will 
never reach a length of 6 inches. It seems improbable, even, that all of them will 
reach 5)^ inches. In the winter-fed lot of the 1910 brood, for example, 11 of the 102 
females included were less than 5)^ inches long, the smallest one having a length of 
only 4 4/5 inches when last measured at the age of 15 years. In the hibernating lot 
of the same brood, at the same age, 17 of the 87 females included were less than 5}/£ 
inches long, and the 2 smallest ones were only 5 inches in length. The first-mentioned 
lot, according to our records, appears to have made an average gain in growth of only 
2.5 millimeters, and the other lot only 4 millimeters during the six years prior to the 
last measurements, or between the ages of 9 and 15 years. 
In the winter-fed lot of the 1911 brood, 10 of the 78 females included were under 
B }/2 inches long, the smallest one having a length of 4 4/5 inches when last measured 
at the age of 14 years. Among the hibernating lot of the same brood at the same age 
11 of the 72 females were less than 5^2 inches long, and the smallest one was 5 }z$ 
inches in length. The winter-fed lot had made an average gain of 3.4 millimeters 
" The males are not considered in this connection as none of them appear ever to reach as great a length as 5 Y> inches, and they 
reach sexual maturity at a much smaller size. 
