is 20 to 25 percent of body length per molt. 

 Adult male crabs grow from 16 to 22 mm. in 

 length per molt, but molt frequency decreases 

 to biennial at about 145 to 165 mm. in carapace 

 length and may be triennial in large adults. 

 Males reach sexual maturity in 4 to 6 years, 

 are recruited to the fishery (minimum legal 

 length about 140 mm.) at about 6 to 8 years, 

 and may reach maximum size in about 11 to 

 13 years. Under the present size restrictions, 

 males are sexually mature 2 years before 

 recruitment to the fishery. 



Since carapace measurements are available 

 for only 65 returns, growth data from this 

 tagging study are limited. The data available 

 are plotted in figure 3. They suggest growth 

 rates similar to those found for king crabs 

 in other locations south of the Alaska Peninsula 

 and in the Bering Sea. The small positive bias 

 in returns showing no growth is due to mea- 

 surement errors up to +4 mm. and the fact 

 that minus measurement errors were re- 

 corded as 0. This bias should not be present 

 in returns showing growth. No detailed analy- 

 sis of growth increment per molt has been 

 made because of the limited data. There are, 



80 

 i 70 



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I 60- 



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 o 



S 50 



however, some interesting observations to be 

 made from these data, since some crabs 

 remained free for as long as 5 years. 



The cluster of points for crabs that show 

 no growth (near on ordinate of figure 3) 

 indicates no observations for crabs at liberty 

 for more than two molt seasons. (Adult king 

 crabs molt in the winter or early spring, and 

 April 1 has been selected for purposes of 

 analysis as the molt anniversary.) This is 

 evidence that most crabs molt at least bien- 

 nially. 



Most crabs in the cluster showing one molt 

 (near 17 mm. on the ordinate of figure 3) 

 were at liberty for one or two molt seasons. 

 Two crabs in this group were recovered after 

 three molt seasons. One of these was 143 mm. 

 in carapace length at the time of release and 

 should have molted twice. The second was 

 178 mm. in carapace length and may represent 

 a biennial molter. Another crab in this group 

 was recovered after four molt seasons. It 

 was 174 mm. in carapace length when re- 

 leased. The fact that this crab had an old 

 shell when released (skipped previous molt) 



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Q. 



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 q: 

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40" 



30 



20 



10 



. 



-10 



100 120 140 160 180 200 



CARAPACE LENGTH AT TIME OF TAGGING (MM.) 



Figure 3.--Growth increment between release and recovery, king crab tagging. Shumagin 

 Islands area. 1957-62. (Growth year considered to extend from April 1 to March 31,) 



