Dentzau and Chittenden Population dynamics of Polydactylus octonemus in the Gulf of Mexico 451 



C. SEPTEMBER-OCTOBER 



Sep 



5M 

 n=17 C/f=3 8 



T ' 1 1 '' i ' — I 1 < 1 



5i 



9M 

 n=22 C/t=3 9 



n^ A-A^" 



-1 ' 1 



13M 

 n=16 C/f=4 



-1 ' 1 '1 "^ 'f ' r 



15i 



10 

 5- 



16M 



n=322 C/f=12 2 



T ^ 1 1 1 



18M 

 n=25 C/f=4 1 



-1 V '' IT ' r- 



>- 



Oct 



5M 



n=2 C/f=l 1 



"""-T 1 1 1 1 



9M 

 1^ 11=7 C/t=0 9 



5i 



■n ' 1 



13M 

 n=6 C/t=13 



-T T ' " ' N" 



15 

 10 

 5- 



16M 

 n=259 C/f=5 



-n "-I r- 



18M 

 0"^ — ' n=38C/f=5 



,-,.--■■ AM, „^ 



T 1 1 



15 

 ID- 

 S' 



22-24M 

 n=186 C/f=2 3 



-1 r 1 1 ^ 



60 120 180 240 300 



D. NOVEMBER-DECEMBER 



51 No 



Summer 

 > — • 



9M 

 n=2 C/t=0 2 



ISM 

 • 0' n=9 C/f=04 



-\ ' r 



5i 



^0 



22-24M 

 n=7 C/t=0 1 



Dec 



13M 

 n=1 C/f=0 1 



T ' r 



16M 

 n=23 C/t=0 5 



' -A" "^f 



-1 r' -' -'V v^ ^ -^ 



18M 

 n=1 C/f=0 1 



22-24M 

 n=65 C/f=0 5 



0- 



l.'il 130 :-10 300 



TOTAL LENGTH Imml 



Figure 1 1 

 (continued) 



(4) P. octonemus almost completely disappeared from 

 trawl catches off Freeport at 9-11 months of age. The 

 collection of one specimen seemingly 15 months old in 

 April 1979 (Fig. 6) suggests a few age-I fish survive 



and remain in the white shrimp community, an inshore 

 fauna described by Hildebrand (1954) and Chittenden 

 and McEachran (1976). However, this would not great- 

 ly affect our estimate of ti. 



