FISHERY BULLETIN: VOL. 73, NO. 2 



Table 2.-Frequency of sexual types in each 20-mni size class for 

 the Catalina Island population of Pimelometopon pulchrum. 



Number Mature Mature 



of fish Immature female Transitional Male 



Standard 



length (mm) 



Table 3.-Frequeney of sexual types in each 20-mm size class for 

 the Guadalupe Island population of Pimelometopon pulchrum. 



Standard 

 length (mm) 



Number 

 of fish 



Immature 



Mature 

 female 



Transitional 



Mature 

 Male 



<100 



100-119 



120-139 



140-159 



160-179 



180-199 



200-219 



220-239 



240-259 



260-279 



280-299 



300-319 



320-339 



340-359 



360-379 



380-399 



>400 





 

 

 

 3 

 5 



10 

 8 



10 

 6 

 5 

 6 

 6 

 2 

 3 

 1 

 3 



Totals 



130 



14 



42 



68 



largest sizes. Transitionals were found in inter- 

 mediate sizes, in numbers which varied seasonally 

 (see below). 



At Catalina, most California sheephead mature 

 at standard lengths between 190 and 230 mm. 

 Sexual transformation occurs over a broader size 

 range beginning at 250 mm, with a peak of ac- 

 tivity apparently occurring at standard lengths 

 between 310 and 330 mm. 



The dwarfing phenomenon found in the 

 Guadalupe population is again evident (Table 3, 

 Figure 8). Maturity begins at a length near 140 

 mm, and the majority of individuals are male by a 

 length of 210 mm. Peak transformation activity 

 appears to occur in the population in fishes rang- 

 ing from 190 to 230 mm in standard length. 



The actual time courses for all these events 

 become evident when the relative frequencies of 



100 

 80 

 60 

 40 

 20 

 



100 

 80 



60 - 

 40 - 



20 



CATALINA 



U- 



GUADALUPE 



<I0 13 17 21 25 29 33 37 



STANDARD LENGTH ( 2 cm groups) 



40 < 



Figure 8. -Proportions of each sexual type in successive 2 cm 

 standard length groupings for the Catalina Island (top) and 

 Guadalupe Island (bottom) populations of Pimelometopon 

 pulchrum. 



Table 4.— Frequency of sexual types in each year class of Pimelo- 

 metopon pulch ru m . 



Age Number Mature Mature 



class of fish Immature female Transitional male 



Catalina 

 population 



1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10-h 



7 

 33 

 34 

 42 

 40 

 27 

 15 

 14 

 8 

 8 



7 

 33 

 34 

 5 

 

 

 

 

 

 















35 



33 



16 



9 



4 



2 



1 





 

 



1 



2 

 3 

 1 

 

 

 





 

 



1 

 5 

 8 

 5 

 10 

 6 

 7 



Totals 



228 



79 



100 



42 



Guadalupe 

 population 



1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10- 



4 



2 



5 



4 



10 



13 



14 



9 



6 



13 





 

 

 

 4 

 6 

 9 

 7 

 5 

 10 



Totals 



80 



11 



23 



41 



the sexual types in each age class are graphed 

 (Figure 9). The curves are based on the frequency 

 distributions listed in Table 4. 



270 



