LOVE ET AL.: LIFE HISTORY AND FISHERY OF CALIFORNIA SCORPIONFISH 



looor , ,000 



800 



600 



O 



(- 

 I 



o 



400 



200 



20 25 30 



TOTAL LENGTH (CM) 



Figure 6.— Length-weight relationship of female California 

 scorpionfish sampled in the Southern California Bight, 1981-83. 

 Squares represent more than 10 individuals, dots represent a single 

 fish. 



800- 



600 



3 



h- 

 X 



o 



uj 

 5 



400 



200 



20 25 30 

 TOTAL LENGTH (CM) 



35 



40 



Figure 7.— Length-weight relationship of male California 

 scorpionfish sampled in the Southern California Bight, 1981-83. 

 Squares represent more than 10 individuals, dots represent a single 

 fish. 



Table 6.— Condition factor (K) of California scorpion- 

 fish from southern California, 1981-83. 



W K SD 



U 



398 2.16 0.25 27,729.5 <0.001 

 256 1.98 0.18 



Males 



May-Sept. 



Oct. -Apr. 

 Females 



May-Sept. 216 2.07 0.28 13,375.5 <0.001 



Oct. -Apr. 180 1.93 0.19 



Sexes combined 



May-Sept. 614 2.13 0.26 104,117.5 <0.001 



Oct. -Apr. 436 1.96 0.19 



All seasons 



Males 654 2.09 0.24 79,709.0 <0.001 



Females 



396 2.00 0.25 



by about 18 cm TL, equivalent to 2 yr of age (Fig. 

 8). Males tended to mature at a slightly smaller size, 

 though all fish were mature by 22 cm TL. 



California scorpionfish spawned from May 

 through August, peaking in July. Ovary and testes 

 sizes varied seasonally (Fig. 9). Ovaries were rela- 

 tively small and constant in size from September to 

 March but began to increase in April and peaked 

 in June and July, dropping precipitously thereafter 



(Fig. 9). During the peak spawning season, ovaries 

 comprised about 5% of total weight (maximum 

 17.5%, minimum 1.0%), while during the transition 

 period, ovaries made up slightly <1% (maximum 

 1.4%, minimum 0.06%). 



Testes followed a similar pattern (Fig. 9). They 

 made up slightly more than 0.3% of body weight 

 during late spring and early summer (maximum 

 0.6%, minimum 0.2%) declining to 0.1% in winter 

 (maximum 0.3%, minimum 0.05%). 



We believe spawning takes place just before, and 

 perhaps after dawn, in the water column. On several 

 occasions, about 1 h before sunrise, while conduct- 

 ing surveys on the California scorpionfish spawn- 

 ing grounds, we observed dozens of scorpionfish 

 near the surface. Fathometer tracings indicated 

 large numbers of fish throughout the water column. 

 These fish disappeared just after sunrise. Commer- 

 cial longline fishermen, targeting scorpionfish on the 

 same grounds, report this is a daily phenomenon. 

 There is no evidence that California scorpionfish 

 behave in this fashion when not in spawning 

 condition. 



107 



