Wilk et 3\ : GSI annual cycles as indicators of finfish spawning in the New York Bight 



779 



Figure 5 



Annual cycle of gonad-somatic indices for red hake Urophycis chuss 

 collected in the New York Bight, June 1974-June 1975, including 

 monthly means, ranges, 95% confidence intervals, and number ex- 

 amined. In addition, percent ripe females per month is given on the 

 upper axis. 



one during March followed by another in September 

 (Fig. 6). Ripe females, 283-396 mm, were collected 

 from February through April. In addition, ripe females, 

 191-360 mm, were present again from August through 

 November. Colton et al. (1979) suggested a spawning 

 time of August through April with an October peak, 

 but did not allude to a bimodal spawning pattern. 

 Barans (1969) observed ripe females, with a minimum 

 length of 225 mm, in the Chesapeake Bight from 

 August through November. In collections made off the 

 Carolinas, ripe spotted hake were found during 

 December (Bigelow and Schroeder 1953). 



In the September sample, ripe females were caught 

 at depths between 12 and 86 m and temperatures of 

 between 11.0 and 17.3°C. In contrast, during March 

 and April ripe females were caught at much deeper and 

 cooler locations (Table 1). Spotted hake range from 

 southern New England to Florida (Hildebrand and 

 Schroeder 1928, Bigelow and Schroeder 1953); how- 

 ever, they are most abundant south of Chesapeake Bay 

 (Barans 1969). In the Chesapeake Bight, Barans (1969) 

 reported their temperature range as 6-20 °C, with a 

 preferred range of 10-12°C. In addition, he gave 190 

 mm as the minimum length for 1 -year-old females, and 

 >280 mm for 2-year-olds. If the spotted hake captured 

 during this study follow the size at ages given by 

 Barans (1969), the population present in spring is com- 

 posed primarily of older fish, with young-of-the-year 

 and yearlings migrating into the area during summer 

 and fall. The apparent split spawning season observed 

 during this study may be attributable to dissimilar 



Figure 6 



Annual cycle of gonad-somatic indices for spotted hake Urophycis 

 regia collected in the New York Bight, June 1974-June 1975, in- 

 cluding monthly means, ranges. 95% confidence intervals, and 

 number examined. In addition, percent ripe females per month is 

 given on the upper axis. 



Figure 7 



Annual cycle of gonad-somatic indices for black sea bass Cmitropristis 

 striata collected in the New York Bight. June 1974-June 1975, in- 

 cluding monthly means, ranges, 95% confidence intervals, and 

 number examined. In addition, percent ripe females per month is 

 given on the upper axis. 



distributional patterns of specific age groups at the 

 northernmost extreme of the species range. 



Black sea bass Centropristis striata 



Mean GSI was highest during July, with ripe females, 

 184-452 mm, collected from May through July (Fig. 

 7). Black sea bass are protogynous hermaphrodites 

 with the size at which females become males extremely 



