782 



Fishery Bulletin 88(4), 1990 



Figure 12 



Annual cycle of gonad-somatic indices for fourspot flounder Para- 

 lichthys oblongus collected in the New York Bight, June 1974-June 

 1975, including monthly means, ranges, 95% confidence intervals, 

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

 is given on the upper axis. 



J J ASONDJFMAMJ 

 1974 1975 



Figure 13 



Annual cycle of gonad-.somatic indices for windowpane Scophthal- 

 mi<.s aquos'u.'i, collected in the New York Bight, June 1974-June 1975, 

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

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

 given on the upper axis. 



Windowpane Scophthalmus aquosus 



The GSI plot for windowpane was bimodal, with peaks 

 in May and again in September (Fig. 13). Ripe females, 

 201-387 mm, were collected from February through 

 October, indicating that windowpane may spawn to 

 some degree in the New York Bight during most of the 

 year. Unfortunately, data for winter are lacking. There 

 was no conclusive evidence that the two peaks repre- 

 sented spawning of either different populations or age 

 classes. In September the mean lengths were 261 and 

 230 mm for females and males, respectively; in May, 

 windowpane were somewhat more abundant and larger 

 with mean lengths of 285 and 247 mm for females and 

 males, respectively. 



Split spawning of windowpane has been reported 

 previously in the Middle Atlantic region. In 1952 and 

 1953, Wheatland (1956) found eggs from May through 

 early July and again from late September through 

 November in Long Island Sound, New York. Temper- 

 atures in the Sound were >20°C from late July through 

 September when eggs were not present. Smith et al. 

 (1975) proposed two patterns of spawning for win- 

 dowpane depending on latitude. First, off New Jersey 

 and New York one prolonged spawning season was 

 hypothesized based on the occurrence of 2-6 mm lar- 

 vae on the inner shelf from June through December 

 1966. Bottom temperatures on the inner shelf that year 

 ranged between 6 and 17°C during August (Clark et 

 al. 1969). Second, off Virginia and North Carolina 

 spawning was interrupted as indicated by the occur- 



rence of larvae in April through June and again in 

 November and December 1966. During summer 1966 

 bottom temperatures ranged between 15 and 25 °C 

 (Clark et al. 1969). Smith et al. (1975) therefore con- 

 cluded that in waters >20°C windowpane stop spawn- 

 ing. 



Windowpane were collected during the May GSI 

 peak at 5.6-13.2°C and 4-51 m; while during the Sep- 

 tember peak they were collected at higher tempera- 

 tures but at similar depths (Table 1). In July and 

 August, when GSI decreased noticeably, maximum bot- 

 tom temperatures were 20-22 °C at nearshore stations. 

 Based on the results of this survey, coupled with the 

 previously cited historical observations, a split spawn- 

 ing season is probably ty|3ical for windowpane in the 

 New York Bight with continuous spawning occurring 

 only during unusually cold summers. 



Yeliowtail flounder Limanda ferruginea 



Highest mean GSI occurred from February to April, 

 with ripe females, 212-422 mm, collected in October 

 and November and February through May (Fig. 14). 

 Howell (1983) observed female yeliowtail off Rhode 

 Island beginning to mature in September, with the 

 peak GSI in April. Colton et al. (1979) reported spawn- 

 ing in the Middle Atlantic from April through August 

 with peaks in May and June. Smith et al. (1975) found 

 the largest concentrations of larvae off New Jersey in 

 April and May. They also reported larvae in abundance 

 off southern New England in May and June. 



