Figure 39. — September 1966. DistributiOD and relative 

 abundance of windowpane, Scophthalmui ofuoiut, larvae. 



they are rare at depths >92 m (Bullis and Thompson 1965). 

 Fraser (1971) found members of the genus Syacium in the 

 Straits of Florida at depths from 2 to 140 m, and questioned 

 records from depths exceeding 182 m. Surface isotherms 

 suggest that both stations where we caught larvae in April 

 were within the influence of the Gulf Stream, and, judging 

 from their size and number, we concluded that the larvae 

 had been transported into the survey area (Table 12). 



In May, larvae were confined largely to the southern end 

 of the survey area. They were most concentrated between 

 capes Hatteras and Lookout over a depth of 50 m (Fig. 44). 

 Their size range and numbers indicated that spawning 

 intensity had increased since the April cruise (Table 12). As 

 on the previous cruise in April, their distribution seemed 

 restricted to the Gulf Stream or its edge. The shoreward 

 limit of their occurrence closely followed the 20°C surface 

 isotherm. 



The catch in June decreased, but the distribution 

 remained essentially the same as in May (Fig. 45). Larvae 

 were most abundant along the outer edge of the shelf off 

 Cape Hatteras, an area where the depth is probably too 

 great for spawning and the Gulf Stream too swift to permit 

 the larvae to remain near the center of spawning. It is 

 improbable that they represented local spawning. 



Larvae were most abundant nearshore between capes 

 Hatteras and Lookout in Aug^ust. These had probably been 

 spawned locally. Although for the first time their 

 distribution extended into the survey area north of Cape 

 Hatteras (Fig. 46), the catch decreased slightly, probably 

 because there was little or no influx from the south such as 

 had been evident during the earlier cruises. 



We made our biggest catch in late September (Table 12). 

 The distribution of larvae extended northward to Virgfinia, 

 well shoreward of the Gulf Stream. The center of abundance 

 occurred at seaward stations between capes Hatteras and 

 Lookout, and probably represented spawning that had 

 occurred south of the survey area (Fig. 47). 



Spawning dropped off sharply by November. We caught 

 fewer larvae than in September, and, with one exception, 

 their distribution had receded to that part of the survey area 

 between the North CaroUna capes. The exception, a single 

 specimen captured off northern Virginia, represented the 

 northernmost occurrence of this species in our survey (Fig. 

 48). 



We caught only six larvae in December (1965), all at 

 stations near the outer edge of the shelf south of Cape 

 Hatteras. None were taken on the following cruise in 

 January and February. Judging from the size of the larvae 

 (Table 12), and their absence on the following cruise, we 

 presumed that spawning had ended sometime in November 

 or, at the latest, early December. Since many of the larvae 

 we caught had been transported into the survey area by the 

 Gulf Stream, it is possible that our catches in December 

 reflected the end of spawning along the entire east coast. 



Like most warmwater fishes, dusky flounder have a 

 protracted spawning season. We caught larvae over a 9-mo 

 period, mostly off the North Carolina coast between capes 

 Hatteras and Lookout (Fig. 49). The spawning season in this 

 area is not very different from that noted for dusky flounder 

 in the Gulf of Mexico (Topp and Hoff 1972) and Tampa Bay, 

 Fla. (Moe and Martin 1965). They postulated, from gonadal 

 observations, that spawning occurred from February to 

 November, peaking in May and June. Our collections indicate 

 that spawning lasts from April to October or November. 

 Larvae were most abundant from May through September, 

 and these months probably represent the height of the 



40 



