Morse and Able: Distribution and life history of Scophthalmus aquosus 



689 



water temperatures (Wigley and Gabriel, 1991; Lange 

 and Lux 6 ). 



There appears to be evidence of latitudinal varia- 

 tion in depth preference from south to north (Table 

 4). The actual depth preference in subareas 1-4 may 

 be shallower than indicated because NMFS seldom 

 samples in depths <10 m. For example, in subarea 

 4, juveniles migrated or settled into an estuary dur- 

 ing spring and tended to move into the ocean during 

 summer (Fig. 12). Few juvenile windowpane were 

 caught inside the estuary by the fall when they had 

 reached lengths between 18 and 26 cm TL. These 

 seasonal movements in and out of estuaries and bays 

 may account for the larger numbers of juveniles taken 

 on the continental shelf in the Middle Atlantic Bight 

 in the spring (Table 4; Fig. 10), although the lack of 

 small juveniles in nearshore waters off New Jersey 

 (Fig. 10) is difficult to explain. In contrast, the Mas- 

 sachusetts trawl survey, which sampled similar 

 depths to those in the New Jersey trawl survey, cap- 

 tured large numbers of juvenile windowpane in the 

 fall. Clearly juvenile windowpane are also a compo- 

 nent of fish assemblages in other estuaries on the 



6 Lange, A. M. T., and F E. Lux. 1978. Review of the other 

 flounder stocks (winter flounder, American plaice, witch floun- 

 der and windowpane flounder) off the Northeast United 

 States. U.S. Dep. Commer., NMFS, Northeast Fish. Sci. Cen- 

 ter, Woods Hole Lab. Ref. No. 78-44, Woods Hole, MA 02543. 



basis of reports from Narragansett Bay (Herman, 

 1963), Long Island Sound (Moore, 1947), Sandy Hook 

 Bay (Wilk and Silverman, 1976), Delaware Bay (de 

 Sylva et al., 1962), Chesapeake Bay (Hildebrand and 

 Schroeder, 1928), North Carolina (Weinstein, 1979), 

 South Carolina (Wenner et al., 1982), and Georgia 

 ( Dahlberg, 1972 ). Thus, further sampling in the shal- 

 low nearshore ocean waters and in adjacent estuar- 

 ies will be necessary to understand completely the 

 nature of seasonal movements and the patterns of 

 habitat use of juveniles, at least in subareas 1-5. 



Timing and location of spawning 



The extensive latitudinal sampling program has 

 helped to discern the seeming inconsistency in the 

 literature regarding the presence of a bimodal spawn- 

 ing season. Split spawning (i.e. peaks in spring and 

 fall) has been previously reported in Long Island 

 Sound, New York (Wheatland, 1956), Great South 

 Bay, New York (Monteleone, 1992), and on the conti- 

 nental shelf off Virginia and North Carolina (Smith 

 et al., 1975). However, Colton et al. (1979), Perlmutter 

 (1939), and Smith et al. ( 1975) reported no evidence 

 for split spawning north of Virginia. We found evi- 

 dence for a split spawning season in all areas except 

 Georges Bank (Fig. 4). Taken together, the available 

 information shows that windowpane begin spawn- 



