Abstract.- Tlie simimer flounder 

 Pnralichthii^ dentatu!< spawned 

 throughout the Mid-Atlantic Bight 

 and Georges Bank during 1977-85. 

 Spawaiing peaked in fall hut extended 

 from September through January. 

 Planktonic larvae (2-13 mm) were 

 most abundant in the Mid-Atlantic 

 Bight September-May. At approx- 

 imately 11-14 mm, some larvae 

 entered New Jersey estuaries; but 

 their occurrence, especially during 

 winter and early spring, was spora- 

 dic. Young-of-the-year were more 

 frequently collected after May. Dur- 

 ing the first summer inshore they 

 grew rapidly and reached 160-320 

 mm TL. Young-of-the-year emigrated 

 from the estuaries in fall and were 

 most abundant on the shallow por- 

 tions of the adjacent continental 

 shelf. Some evidence suggests that 

 young-of-the-year in the northern 

 Mid-Atlantic Bight reach a larger 

 size than those from the southern 

 portion. An hypothesis to explain the 

 observed rarity of small juveniles in 

 northern estuaries in some years is 

 that some juveniles utilize the conti- 

 nental shelf as a nursery and enter 

 estuaries at a larger size. This hypoth- 

 esis requires testing. 



Patterns of Summer Flounder 

 Paralichthys dentatus Early Life 

 History in the Mid-Atlantic Bight 

 and Mew Jersey Estuaries 



Kenneth W. Able 



Institute of Marine and Coastal Sciences and Biological Sciences 



Rutgers University, New Brunswick, New Jersey 08903 



Present address Marine Field Station, Rutgers University, Tuckerton, New Jersey 08087 



R. Edmond Matheson 



Institute of Marine and Coastal Sciences and Biological Sciences 

 Rutgers University. New Brunswick, New Jersey 08903 

 Present address Florida Marine Research Institute 

 St Petersburg, Florida 33701 



Wallace W. Morse 

 Michael P. Fahay 



Sandy Hook Laboratory, Northeast Fisheries Center 



National Marine Fisheries Service, NOAA, Highlands, New Jersey 07732 



Gary Shepherd 



Woods Hole Laboratory, Northeast Fisheries Center 



National Marine Fisheries Service, NOAA, Woods Hole, Massachusetts 02543 



Manuscript accepted 18 September 1989. 

 Fishery Bulletin, U.S. 88:1-12. 



The summer flounder ParaUchtlujs 

 dentatus inhabits estuarine and 

 continental shelf waters from Nova 

 Scotia (Leim and Scott 1966) to 

 Florida (Gutherz 1967). Over much of 

 this range it supports important 

 commercial and recreational fisheries 

 (Grosslein and Azarovitz 1982). The 

 economic importance of P. dentatus 

 has prompted research on various 

 aspects of its biology (see Scarlett 

 1982, Grosslein and Azarovitz 1982, 

 Rogers and Van Den Avyle 1983), 

 but the spatial and temporal patterns 

 of spawning and the nursery areas 

 are not well known. Our understand- 

 ing of the timing and distribution 

 of spawning in the Mid-Atlantic 

 Bight is based on examination of 

 adult gonads (Morse 1981) and larval 

 surveys (Smith 1973, Smith et al. 

 1975, Morse et al. 1987). Spawning 

 occurs at temperatures of 12-19°C 

 (Smith 1973), eggs and larvae are 



pelagic, hatcliing in the laboratory 

 occurs approximately 48-96 hours 

 after fertilization at 15-21°C (Johns 

 and Howell 1980, Johns et al. 1981), 

 and the pelagic larvae begin trans- 

 formation at 9-12 mm SL (Smith 

 and Fahay 1970, Smigielski 1975). 

 Major nursery areas are assumed 

 to occur in estuaries from Virginia 

 and south (Poole 1966, Powell and 

 Schwartz 1977, Grosslein and Aza- 

 rovitz 1982), although juveniles also 

 occur in estuaries in the northern 

 Mid-Atlantic Bight (Poole 1961, 

 Pearcy and Richards 1962, Pacheco 

 and Grant 1973). Juveniles, pre- 

 sumably, leave estuaries in fall, 

 migrate offshore to overwinter, 

 and return to the estuaries in spring 

 with the adults (Hamer and Lux 

 1962, Murawski 1970), Although 

 some individuals have been found 

 north and east of their estuarine 

 and offshore tagging locations, 



