Barbien et al.: Maturity, spawning, and ovarian cycle of Micropogonias undulatus 



681 



Immature 



Next spawning 

 season 



I 



Sexual maturity 



Resting I 



Developing 



\ 



Resorption 



First batch of 

 advanced yolked oocytes 



Fully developed 



Regressing 



Redeveloping jy 



Running-ripe 



Ovulation 



ydration 



= Gravid 



Spawning phase 



Figure 8 



Diagrammatic representation of the ovarian cycle of Atlantic 

 croaker, Micropogonias undulatus (see text for details). 



The presence of small juveniles (<20 mm TL) in the 

 York River from August/September through May/ 

 June has prompted suggestions that north of Cape Hat- 

 teras spawning of Atlantic croaker may also continue 

 through spring (Haven, 1957; Chao and Musick, 1977). 

 However, our results confirm previous reports (Wal- 

 lace, 1940; Colton et al., 1979; Morse, 1980) that in the 

 Chesapeake Bay and mid-Atlantic regions spawning 

 is essentially completed by the end of December. 



Although Welsh and Breder ( 1923) suggested that 

 spawning might take place in large estuaries such 

 as the Delaware and Chesapeake bays, this study 

 represents the first documented report of estuarine 

 spawning for Atlantic croaker. Previous studies have 

 consistently described Atlantic croaker as strict ma- 

 rine spawners whose larval and juvenile stages mi- 

 grate into estuarine nursery areas (Pearson, 1929; 

 Hildebrand and Cable, 1930; Wallace. 1940; Haven, 



