CHAO and MUSICK: LIFE HISTORY OF JUVENILE SCIAENID FISHES 



FIGURE 14.— Length-frequency dis- 

 tributions of silver perch, Bairdiella 

 chrysoura, by river distance (strata) up- 

 stream of the York River estuary. 

 Pooled total, August to October 1972- 

 74. Strata: A-G in York River, M = 

 Mattaponi River, P = Pamunkey River. 

 Frequencies expressed as log (x + 1) at 

 5-mm increments. 



A +B 

 Slrolo 



2.5 



1.5 



0.5 

 2.5 

 1.5 

 0.5- 

 2-5 

 1.5 

 0.5 

 2 5- 

 1.5 

 0.5 

 2.5- 

 1.5- 

 0.5- 

 2.5 

 1.5 

 0.5 

 2.5 

 1.5 

 0.5- 



N = 2l 



l~l 



-nn 



n 



,r^np-^ 



i~i 



i~i i~i 



rn i ^ 



10 30 50 



TOTAL LENGTH [inn 



FIGURE 15.— Length-frequency dis- 

 tributions of silver perch, Bairdiella 

 chrysoura, by depth of York River. 

 Pooled total, August to October 1972- 

 74. Frequencies expressed as log (x + 1) 

 at 5-mm increments. 



70 90 110 



TOTAL LENGTH (mm) 



(1914). Welsh and Breder (1923) made further ob- 

 servations from material obtained at Atlantic 

 City, N.J. Jannke (1971) described larval silver 

 perch from the Everglades National Park, Fla., 

 and showed that larvae of 2 to 3 mm "notochord" 

 length were present all year round. Hildebrand 

 and Schroeder (1928) reported ripe fish of both 

 sexes in Chesapeake Bay (24 m deep, off 

 Chrisfield, Md.) as early as 16 May. This suggests 

 that silver perch may spawn in the deeper waters 

 of lower Chesapeake Bay and nearshore waters in 

 late spring and early summer. Because of its rela- 

 tively small size, commercial landings of silver 

 perch are relatively small. Silver perch move 

 oceanward and probably to the south of 

 Chesapeake Bay in winter. Large numbers cap- 

 tured by commercial haul seines between Virginia 

 Beach, Va., and Kitty Hawk, N.C., have been ob- 

 served in fall (J. A. Musick, pers. obs.). 



Micropogonias undulatus (Linnaeus) — Atlantic Croaker 



EARLY LIFE HISTORY IN YORK RIVER.— 

 Young-of-the-year croaker first entered the trawl 

 and beach seine catches in August and stayed in 

 the York River throughout the winter (Figure 16, 

 mode I). They left the estuary between August and 

 September of the following year as yearlings (Fig- 

 ure 16, mode III). Large croaker (more than 1.5 yr 

 old) were caught only sporadically in this study 

 due to gear avoidance, but they were present from 

 February to September. There were apparently 

 two to three length groups (modes) of young-of- 

 the-year croaker in September 1972-74. Mode II 

 was different from mode I and mode III of 1972 and 

 1974 (Figure 16). The former group did not stay in 

 the York River over winter, but entered the es- 

 tuary as early as May (Figure 16, mode II). Most of 

 this group left in November 1972-74. 



675 



