BATH and O'CONNOR: BIOLOGY OF WHITE PERCH IN HUDSON RIVER ESTUARY 



Table 7.— Growth history of white perch females in the Hud- 

 son River between Haverstraw and Bear Mountain, N.Y., 

 1963-69. 



Growth 



Growth increment for year of life 



o 



to 

 en 

 en 



100 120 140 160 180 200 

 STD Length (mm) 



Figure 10.— Relationship between fecundity and standard 

 length in female white perch collected during May and June 

 from the Hudson River between Nyack and Bear Mountain. 

 N.Y. 



Table 8. — Mean ovary weight expressed as percentage of body 



weight. 



than males (Elrod and Hassler L969). Chi square 

 analysis of data from individual collections 

 showed the difference to be significant ( x 2 1 32. 1 : 

 P<0.001). During May and June the population 

 consisted of 70.1% mature males and females and 

 29.9% immature fish. From July to November 

 the population consisted of 40.6% mature males 

 and females and 59.4% immature fish. The 

 change observed in the population between 

 mature and immature individuals was due to the 

 recruitment of young-of-the-year fish into the 

 population sampled by our gear. 



DISCUSSION 



The growth and reproductive characteristics 

 of white perch from the Hudson River compare 

 favorably with data from other riverine systems. 

 The maximum age attained in the Hudson River 

 is about 7 yr, and maximum size is about 200 mm. 

 Other data from the Hudson River (Lawler, 

 Matusky and Skelly Engineers footnote 6; Texas 

 Instruments Inc. footnote 7) show maximum age 

 to be 7 and 9 yr, respectively, with a maximum 

 size of from 200 to 222 mm. White perch from the 

 Connecticut River, Conn. (Marcy 1976; Marcy 

 and Richards 1974) attained a maximum age of 

 about 8 yr, but grew to a maximum size of more 

 than 280 mm. Wallace (1971) and Miller (1963) 

 studied brackish water segments of the Dela- 

 ware River estuary white perch populations and 

 reported maximum ages of 8 and 10 yr, respec- 

 tively. However, Wallace obtained a maximum 

 size (~175 mm) smaller than found in Miller's 

 (~257 mm) and smaller than in other riverine 

 populations. White perch from the Patuxent 

 River, Md., and the Roanoke River, N.C., had a 

 greater maximum age, up to 10 yr; however, the 

 size attained at 7 yr is approximately the same as 

 in the Hudson River, from 190 mm to 205 mm 

 (Conover 1958; Mansueti 1961). In Figure 11 we 

 have plotted calculated standard lengths by age 

 groups for white perch from five riverine sys- 

 tems. A similarity of growth rates for most pop- 

 ulations is obvious except for the Connecticut 

 River where perch grow more rapidly through- 

 out their life span. Such rapid growth is more 

 characteristic of white perch in freshwater im- 

 poundments than of riverine populations (Thoits 

 1958). 



The rapid growth of perch in the Connecticut 

 River may be attributed to a longer growing sea- 

 son; the onset of annulus formation occurs nearly 

 2 mo earlier than in the Hudson River. However, 



607 



