STANDARD and CHITTENDEN: REPRODUCTION. MOVEMENT, AND POPULATION OF BANDED DRUM 



60 

 45 

 30 

 15 





 20 

 15 

 10 



5 





 10 



5 

 



15 

 10 



5 







10 



5h 

 



10 

 5 

 

 5 

 

 5 

 



Immature 

 n=929 

 x=50 



1 1 1 1 1 



Maturing Virgin 



n = 487 



x = 87 



Early Developing 



n =175 

 x = 120 



, ^\ 



i ' i 



Late Developing 

 n 119 

 x = 146 



~I r— 



Gravid 

 n = 69 

 x = 147 



■> r 



A. 



Ripe 

 n = 57 

 x = 149 



-i 1 1 r— 



Spawning/Spent 

 n = 31 x=149 



A. 



— i — > — i — r 



Resting 

 n=47 x-150 



^-V 



/V\ 



FIGURE 

 Larimus 



maturit\ 



1 — — ' 1 



40 80 120 160 200 



TOTAL LENGTH (mm) 



4. — Length frequencies of immature and female 

 fasciatus by gonad maturity stage. See Table 1 for 

 stage criteria. 



December through March. Almost all fish were in 

 the Immature, Maturing Virgin, Early Develop- 

 ing, or Resting stages in that period (Fig. 5). Few 

 were in the Late Developing stage then and none 

 were Gravid or Ripe. In addition, mean and 

 maximum GSI values were lowest during the 



December-March period (Fig. 3) as were the slopes 

 and elevations of regressions of ovary weight on 

 length (Fig. 2). Gonad analyses are supported by 

 the absence offish 20-80 mm from late February to 

 mid-June each year (Fig. 6) with the exception of 

 fall-spawned fish whose growth in late winter and 

 spring is clearly followed. 



Although L. fasciatus spawn within a broad 

 time period, spawning primarily occurs during 

 what we interpret as two discrete periods, a major 

 fall period (September-November) and a very 

 minor spring period (April-June). Mean and/or 

 maximum GSI values were highest in the periods 

 May-June and September- November, and these 

 peaks were separated by troughs in the periods 

 July-August and December- April (Fig. 3). Al- 

 though few fish were Ripe in August, nearly all 

 were in Late Developing, Gravid, Ripe, and 

 Spawning/Spent stages from September through 

 November (Fig. 5); few were in Immature, Matur- 

 ing Virgin, or Early Developing stages then. Fall- 

 spawned fish greatly predominated each year and 

 formed length-frequency modes easily followed 

 through the spring and summer after their re- 

 cruitment in fall and winter (Fig. 6). A minor 

 spring spawn is indicated by distinct, but not 

 abundant, groups offish 40-80 mm in the periods 

 August 1980 and June- August 1981 ( Fig. 6 ) and by 

 the occurrence of a few (14) Gravid and Ripe stage 

 fish from April through June and Late Developing 

 fish in March (Fig. 5). No recently recruited 

 spring-spawned fish were evident after August 

 (Fig. 6), but they may be represented by the few 

 intermediate-sized fish from an unclear spawned 

 group in January and March 1980 and February 



1981. 



Little or no spawning of L. fasciatus occurs in 

 July and August. No fish 20-40 mm (1-3 mo old) 

 were captured from July through October ( Fig. 6). 

 Only two fish were Gravid or Ripe during July and 

 August and few were in the Late Developing stage 

 then (Fig. 5). 



Calculated hatching dates agree with the major 

 fall-spawning period — September- November — 

 indicated by gonad and length-frequency 

 analyses. Depending on data points included, cal- 

 culated hatching dates were 27 July or 15 October 

 1978, 17 September 1979, and 27 August or 17 

 October 1980 (Table 4). Hatching dates of 15 Oc- 

 tober and 17 October seem most realistic for 1978 

 and 1980. The earlier dates for those years are 

 based on regressions fitted to all collections. The 

 earliest two collections in those years, however, 

 probably contribute upwardly biased size data 



345 



