Flores-Coto and Warlen: Spawning time, growth, and recruitment of larval Leiostomus xanthurus 



1 I 



JAN ' FEB ' MAR 

 COLLECTION OATE 



Figure 2 



Weekly mean density ( larvae/100 m' I of spot Leiostomus 

 xanthurus larvae in collections at Pivers Island in the New- 

 port River estuary, November 1987 to May 1988 (no larvae 

 caught before 2 December). Mean weekly surface-water tem- 

 perature calculated from hourly measurements at Pivers 

 Island. 



37 and 108 d, (x=82.4d); weekly mean SL varied from 9.2 

 to 22.2 mm (jr=17.2mm). The weekly mean age and SL of 

 spot larvae (Fig. 3) increased from the beginning of the re- 

 cruitment period, when the youngest and smallest larvae were 

 caught, to the beginning of the period of peak recruitment 

 density (10 February). Thereafter, average values remained 

 high, only decreasing during the last 3 weeks. The age and 

 size distributions of all spot larVae recruited to the estuary 

 (Fig. 4) indicated that 68% were between 75 and 95 d, and 80% 

 were between 15.1 and 20.0 mmSL. The mean age (±SE) and 

 SL (±SE) of larvae corresponding to the three recruitment 

 periods of different densities were 50.4 (±2.7), 84.6 (±1.4), 

 and 62.6d (±3.8), and 11.8 (±0.49), 17.7(±0.31), and 13.4mm 

 (±0.69). 



Spawning time Spawning, which was continuous over a 5- 

 month period, began near mid-October and ended about mid- 

 March (Fig. 5). Over 99% of spawning occurred from 1 Novem- 

 ber to 24 January (22 weeks). Only about 1% was contributed 

 by 9 weekly cohorts: 2 before and 7 after the main spawning 

 period. Cohorts from 22 November to 10 January contributed 

 >80% of total larvae (Fig. 5). The midpoint in spawning was 

 the week of 20 December. 



E 



E ,6 



I 

 I- 



i " 

 Ul 



Q 

 LU 



a 



NOV I DEC I JAN I FEB I MAR I APR I MAY 



COLLECTION DATE 



Figure 3 



Mean standard length (mmllSEl and age (dilSEl 

 of spot Leiostomus xanthurus larvae collected 

 weekly, November 1987 to May 1988, at Pivers Is- 

 land in the Newport River estuary (no larvae caught 

 before 2 December). 



B 



.cm 



UlU 



20 22 24 



STANDARD LENGTH 



Figure 4 



Percentage distribution of larval spot Leiostomus 

 xanthurus recruited to the Newport River estuary, No- 

 vember 1987 to May 1988, by (A) estimated age (5d 

 intervals) and (B) standard length ( 1 mm intervals). 



