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



76" 



3-6 



/ 



ATLANTIC OCEAN 



50 100 



75' 



74* 



^^i 



VJ"\ 



ATLANTIC OCEAN 



Figure 7 (continued) 



larvae were 9.3mmSL and 46 d 

 old. 



Within-season growth was 

 compared for similar-age larvae 

 collected at Pivers Island be- 

 tween early (early February) and 

 late (early April) portions of the 

 peak recruitment period and be- 

 tween early (early February) and 

 post-peak recruitment periods 

 (late April). The mean growth 

 rate (0.195 mm/d) of 15 larvae 

 <17.7±1.30mmSL, 82.5±2.56 

 growth increments) collected 3 

 and 10 February ( early peak) was 

 not significantly different (r-test, 

 P=0.09> from that (0.204 mm/d) 

 of 15 larvae (18.2±0.98mmSL, 

 81.9±3.19 growth increments) 

 collected 6 and 13 April (late 

 peak). However, the mean growth 

 (0.214mm/d) of 12 larvae 

 (14.9±1.45mmSL, 62.3±3.77 

 growth increments! collected on 

 3 February (early peak) was sig- 

 nificantly different (r-test, 

 P<0.01) from that (0.194mm/d) 

 for 10 larvae (13.4±0.64mmSL, 

 60.7±3.43 growth increments) 

 collected in late April (post-peak). 



Discussion 



than the 1.6-1.7 mmSL measured on laboratory-reared 

 larvae by Powell & Gordy (1980) and estimated from 

 wild specimens by Warlen & Chester (1985). In 

 the log-transformed model (Fig. 9), age accounted for 

 98% of the variation in length. Age-specific growth rate 

 declined from 5.8%/d at age 10 d to <0.7%/d at age 

 100 d. Maximum absolute growth rate occurred when 



The spawning period of spot in 

 the 1987-88 season was appar- 

 ently a continuous process occur- 

 ring over 5 months from mid- 

 October to mid-March. Although 

 spawning was protracted, the 

 greatest concentration occurred 

 in the 2-month interval from 

 mid-November to mid-January 

 when 90% of the estuarine- 

 recruited larvae were spawned. 

 This information, while generally 

 agreeing with earlier work on fish collected in North 

 Carolina (Hildebrand & Cable 1930, Warlen & Chester 

 1985) and South Carolina (Beckman & Dean 1984), is 

 the first to be estimated from back-calculated birthweek 

 distributions on larvae collected weekly over the en- 

 tire estuarine recruitment period. The contribution of 

 birthweeks to the larval catch each week was based on 



