814 



Fishery Bulletin 101(4) 



26 cm and 18 to 26 cm, respectively. The mullet from the 

 Margarita zone were mainly juveniles and small adults 

 (Fig. 5). 



Maturity and reproductive periodicity 



An examination of gonad maturity revealed that 90% of 

 the male and female mullet in the Margarita zone were 

 immature or at developing stages (I and II) and only 10% 

 in developed and spawning stages (III and IV). In contrast, 

 53.8% of females and 42.8% of males of the population of 

 generally larger mullet sampled at Chacopata were in 

 developed and spawning stages. Finally in the Cariaco Gulf 

 zone, where the fish were of intermediate size, compared 

 to fish at Margarita and Chacopata, 41.2% of females and 

 32.7% of males were in developed and spawning stages. 



Throughout our study, sexually mature (stage-Ill) fish 

 were present in the samples from the Chacopata fishery 

 (Fig. 6), and their abundance showed a marked seasonal 

 pattern. Mature and spent fish were least abundant 

 (<25% of the population) between September and January 

 and most abundant from April to August 1992 and May to 

 June 1993. In contrast, in the Margarita fishery, immature 

 (stage-I) fish dominated the samples and mature fish only 

 occurred sporadically (Fig. 6). Finally, in the Cariaco Gulf 

 zone, immature and maturing fish (stage-I, and stage-ID 

 generally dominated the population, except in July when 

 mature fish became abundant. 



Otolith microstructure 



The otolith of M. curema had a round nucleus with a mean 

 radius of 9.26 ^m (95% confidence interval (CI)=0.54, n=8), 

 and the dark area in the center had a mean diameter of 

 4.97 jjm (CI=0.82, n=8). The otolith was round during the 

 larval period and became ovoid when mullet reached 10-12 

 mm (SL). In the early juvenile stage (18-20 mm SL), the 

 otolith was strongly elongated and the anterior end was 

 arrow-like. In juveniles (>20 mm SL), the otolith was always 

 thin, concave, and umbrella shaped in form (Fig. 3). 



Validation of otolith increment lines 



The otolith increments counted for the first strong cohort 

 present in the lagoon during March and April 1992 dem- 

 onstrated that the average number of increments added 

 during the 14-day interval between sampling collections 

 was close to 14 days (Table 1). This indicated that otolith 

 increments were formed daily, as observed in other species 

 of mullet. 



Chacopata 



_LL 



Margarita 



160 

 140 

 120 

 100 



80 



60 



40 



20 





 160 



140 



120 

 - 100 

 I 80 



C 



I 60 



40 



20 





 180 



160 



140 



120 



100 



80 



60 



40 



20 







12 14 12 16 18 20 22 24 26 28 30 32 34 36 38 

 Standard length (cm) 



Figure 5 



Length-frequency distributions of white mullet surveyed 

 in the commercial catches from the three fishery zones 

 of northeast Venezuela. 



Cariaco Gulf 



Juvenile recruitment 



The catch-per-unit-of-effort measurements for juveniles 

 captured in La Restinga Lagoon demonstrated a seasonal 

 pattern and high recruitment from March to early July 

 1992 and from late March to May 1993, and low recruit- 

 ment during the remaining months (Fig. 7). The recruit- 

 ment peak in 1992 was more than twice that in 1993. The 

 periods of strong recruitment were associated with the 



rainy season in northeastern Venezuela (Fig. 7), as previ- 

 ously reported by Okuda et al. (1978), Gomez (1983), and 

 Ferraz-Reyes(1989). 



The discontinuous length-frequency distributions of 

 juveniles sampled biweekly suggested the presence of four 

 cohorts in the lagoon during the study period (Fig. 8). Two 

 cohorts were present on 5 March 1992, the first sampling 

 date. The cohort of smaller juveniles, referred to as the 

 first cohort, had a mean length of 29.8 mm (range of 18 to 



