Marin et al,: Reproduction and recruitment of Mugil curema 



811 



n 



Sea 



— 1 — 



65° 



Santa Fe Gulf 



Figure 2 



Map of the northeastern coast of Venezuela showing locations mentioned in the text. 



collected periodically throughout the entire study period 

 at the La Salle meteorological station, next to La Restinga 

 Lagoon on Margarita Island. 



Total (TL) and standard (SL) lengths of adult mullet 

 were measured to the nearest 0.5 cm and total and gut- 

 ted body mass were recorded to the nearest 0.1 g. Sexual 

 maturity was determined by observation of the gonads and 

 gonadal stages were classified as follows: 



Stage I Ovaries transparent and inconspicuous, whit- 

 ish-yellow in color and rounded with a small 

 diameter. Testes longer than ovaries and rib- 

 bonlike in form. 



Stage II Ovaries rounder and wider than in stage I, and 

 yellow in color. Testes thinner, and wider than 

 stage I, but still with thin edges and a ribbon- 

 Uke form; white in color. 



Stage III Ovaries large, pale yellow, smooth in appear- 

 ance, turgid, and round. Ovocytes easily distin- 

 guished macroscopically (as granular). Testes 

 milky-white in color (bright), turgid, and wider 

 in appearance and having thicker edges than in 

 stage II. 



Stage rV Spawned (spent) ovaries purple and wrinkled in 

 appearance. Testes whitish, or transparent with 

 white patches, and wrinkled in appearance. 



Recruitment periodicity was documented from samples 

 of juveniles seined at semimonthly intervals at the mouth 

 of La Restinga Lagoon (Fig. 2). The 2-cm mesh beach seine 

 measured 1.5 m deep and 50 m long. Juvenile white mullet 

 were distinguished from other juvenile mullets according to 

 the descriptions of Alvarez-Lajonchere et al. ( 1976). White 

 mullet juveniles were characterized by a scaly gray appear- 

 ance as opposed to the shiny metallic gray appearance of a 

 sympatric mullet species (Mugil incilis). For white mullet, 

 recruitment is defined as the appearance of juveniles in 

 coastal areas (Vieira, 1991). We calculated catch per unit 

 of effort (CPUE) as the number of juveniles per seine haul. 

 For all samples, standard length of fish was measured to 

 the nearest 1 mm. Otolith analysis was restricted to one 

 sampling period per month. After examining size-fre- 

 quency distributions of juveniles captured in the lagoon, 

 the otoliths of approximately 20 individuals representing 

 all cohorts collected on a given sampling date were ana- 

 lyzed. The otoliths (sagittae) were removed with needles, 

 rinsed in water, and then attached to strips of masking 

 tape. The otolith was then sanded to obtain a transversal 

 section (Fig. 3) with a thickness of approximately 20 ^m 

 by using the technique described by Secor et al. ( 1992) and 

 a metallurgic jig adapted from Neilson and Geen (1986). 

 Readings of the number of increments were made along the 

 curvilinear surface running from the nucleus to the edge of 

 the otolith (Fig. 3). Because daily growth increments were 



