810 



Fishery Bulletin 101(4) 



Location ^ FMAMJJ ASOND 



I I I I I I I I I I I I 



Cariaco Gulf, Venezuela 

 (Franco, 1986) 1.2 



La Restinga Lagoon, Venezuela 

 (Angell, 1973) 1,2 



Patanemo Lagoon, Venezuela 

 (Blanco, 1985) 2 



Tunas de Zaza. Cuba 

 (Alvarez-Lajonchere, 1980)2 



Cuba 



(Garcia and Bustamante, 1981) 3 



Guerrero Stale Lagoons, Mexico 

 (Yanez-Arancibia, 1976) 3 



Gulf of fdlexico 

 (Ibanez-Aguirre, 1993) 3 



Southern Texas, USA 

 (Moore, 1974) 3 



South Florida, USA 

 (Anderson, 1957) 3 



North Carolina, USA 

 (Jacol, 1920) 3 



Figure 1 



Spawning periods for white mullet (Mugil curema) in tropical waters, based on the 

 histological observations of gonads (1), macroscopic observations of gonads (2), and 

 estimated from the arrival of juveniles in coastal areas (3). Thin horizontal lines indi- 

 cate periods of continuous but minor spawning between periods of peak spawning. 



able food in coastal lagoons, river deltas, and estuarine 

 mangrove areas have been identified as important factors 

 influencing the recruitment of juvenile Mugilidae (Yafiez- 

 Arancibia, 1976; Blaber and Blaber, 1980; Blaber, 1987; 

 Vieira, 1991), Based on macroscopic gonad observations of 

 schools of white mullet captured offshore, Etchevers (1974) 

 proposed that the spawning of white mullet recruiting 

 along the southern coast of Margarita Island, Venezuela, 

 occurs between La Tortuga Island and Margarita Island 

 in the vicinity of the 1000-m deep Cariaco trench (Fig. 2). 

 Seasonal environmental variability in this area is mainly 

 generated by the alternation between upwelling during the 

 dry season and freshwater discharge during the wet season 

 (Gomez, 1983;Muller-Kargeret al., 1989). The rainy season 

 strongly influences the eastern Caribbean as freshwater 

 plumes from the Amazon and Orinoco Rivers lower salini- 

 ties throughout the region. Both upwelling and freshwater 

 runoff produce intense peaks in coastal primary production 

 (Gines 1972; Ferraz-Reyes et al,, 1987; Miiller-Karger et 

 al,, 1989), which could influence spawning periodicity and 

 recruitment success. The purpose of this study was to docu- 

 ment the periodicity of reproduction and recruitment of A/, 

 curema along the southern coast of Margarita Island and 

 to examine their relationship with environmental signals, 

 particularly those associated with upwelling. 



Methodological advances in counting daily growth 

 increments in otoliths of marine fishes (Pannella, 1971; 



Campana and Nielsen, 1985) have greatly aided studies 

 of the age, growth, and recruitment of larval and juvenile 

 fishes (Wilson and Larkin, 1980; McBride and Conover, 

 1991; Jenkins and May, 1994; Sirois and Dodson, 2000). 

 For the striped mullet (M, cephalus), a close relative of the 

 white mullet, Radtke (1984) showed that the first incre- 

 ment is formed one day after hatching and that additional 

 increments are formed daily thereafter. Daily growth rings 

 have also been demonstrated in laboratory studies for M. 

 so-iiiy by Li et al, (1993). In the present study, we examined 

 the microstructure of the otoliths of juveniles recruiting 

 to a coastal lagoon in order to back-calculate the date of 

 hatching and hence the time of successful spawning. We 

 first validated that otolith growth increments of juvenile 

 M. curema were formed daily. 



Material and methods 



Reproductive periodicity was documented from samples 

 of adult fish taken monthly from commercial catches in 

 three fishery zones in Venezuela: 1) the Chacopata zone, 

 located between Chacopata lagoon and Coche and Cubagua 

 Islands; 2) the Cariaco Gulf zone; and 3) the Margarita zone 

 located along the southern coast of Margarita Island and 

 the northern coast of Cubagua Island (Fig, 2), Measure- 

 ments of water temperature, salinity, and rainfall were 



