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Fishery Bulletin 101(3) 



Figure 1 



Map of the Campeche Bank, Mexico, showing the geographic distribution of sampling locations (•) for black 

 grouper (Mycteroperca bonaci) observed during the period 1996-2000. Samping locations marked (O) are 

 where ripe-running female black grouper were caught. Sample locations: 1 = April 1996; 2 = April and May 

 1996; 3,4 = May 1996; 5 = November 1996; 6, 7 = December 1996; 8 = Januai-y 1997; 9 = January and Febru- 

 ary 1997; 11 = Febi-uary 1997; 12 = May 1997; 13 = June 1997; 14 = June and July 1997; 15 = July 1997; 16 

 = July and August 1997; 17, 18 = August 1997; 19 = September 1997; 20 = September and October 1997; 

 21 = October and November 1997; 22 = November 1997; 23 = December 1997; 24,25 = January 1998; 26 = 

 January and February 1998; 27 = February and March 1998; 29 = March 1998; 30,31 = June 1998; 32 = July 

 1998; 33 = August 1998; 34 = August and September 1998; 35 = September 1998; 36 = April 1999; 37,38 = 

 May 1999; Alacranes Reef was sampled November and December 1999, January, February, and August to 

 November 2000. No black giouper were caught in sample locations 10 (22''33'-88°24'W; February 1997) and 

 28 (22°30'N-89°30W; March 1998). 



the Campeche Bank decreased between 1991 and 1997, 

 the Mexican government proposed management measures 

 to protect the grouper resource, but without considering 

 the biological characteristics and fishery aspects of each 

 exploited species (SEMARNAP, 2000a, 2000b). Given that 

 sustainable resource management is founded on stock as- 

 sessments and knowledge of the biology of exploited species 

 (Sadovy, 1997 ), more information on the biology of the most 

 abundant groupers from the southern Gulf of Mexico in 

 general, including Campeche Bank, is necessary to imple- 

 ment and refine management strategies. 



This lack of knowledge is especially acute for Campeche 

 Bank black grouper. For example, although growth, feed- 

 ing, and reproduction of the Yucatan red grouper are well 

 documented, none of this information is available for the 

 black grouper in this region (Brule and Deniel, 1994; Brule 

 et al., 1994, 1999). This lack of information is alarming be- 

 cause M. bonaci can account for 40% of the grouper catch 

 by weight for some commercial vessels, and if this species 

 is not included in stock monitoring and reproduction stud- 

 ies, effective overall management of the southern Gulf of 

 Mexico grouper fishery could be seriously undermined 

 (Colas-Marrufo et al., 1998). 



With the final aim of defining more accurate and effi- 

 cient management practices for the Campeche Bank gi-ou- 

 per fishery, we present analyses of sexual status, sexual 

 cycle, spawning season, size at sexual maturation, and 

 sex change for black gi-ouper from the southern Gulf of 

 Mexico. 



Materials and methods 



Black grouper were collected from commercial catches 

 taken from rocky bottoms in both offshore and inshore 

 waters of the Campeche Bank and in the shallow waters 

 of the Alacranes Reef complex. Alacranes Reef is the most 

 important complex of coral reefs located on the Yucatan 

 continental shelf Because of its high scientific and eco- 

 nomic potential, the Mexican government declared this reef 

 a National Marine Park in June 1994 (Fig. 1). In offshore 

 waters, black grouper (/i =880) were caught by the long-line 

 industrial fleet from 38 locations mainly situated in the 

 northeastern part of the Campeche Bank, at depths rang- 

 ing from 40 to 210 m, between April 1996 and May 1999. 

 In inshore waters, some specimens (n=39) were obtained 



