463 



Abstract— An analysis was made of 

 sexual pattern, spawning season, sizes 

 at sexual maturation, and sex change 

 in black grouper {Mycteroperca bonaci ) 

 from the southern Gulf of Mexico. 

 Samples were taken between 1996 and 

 2000, from industrial and small-craft 

 commercial fisheries, in offshore and 

 inshore waters of the continental shelf 

 of the Yucatan Peninsula iCampeche 

 Bank), including the shallow waters of 

 National Marine Park Alacranes Reef 

 For all collected specimens (/! = 1229), 

 sex and maturation condition were 

 determined by histological analysis of 

 the gonads. The offshore sample con- 

 sisted of 75.1% females, 24.3% males, 

 and 0.6% transitional-stage fish. All 

 individuals collected from inshore 

 waters were females. Gonadal structure 

 and population structure characteris- 

 tics for Campeche Bank black grouper 

 were consistent with the characteristics 

 of monandric protogynous hermaphro- 

 dism for a serranid fish. Sexually active 

 males and females were observed year- 

 round, although ripening females, with 

 stage-Ill, -IV, and -V vitellogenic oocytes 

 in the ovaries, dominated in samples 

 taken between December and March. 

 In addition, peak occurrence of ripe- 

 running females with hyaline oocytes 

 or postovulatory follicles (or both) in 

 the ovaries was recorded in January 

 and February. A few precocious females 

 began spawning in October and Novem- 

 ber, and others were still in spawning 

 condition in May and June. Fifty per- 

 cent maturity of females was attained 

 at 72.1 cm fork length (FL). Median size 

 at sexual inversion was 103.3 cm FL, 

 and 50% of the females measuring 111.4 

 cm FL had transformed into males. The 

 southern Gulf of Mexico grouper fishery 

 was considered deteriorated and lacked 

 a well-defined management strategy. 

 Results of the present study provide 

 helpful information on black grouper 

 reproduction in this area and could help 

 Mexican authorities choose appropriate 

 management strategies for this fishery, 

 such as minimum size limit, closed fish- 

 ing season, and protection of spawning 

 aggregations. 



Reproduction in the protogynous black grouper 

 (Mycteroperca bonaci (Poey)) from the 

 southern Gulf of Mexico 



Thierry Brule 



Ximena Renan 



Teresa Colas-Marrufo 



Yazmin Hauyon 



Armin N.Tuz-Sulub 



Centra de Investigacion y de Estudios Avanzados del IPN Unidad Merida 



Antigua Carretera a Progreso km. 6 



Apartado postal 73 Cordemex 



Codigo Postal 97310 Merida 



Yucatan, Mexico 



E-mail address (lor T. Brule), ibrulecfimda.cinveslav.mx 



Christian Deniel 



Institut Universitaire Europeen de la Mer, Ressources Halieutiques-Poissons Manns 

 Unlversite de Bretagne Occidentale 

 Place Nicolas Copernic 

 Technopole Brest Iroise 

 29820 Plouzane, France 



Manuscript approved for publication 

 11 February 2003 by Scientific Editor 



Manuscript received 4 April 2003 at 

 NMFS Scientific Publications Office. 



Fish. Bull. 101:463^75 (2003). 



The black grouper {Mycteroperca bon- 

 aci) is one of the 20 most commonly 

 sought serranid fishes in the tropical 

 western Atlantic region (Sadovy, 1994). 

 The species ranges from Massachusetts 

 and Bermuda to southeastern Brazil 

 (Bohlke and Chaplin, 1993; Fischer, 

 1978; Bullock and Smith, 1991; Begossi 

 and Figueiredo, 1995). It is found on 

 irregular bottoms such as coral reefs, 

 drop-off walls, and rocky ledges, in 

 depths from 10 to at least 100 m (Roe, 

 1977; Manooch and Mason, 1987; Bull- 

 ock and Smith, 1991; Heemstra and 

 Randall, 1993; Huntsman et al., 1994). 

 According to Shapiro (1987), the sa- 

 lient feature of grouper reproduction 

 is protogynous hermaphroditism. The 

 first reasonable evidence of protogyny 

 in M. bonaci was published by Smith 

 (1959), although there have been other 

 occasional reports on black grouper re- 

 production (Erdman, 1956; Smith, 1961, 

 1971, 1972; Naranjo in Garcia-Cagide 

 et al., 1994). Systematic study of sexual 

 pattern and sexual maturation in the 

 species has only been carried out by 

 Garcfa-Cagide and Garcia (1996) in 

 Cuban waters and by Crabtree and 



Bullock (1998) in Florida waters. This 

 grouper has been reported to form 

 spawning aggregations in the Gulf of 

 Mexico and Caribbean Sea (Fine, 1990; 

 Carter and Perrine, 1994; Domeier and 

 Colin, 1997; Eklund et al., 2000). 



Black grouper is an important com- 

 mercial and recreational fin fish re- 

 source in Bermuda, southern Florida, 

 Cuba, the southern Gulf of Mexico, and 

 Venezuela (Manooch and Mason, 1987; 

 Cervigon, 1991; Heemstra and Randall, 

 1993; Claro et al., 1994). In the southern 

 Gulf of Mexico between 1989 and 1999, 

 groupers accounted for 18-307< of the 

 total offshore commercial marine re- 

 sources harvested from the Campeche 

 Bank (the continental shelf surround- 

 ing the northern coast of the Yucatan 

 Peninsula) and resources landed in 

 inshore waters off the state of Yucatan 

 (SEMARNAP, 2000a). At least 18 grou- 

 per species are commercially exploited 

 in this region — the most important of 

 these by catch number and weight are 

 red grouper {Epinephelus morio), fol- 

 lowed by black grouper and gag {Myc- 

 teroperca microlepis) (Colas-Marrufo et 

 al., 1998). Because grouper landings in 



