The groupers (Serranidae) are a commercially important family of fish in many parts of the world as well as in the Galapagos Islands. Recent assessments of the family suggest that the group might be particularly vulnerable to fishing (GWSG 2007), and it has also been suggest that their genetic diversity may be threatened due to overfishing (GWSG 2007). According to the groupers and wrasse specialist group (GWSG), an assessment of all grouper species is needed to examine the sub-family as a whole and set conservation and management priorities as necessary (GWSG 2007). One of the groupers studied, the misty grouper Epinephelus mystacinus (Poey 1852), recently renamed Hyporthodus mystacinus (Craig and Hastings 2007) , has been described as a “mysterious” and “rarely seen” grouper species (Schobernd 2004). High genetic diversity has traditionally been associated with good health of populations, and would signal a good future for traditional fishing of H. mystacinus. In other words, for fishing of H. mystacinus to continue at a sustainable level, it is imperative to maintain a high genetic diversity, and this would require a proper management plan.

The Serranidae family are known to be monoecious with some functional hermaphrodites; more specifically, groupers are protogynous hermaphrodites, which means that they change sex from females to a few dominant males(Nelson 1994). However, not enough is known of H. mystacinus to determine whether this sex change can be applied to the species or not, but it could imply that the larger sized H. mystacinus would tend to be males and the smaller ones usually females. This fact alone requires special management for the species with regards to the allowable size to be caught.

Furthermore, a study by Birkeland and Dayton revealed that older individuals of some fish species produce larvae that have substantially better survival potential than do larvae from younger fishes (Birkeland and Dayton 2005). If this were applied to H. mystacinus, this could mean that the larger females are more important in producing viable offspring than the smaller ones. The combination of these two factors (their hermaphroditic characteristic and the more optimal production of the larger individuals which usually tend to have exponentially greater fecundity) is important since commercial and traditional fisheries often target the larger fish. The protection of larger or older individuals is necessary for the sustainability of species currently exploited by humans (Birkeland and Dayton 2005).