The serranids, or groupers and seabasses, are ubiquitous predators on Caribbean coral reefs and come in all shapes and sizes. Groupers are, or more accurately, were the basis of large and important fisheries throughout the region, but have become rare on fished reefs and some species are even endangered. This large and diverse family is composed of several clearly-defined subfamilies. Those subfamilies with Caribbean reef-associated representatives include the conspicuous groupers (Epinephelinae), the numerous small seabasses and hamlets (Serraninae), the deep-water basslets (Liopropominae), the soapfishes (Grammistinae), and the small reef-bass Pseudogramma gregoryi (also can be considered either a Grammistinine or a Pseudogrammatinine). There are many serranids in the region found only in deep water and not associated with coral reefs, nevertheless they are included in this section for completeness.
Larval serranids can be recognized by their relatively wide body, particularly large terminal mouth, large round eye, continuous spinous and soft dorsal fins with stout, sometimes serrated, dorsal-fin spines, and three stout spines in a short anal fin (note these characters are not all shared by the Grammistinae). Unfortunately, these characters are shared with many other percoid fishes and some serranid fin-ray counts can overlap with the abundant snappers (Lutjanidae) and grunts (Haemulidae). Within each of these families there is variation in the larval body form and meristics and often marked ontogenetic changes as well, leading to some similarity in appearance and the distinction sometimes can be difficult.
In the earlier stages, the larvae of the three families are quite similar and separation is a problem. The serranids and lutjanids even share their basic marking patterns, with melanophores on the spinous dorsal-fin membranes and on the anal fin base and caudal peduncle. A useful distinction is that serranids typically have a melanophore at the angle of the jaw and melanophores on the pectoral-fin rays, which, if present, immediately separate them from the other families. Lutjanids have a post-cleithral spine, not present in the other families, but it is not easy to see. In general, the three families have a different look as later larvae: serranids generally have large jaws with a sharp jawline (essentially a much wider gape than the others) and a particularly wide maxilla, snappers have less prominent jaw lines and an enlarging non-serrated preopercular spine, while grunts typically have smaller larvae with shorter dorsal-fin spines, and, importantly, the third anal-fin spine develops as a segmented ray in larvae and small juveniles.
Although serranid larvae share the basic features listed above, the size at settlement varies widely within the family: hamlets and basslets settle very small, from 5-10 mm SL, while some epinephelines settle particularly large, sometimes reaching up to two inches in length while still pelagic.
The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some cases less than 10 cm (3.9 in), the giant grouper (Epinephelus lanceolatus) is one of the largest bony fishes in the world, growing to 2.7 m (8 ft 10 in) in length and 400 kg (880 lb) in weight.[2] Representatives of this group live in tropical and subtropical seas worldwide.
Many serranid species are brightly colored, and many of the larger species are caught commercially for food. They are usually found over reefs, in tropical to subtropical waters along the coasts. Serranids are generally robust in form, with large mouths and small spines on the gill coverings. They typically have several rows of sharp teeth, usually with a pair of particularly large, canine-like teeth projecting from the lower jaw.[3]
All serranids are carnivorous. Although some species, especially in the Anthiadinae subfamily, only feed on zooplankton, the majority feed on fish and crustaceans. They are typically ambush predators, hiding in cover on the reef and darting out to grab passing prey. Their bright colours are most likely a form of disruptive camouflage, similar to the stripes of a tiger.[3]
Many species are protogynous hermaphrodites, meaning they start out as females and change sex to male later in life.[3] They produce large quantities of eggs and their larvae are planktonic, generally at the mercy of ocean currents until they are ready to settle into adult populations.
Like other fish, serranids harbour parasites, including nematodes, cestodes, digeneans,[4] monogeneans, isopods, and copepods. A study conducted in New Caledonia has shown that coral reef-associated serranids harbour about 10 species of parasites per fish species.[5]
In recent times, this family has been proposed to be split. The two hypothetical families emerging from the remains of the possibly-obsolete taxon are the families Epinephilidae and Anthiadidae. This taxonomic separation is recognized by some authorities, including the IUCN.[6] Recent molecular classifications challenge the validity of the genera Cromileptes (sometimes spelled Chromileptes) and Anyperodon. Each of these two genera has a single species, which were included in the same clade as species of Epinephelus in a study based on five different genes.[7]
The subfamilies and genera are as follows:[8][9]
The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some cases less than 10 cm (3.9 in), the giant grouper (Epinephelus lanceolatus) is one of the largest bony fishes in the world, growing to 2.7 m (8 ft 10 in) in length and 400 kg (880 lb) in weight. Representatives of this group live in tropical and subtropical seas worldwide.
