Groupers and snappers are among the most impressive types of fish found in abundance in most of the world’s oceans. These fish belong to the Perciformes (Percomorphi) order – the largest order of vertebrates, including more than 40% of the world’s bony fish – and are also known to comprise a diverse range of carnivore species. Both snappers and groupers are benthic feeders, feeding mostly on crustaceans, small fish, worms and invertebrates. Both species inhabit coral reefs and are known to be quite nimble and active in their movements, some species able to ambush their prey, while others are active predators.
There are quite a few characteristics that both groupers and snappers share. First of all, their size is generally similar, growing to about 1-2 meters in length at most. Some species of groupers are somewhat larger and less capable of moving through water as easily – in certain cases, even being able to grow to 100 kg in weight and several meters in length – while snappers are somewhat smaller, but can still grow up to a length of about 1 meters. Nevertheless, neither species are dangerous to humans, and even in the case of giant groupers, attacks on humans have not been confirmed. Finally, both species may harbor parasites, isopods, nematodes and digeneans.
Groupers vary greatly in physical characteristics, as well as in their mating and feeding habits, depending on each particular species. Most groupers are teleosts. They have large bodies and mouths and usually swallow their prey in whole, instead of biting and chewing. Snappers, on the other hand, are active carnivores and scavengers. Coral breams are a good example of the latter, while some species of emperors have molariform teeth that they use to consume mollusks and crabs. Sweetlips have a curious feeding habit. Being nocturnal, they venture out from their habitats, often in groups, seeking bottom dwelling invertebrates such as shrimp, crabs and bristle worms.
Groupers are mostly hermaphrodites, maturing only as females and later being capable of changing their sex during adulthood. Curiously enough, larger males actually end up controlling “harems” of 15 or more females. In species like Anthias, the largest female in the group generally takes the place of a dominant male, in case it perishes. For snappers, the reproductive cycle is quite different, being night-time spawners and often spawning during the end of the colder seasons. Schools of fish rise and fall in warmer waters, releasing eggs and sperm, while eggs are externally fertilized, and float near the surface for up to two days before hatching.
Most snappers can be found in both shallow and deeper areas of the ocean – including up to 500 meters in depth – and most tropical waters, including the Eastern Atlantic, as well as the Pacific and Indian Ocean. Emperor breams in particular are spotted in the tropical waters of the Pacific, while some species are also found in places such as Thailand and the Eastern Indian Ocean. Groupers are even more widespread, being found in all the tropical seas and oceans of the world. Anthias are a good example, being among the most well-known species of grouper in the world. The first members of this species were discovered as early as the 1750s in the Mediterranean.