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Fishes in Focus
If there was ever a family of fishes to which the description of'beauty and the beast' could be given, then the triggerfishes are that family. Yet, despite their reputation for being belligerent bruisers, triggers often attract the attention and interest of reef hobbyists. Along with their outlandish body plan and bold patterning, these fishes are desirable for being some of the most behaviourally interesting, intelligent and 'interactive' of all ornamental marine fishes. Relatively advanced in evolutionarily terms, they are known to learn from previous experiences, yet they are also notoriously unpredictable in terms of temperament in captivity. Even so, keeping a trigger can have a fairy-tale ending ... if you can prepare for their'Jekyll and Hyde'personalities, that is.
Closely related to (and grouped into the order Tetraodontiformes with) the cowfishes, filefishes and oufferfishes, triggerfishes are members of the family Balistidae. This family comprises of 11 genera and around 40 species (about half of which may enter the ornamental trade). Certain characteristics are common across the family, specifically the weird rhomboid, laterally compressed body shape, dorsal and pelvic fin spines (of which the dorsal spine can be locked into place, giving the family its common name), tough leathery skin, specialised dentistry and high-mounted eyes that can rotate independent of one another. As well as those spines, the anal and posterior dorsal fins are interesting in that they are used for primary locomotion, rippling from side to side to provide forward or reverse movement. This allows the fish to hover around above the substrate as it scans for its next meal. The caudal fin is saved for emergency bursts of speed, such as evading predators.
Distributed across the tropical and subtropical Atlantic, Indian and Pacific Oceans, but with greatest species richness in the Indo-Pacific, most triggerfishes are solitary, diurnal carnivores. Although most favour shallow coastal environments such as coral reefs, some are pelagic. Other than the few planktivorous species, many triggers consume a wide variety of invertebrates including hard-shelled molluscs and echinoderms. With two sets of teeth, the first a set of sharp incisors and the second set adapted for crushing prey, they are well equipped for this diet. Actually, they can deliver a painful bite to humans too, indeed certain trigger species...