May 10 2009
Trigger Happy
Whilst taking a relaxing swim 20 metres (66 foot) offshore, my brother and I came across a species of marine life we have not encountered in the last two years, it is not a rare species of marine life nor is it a common one, the species is the Balistes Capriscus (Grey Triggerfish). The one we saw was 30cm (12 inches) long. We watched the Triggerfish in awe before spending a few minutes following it. We kept a safe distance of 3 metres (10 foot) for our own safety, for the Triggerfish is known to attack divers and snorkellers. After a few minutes of being hot on its tail we came across growth covering a hard bottom object, and as we were swimming above it we saw 13 blurred images slowly come into view, which soon materialised into 13 grey Triggerfish, they were all over 30cm (12 inches) long, the biggest was 45cm (18 inches), whereas the smallest was the one we had followed, every time we’ve ever seen a Triggerfish it was always by itself, so when we saw there was more then one we were “trigger happy.” As we watched we noticed that they swam up to the surface before spending some time on the seabed. We then got a net, which we would use to try to catch one so we could get a photograph, but by the time we had returned they were gone. The following day when we returned to the beach we came across more Triggerfish, but this time we had a camera on hand.
Grey Triggerfish is 1 out of 30 different species of Triggerfish but is the only one that is recorded to in the Mediterranean. They can be found in a wide range of places all over the world, from the eastern Atlantic Ocean of England and Ireland. All over the Mediterranean and in the western Atlantic from Nova Scotia (Canada) to Argentina southeast to Bermuda and then south to Argentina, and also where it is most common from the coastal waters of Florida to the gulf of Mexico.
They belong to the Balistidae family, and the Capriscus species, their genus is Balistes, and their order is the Tetraordontiformes. They are light grey to an olive-brown or yellowy brown colour, but when they are out in open water they appear to have a dull grey colour, but they have the ability to change their colouration to blend in with their surroundings. It has faint broad dark blotches on its upper body and has often-white dots and lines on the lower body and fins. It has blue spots and lines that can be found are on the upper body and dorsal fin. They have a pale narrow band on the chin and a blue upper ring around the eye. The dorsal and anal fins appear to have a marbled colour and as they age the Grey Triggerfish fade in colour.
Triggerfish have a flat (compressed) but deep body covered with tough leathery skin, they also have spines on their two dorsal fins, and this is where it gets its common name. The first dorsal fin has three spines, which would be locked in an erect position for when it would need to defend itself against predators and as an anchoring device. When threatened they will dive into tight crevice and erect and lock its first dorsal fin into place to, wedge itself in tightly, and secure or ‘anchor’ itself in the crevice. The first spine is very strong and is connected to the second spine. When it is depressed, the second spine acts as a trigger, releasing the first spine*. The second dorsal fin can be located directly above the anal fin that is almost identical. The dorsal fins are its primary means of locomotion and are flapped back and forth in unison, which propels the triggerfish. In large adult Grey Triggerfish the caudal fin lobes are elongated. The eyes of the fish can be located a short distance from the mouth. The scales that cover the front half of body are large and plate-like while the scales that cover the posterior are smooth. There are one or more enlarged scales located behind the gill opening. The small opercula can be located directly above the pectoral fins, which are short and rounded.*
As for their dentition, they have a small mouth with strong jaws which contain eight strong needle-like specialised teeth which they use to bore holes in their hard-shelled prey and to eat them. They are a diurnal predator, they eat mussels, shrimp, crabs, sea urchins, sand dollars, sea stars, sea cucumbers, and bivalve molluscs, but when they are juveniles and are with the sargassum they feed on algae, plankton and other planktonic animals.
Triggerfish like to inhabit near shore or offshore locations like lagoons and bays, they prefer reefs and ledges as well as man-made wreckage.
Adults prefer the seabed, juveniles the surface near the sargassum (a seaweed that you can usually find floating on the surface of clear blue water). This seaweed is vital to the survival of a juvenile fish, the bigger it is the more protection it offers. During the autumn when Triggerfish are 5-7 inches (12.7-17.8cm) long they will leave their protection and descend to the sea floor. The grey triggerfish reproduce during July to September when the water is a lot warmer and spawn during spring and summer.
The Balistes capriscus can grow up to 76cm (30 inches) and weigh up to 5.9 kg (13 pounds), females can grow larger and live longer then the male, they have a life expectancy of 13 years and reach sexual maturity when they are two years of age, when they are 30cm (1 foot) long. They lay their eggs in their nests on the sea bottom. Depending upon the size of the female, they can lay up to 100,000 eggs. Their mating is purely random and has no long-term bonding. the adults guard their eggs against anyone who approaches their nests, like snorkellers, divers and swimmers (if you see a Triggerfish when you are in the water, do not directly interact with it or try to touch them. Just give them some space and leave them alone because they can attack if they feel provoked).
Known predators that feed on this fish are Tuna, dolphin, amberjack, sailfish and sharks and groupers.
The Grey Triggerfish is a commercially and recreationally important fish for eating. Their flesh is considered to be of excellent quality. It can be consumed fresh, smoked, and dried/salted and it is also highly prized as a show fish in public aquariums and sea life centers. Though they are considered edible, other species of this fish are not recommended for human consumption.
