Marine Wildlife Encyclopedia
Atlantic Trumpetfish Aulostomus maculatus
Species ID: A.AM
Description: A long slender fish with small fins at the rear of the body and a thickelongated snout with a pointed barbel on the lower jaw. These fish can change colour at will, although three basic colour schemes exist: reddish brown, gray with a blue snout, and yellow. Common markings include pale horizontal stripes and dark speckles. Sexes appear similar and juveniles resemble adults
Maximum Size: 1 m (3 ft)
Status: Not currently on the IUCN endangered species list
Atlantic Trumpetfish & People: May be consumed locally, but not important in commercial fisheries or the aquarium trade
Geographical Range: Found throughout the Caribbean, but is more common in the Lesser Antilles (south-east Caribbean)
Coral Reef Zone: Found in the back reef and fore reef zones
Favourite Habitat: Trumpetfish prefer habitats with vertical structures, such as gorgonian corals, in which they can camouflage themselves
Depth: 2-25m (6–82ft)
A Day in the Life
Dawn: Found stalking prey on the reef, when the low light augments its natural camouflage and increases hunting success
Day: Stalking prey by mimicking vertical structures like sponges and soft corals
Dusk: Stalking prey, and may also move into the deeper fore reef zone to spawn
Night: Found hiding under ledges, or camouflaged next to vertical structures
Who Eats Who?
Trumpetfish are predators, and consume many small reef creatures, such as shrimps, chromis, wrasses, juvenile grunts and soldierfish. Trumpetfish themselves are vulnerable to a variety of large reef predators like grouper, snapper, jacks, and sharks.
Scuba Diver & Snorkeler Best Practices
Refrain from feeding marine life. Coral reef organisms should never be fed. Although this may seem like a harmless practice that allows you to get close to your favourite organisms, it actually disturbs normal feeding patterns and diets. Scientists have documented turtles being fed bread, dog food and even cheese—none of these foods are found naturally in the marine environment, and they can cause untold stress to the organisms that consume them. Conditioning wild animals to become comfortable with hand-feeding by humans alters their behaviour and makes them more vulnerable to capture, which directly affect their survival—this is particularly a concern for endangered sea turtles.
Trumpetfish remain still if they believe they are well camouflaged, but are wary and often move away when snorkelers or divers come too close. A slow, indirect approach is recommended.
Trumpetfish are carnivores specialized in the capture of small fishes and, occasionally, small crustaceans. They are generally passive ambush predators which hunt during daylight hours from the concealment of soft corals or from under coral ledges. They lie in wait until the opportunity arises for a lightning-fast strike, curving the rear half of their body into an S shape and rapidly straightening, resulting in a rapid lunge towards the target.
These fish are also known to stalk prey in partnership with other reef fish, using them as moving cover to hide their approach from prey. Interestingly, the Pacific cousins of trumpetfish and cornetfish are natural predators of juvenile red lionfish. The red lionfish is a ravenous carnivore that has recently been introduced into the Caribbean, where populations are growing unchecked in the absence of experienced natural predators. With time, Caribbean trumpetfish and cornetfish may also learn to consume this invasive species and help control their numbers.
Observe, record & share:
O A.AM-101 – Stalking: Stalking and striking at prey in the open
O A.AM-102 – Ambush: Striking at unsuspecting prey from a concealed position
O A.AM-103 – Shadow-feeding: Stalking while hiding alongside other reef fish and using them as a mobile cover, thus improving their chances of approaching prey undetected
O A.AM-104 – S-shape: Trumpetfish curve the body into an S-shape before striking at prey
Attack & Defense Behaviour
Trumpetfish do not defend territories and their main defensive concern is avoiding predators. They are poor long-distance swimmers and rely mainly on a quick escape to nearby cover where they can use their excellent camouflage skills to hide from large predators like snappers and groupers. Trumpetfish can camouflage themselves using their thin, elongated shape to blend into vertical reef features like sea whips, sea plumes, and other gorgonians. They can also change colours rapidly to blend away into the background and avoid being seen.
Observe, record & share:
O A.AM-201 – Shape camouflage: When they feel threatened, trumpetfish often imitate gorgonian branches or sponges by floating vertically and swaying with them in the current
O A.AM-202 – Colour camouflage: Trumpetfish can change colour to blend into a new background
Although spawning has never been scientifically documented in this species, eye-witness accounts suggest that this species practices pelagic broadcast spawning, where males and females rush to the sea surface to release their eggs and sperm, which disperse into the open ocean. Courtship sessions may be interrupted as several males fight over the right to spawn with ripe females, which appear swollen with eggs. Just before spawning, males darken their colour, swim alongside the female, and may hover vertically along with their chosen partner. There is no evidence of sex change in this species. Spawning occurs year-round in the hours just before sunset, although reproductive activity peaks in the winter months from November to January.
Observe, record & share:
O A.AM-301 – Ripe female: Females full of eggs, and ready to spawn, have swollen bellies
O A.AM-302 – Male competition: Ripe females are often chased by multiple males, who may fight with each other for exclusive spawning rights
O A.AM-303 – Courtship: Just before spawning, males deepen their colour, and swim alongside or hover vertically with their chosen female
O A.AM-304 – Spawning rush: Following ripe females at a distance may increase the chances of witnessing spawning, during which males rise with females high above the reef where eggs and sperm are released simultaneously
Shadow-feeding: Trumpetfish prefer to shadow other reef fish species (often herbivorous species) the same colour as themselves, thereby increasing the effectiveness of their camouflage. Thus, yellow individuals prefer to shadow other yellow fish such as Spanish hogfish; reddish brown individuals prefer to shadow grouper and darker parrotfish; and dull grey individuals with blue snouts prefer to blend in with schools of blue fish such as blue tang,blue chromis, and creole wrasse, where their snouts are mistaken for a member of the school Occasionally, trumpetfish may even attempt to shadow a diver!
Did You Know?
• Eels, snapper, and grouper are all predators of trumpetfish, and some of the shorterbodied predators often succeed in consuming trumpetfish longer than they are by folding this awkward prey over in their stomachs
• The fantastic range of yellow, brown and red colour patterns that trumpetfish use for camouflage is produced by controlling the concentration of pigments in specialized cells called chromatophores. In contrast, blue colours are achieved by small shiny particles that reflect blue light, rather than by pigments. Cells producing these shiny particles are called iridiophores after the iridescent colour they produce.
What to do?
Share your observations today!: Discover your species of interest, observe its behaviour, and share your pictures and videos with friends and coral reef enthusiasts around the world! Upload media to the web, tagged with species common name (ex.: trumpetfish) and species ID code (ex.: A.AM) or species behaviour code (ex.: A.AM-101)