Aulostomus maculatus Valenciennes, 1841

Taxonomic Information

Aulostomus maculatus Valenciennes, 1841, commonly called trumpetfish, is closely related to cornetfish.

Size

This species has an average total length of 60 centimetres (24 inches), can reach just over 36 inches (91 centimetres), and has a maximum reported total length of 100 centimetres (39 inches).

Body and Head Shape

It has a greatly elongated, compressed body, with a compressed head featuring small jaws at the tip of its long, tubular snout.

A distinct barbel sits on the chin, at the tip of the lower jaw.

Fin Positioning

The dorsal and anal fins are positioned toward the posterior of the body.

Dorsal Fin Structure

In front of the dorsal fin, there are 8-12 well-spaced, isolated spines; the dorsal fin itself has 12 spines and 12-25 soft rays.

Anal and Caudal Fin Structure

The anal fin has 21-25 soft rays, and the caudal fin is rounded.

Baseline Coloration

The most common coloration for this species is mottled brown to reddish brown, marked with irregular black or brown spots.

Color Variation and Camouflage

Individuals may also be blue-gray, bright yellow, or green, and the species can change its color to camouflage itself.

Body Markings

Transverse silvery streaks run across the head and flanks, and there is a black bar at the base of both the dorsal and anal fins, which is sometimes reduced to a spot.

One or two spots may be present on the tail.

Distribution Range

Aulostomus maculatus is widespread across the tropical waters of the western Atlantic Ocean, ranging from Florida to Brazil, and including the Caribbean Sea and the Gulf of Mexico.

Taxonomic Note on Range Records

Records of this species from the southernmost part of this range may actually refer to the related species Aulostomus strigosus.

Feeding Guild

Trumpetfish is a largely piscivorous ambush predator.

Shadowing Hunting Behavior

It hides among schools of large herbivorous fish, shadowing them until it gets close enough to strike at prey.

Ambush Hunting Posture

It can also orient itself vertically among gorgonians or drift with the current, capturing any prey that swims beneath it.

Prey Capture Mechanism

It sucks prey into its mouth, which contains elastic tissue that allows the mouth to open as wide as the diameter of the fish’s body.

The sudden opening of the mouth creates a vacuum that pulls prey inside.

Recorded Prey Items

Recorded prey includes the fish ocean surgeon (Acanthurus bahianus), blue chromis (Chromis cyanea), tomtate grunt (Haemon aurolineatum), French grunt (Haemulon flavolineatum), longspine squirrelfish (Holocentrus rufus), downy blenny (Labrisomus kalisherae), dusky blenny (Malacoctenus gilli), redlip blenny (Ophioblennius atlanticus), rusty reefgoby (Priolepis hipoliti), spotted goatfish (Pseudupeneus maculatus), reef squirrelfish (Sargocentron coruscum), yellowtip damselfish (Stegastes pictus), and Bluehead wrasse (Thalassoma bifasciatum), as well as shrimp.

Damselfish Aggression

The damselfish Stegastes planifrons often aggressively attacks trumpetfish, but these attacks do not appear to interfere with the trumpetfish's hunting.

Association with Parrotfish

Trumpetfish are normally solitary hunters, but they frequently associate with schools of striped parrotfish (Scarus iseri) to avoid attacks from S. planifrons.

Feeding Rate in Groups

In these groups, trumpetfish have higher feeding rates than solitary individuals.

Aquarium Trade Role

Aulostomus maculatus is likely a minor component of the aquarium trade.

Fisheries Relevance

It is often caught in seines and traps by fisheries, where it is considered to have only minor commercial interest.