Fish
Atlantic Tarpon
Megalops atlanticus · also called atlantic tarpon, silver king
The Atlantic tarpon is a huge, chrome-bright fish of warm coastal waters, known to anglers as the silver king. It can weigh as much as a person and more, it survives in stagnant backwaters by gulping air like a lungfish, and when hooked it launches its whole body clear of the surface in a series of thrashing leaps.
Overview
Atlantic tarpon live in the warm Atlantic on both sides — from Virginia to Brazil in the west, including the Gulf of Mexico and Caribbean, and along West Africa in the east. Adults commonly run 1.2–2 m and 25–80 kg, with the largest exceeding 2.5 m and 160 kg. The body is deep and slab-sided under large, mirror-bright scales.
An air-breathing fish
The tarpon’s swim bladder connects to the gullet and is lined with spongy, blood-rich tissue that works as a primitive lung. Rolling at the surface to gulp air, a tarpon can live and feed in warm, oxygen-poor lagoons and canals that would kill other large fish — useful nursery habitat for the young, which have few predators there.
The jump
A hooked tarpon makes repeated powerful leaps, sometimes clearing two metres, shaking its head to throw the hook. Anglers are taught to “bow to the king” — dropping the rod tip toward a jumping fish so the line does not snap.
An ancient fish
Tarpon belong to an early-branching group of bony fishes and hatch as a transparent, ribbon-like leptocephalus larva — the same odd larval form found in eels — which drifts inshore before transforming.
Status
The Atlantic tarpon is Vulnerable and declining. It is slow to mature, lives 50 years or more, and depends on estuary and mangrove nurseries that are being lost. Because its flesh is bony and poorly regarded, the fishery is overwhelmingly catch-and-release.
Atlantic Tarpon: common questions
Why can the Atlantic tarpon breathe air?
Its swim bladder, the gas-filled organ most fish use only for buoyancy, has an open connection to the gullet and an inner surface folded into spongy, blood-rich tissue that can absorb oxygen from air. When a tarpon rolls at the surface and gulps, it is effectively taking a breath into this accessory lung. The ability lets tarpon live and feed in shallow, warm, poorly oxygenated backwaters, canals, and stagnant lagoons that would kill most fish of their size, and it is one reason young tarpon can use marginal nursery habitats that hold few predators. In well-oxygenated water tarpon still breathe mainly through their gills.
How big do tarpon get and how fast do they grow?
Adult tarpon commonly run from about 1.2 to 2 metres and 25 to 80 kilograms, and exceptional fish exceed 2.5 metres and 160 kilograms. Growth is fairly quick in the early years but they are long-lived and slow to mature, often not spawning until somewhere between seven and thirteen years old, and individuals have been aged at over 50 and in some cases past 80 years. This combination, a big fish that takes years to reach breeding age and then breeds over a long lifespan, means tarpon stocks recover only slowly from overfishing or habitat damage.
Why do anglers release almost every tarpon they catch?
Partly by choice and partly by rule. Tarpon flesh is full of small bones and is not considered good eating in most of the range, so there is little reason to keep one for food. At the same time the tarpon fishery is economically important as a sport and tourism resource, supporting guides, lodges, and tackle businesses, and a live tarpon can be caught many times over its long life. Several jurisdictions now protect tarpon with catch-and-release-only regulations or require a special tag to keep one, reinforcing a release ethic that most tarpon anglers already follow.
What is a leptocephalus, and do tarpon really have one?
A leptocephalus is a strange larval stage, a flat, clear, leaf- or ribbon-shaped creature with visible internal organs and simple needle-like teeth, that drifts in the open ocean feeding on tiny particles before transforming into the adult body form. It is best known from eels, but tarpon, along with bonefish and ladyfish, share it because they belong to the same broad ancient lineage of bony fishes. A tarpon leptocephalus hatches offshore from eggs spawned in the open sea, drifts toward the coast over some weeks, then shrinks and metamorphoses into a tiny recognisable tarpon that moves into estuaries and marshes.