Alabama State Saltwater Fish

Fighting Tarpon

(Tarpon atlanticus)

Adopted on September 9, 1955.

The fighting tarpon (Tarpon atlanticus), a silvery, saltwater game fish that can reach weights of 100 pounds, ranges off the coast Alabama and the Mobile estuary.

In 1955, Act no. 564 was approved and designated the tarpon to be the state fish of Alabama. Later it became the state saltwater fish because of the 1975 declaration of the largemouth bass as the state freshwater fish.

Source:
Act 55-564, Acts of Alabama, September 9, 1955
Alabama State Emblems, Alabama Department of Archives and History, nd.

Description of the Alabama State Saltwater Fish

Externally, the almost vertical, silvery sides made up of large scales are the most distinctive feature of the tarpon. The tarpon has a superior mouth with the lower mandible extending far beyond the gape. The fins contain no spines, but are all composed of softrays. The dorsal fin appears high anteriorly and contains 13-15 softrays with the last ray greatly elongated into a heavy filament. The caudal is deeply forked, and the lobes appear equal in length. The anterior portion of the anal fin is deep and triangular. The fin has 22-25 softrays, with the last ray again elongated as in the dorsal fin, but shorter and only present in adults. The tarpon has large pelvic fins, and long pectoral fins containing 13-14 softrays.

Perhaps the most unique internal feature of the tarpon is the modified swim bladder. This swim bladder contains spongy alveolar tissue and has a duct leading to the esophagus that the tarpon may fill directly with air gulped from the surface. This feature allows the tarpon to take oxygen directly from the atmosphere and increases its tolerance of oxygen-poor waters. In fact, studies have shown that tarpon must have access to atmospheric oxygen in order to survive, and that juvenile tarpon are obligatory air-breathers. Adults living in oxygen-rich waters still roll and gulp air, probably as an imitative pattern based on visual perception of other tarpon.

The synonym "silver king" refers to the predominant bright silver color along the sides and belly of the tarpon. Dorsally, tarpon usually appear dark blue to greenish-black. However, the color may appear brownish or brassy for individuals inhabiting inland waters. The dorsal and caudal fins have dusky margins and often appear dark.

Habitat

Tarpon populate a wide variety of habitats, but are primarily found in coastal waters, bays, estuaries, and mangrove-lined lagoons within tropical, subtropical, and temperate climates (45° N-30° S). The normal habitat depth extends to 98 feet (30 m). Although a marine fish, tarpon can tolerate euryhaline environments (0-47 parts per thousand) and often enter river mouths and bays and travel upstream into fresh water. In addition, tarpon can also tolerate oxygen-poor environments due to a modified air bladder that allows them to inhale atmospheric oxygen. The only variable that seems to limit their choice of habitat is temperature, and research shows tarpon to be thermophilic. Rapid decreases in temperature have been known to cause large tarpon kills. During such temperature drops, tarpon usually take refuge in warmer deeper waters.

Taxonomic Hierarchy of the Fighting Tarpon