This species is one of the largest molluscs native to the Caribbean Sea, and tropical northwestern Atlantic, from Bermuda to Brazil, reaching up to 35.2 centimetres (13.9 in) in shell length.

The adult animal has a very large, solid and heavy shell, with knob-like spines on the shoulder, a flared, thick outer lip, and a characteristic pink or orange aperture (opening).

[11] The external anatomy of the soft parts of A. gigas is similar to that of other snails in the family Strombidae; it has a long snout, two eyestalks with well-developed eyes, additional sensory tentacles, a strong foot and a corneous, sickle-shaped operculum.

The shell and soft parts of living A. gigas serve as a home to several different kinds of commensal animals, including slipper snails, porcelain crabs and a specialized species of cardinalfish known as the conchfish Astrapogon stellatus.

[14] The specific name is the ancient Greek word gigas (γίγας), which means "giant", referring to the large size of this snail compared with almost all other gastropod molluscs.

[3] In the first half of the 20th century, the type material for the species was thought to have been lost; in other words, the shell on which Linnaeus based his original description and which would very likely have been in his own collection, was apparently missing, which created a problem for taxonomists.

In this case, the neotype was not an actual shell or whole specimen, but a figure from a 1684 book Recreatio mentis, et occuli, published 23 years before Linnaeus was born by the Italian Jesuit scholar Filippo Buonanni (1638–1723).

[14][16][17][18] In 1953 the Swedish malacologist Nils Hjalmar Odhner searched the Linnaean Collection at Uppsala University and discovered the missing type shell, thereby invalidating Clench and Abbott's neotype designation.

[11] Although this notch is not as well developed as elsewhere in the family,[18] the shell feature is nonetheless visible in an adult dextral (normal right-handed) specimen, as a secondary anterior indentation in the lip, to the right of the siphonal canal (viewed ventrally).

[34][36][37] The overall shell morphology of A. gigas is not solely determined by the animal's genes; environmental conditions such as location, diet, temperature and depth, and biological interactions such as predation, can greatly affect it.

[43] Index Testarum Conchyliorum (published in 1742 by the Italian physician and malacologist Niccolò Gualtieri) contains three illustrations of adult shells from different perspectives.

One of the most prized shell publications of the 19th century, a series of books titled Illustrations conchyliologiques ou description et figures de toutes les coquilles connues, vivantes et fossiles (published by the French naturalist Jean-Charles Chenu from 1842 to 1853), contains illustrations of both adult and juvenile A. gigas shells and one uncoloured drawing depicting some of the animal's soft parts.

[44] Almost forty years later, a colored illustration from the Manual of Conchology (published in 1885 by the American malacologist George Washington Tryon) shows a dorsal view of a small juvenile shell with its typical brown and white patterning.

The tip of each eyestalk contains a large, well-developed lensed eye, with a black pupil and a yellow iris and a small, slightly posterior sensory tentacle.

[45] The species has a large and powerful foot with brown spots and markings towards the edge, but is white nearer to the visceral hump that stays inside the shell and accommodates internal organs.

Attached to the posterior end of the foot for about one third of its length is the dark brown, corneous, sickle-shaped operculum, which is reinforced by a distinct central rib.

[39] A. gigas females may spawn multiple times during the reproductive season,[37] which lasts from March to October, with activity peaks occurring from July to September.

[55] Afterwards, the emerging two-lobed veliger (a larval form common to various marine and fresh-water gastropod and bivalve mollusks)[57] spend several days developing in the plankton, feeding primarily on phytoplankton.

[52] After the metamorphosis, A. gigas individuals spend the rest of their lives in the benthic zone (on or in the sediment surface), usually remaining buried during their first year of life.

[37][62] The critical nursery habitats for juvenile individuals are defined by a series of characteristics, including tidal circulation and macroalgal production, which together enable high rates of recruitment and survival.

Those coccidian[66][67] parasites, which are spore-forming, single-celled microorganisms, initially establish themselves in large vacuolated cells of the host's digestive gland, where they reproduce freely.

[66] Aliger gigas is a prey species for several carnivorous gastropod mollusks, including the apple murex Phyllonotus pomum, the horse conch Triplofusus papillosus, the lamp shell Turbinella angulata, the moon snails Natica spp.

It is consumed raw, marinated, minced or chopped in a wide variety of dishes, such as salads, chowder, fritters, soups, stew, pâtés and other local recipes.

South Florida bands (such as the Tequesta), the Carib, the Arawak and Taíno used conch shells to fabricate tools (such as knives, axe heads and chisels), jewelry, cookware and used them as blowing horns.

[76] In central Mexico, during rain ceremonies dedicated to Tlaloc, the Maya used conch shells as hand protectors (in a manner similar to boxing gloves) during combat.

[76] Ancient middens of L. gigas shells bearing round holes are considered an evidence that pre-Columbian Lucayan Indians in the Bahamas used the queen conch as a food source.

Due to the sensitive nature of the animal and the location of the pearl-forming portion of the snail within the spiral shell, commercial cultivation of pearls is considered virtually impossible.

[83] Queen conch populations have been rapidly declining throughout the years and have been mostly depleted in some areas in the Caribbean due to the fact that they are highly sought after for their meat and their value.

[61] On 13 January 2019, the Bahamas' Department of Marine Resources announced it would be making official recommendations to better protect the conch, including ending exports and increasing regulatory staff.

[39] The listing was proposed by the United States making queen conch the first large-scale fisheries product to be regulated by CITES (as Strombus gigas).