page_title: Aliger gigas
section_title: Life cycle
hierarchical_section_title: Aliger gigas / Life cycle
caption_attribution_description: English: Eustrombus gigas in a seagrass bed, Rice Bay, San Salvador Island, Bahamas. June 24, 1999.
context_page_description: Aliger gigas, originally known as Strombus gigas or more recently as Lobatus gigas, commonly known as the queen conch, is a species of large edible sea snail, a marine gastropod mollusc in the family of true conches, the Strombidae. 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 in shell length. A. gigas is closely related to the goliath conch, Lobatus goliath, a species endemic to Brazil, as well as the rooster conch, Lobatus gallus.
  The queen conch is herbivorous. It feeds by browsing for plant and algal material growing in the seagrass beds, and scavenging for decaying plant matter. These large sea snails typically reside in seagrass beds, which are sandy plains covered in swaying sea grass and associated with coral reefs, although the exact habitat of this species varies according to developmental age. 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.
context_section_description: Aliger gigas is gonochoristic, which means each individual snail is either distinctly male or distinctly female. Females are usually larger than males in natural populations, with both sexes existing in similar proportion. After internal fertilization, the females lay eggs in gelatinous strings, which can be as long as 75 feet (23 m). These are layered on patches of bare sand or seagrass. The sticky surface of these long egg strings allows them to coil and agglutinate, mixing with the surrounding sand to form compact egg masses, the shape of which is defined by the anterior portion of the outer lip of the female's shell while they are layered. Each one of the egg masses may have been fertilized by multiple males. The number of eggs per egg mass varies greatly depending on environmental conditions such as food availability and temperature. Commonly, females produce 8–9 egg masses per season, each containing 180,000–460,000 eggs, but numbers can be as high as 750,000 eggs. A. gigas females may spawn multiple times during the reproductive season, which lasts from March to October, with activity peaks occurring from July to September.
  Queen conch embryos hatch 3–5 days after spawning. At the moment of hatching, the protoconch (embryonic shell) is translucent and has a creamy, off-white background color with small, pustulate markings. This coloration is different from other Caribbean Lobatus, such as Lobatus raninus and Lobatus costatus, which have unpigmented embryonic shells. Afterwards, the emerging two-lobed veliger (a larval form common to various marine and fresh-water gastropod and bivalve mollusks) spend several days developing in the plankton, feeding primarily on phytoplankton. Metamorphosis occurs some 16–40 days from the hatching, when the fully grown protoconch is about 1.2 mm high. 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.
  The queen conch reaches sexual maturity at approximately 3 to 4 years of age, reaching a shell length of nearly 180 mm and weighing up to 5 pounds. Individuals may usually live up to 7 years, though in deeper waters their lifespan may reach 20–30 years and maximum lifetime estimates reach 40 years. It is believed that the mortality rate tends to be lower in matured conchs due to their thickened shell, but it could be substantially higher for juveniles. Estimates have demonstrated that its mortality rate decreases as its size increases and can also vary due to habitat, season and other factors.
caption: A subadult individual in a seagrass bed, Rice Bay, San Salvador Island, Bahamas
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