II.  HABITAT AND DISTRIBUTION 

Regional Occurrence:
Strombus gigas is native to north and Central America. It is encountered along the Atlantic coast from South Carolina to the Florida Keys and in the Caribbean Sea and the Bahamas islands at depths from 0.3 to 18 m. S. gigas migrates en masse in offshore directions moving in a flood tide direction (Stoner et al. 1988, Stoner and Lally 1994). Juvenile queen conch are found in shallow, inshore seagrass meadows whereas adults are found in deeper algal plains and seagrass meadows distinct from juveniles (Stoner 1989). Juveniles move in large aggregations that most likely afford them protection from predation (Stoner and Lally 1994).

IRL Distribution:
Juvenile Strombus gigas occur in the shallow seagrass beds of the Indian River Lagoon.

III. LIFE HISTORY AND POPULATION BIOLOGY

Age, Size, Lifespan:
Queen conch reach sexual maturity at approximately 3 1/2 to 4 years reaching a shell length of at least 180 mm and up to 5 pounds (Stoner 1989). Juvenile shells reach a length of 50 to 70 mm in the first year before they emerge from the sand (Stoner et al. 1988). The maximum reported size is 352 mm. Strombus gigas are recorded to live 6 to 7 years and as long as 20-30 years in deeper waters.

Abundance:
Densities of juvenile queen conch are usually 1 conch per meter square but have been recorded as high as 2.1 per meter square (Stoner et al. 1988). In southern Exuma Cay in the Bahamas, the average density of the conch was reported to be 1.72 per meter square in 1984 (Wicklund et al. 1991). Two year old queen conch have been observed to aggregate in even greater densities during periods of heavy wave action (Stoner 1989).

Locomotion:
Strombus gigas moves by a unique shell-thrusting motion called "leaping" (Hesse 1980). The queen conch uses its claw-like operculum to dig into the sand and then "pole" forward by extending the foot (Rupert and Barnes 1994). This is a very different mode of transportation from other gastropods.

Reproduction:
Adult queen conch migrate to shallow, warmer inshore waters to mate and lay their eggs (Stoner et al. 1988). The peak reproduction period is from April to August. The queen conch lay between 180,000 - 460,000 eggs in gelatinous strings some as long as 50 -75 feet. Females may spawn many times during a reproductive season (Stoner et al. 1996).

Embryology:
Planktotropic (feeding) larvae emerge and travel long distances in the water column (Davis et el. 1993). At approximately 18 days, the swimming veliger shifts to a swimming/crawling stage that allows it to move along the substratum and find an appropriate place to settle and metamorphose (Davis 1994). Metamorphosis occurs in response to environmental cues from algae and seagrasses (Davis 1994). After larval recruitment, metamorphosis, and settlement of plantonic larvae, the juveniles live in the sand for the first year until they reach 5-10 cm (Stoner et al. 1988, Stoner 1989). Once the juveniles emerge, they move to the seagrass beds to feed on plant detritus and algae, staying there for the next 2 years (Stoner et al. 1988, Stoner 1989).