The nurse shark (Ginglymostoma cirratum) is a common coastal shark of the western Atlantic–Caribbean, in family Ginglymostomatidae. A nocturnal, benthic ambush predator, it often rests in groups under ledges or in caves by day, and is frequently encountered by divers.
Ecology & Behaviour
Diet: demersal fishes, crustaceans and molluscs (e.g., lobsters, crabs, octopus); the mouth generates strong suction to extract prey.
Activity: diurnal resting, nocturnal foraging; strong site fidelity and small home ranges.
Reproduction: aplacental viviparous; gestation ~5–6 months; litters of ~20–30 pups; breeding may be biennial.
Identification
Prominent barbels on the snout; subterminal mouth with small, fine teeth; both dorsal fins are set posteriorly; short caudal peduncle; overall uniform brownish‑tan colour (juveniles with pale spots). Small spiracles behind the eyes.
Size & Longevity
Length: commonly 2.0–3.0 m (rarely larger).
Weight: typically 70–110 kg (large females heavier).
Life: ~25–35 years (region‑dependent).
Range & Habitat
Primarily the western Atlantic (SE USA to the Caribbean and Brazil), including the Gulf of Mexico and Bahamas; favours coral reefs, seagrass meadows, mangroves and sandy bottoms, usually at 1–40 m.
Threats & Conservation
Fisheries: takes in small‑scale coastal fisheries and recreational catches; incidental net entanglement.
Habitat degradation: reef decline, mangrove loss and coastal pollution.
Human interaction: baiting/handling can cause bites and behavioural change.
IUCN global status: Vulnerable (VU). Priorities: spatio‑temporal protection of key habitats/resting sites, bycatch mitigation & safe release, and responsible wildlife tourism (no feeding/touching; distance and group‑size limits).
