Why are these migratory, torpedo-shaped predators known as the garbage cans of the sea?

Nature · Published 3 October 2026 Swipe more like this →

In short: Requiem sharks are a diverse family of migratory, live-bearing predators found in warm seas worldwide. From the tiny Australian sharpnose to the massive oceanic whitetip, these agile hunters are often called the garbage cans of the ocean because they consume almost anything, including non-food items like discarded human trash.

The family Carcharhinidae, commonly known as requiem sharks, comprises about 60 species across 10 genera. These sharks are defined by their round eyes and gill slits positioned over the pectoral fin base. Their scientific name, proposed by D.S. Jordan and B.W. Evermann in 1896, derives from Greek terms for sharp or jagged and a rasp, referencing their characteristic rough skin. While the name 'requiem' is often linked to the Latin word for rest, this etymology is disputed, with some scholars suggesting it stems from an Old French verb meaning to grimace while baring teeth.

These sharks are highly effective hunters, utilizing elongated, torpedo-shaped bodies to navigate oceans with speed and agility. While many hunt solo, some species like lemon and whitetip reef sharks engage in cooperative feeding, using coordinated attacks to secure prey. Their diet is remarkably broad, ranging from squid and seabirds to marine mammals. Because they are migratory, they often follow food sources across entire oceans, though some species are capable of resting motionless on the seafloor for extended periods.

The group has a deep evolutionary history, with the oldest known member, Archaeogaleus lengadocensis, dating back to the Early Cretaceous period in France. Today, they are frequently cited in reports of shark incidents involving humans. However, experts note that 'requiem shark' is a collective term for a group of similar species rather than a single animal, making precise identification in incident reports difficult. Despite their reputation, these sharks remain essential, highly diversified predators that have thrived in coral reef habitats since the beginning of the Cenozoic era.

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