Galapagos shark

What it is

This species is a large requiem shark with a streamlined body typical of its family. It has a wide rounded snout and round eyes. The first dorsal fin is tall and sickle-shaped, originating above the rear tips of the pectoral fins. A low ridge runs along the midline to the second dorsal fin. Colouration is brownish grey above and white below, with a faint white stripe on the sides. Fin edges are darker but not prominently marked. Adults commonly reach three metres in length.

Where it lives

Found mainly off tropical oceanic islands, this shark inhabits the Atlantic, Indian and Pacific Oceans. Locations include Bermuda, the Hawaiian Islands, the Galapagos Islands and Lord Howe Island. It prefers rugged reef habitats with clear water and strong converging currents. Groups form around rocky islets and seamounts. Juveniles stay in shallow water under twenty-five metres deep, while adults venture to depths of one hundred and eighty metres.

How it lives

An active predator, it often appears in large aggregations rather than true schools. It dominates blacktip sharks but defers to silvertip sharks of similar size. Diet consists mainly of bottom-dwelling bony fishes and octopuses. Larger individuals eat rays, smaller sharks, sea lions and marine iguanas. They may perform threat displays involving arched backs and gaping jaws when confronted. Parasitic flatworms attach to their skin, and some fish rub against them to remove parasites.

Breeding and life cycle

Reproduction is viviparous, with embryos sustained by a placental connection. Mating occurs from January to March, leaving bite scars on females. Gestation lasts about one year. Females give birth to four to sixteen pups in shallow nursery areas. Birth size varies geographically, ranging from fifty-seven to eighty centimetres. Juveniles remain in shallow water to avoid predation by adults. Males mature at six to eight years, females at seven to nine years.

Fish and people

Fisheries catch this species across its range for meat considered of excellent quality. Divers encounter them frequently at sites like Wolf and Darwin islands. They are inquisitive and persistent, often approaching swimmers or boats. Attacks on humans are rare but documented, including one fatal incident. Excited sharks are difficult to deter and may incite feeding frenzies if threatened. Populations in the Kermadec and Galapagos Islands are protected within marine reserves.

Status and threats

The IUCN assesses this species as Least Concern, though populations face heavy fishing pressure. Its slow reproductive rate limits recovery from depletion. It may have disappeared from some Central American sites. The New Zealand Department of Conservation classifies it as Not Threatened but Conservation Dependent. Fragmented distribution puts regional populations at risk despite overall common status in places like Hawaii.

Relatives and look-alikes

It belongs to the obscurus group within the genus Carcharhinus. Closest relatives include the dusky shark, oceanic whitetip shark and blue shark. It is difficult to distinguish from the dusky shark and grey reef shark. Differences include taller dorsal fins and larger teeth compared to the dusky shark. Vertebral counts also differ, with fifty-eight precaudal vertebrae in this species.

Questions people ask about Galapagos shark

Good reading and sources

• Galapagos shark on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data