Bluestripe snapper

What it is

This snapper has a moderately deep body with a steeply sloped head profile. Its most striking feature is the bright yellow colour of its back and sides, which fades to white on the belly. Four distinct blue stripes run lengthwise along its flanks, accompanied by fainter grey lines below. The fins are mostly yellow, and the tail is slightly notched. Adults can grow to 40 cm, though most remain smaller than 25 cm. It belongs to the family Lutjanidae and is easily identified by these vivid markings when fresh or alive.

Where it lives

Native to the Indian Ocean, this species ranges from the Red Sea and African coast eastward to India, China, Southeast Asia, Australia, and Pacific islands. It inhabits coral reefs in shallow lagoons and outer slopes. While commonly found at depths up to 60 metres, it has been recorded as deep as 265 metres in the Red Sea. In Hawaii, it also occupies seagrass beds and sandy areas. Young fish prefer sandy substrates, while adults move to deeper reef structures.

How it lives

Juveniles school together on sandy bottoms, but larger individuals become more solitary around caves and wrecks. They form large daytime aggregations near coral formations. Their diet is varied, including fish, shrimp, crabs, squid, and planktonic crustaceans, as well as some plant matter. Food choices depend on local availability and the age of the fish. They engage in a mimicry relationship with the goatfish Mulloidichthys mimicus, which shares their colouration for protection against predators.

Breeding and life cycle

Sexual maturity is reached at lengths between 20 and 25 cm. Spawning takes place throughout most of the year in lower latitudes. In the Andaman Sea, peak activity occurs during November and December. The eggs are small, measuring less than one millimetre in diameter. Hatching requires water temperatures between 22 and 25 degrees Celsius. This reproductive strategy allows for continuous population maintenance in tropical waters.

Fish and people

Fishers catch this snapper using handlines, traps, and gill nets across its range. It is sold fresh in many markets but commands low prices. In Hawaii, it was introduced in the 1950s to boost food fishing but is now viewed as a pest that competes with native species. Spearfishing contests target it there. The fish is also popular in the aquarium trade due to its bright colours. It holds cultural significance in the Red Sea, where its Arabic name kasmira is used.

Status and threats

The species is widespread and commercially exploited but faces no global extinction threat mentioned in the data. In Hawaii, it is considered invasive. Concerns exist that it outcompetes native goatfish for shelter and food, particularly at high densities. It may have introduced a parasitic nematode to Hawaiian waters, affecting native fish populations. Management efforts in Hawaii include removal programmes to protect local ecosystems.

Relatives and look-alikes

It is often confused with other snappers due to similar body shapes. In Hawaii, it interacts closely with the yellow-fin goatfish, competing for space. It mimics the colouration of the goatfish Mulloidichthys mimicus. As a member of the Lutjanidae family, it is related to other reef-dwelling snappers and groupers, though it lacks close relatives in the Hawaiian archipelago prior to its introduction.

Questions people ask about Bluestripe snapper

Good reading and sources

• Common bluestripe snapper on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data