Blackspot Emperor

Lethrinus harak, commonly known as the thumbprint emperor, blackblotch emperor, or blackspot emperor, is a marine ray-finned fish species within the family Lethrinidae. This species inhabits the Indo-Pacific region.

Originally described as Sciaena harak in 1775 by Danish zoologist Johan Christian Fabricius, the species was included in the work Descriptiones animalium edited by Carsten Niebuhr. Fabricius's description was based on the notes of Peter Forsskål, who had been part of an expedition to Arabia with Niebuhr. Although no precise type locality was specified, it is presumed to be the 🌊 Red Sea. Some taxonomists categorize the genus Lethrinus within the monotypic subfamily Lethrininae, while placing other genera in the subfamily Monotaxinae. However, the fifth edition of Fishes of the World does not recognize traditional subfamily divisions within the Lethrinidae family, classifying it instead within the order Spariformes.

The species name "harak" was adopted by Forsskål from the Arabic name "Abu m’hárrak" used for this fish in the 🌊 Red Sea region.

Lethrinus harak features a dorsal fin supported by 10 spines and 9 soft rays, and an anal fin with 3 spines and 8 soft rays. It exhibits an olive-green coloration that transitions to a paler shade towards the belly and can reach a maximum length of 50 cm (approximately 20 inches), though more commonly measures around 30 cm (12 inches). A distinctive large, dark, elliptical blotch is present on its sides just below the lateral line, often bordered with yellow. Pale blue dots may appear surrounding the nostrils and along the lower rim of the eyes. The caudal fin appears reddish or orange, while the pelvic, dorsal, and pectoral fins range from pinkish to white. The species possesses a somewhat protractile mouth with notably thick lips. The maximum recorded weight is 2.9 kg, and the species can live up to 15 years.

Lethrinus harak is widely distributed across the Indo-Pacific, occurring along the eastern African coast from the northern 🌊 Red Sea to 🇿🇦 South Africa, including the islands of the western 🌊 Indian Ocean, the 🇲🇻 Maldives, 🇱🇰 Sri Lanka, southern 🇮🇳 India, the Andaman Sea, and the Indo-Malayan Archipelago, extending into the 🌊 Pacific Ocean as far east as 🇼🇸 Samoa, north to 🇯🇵 Japan, and south to northeastern 🇦🇺 Australia.

This species thrives at depths up to 20 meters (66 feet) in environments featuring sandy substrates, coral rubble, mangroves, inshore seagrass beds, lagoons, and channels. Non-migratory in nature, it may form small schools or exist as solitary individuals. Seagrass beds serve as vital nursery habitats.

Lethrinus harak's diet consists of crustaceans, molluscs, polychaetes, echinoderms, and small fishes. Typically solitary, it may occasionally join small schools. The species is territorial, maintaining defined home ranges that are size-determined through intraspecific competition—the larger the individual, the larger its range. It is suspected to be a protogynous hermaphrodite, capable of gathering in spawning aggregations. In 🇯🇵 Japan, spawning has been observed from April to November, while in Guam, spawning occurs year-round.

The species is primarily caught using seine fishing, gillnets, traps, and handline methods and is typically marketed fresh. In Guam, Lethrinus harak is heavily fished through hook and line, gillnets, and spearfishing techniques.