Blackmargin Barracuda

The Blackfin Barracuda (Sphyraena qenie), also known as the Chevron Barracuda and Blackmargin Barracuda, is recognized for its assertive predatory behavior.

This species is distributed from the 🌊 Red Sea and East Africa to the Indo-Western Pacific, extending to 🇵🇫 French Polynesia, and typically inhabits tropical and temperate waters. The 🌊 Indo-Pacific Ocean provides an optimal environment for Sphyraena qenie due to its tropical and subtropical conditions. The species was first recorded in 🇮🇳 Indian waters in 1966, although it remains rare in the tropical Eastern Pacific. In 🇯🇵 Japan, the presence of Sphyraena qenie is noted around several islands, including Ryuku, Amami Oshima, Yonaguni, Tanega, and Ishigaki. Notably, only adult specimens migrate to Ryuku Island from tropical regions when temperatures rise significantly. They also appear near Okinoerabu Island from July to October each year.

Commonly found in coral reefs down to depths of 50 meters (160 feet), Sphyraena qenie forms large schools. During the late afternoon through dusk, these barracudas venture into deeper waters to hunt.

Sphyraena qenie can reach a maximum length of 140 cm (55 in) and is distinguished by its distinctive long black lateral bands forming a v-shape across its body. These bands, numbering 18 to 22, differentiate it from similar species such as Sphyraena jello and Sphyraena putnamae. The species is characterized by elongated last rays on the second dorsal fin and anal fins, and a blackish caudal fin. A notable feature of this species is the absence of gill rakers. The upper jaw, or maxilla, aligns vertically through the front of the eyes, with a longer lower jaw having a conical tip unique to this species. Unlike other barracudas, Sphyraena qenie's preopercle lacks a slim flap. The anal fin is centrally located beneath the second dorsal fin, adjacent to the heart region. The species differs from Sphyraena putnamae by having more longitudinal scale rows relative to the eye and preopercular margin. Additionally, S. qenie exhibits a shorter upper jaw, longer anterior rays on dorsal and anal fins, and a slimmer body insertion. Initially thought to be a smaller variety of Sphraena nigripinnis, it was later differentiated by the forked caudal fins with well-developed lobes in Sphyraena nigripinnis.

A study conducted in remote Oceania investigated mercury (Hg) levels within coral reef systems using Sphyraena qenie as a bioindicator. The study revealed elevated mercury concentrations per global health standards in reef predators inhabiting unimpacted waters, suggesting caution in consuming these top-tier trophic reef fish.