Lowfin Chub

Kyphosus vaigiensis, commonly known as the brassy chub or brassy drummer, is a marine ray-finned fish species within the family Kyphosidae. This largely herbivorous sea chub exhibits a circumglobal distribution. Recent studies suggest that some species formerly identified in the Kyphosus genus might be junior synonyms of Kyphosus vaigiensis.

Morphologically, K. vaigiensis has an elongated, oval body shape with a moderately emarginate caudal fin. The species features a small head, a short snout, and a terminal mouth equipped with small, incisor-shaped teeth, supplemented by additional teeth on the palate and tongue. Its dorsal fin includes 10-11 spines and 13-15 soft rays, while the anal fin has 3 spines and 12-14 soft rays. The dorsal fin folds into a protective sheath. Notably, scales are present in the interorbital region. The fish's coloration is silvery with a bluish sheen, adorned with 23-29 golden horizontal lines. A distinctive golden streak is observed below the eye. The fins are typically grey or slightly darker than the body. The maximum recorded length is 70 centimeters, though more commonly, individuals measure around 50 centimeters.

K. vaigiensis inhabits warm seas worldwide, with a notable presence in the 🌊 Pacific Ocean from the coast of the Americas to regions as far as 🇯🇵 Japan and 🇦🇺 Australia. Its 🌊 Indian Ocean distribution ranges from the 🌊 Red Sea to the eastern coast of Africa and 🇲🇬 Madagascar. In the eastern Atlantic, it is found around Ascension Island, St Helena, and São Tomé Island, while the western Atlantic population includes regions from the Yucatan to the Caribbean and 🇧🇲 Bermuda. In the Mediterranean Sea, K. vaigiensis was first documented in Spain in 1998 and has since appeared off several European coasts, potentially establishing a breeding population.

The species primarily resides over hard, algal-coated substrates in exposed surf-swept outer reef flats, lagoons, and seaward reefs, at depths up to 24 meters. Adults are typically found near rocky reefs along the shoreline, whereas juveniles might inhabit the open ocean near the surface, feeding on small crustaceans. Adults exhibit seasonal carnivory, feeding on Petalonia binghamiae in the winter. While solitary at higher latitudes, they form social groups in the tropics, often schooling with related species such as K. bigibbus, K. cinerascens, and K. sectatrix.

Initially described as Pimelepterus vaigiensis in 1825 by Jean René Constant Quoy and Joseph Paul Gaimard, with its type locality at Waigeo in modern West Papua, K. vaigiensis includes what were previously considered separate species, Kyphosus analogus and Kyphosus incisor, due to overlapping morphological and molecular characteristics.