Bermuda Chub

When diving along shallow tropical reefs, Bermuda chubs are easy to spot due to their oval silhouettes and schooling habits. They frequently patrol shallow reef crests, reef flats, and surge zones where water movement is energetic. Divers approaching a school should maintain slow, non-threatening movements, as these fish often move in small to medium-sized groups above coral heads, rocky outcrops, or seagrass beds down to depths of 30 metres.

Pay close attention to subtle visual markings when attempting identification. Look for the pale, white-bordered streak running beneath the eye from the mouth to the gill cover, as well as the faint horizontal gold or bronze lines along the silver-grey body. Keep in mind that visual identification between the Bermuda chub (*Kyphosus sectatrix*) and the Yellow sea chub (*Kyphosus incisor*) underwater is widely acknowledged as impossible; exact species confirmation requires counting fin rays on a captured specimen. Enjoy watching their synchronized swimming along shallow reef margins.

Bermuda chubs are non-migratory reef residents found year-round across tropical and subtropical waters worldwide. Because they inhabit stable, warm marine environments from Florida, the Bahamas, and the Caribbean Sea to the Indo-Pacific and Eastern Atlantic, divers can expect encounters regardless of the month, provided regional diving conditions and sea states allow access to shallow reefs.

Seasonal surface conditions may dictate the best times to observe them in shallow surge zones or exposed reef flats where water clarity is critical. In regions subject to seasonal swells or winter storms, target calm weather windows when surge is minimal to comfortably explore shallow reef tops down to 30 metres. Additionally, floating mats of *Sargassum* weed drift across oceanic waters at various times of the year, carrying juvenile chubs that shelter beneath the weed rafts. These juveniles utilize floating vegetation to disperse across vast distances, making pelagic Sargassum drifts a unique location for floating surface encounters.

The Bermuda chub is a shallow-water species with a depth distribution extending from the surface down to approximately 30 metres. It inhabits a broad variety of coastal habitats, including coral reefs, rocky substrates, reef flats, seagrass beds, and sandy areas adjacent to reef structures. It is particularly well adapted to living in high-energy surge zones along the upper margins of shallow reefs where wave action washes over algal-covered rocks.

Geographically, *Kyphosus sectatrix* boasts a vast circumglobal distribution throughout tropical and subtropical seas. In the Western Atlantic, it ranges from Bermuda and the Sargasso Sea through Florida, the Gulf of Mexico, the Caribbean, and south to Brazil. In the Eastern Atlantic, records exist from the Azores, Canary Islands, Ascension, St Helena, Portugal, and the Mediterranean. Its range extends across the Indian Ocean to Indonesia and the Red Sea, and across the Pacific from southern Japan, Australia, and New Zealand to Hawaii, French Polynesia, and the Revillagigedo Islands.

Bermuda chubs are omnivorous grazers that feed primarily on plant material, with a strong dietary preference for benthic algae—especially brown algae. They graze actively across shallow reef tops, rocks, and seagrass beds, using their specialized J-shaped incisor teeth to scrape macroalgae and organic material off hard substrates. In addition to plant matter, their diet includes small benthic invertebrates such as small crabs and molluscs, which are ingested while foraging over rocky and sandy substrates.

These opportunistic feeders also adapt their foraging strategies to exploit novel food sources in their environment. Off the Fernando de Noronha Archipelago in the southwestern Atlantic Ocean, Bermuda chubs have been documented engaging in a unique feeding behaviour: picking out and consuming the faeces and vomit produced by spinner dolphins (*Stenella* spp.). Researchers suggest this behaviour represents a simple behavioural transition from picking drifting plankton particles out of the water column to targeting mammalian waste.