The giant barrel sponge, also called the rum barrel, owes its name to its gigantic and characteristic shape, which resembles that of a barrel that in the Caribbean can only contain the local alcohol: rum !
The giant giant barrel sponge can be found in the Caribbean sea, notably in the 'Cousteau Reserve' in Guadeloupe !
The giant barrel sponge has a cylindrical shape, bulging in the middle. It is sometimes possible to encounter specimens that are less round but rather slightly flattened when the sponge develops in an area subject to currents.
Ranging in color from brown to reddish, the giant barrel sponge is hard and rough in consistency and its appearance resembles that of a « pumice stone ». Its outer surface is irregular and presents a succession of ridges and canyons. In contrast, the inner surface of the giant barrel sponge is smooth but equally rough !
The opening of the sponge, or osculum, usually has a serrated contour.
The size of the giant barrel sponge is imposing, with measurements—enough to make anyone pale!—of more than 6.5 feet in height for a diameter of 3.3 to 6.5 feet. A sponge that makes an impression !
It may sometimes present a secondary chimney when it is located in a current zone.
Geographic range
The giant barrel sponge can be found in the tropical waters of the western Atlantic ocean and the Caribbean sea, from Florida in the north to Brazil in the south, including the Bahamas islands. The « Cousteau Reserve » in Guadeloupe hosts a large population of giant barrel sponges.
Habitat
The giant barrel sponge develops on the rocky bottom of coral reefs from a depth of 33 feet and can extend to depths of over 328 feet.
Most often solitary, you will also have the opportunity to encounter several specimens grouped together.
Diet
The giant barrel sponge feeds on microorganisms contained in the water, which it filters throughout the day.
The outer surface of the giant giant barrel sponge has a particularly rugged but regular relief!
Impressive and fragile at the same time: the giant giant barrel sponge !
The base of the giant giant barrel sponge features several small chimneys !
Reproduction
The giant barrel sponge reproduces sexually by releasing male and female gametes into the water.
Did you know ?
A food source for some sea turtles, so don't be surprised to find giant barrel sponge specimens with bite marks near their openings !
Close-up of the smooth inner surface of the giant giant barrel sponge !
Imposing but fragile at the same time ! Preserve this sponge, as it is the largest species of sponge in the Caribbean sea !
A method for calculating the approximate age of a giant barrel sponge has been suggested, but what to think of the result obtained ? I'll leave that to your judgment !
The blueface angelfish is a very colorful fish of the tropical coral reefs of the Indo-Pacific, recognizable by its bright blue head and its bluish body finely reticulated with yellow.
Wednesday, February 18th 2026
The Atlantic tarpon
The Atlantic tarpon is a large coastal fish that can grow up to 8 feet long and weigh over 330 pounds, with a silvery body covered in large, reflective scales. Known as the Silver King, it is famous for its spectacular leaps and fierce fight when hooked by sport fishermen.
Friday, January 30th 2026
The dugong
Discover the dugong, a gentle “sea cow” of tropical waters. Learn about its habitat, diet, reproduction, morphology, and the threats facing this unique marine mammal.
