Blue Zoo: Goliath Grouper
Featuring one amazing marine animal per week.
The Atlantic goliath grouper (Epinephelus itajara) is a massive fish that can reach 2.5 meters (8 ft) long, weigh 360 kilograms (almost 800lbs), and reach 30 years old! It’s found throughout much of the tropical Atlantic, including the Gulf of Mexico, Caribbean, coast of Brazil, and parts of West Africa.
Because of their size and the quality of their meat, groupers were a favorite target for both sport and commercial fishermen. There were hunted to the verge of extinction, and were commercially extinct by the late 1980s. Finally, they were recognized as a critically endangered species and have been fully protected in the US since 1990, and in the Caribbean since 1993. So far, it looks like the protections are helping the population recover, but since the fish is slow to grow and reproduce, a full recovery will take many more years.
Goliath groupers may swim hundreds of miles to reach spawning sites. Other than that, they are territorial and spend most of their lives in a very small area. In fact, the Aquarius Reef Base has its own resident grouper!
When they feel threatened, they defend their territory with a loud booming sound, which they are famous for.
According to Mark Patterson, a marine biologist and aquanaut, this noise probably occurs when a grouper rapidly expands its mouth and causes suddenly decreased pressure, called a cavitation bubble. For a split second during this event, the water inside the fish’s mouth turns to vapor and may become hotter than the surface of the sun! When the bubble collapses, it makes a sound so loud it can be felt inside a nearby diver’s chest!
Photo by Albert Kok via Flickr, Wikimedia Commons.