West Indian Manatee

Lore & Background

The West Indian manatee belongs to the order Sirenia, which became aquatic around 40 million years ago. The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, they had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly. The most primitive sirenian, †Prorastomus, was found in Jamaica, unlike other marine mammals which originated from the Old World. The first known quadrupedal sirenian was †Pezosiren from the early middle Eocene. The earliest known sea cows, of the families †Prorastomidae and †Protosirenidae, were both confined to the Eocene, and were pig-sized, four-legged, amphibious creatures. The first members of Dugongidae appeared by the middle Eocene. At this point, sea cows were fully aquatic. Marine mammals were first hunted by aboriginal peoples for food and other resources. Commercial hunting led to the extinction of the Steller's sea cow, a sirenian. Other than being hunted, marine mammals can be killed as bycatch from fisheries, where for example they can become entangled in nets and drown or starve. Increased ocean traffic causes collisions between fast ocean vessels and large marine mammals. Habitat degradation also threatens marine mammals and their ability to find and catch food. Noise pollution may adversely affect echolocating mammals, and the ongoing effects of global warming degrade Arctic environments.

In Their Own Story

In the warm, shallow waters of the Caribbean and Gulf Coast, a West Indian manatee glides slowly through seagrass meadows. It feeds on seagrass and freshwater aquatic plants, consuming large quantities daily. As a fully aquatic mammal, it never leaves the water, surfacing regularly to breathe. It is a member of the family Trichechidae, one of three species of manatees. The manatee's presence is a sign of healthy seagrass ecosystems, which it helps maintain by grazing. However, it faces threats from boat collisions, habitat degradation, and bycatch in fisheries. Conservation efforts are critical, as the species is currently listed as Vulnerable.

Reader's Guide

The West Indian manatee is found in warm coastal waters, estuaries, rivers, and springs throughout the Caribbean, Florida, and parts of Central and South America. It requires warm water temperatures and is often found in areas with abundant aquatic vegetation. Its diet consists primarily of seagrasses and freshwater aquatic plants. As a fully aquatic species, it is an obligate water dweller, spending its entire life in the water. It is a slow-moving herbivore that plays a key role in maintaining marine ecosystems by regulating the growth of seagrass and other aquatic plants. The manatee is vulnerable to threats such as boat strikes, habitat loss, and pollution. Conservation measures include protecting critical habitats and enforcing speed zones in waterways.

Did You Know?

• The West Indian manatee is a sirenian, or sea cow, and is fully aquatic, spending its entire life in the water.
• Sirenians became aquatic around 40 million years ago, with the first appearance in the fossil record during the early Eocene.
• The most primitive sirenian, †Prorastomus, was found in Jamaica, unlike other marine mammals which originated from the Old World.
• Commercial hunting led to the extinction of the Steller's sea cow, a relative of the West Indian manatee.
• Marine mammals can be killed as bycatch from fisheries, where they can become entangled in nets and drown or starve.