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Caribbean Monk Seal (Monachus tropicalis)

Status | Species Description | Habitat | Distribution | Population Trends | Threats | Conservation Efforts | Regulatory Overview | Taxonomy | Key Documents | More Info


Delisted from ESA - extinct

Species Description

375-600 lbs (170-270 kg) as adults;
Newborn pups  weighed 35-40 lbs (16-18 kg)
up to 8 ft (2.4 m) as adults;
Newborn pups were probably about 3 ft (1 m)
 brownish and/or grayish, fairly large, long, and robust body
fish and crustaceans
records suggest that they "hauled out" in large social groups of 20-40

The Caribbean monk seal, also known as the "West Indian" monk seal, is a phocid or true seal. It was last sighted in 1952 and is considered extinct. This species is related to (same genus, Monachus) the Mediterranean monk seal and Hawaiian monk seal. Both of these species are considered to be critically endangered.

Caribbean monk seals had a fairly large, long, robust body, and could grow up to about 8 ft (2.4 m) in length and weighed 375-600 lbs (170-270 kg). Males were probably slightly larger than females, which is similar to Mediterranean monk seals (Shirihai and Jarrett 2006). Like other monk seals, they had a distinctive head and face. Their head was rounded with an extended broad muzzle. Their face had relatively large wide-spaced eyes, upward opening nostrils, and fairly big whisker pads with long light-colored and smooth whiskers. When compared to the body, their foreflippers were relatively short with little claws and their hindflippers were slender. They were brownish and/or grayish, with the underside lighter than the dorsal area. Adults were darker than the more paler and yellowish younger seals. Caribbean monk seals were also known to have algae growing on their pelage, giving them a slightly greenish appearance, which is similar to Hawaiian monk seals.

Historical records suggest that this reclusive species may have "hauled out" at sites (resting areas on land) in large social groups (typically 20-40 animals) of up to 100 individuals throughout its range (Jefferson et al. 2008). The groups may have been organized based on age and life stage differences. Their diet probably consisted of fish and crustaceans.

According to historical records, Caribbean monk seals had a long pupping season, which is typical for pinnipeds living in subtropical and tropical habitats. In Mexico, breeding season peaked in early December. Like other monk seals, this species had four retractable nipples for suckling their young. Newborn pups were probably about 3.3 ft (1 m) in length and weighed 35-40 lbs (16-18 kg) and reportedly had a sleek, black lanugo coat when born (Jefferson et al. 2008).


Caribbean monk seals used to be found in warm temperate, subtropical and tropical waters of the Caribbean Sea, Gulf of Mexico, and the west Atlantic Ocean. They probably preferred to haul out at sites on isolated and secluded atolls and islands, but occasionally would visit the mainland coasts and deeper waters offshore. They may have fed in shallow lagoons and reefs.


Caribbean monk seals had a historical "endemic" widespread range throughout the Caribbean Sea, Gulf of Mexico, and west Atlantic Ocean.
In U.S. waters, they used to be found in the tropical West Atlantic, from the Florida Keys and along the coast up to the states of Georgia and South Carolina. In the Gulf of Mexico, their range included the north-east and southern portions (but not the northern and western areas).

They were also found on the east coast of Central America and north coast of South America. Guyana may have been the easterly extent of their distribution in South America. In the Caribbean, they were known to occur in the Greater and Lesser Antilles, Cuba, Jamaica, and other local waters (Shirihai and Jarrett 2006). Historical records indicate they had breeding grounds in the Bahamas and Yucatan, Mexico (Arrecife Triangulos). Their migration patterns and other movements are not known.

Population Trends

Despite broad and intensive surveys, this species has not been seen since the early 1950s. Sightings of Caribbean monk seals are occasionally reported, but these are most likely harbor seals, harp seals, or hooded seals that have ventured a long distance from their normal habitats.

In March 2008, we completed a five-year status review [pdf] of the species and concluded that the species is extinct. A final rule to delist the Caribbean monk seal from the ESA published in the Federal Register (73 FR 63901) on October 28, 2008.



Conservation Efforts

Even though the Caribbean monk seal has not been sighted alive since the early 1950s, it was still listed as "endangered" under the Endangered Species Act (ESA) from 1967 until 2008. In 2008, NMFS concluded that the species is extinct. The IUCN Red List of Threatened Species This link is an external site. also considers Caribbean monk seals to be "Extinct."

Regulatory Overview

The Caribbean monk seal was listed as endangered throughout its range on March 11, 1967 under the Endangered Species Preservation Act of 1966 (a predecessor to the Endangered Species Act of 1973). This species was then protected under the Marine Mammal Protection Act of 1972 as amended and the Endangered Species Act of 1973 from its listing in 1967 to its delisting due to extinction in 2008.

In March 2008, NMFS completed a five-year status review [pdf] of the species and, based on the best available information, concluded that the species is extinct. The review also recommended that the species be removed from the list of threatened and endangered species under the ESA. A proposed rule to delist [pdf] the species from the ESA published in the Federal Register (73 FR 32521) on June 9, 2008. The final rule to delist [pdf] the species published in the Federal Register (73 FR 63901) on October 28, 2008.


Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Phocidae
Genus: Monachus
Species: tropicalis

Key Documents

(All documents are in PDF format.)
Title Federal Register Date
Final Rule to Delist Due to Extinction 73 FR 63901 10/28/2008
Proposed Rule to Delist from the ESA 73 FR 32521 06/09/2008
5-Year Review n/a 03/07/2008
  • Initiation of 5-Year Review
71 FR 69100 11/29/2006
ESA Listing Rule 32 FR 4001 03/11/1967

More Information

Updated: January 15, 2015