Manta Rays (Manta spp.)


CITES Status | Taxonomy | Description | Habitat | Distribution | Threats

 

CITES Status

oceanic-whitetip-shark

Giant Manta Ray, Credit: Copyright © Brian Skerry

Proposed by Brazil, Colombia and Ecuador for listing in Appendix II at CoP16.

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Rajiformes
Family: Mobulidae
Genus: Manta
Species: spp.

Manta rays were split into two species in 2009:

  • Manta alfredi (added in 2009)
  • Manta birostris

Additionally, a third species in the Caribbean may soon be declared.

This page includes information on all the Manta species.

Description

Weight: M. birostris: up to 5,300 pounds (2,400 kg)
M. alfredi: up to 3,000 pounds (1,350 kg)
Length: M. birostris: 25 feet (8 m)
M. alfredi: 15.5 feet (5 m)
Appearance:  large diamond-shaped body with black backs and a mostly white belly, some have species- and individual-specific black markings
Lifespan: about 40 years; they reach sexual maturity at 10 years
Diet: plankton
Behavior: Gestation is thought to last 10-14 months, and they typically give birth to one pup every 2-3 years.

Manta rays are slow-growing, large-bodied migratory animals with small, highly fragmented populations that are sparsely distributed across the tropics of the world. They are characterized by their large diamond-shaped body with elongated wing-like pectoral fins, ventrally placed gill slits, laterally placed eyes, wide terminal mouths, and paired cephalic lobes (making them the only vertebrate animals with 3 paired appendages).

Manta rays have among the lowest "fecundity" of all elasmobranchs (a subclass of cartilaginous fish), typically giving birth to only one pup every two to three years (or longer in some subpopulations) after reaching maturity at 10 years on average. Gestation is thought to last 10 to 14 months.

Habitat

Manta spp. are pelagic planktivores. Manta birostris is thought to be a seasonal visitor along productive coastlines with regular upwelling, in oceanic island groups, and near offshore pinnacles and seamounts. They visit cleaning stations on shallow reefs, are sighted feeding at the surface inshore and offshore, and are also occasionally observed in sandy bottom areas and seagrass beds. Manta alfredi are commonly sighted inshore, but are also observed around offshore coral reefs, rocky reefs and seamounts. This species is often resident in or along productive near-shore environments, such as island groups, atolls, or continental coastlines, and may also be associated with areas or events of high primary productivity (e.g., upwelling).  Manta birostris has longer migration distances and is more solitary than M. alfredi, though they can aggregate to feed or mate. The third species exhibits similar habitat preferences to M. alfredi.

Distribution

Manta spp. are circumglobal in range, with the two described species overlapping in some locations. Manta birostris is the more widely distributed, inhabiting tropical, subtropical, and temperate waters, while M. alfredi is found in tropical and subtropical waters. The third putative species appears to be a regional endemic limited to the Gulf of Mexico, the Caribbean, and along the eastern coast of the United States.

Threats

  • targeted fisheries
  • bycatch

The prebranchial appendages (or gill plates), which Manta spp. use to filter planktonic food from the water, are highly valued in international trade for use in traditional medicine. Cartilage and skins are also traded internationally while meat is consumed or used for bait locally. A single mature M. birostris can yield up to 15.5 pounds (7 kg) of dried gills that retail for up to $680 per kilo in China.

Manta rays are caught throughout their global warm water range in the Atlantic, Pacific, and Indian Oceans in commercial and artisanal fisheries. Fishermen targeting Manta rays primarily use harpoons and nets, while significant manta bycatch occurs in purse seine, gillnet, and trawl fisheries targeting other species.  Alterations to terrestrial ecosystems have also been shown to affect Mantapopulations. At Palmyra Atoll in the Pacific, a study linked declines in the manta rays' planktonic food source to areas where native trees have been replaced by cultivated palms.

Additional Information

The United States strongly supports shark and manta ray proposals and applauds the leadership of the proponent countries. What are the benefits of listing a marine species in CITES appendix II? Click here to learn more.

Read more about the manta rays at the following links: