July 8, 2025
Species Spotlight: Giant Manta Rays
BY: Maya Lozinsky
Manta rays consist of two species: reef manta rays (mobula alfredi), and their larger, more elusive counterparts, giant manta rays (mobula birostris). Today’s blog spotlights the giant manta ray, the true titan of the open ocean.
DISTRIBUTION
Manta rays live in most tropical, subtropical, and temperate waters of the world. These large swimmers can be found in both coastal and oceanic waters up to a depth of 1,000 meters. They’ve been observed in waters as cold as 66° F, and as warm as 86° F. Notably, although the population of giant manta rays is sparsely distributed, a large concentration of the population has been observed off the coast of Ecuador.
SIZE & REPRODUCTION
Manta rays are elasmobranchs, a category of fish which include sharks, rays, and other cartilaginous fish – meaning, their skeletons are made of cartilage instead of bone. Giant manta rays, sometimes referred to as oceanic manta rays, are the world’s largest rays and can grow a wingspan of up to 26 feet and can weigh over 5,000 lbs. The name of the manta ray is inspired by their vast size and comes from the Spanish word for blanket: manta. The spots found on their belly – properly known as a ventral surface – are unique to each manta, like fingerprints are to humans! These creatures grow very slowly and produce one pup every 4-5 years on average. Some sources report that giant manta rays can live for up to 20 years.
DIET
Manta Rays are filter feeders: they obtain food by taking in surrounding water through their large mouths and filtering food particles and organisms. Giant manta rays have two protruding structures in the front of their mouths called cephalic lobes, which help channel water into their mouths. The water glides over their gill plates which are located in the back of their mouths and food gets trapped in their built-in ‘filters,’ made of tissue that stretch between their gills. Because of this, manta rays don’t actually use their teeth while they feed! Giant manta rays are migratory animals and may migrate to follow the movement of zooplankton, their main source of food. Manta rays have also been observed consuming copepods, mysids, decapod larvae, shrimp, and small to moderately sized fish.
THREATS
According to the International Union for Conservation of Nature, manta rays have been endangered since 2019. Manta rays are caught by both industrial fishers as bycatch and artisanal fishers for trading. In some countries, manta rays are targeted for fishing because of the high demand for their gill plates. Giant manta rays are easily targeted due to their large size, slow swimming speed, and predictability. Furthermore, these species are especially susceptible to population depletion due to their slow reproduction rate.
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