Decoding The Life Cycle of Manta Rays – and Our Role in Their Survival

Manta rays are among the ocean’s most enigmatic creatures. With wingspans reaching up to 7 meters (23 feet), they glide through the waters with grace and ease. But beyond their physical allure lies a complex life cycle intricately tied to the health of marine ecosystems. 

From their early days as pups to their solitary lives, every stage of a manta ray’s life is a testament to the wonders of nature and the importance of conservation.

The Birth of a Manta Ray Pup

The life cycle of manta rays begins in the open ocean, where females give birth to live pups after a gestation period of over a year. Unlike many marine creatures, manta rays do not lay eggs; instead, they give birth to fully-formed pups that are miniature versions of their parents.

This mode of reproduction, known as ovoviviparous, ensures that the young have a higher chance of survival in the vast and predator-filled oceans. 

→ Curious about manta ray reproduction and pregnancy? Read more about it here!

Born with their wings rolled up (like a burrito!), pups quickly unfurl them to begin their lives in the water. Check out the fetal folds of baby Kamala Ray here.

Born to Glide: Early Life

Newborn manta rays are independent from birth and equipped with the skills to navigate the complexities of the ocean. Manta rays do not seem to care for their pups once they are born.

Big Bertha Ray, one of the regulars on the moonlight swim, has been pregnant many times since she was identified in 1992; on two different occasions after giving birth, shortly after, we saw new pups: Vinny was identified in 2006, and Nick in 2011.

There is no concrete proof that Big Bertha is the mother of Vinny or Nick other than their similar markings (refer to the picture below). They were often seen together at the Manta Airport location, but this setup is all about food. There is no evidence that they hung out together after leaving the site. 

This story reinforces the idea that mantas are solitary creatures right after birth.

Young mantas must learn to find food and avoid predators, a task made increasingly difficult by human impacts on the ocean.

Lifestyle: Reef Mantas vs Pelagic (Giant) Manta Rays

From birth, the lifestyle and behavior of the two species of manta rays (pelagic and reef manta) differ completely.

As the name indicates, reef manta rays stay close to the ocean reefs. Several Kona manta rays call the West Coast of the Big Island their “home” (Lefty for 37 years, Big Bertha for 32+ years) and have proven that they could cover 20-40 miles of distance swimming within 2-3 days. Other Kona mantas have been seen once only or twice in 15 years (Lehua Ray). Jolene Ray is also a great example of how she has covered a distance of 40-50 miles when she was sighted in Kauna’oa Bay and 48 hours later at the Kona airport location.  

However, the more mysterious pelagic mantas embark on long migrations spanning thousands of miles. Their migratory patterns are still an enigma, but researchers believe they are influenced by ocean currents, water temperature, and plankton availability, their primary food source.

Human activities have begun to alter the routes and behaviors of manta rays. Overfishing depletes their food sources, while pollution and climate change disrupt the delicate balance of their marine habitats. These challenges highlight the importance of understanding and protecting manta rays, not only for their sake but for the health of the entire ocean.

Threats and Conservation

Manta rays face numerous threats from human activities. 

• Manta rays are regularly found entangled in fishing nets or injured by hooks and other fishing gear.
• Mantas are hunted for their gill plates, which are highly valued in some branches of traditional medicine. 
• Pollution and global warming have a severe impact on the fragile marine ecosystem. 
• The increase in marine traffic poses a threat to their well-being.
• And last but not least, manta ray tourism is becoming more dangerous for manta rays year after year.

Conservation efforts are crucial for the survival of manta rays. 

Protected marine areas, responsible marine tourism, and stricter fishing regulations are among the measures that can help safeguard these majestic creatures. By supporting such initiatives, we can ensure that manta rays continue to grace our oceans for generations to come.

How Old Can Manta Rays Get? What’s their Life Expectancy? 

We don’t know for sure, as manta rays are hard to track, but we believe they can live up to 50-80 years if human threats do not thwart them. Lefty Ray was one of the oldest reef manta rays we personally knew; she was first identified in 1979. 

Lefty survived at least one nasty encounter with a boat propeller that left her scarred, and she sustained a paralyzed cephalic fin from a different accident, so, amazingly, she made it that far. We don’t know what happened to her after April of 2016. 

Manta rays do not have many natural predators besides humans; sharks are their main (and possibly only) real threat in the marine ecosystem.

Why Mantas Matter

The life cycle of manta rays mirrors the health of our oceans. These gentle giants play a vital role in marine ecosystems, serving as indicators of ocean health. Protecting them is not just about preserving a single species; it’s about ensuring the vitality of the marine environment as a whole.

For those who have experienced the joy of swimming with manta rays, their protection is a personal endeavor to ensure that future generations can also experience the ocean’s wonders.

By understanding and protecting the life cycle of manta rays, we take a step towards a more sustainable relationship with our planet’s blue heart.