Marine Life & Conservation Blogs
Creature Feature: Butterfly Rays

In this series, the Shark Trust will be sharing amazing facts about different species of sharks and what you can do to help protect them.
As we’re currently in butterfly season, this month we decided to concentrate on the Butterfly Rays!
Within the family Gymnuridae, there are two genera and 12 species of Butterfly Ray. These species are morphologically different to lots of other rays because of the width of the disc and pectoral fins – in contrast to many other species of Butterfly Ray, their bodies are much wider than they are long, especially considering their very short tail. This gives them the appearance of gliding or flying across the sand.
Gymnura altavela – Spiny Butterfly Ray
Gymnura australis – Australian Butterfly Ray
Gymnura crebripunctata – Longsnout Butterfly Ray
Gymnura japonica – Japanese Butterfly Ray
Gymnura lessae – Lessa’s Butterfly Ray
Gymnura marmorata – California Butterfly Ray
Gymnura micrura – Smooth Butterfly Ray
Gymnura natalensis – Backwater Butterfly Ray
Gymnura peocilura – Longtail Butterfly Ray
Gymnura sereti – Seret’s Butterfly Ray
Gymnura tentaculata – Tentacled Butterfly Ray
Gymnura zonura – Zonetail Butterfly Ray
Today we’re taking a look at Gymnura altavela, the Spiny Butterfly Ray. Like all Butterfly Rays, the Spiny Butterfly Ray is a demersal species, meaning it spends the majority of its time on the bottom of the seabed. Butterfly Rays are known for their burying behaviour in the sand, a technique they use to camouflage themselves when they are resting during the day. This protects them from predators, in some areas larger sharks. It also aids them in their ambush hunting technique – by hiding themselves under the sand they are able to easily snatch up their dinner – usually crustaceans, molluscs or other small fish – as they swim by unawares. This behaviour can leave tell-tale butterfly-ray shaped imprints in the bottom of the seabed.
Spiny Butterfly Rays can grow up to 260 cm (disc width (wingspan)), although average is around 200 cm. They give birth to live young, and each litter consists of 1-8 pups. This species has also been found to aggregate, likely for mating. One study found that aggregations of primarily females in the coastal regions off Gran Canaria may correlate with the shifting water temperature.
It is estimated that the species has undergone a population reduction of 50-79% over the last 33 years. This is primarily due to fishing pressure – the Spiny Butterfly Ray is targeted and bycaught in both industrial and artisanal fisheries types using a variety of gear types. The species is now Critically Endangered in the Mediterranean and Southwest Atlantic.
Scientific Name: Gymnura altavela
Family: Gymnuridae
Maximum Size: 260 cm (disc width)
Diet: crabs, shrimps, various invertebrates, fishes, small crustaceans, and molluscs.
Distribution: throughout the Atlantic and Mediterranean and Black Seas.
Habitat: muddy and sandy substrates down to 150m.
Conservation status: Critically Endangered in the Mediterranean and Europe, Endangered Globally.
For more great shark information and conservation visit the Shark Trust Website
Banner Image: ©Tomas Willems. Main image: ©Andy Murch
Marine Life & Conservation Blogs
Shark Trust Expedition Dives in The Bahamas

In our last blog we talked about why the Shark Trust had been in The Bahamas in December. With the underwater part of the expedition focused on getting 360 footage for a new immersive shark experience, OneOcean360: A Shark Story, that will be launched later this year. Now, let’s tell you a little bit more about the diving we did, along some more surprising shark sightings!
The Shark Trust 3-island expedition, which was fully funded and supported by the Bahamas Ministry of Tourism, started in Nassau. And we were booked to do 2 days of diving with Stuart Cove’s Dive Bahamas. We packed in as much diving as possible, leaving as soon as the boat was loaded and returning as the sun was setting, covering 7 dive sites over the 2 days, with a mix of reef and wrecks to ensure we got as much varied footage as possible.
Pumpkin Patch saw us hang out with a very chilled turtle while Caribbean Reef Sharks swam along the drop off beside us. We visited a “wreck” structure built for the filming of a James Bond film that was now covered in bright corals and home to a multitude of reef fish. Steel Forest saw us diver some “proper” wrecks that have been sunk alongside each other. Glass fish swirled under overhangs and larger fish hung motionless in the wheelhouse. Southern Sting rays lay buried in the sandy seabed alongside. Our final dive of the day, as the sun started to set, Ridges, combined a reef and wreck where we caught a fleeting glimpse of a Bull Shark as we ascended the line. It was a great diving day that gave us the perfect introduction to the underwater world of The Bahamas.
Our second day was going to focus on getting close up footage of Caribbean Reef Sharks on both wrecks and reef. The Ray of Hope and Big Crabs wrecks are perfect for this. With our guide placing bait boxes inside the wrecks to attract the sharks, and with our cameras setup on the wreck structure, we could back away and let the sharks do their thing without us disturbing them or being in the 360 filming frame. With clear water and plenty of sharks, the footage we came away with in pretty striking.
Next stop: Bimini. Great Hammerhead Sharks are the number one attraction here. And we were able to join Neal Watsons Bimini Scuba for a 2-tank dive with these magnificent sharks, along with the Nurse Sharks that like to join in with the experience. But we were also able to snorkel with juvenile Lemon Sharks in the Mangroves, see Bull Sharks and spotted eagle rays from a submarine experience and from the dock side. Our second day of diving saw us dive the SS Sapona wreck and then experience the Caribbean Reef Sharks on the reef. Bimini really does allow you to pack in a load of shark and ray experiences in a short space of time.
Finally, we headed to Grand Bahama. Whilst much of our time was spent above the water meeting people working to conserve different marine habitats (watch this space for more information on this) – we did manage to squeeze in a couple of dives on the reefs here and were delighted to see both Caribbean Reef Shark and Southern Stingrays on both. Our final shark and ray experience saw us take a tour to Sandy Cay with Keith Cooper. We were able to get footage of stingrays, lemon and blacktip reef sharks on the seagrass and over the sandy seabed. Sometimes just in ankle deep water.
If you are heading to the Go Diving Show – then you will be able to see a short 360 film, using our VR headsets, that shows many of these experiences. Please come and say hello to the Shark Trust team on the Diverse Travel stand (340). We will also be on The Bahamas stand twice a day to chat to people about our experiences on the islands. And Diverse travel will have special offers on travel to The Bahamas should you want to follow in our fin-kicks.
To find out more about the work of he Shark Trust and how you can support us, visit out website www.sharktrust.org
Blogs
Evolution of Manatees in Florida

Op-ed by Beth Brady, PhD, Senior Science and Conservation Associate, Save the Manatee® Club
Recent news articles and broadcasts have claimed that manatees are not native to Florida or only arrived on Florida’s west coast in the 1950s. These claims, based on limited anthropological records, point to where manatees were historically exploited by humans and assume that a lack of evidence means manatees were absent from certain areas. However, absence of evidence is not evidence of absence—it’s like looking for stars in the daytime; just because you can’t see them doesn’t mean they’re not there. Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.
The Florida Fish and Wildlife Conservation Commission (FWC), which manages Florida manatee populations, has created a manatee timeline highlighting key dates and notable information about manatee presence in Florida (https://myfwc.com/education/wildlife/manatee/timeline/). Historical records suggest that manatees have been observed in Florida as far back as the 1500s, with some details presented by the Florida Fish and Wildlife timeline aligning with evidence presented in the publication.
Manatee species, such as the African manatee and the Antillean manatee, continue to be poached by humans (Marsh et al., 2022). As a result, these species are difficult to observe in the wild and may adapt by foraging at night to avoid human encounters (Rycyk et al., 2021). This behavior could help explain why historical Florida manatee populations that were hunted by humans are absent from middens and rarely mentioned in historical accounts.
Further, the publication only briefly touches on the paleontological record and genetic evidence, which indicate that manatees have existed in Florida for a much longer period. Fossil and genetic evidence reveal a rich history of manatees in Florida. Manatees belong to the order Sirenia, which includes the Amazonian, African, and West Indian manatee species. While Sirenian fossils have been found globally, only Florida and the Caribbean contain specimens from every epoch over the past 50 million years (Reep and Bonde, 2006). The modern manatee, as we know it, emerged in the Caribbean about 2 million years ago (Domning, 1982).
The evolution of manatees during the Pleistocene epoch provides valuable insights into how environmental changes shaped their distribution and genetic diversity. During the Pleistocene epoch (2.59 million to 11,700 years ago), there were roughly 20 cycles of long glacial periods (40,000–100,000 years) followed by shorter interglacial periods lasting around 20,000 years. At the start of these warmer periods, Caribbean manatees migrated northward with the warming waters (Reep and Bonde, 2006). Water currents and thermal barriers isolated these manatees from populations in Mexico and the Caribbean, leading to genetic divergence. Fossil evidence indicates that Trichechus manatus bakerorum lived in Florida and North Carolina about 125,000 years ago but did not survive the last glacial period, which began 100,000 to 85,000 years ago (Domning, 2005). This subspecies was eventually replaced by modern Florida manatees.
This evolutionary theory is further supported by genetic evidence. Research indicates that Florida manatees trace their evolutionary origins to Caribbean ancestors that migrated northward over the past 12,000 years (Garcia-Rodriguez et al., 1998). A 2012 study by Tucker et al. reinforces this theory, showing higher genetic diversity in manatees on Florida’s west coast compared to those on the east. Over time, core populations migrated northward, with some groups moving south and east along the Florida coastline before heading north along the Atlantic. This migration pattern left the west coast population with greater genetic diversity, while the east coast population retained only a smaller subset. These findings suggest that the founding population of Florida manatees—arriving approximately 12,000 years ago—originated along Florida’s southwestern coast, which became the center of the state’s manatee population (Reep and Bonde, 2006). The process of vicariance further supports this hypothesis; as geographic and ecological barriers emerged, they likely isolated the Florida manatee populations from their Caribbean ancestors. This isolation likely limited migration back and forth between regions, fostering the establishment of local populations in southwestern Florida.
Manatees are not only a cherished symbol of Florida’s natural heritage but also a species with deep evolutionary and historical ties to the region. In sum, despite recent claims questioning their nativity, extensive fossil and genetic evidence confirms that manatees have been present in Florida’s waters for thousands of years, with ancestors dating back over 12,000 years. We agree with the authors of the published article that protecting these iconic creatures and their habitats is essential to preserving Florida’s unique ecological identity for future generations
Beth Brady is the Senior Science and Conservation Associate at Save the Manatee Club whose work focuses on manatee biology and conservation. She has her PhD from Florida Atlantic University and her Master’s in Marine Science from Nova Southeastern University.
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