Guide to Bull Rays (Aetomylaeus bovinus)

A bull ray in South Tenerife at Bufadero dive site
A bull ray gliding through Bufadero in South Tenerife. Photo by Espe Kanela.

What is a Bull Ray? How can I identify one?

Bull rays are sting rays and thus are part of the subclass called elasmobranchii, which means that they are grouped with sharks, rays and sting rays as they are all considered cartilaginous fishes!

The name bull ray comes from the fact that its head is long, flat and has a rounded snout (in Africa they call them duckbill rays!). These fantastic creatures live for roughly 14 years and ranging from 29.5cm to 129.2cm in size.

They are easy to spot due to their bright blue lines on their backs which in fact acts as their thumb print! Each bull ray has a unique pattern on their back that allows organizations such as Sharklab-Malta to track the population and migration pathways!

Read More: Ultimate Guide to Rays

Where Can You Find Bull Rays?

Juvenile bull rays (such as the ones I worked with) love the shallow sandy shores of roughly 10–15m (31-50ft) deep, whereas adults can reach a depth of 65m (213ft)!

Bull rays can be found in the Mediterranean Sea, the Black Sea and off the coast of South Africa, unfortunately, the full distribution of bull rays is still unknown.

Are Bull Rays Aggressive?

Just like all animals, they must be treated with respect and to keep you and the bull rays safe from harm, do not swim close to them nor from behind as they will become defensive and could strike you with their barb (a sharp strong needle like structure attached to their tails). They are not aggressive by nature but when they feel threatened, they will try and protect themselves!

This however, does not mean you cannot dive with them! They are fantastic creatures to see in the wild and I encourage you to see their beauty!

Read More: Top 10 Most Dangerous Marine Animals 

Bull Ray found in Malta. Image: Nouska Smith
A Bull Ray gliding along the sandy floor. Image: Nouska Smith

Threats to Bull Rays

Unfortunately, bull rays are critically endangered, and are targeted by locals as a form of sport and consumption (even though they are not tasty nor hold a lot of meat), as well as having their habitats destroyed by trawling, fisheries, pollution, etc.

They are often caught as by-catch meaning they are non-targeted fish yet are caught by large nets and die within these nets causing their unstable population to decrease.

Read More: How Does Ocean Pollution Affect the Environment? 

Bull Ray Diets

Bull rays spend most of their time feeding on the sandy sea bed and water columns and hunt for various invertebrates such as crabs, hermit crabs, squids, prawns and mollusks! When they want to reproduce, (the males and females have to be roughly 100cm (40 in) in size to be mature enough for reproduction) they migrate to shallower waters and produce an average of six offspring. There, these juvenile bull rays grow and learn the way of life with the protection of the coastal zones!  

I hope that this has inspired you to find these fantastic creatures on your next snorkel or dive and see them in their full glory! It is time to spread the word on these threatened species and keep them present for all future generations to see and enjoy! 

For additional information, here are some links to research papers and websites:

BAŞUSTA, N., & ASLAN, E. (2018). Age and growth of bull ray Aetomylaeus bovinus (Chondrichthyes: Myliobatidae) from the northeastern Mediterranean coast of Turkey [Ebook].

Moreno, J., Solleliet-Ferreira, S., & Riera, R. (2021). Distribution and Abundance of Coastal Elasmobranchs in Tenerife (Canary Islands, NE Atlantic Ocean) with Emphasis on the Bull Ray, Aetomylaeus bovinus. Thalassas: An International Journal Of Marine Sciences. doi: 10.1007/s41208-021-00316-1

Akyol, O., Aydın, I., El Kamel-Moutalibi, O., & Capapé, C. (2017). Bull ray,Aetomylaeus bovinus(Geoffroy Saint-Hilaire, 1817) (Myliobatidae) in the Mediterranean Sea and captures of juveniles from Izmir Bay (Aegean Sea, Turkey). Journal Of Applied Ichthyology, 33(6), 1200-1203. doi: 10.1111/jai.13420

I had the joy of working with Bull rays (Aetomylaeus bovinus) in Malta with Sharklab-Malta as part of my work experience for my marine biology course! I gained lots of knowledge about them on the way and would love to share with you want I know and how you could spot them when you are snorkeling or diving around the beaches in Europe or even on the coasts of Africa!