Elasmobranch A-Z (Part 2: Q-Z)

Q is for...Questions! We know a fair amount about the sharks, skates & rays in our local waters however there are still a few unanswered questions.

For example, why does a Basking shark breach? Breaching is when a marine species rises and break through the waters surface. Basking sharks are thought to do this to remove parasites. However, some theories suggest they may also be doing this to compete during courtship! But the official reason still remains a mystery!

If you have any questions about local shark and skate species let us know and we will do our best to answer them for you 🦈

R is for.... (blonde) Ray! Many skates in our local seas are referred to as rays. This is because historically many were named on appearance (with rays and skates looking similar at first glance). On closer inspection many of these 'rays' had the distinguishing features that actually make them skates. For example, skates have slightly thicker tails and are oviparous, meaning they lay eggs.

One of these species is the Blonde ray! The blonde ray is a larger skate species that lives on the seabed, preying on species such as crabs and cuttlefish 🦀🦑

This species is categorised as Near Threatened on the IUCN red list. The Sea Deep project has collected data on these species, tagging 6 individuals and collecting 22 egg cases! With this invaluable data we can understand how the Blonde ray is using are waters and implement protection measures to safeguard this species for the future!

S is for...Spotted ray! The spotted ray is one of the smaller skate species found in our local waters. They measure on average 80cm in length and weigh 4.5kg.

They can be identified by their spotted markings along the top of their back and wings, yet these spots do not extend to wing tips. This can be a key distinguishing feature between the spotted ray and the blonde ray which is also covered in a spotted pattern, however the blonde ray has spots that extend to the tips of their wings.

Spotted rays lay roughly 60-70 egg cases a season! These are the most recorded skate eggcase in the Sea Deep project.

T is for... Thornback ray! Named after the thorny bucklers that run down its spine, the thornback ray is a species found in our local waters.

On average they measure 140 cm in length and weigh up to 18kg.

They are one of the more common species of skate found in our waters, with 44 individuals having been tagged by our volunteer anglers and 90 thornback egg cases having been found and recorded by the Sea Deep project.

This data helps us understand how the thornback ray uses our local seas. With this information we can advocate for effective measures to protect the sharks and skates in our waters, safeguarding them for future generations.

U is for...Undulate ray! The Sea Deep project has found 6 undulate ray egg cases around our coasts, however we have no tag records of the species from our volunteer anglers. This suggests that the undulate ray is either very rare in our waters or might not live in our local seas at all 🌊

Undulate rays prefer the warmer waters off the south coast of the British Isles. An increase in undulate rays in NI waters in the future would suggest our waters are increasing in temperature, allowing the undulate ray to expand their range northwards. Therefore, this species may be an important indicator species for the impacts of climate change in our local environment. This highlights why it's important to monitor trends of sharks and skates around our coasts.

V is for... Viviparous! One method for which sharks reproduce is viviparous reproduction. This involves shark young developing inside the mother, being fed by a placenta which transfers nutrients and oxygen. The shark then gives birth to live young!

Sharks in our local waters that display viviparous reproduction include the Porbeagle, which can be pregnant for an average 8-9 months before giving birth to live shark pups 🦈

W...Why are many shark species in our waters endangered and What can we do to conserve them?

Historically, overfishing of sharks and skates in our waters resulted in species declines. In addition to this, certain shark and skate life history characteristics (long pregnancies and small litter sizes) make it difficult for populations to recover.

With the support of our volunteer anglers and the general public, Sea Deep is working to collect data on our local shark and skate species through our NI wide tagging programme and shark egg case surveys. These activities allow us to understand what species we have around our coastline and how they are using our local waters.

With this information we can advocate for increased protection for our most vulnerable species through conservation measures such as MPA's (marine protected areas). These areas will allow populations to recover and therefore safeguard our sharks and skates for future generations.

X is for... eXtreme adaptations! Sharks, skates and rays have some amazing adaptations that allow them to survive in their preferred habitats!

For example, skates have adapted to hunt effectively on the seabed. Skates bury themselves in the sand before ambushing their prey. As their gills are positioned on their underside, they have additional respiratory organs called spiricles (positioned behind their eyes) that allow them to intake oxygen when hunting.

Y is for... whY are sharks important? Sharks are apex predators. They sit at the top of many marine food webs, helping maintain a healthy and balanced marine environment 🦈

Therefore healthy shark populations = healthy seas 🌊

At Sea Deep, we are working to conserve local shark and skate populations through our tagging programme! By tagging individual sharks and skates, our dedicated volunteer anglers help us monitor these species so we can put in place effective conservation measures that will safeguard them for future generations and also maintain the health of our seas.


Z is for...Zooplankton! For our final A-Z shark post we are going to talk about zooplankton.

Zooplankton are microscopic organisms that, along with phytoplankton, make up the base of marine food webs. They're also a favourite food of the largest shark that visits our local seas... the Basking shark!

In the warm summer months Basking sharks will be found 'basking' at the sea surface, consuming large blooms of plankton. They filter the zooplankton from the water using their gill rakers.

The largest shark in our seas is therefore supported by the smallest of organisms, showing that the smallest of things really do make a big difference. By getting involved with Sea Deep, even in the smallest of ways, you will be making a massive difference for sharks and skates in our waters.