Sometimes called the 'couch potatoes of the sea', nurse sharks are famous for their laid back attitude to life spending most of their days cosied up in piles, napping. But their gentle, docile nature doesn't make them any less special. In this episode, we sit down with SOSF project leader and PhD Researcher Sergio Madrigal Mora - who has spent a lot of time hanging out with the Labradors of the shark world - to discuss how nurse sharks are perfectly adapted to life in the tropics and why they form 'cuddle huddles' on the sea floor. And, we learn more about Sergio's research into the influence of changing temperatures on the movements of Pacific nurse sharks in Costa Rica's St Elena Bay.

Shownotes: www.saveourseas.com/worldofsharks/podcast

You can follow Sergio on Instagram: @sergiomm_77 or @tiburones_ucr. You can find us across all platforms as @saveourseasfoundation.

Papers mentioned in this episode: https://www.int-res.com/abstracts/meps/v750/meps14733, https://www.sciencedirect.com/science/article/pii/S0022098125000589, https://connectsci.au/mf/article/75/2/MF23162/61130/Long-distance- dispersal-of-the-endangered-Pacific

We know sharks have incredible senses, but just how good is their eyesight? In this episode, we explore the world through a shark's eyes with fish vision expert Dr Lily Fogg. How does fish vision compare to our own? How do the eyes of a fish living on a vibrant coral reef differ from those hanging out in the murky depths? And do sharks see in technicolour, or multiple shades of grey?

We also take a dive deep into Lily's most recent research, which investigated the eyes of the world's longest living vertebrate: the greenland shark. Her findings challenge a commonly held perception of these ancient creatures, and push the boundaries of what we thought was physiologically possible...

Shownotes: www.saveourseas.com/worldofsharks/podcast

You can read the full study on greenland shark vision here: https://www.nature.com/articles/s41467-025-67429-6

You can find SOSF on social media by searching for @saveourseasfoundation across all platforms.

To kick off our new season, we're diving into our mailbag to answer your burning questions! From speedy sharks to mimicry and even fossilised shark poop, we're leaving no stone unturned...

Thank you to everyone who sent in a question - we had so many we ended up doing two episodes! Part 2 will be out later in the season.

Questions answered (with timestamps):

• 04.54: Do any sharks, other than megamouth sharks, use mimicry?
• 14.15: Are megamouth sharks regional endotherms?
• 19.22: Do magnetic shark deterrents work?
• 30.28: Are hydrothermal vent species able to move around?
• 32.54: How do we know which prehistoric shark fossilised poop came from?
• 41.13: How do basking sharks find their food?
• 47.49: Which is the fastest shark?
• 52.34: If you could pass one international law to help sharks, which would it be?

You can also read our answers in the shownotes: www.saveourseas.com/worldofsharks/podcast