On the 19th June 2015, Marazion School joined the Shark Trust in search of mermaids’ purses as part of the citizen science recording project, the Great Eggcase Hunt. The school group gathered on the local beach where they learnt about the biology of sharks and their cousins the skates and rays. They also discovered which species are found right here in British waters – from the huge gentle giant the Basking Shark, to the speedy Shortfin Mako and the bottom-dwelling skate – while also learning about more unusual species such as the sawfish. Different species were measured out on the beach using cones as markers to demonstrate the huge difference between the largest and the smallest sharks and a fantastic sand sawfish was created.
While many species of shark give birth to live young, others are oviparous, meaning they are egglaying species. The Great Eggcase Hunt’s illustrated skate life-cycle (along with skate and eggcase puppets) helped to explain the process that the embryo goes through once an egg has been deposited on the seafloor, through to when the young shark or skate emerges as a fully formed miniature version of the adult. Eggcases have different appearances, with some features used to anchor the capsule to a substrate (such as seaweed or the seabed) – this keeps them securely in place while the embryo develops. The Great Eggcase Hunt identification guide was used to compare the morphology of different species, from the huge Flapper Skate eggcase which is larger than an adult’s hand, to the tiny Smallspotted Catshark eggcase which has tendrils that tightly wrap around seaweed. Eggcases of some species are harder to distinguish from one another so a keen eye for detail is needed when trying to identify what has been found. Having taken a closer look at what we were searching for, it was time to start eggcase hunting…
What did the pupils learn?
“We learnt how to identify different types of shark eggcases and ray eggcases.” – Jemima, age 9.
“We learnt how to tell the difference between a ray eggcase and a shark eggcase.” – Caidan, age 9.
What did they think of the event?
“It was awesome, I’d really like to do it again.” – Layla, age 9.
“We found loads of barrel jellyfish.” – Leo, age 5.
“The models of the sharks were great, we learnt lots about their body parts.” – Enid, age 10.
“Hopefully it made people think differently about sharks, because I don’t think many people like them very much.” – Caidan, age 9.
The results from the successful Great Eggcase Hunt with Marazion School were recorded on the Great Eggcase Hunt database and added to the online maps which show the broad distribution and abundance of egglaying species around the British coast. Over 87,000 individual eggcases have been recorded to date, and the project is rapidly gathering momentum!
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This article was first published in NAEE’s journal, Environmental Education (Vol. 111). To read more articles like this, you can join the Association and receive three journals a year.