The Easter season is upon us, and you will notice bunnies, chicks, and eggs in most stores, regardless of whether you celebrate the religious holiday. The holiday is fast approaching! Kids will soon be unleashed into backyards to find eggs left behind by the Easter bunny. But instead of collecting the same old egg this year, how about collecting something different?
In some sharks, and in all true skates, reproduction occurs by laying eggs. An embryo lies inside a … [+]
Developed by The Shark Trust in 2003, The Great Eggcase Hunt aims to determine valuable information about egg-laying sharks, skates, chimaeras, and rays around the world. In some sharks, and in all true skates, reproduction occurs by laying eggs. An embryo lies inside a tough leathery capsule that protects it while it develops. After several months, they hatch and a full-grown shark or skate emerges. The discarded egg cases (also known as “mermaid’s purses”), that once held so much life, often wash up on beaches when empty. By analyzing the eggcase’s size, shape, and features, scientists can determine which species laid it. “What began as a British project has now expanded around the world,” says The Shark Trust. “We’ve got records from Ecuador to South Africa to Australia, and many places in between. In total, we’ve had 49 species reported from 30 countries!” In addition to recording over 375,000 individual egg cases, they are working on multiple collaborations and sister projects in various parts of the world.
But why egg cases? “Empty eggcases can help indicate species presence and diversity. By recording your finds, you’re helping us to discover more about egglaying species in our waters,” explains the project’s website. “Eggcases wash up all year round. So, whatever the time of year keep your eyes peeled!”
“Empty eggcases can help indicate species presence and diversity. By recording your finds, you’re … [+]
The egg case hunt couldn’t be easier – all you need is a bucket, a phone, and willing hands! The eggcases are frequently found along the strandlines, the beach area where you see seaweed wash up. Occasionally, they are still wet, and sometimes they are dried up. You can use the bucket to rehydrate the eggcase and help it return to its normal shape and size by submerging it in seawater for a short period of time. If you find an egg case, you can submit a photo to The Great Eggcase Hunt to contribute to the ongoing research. The program’s app contains a customized identification guide for geographic locations, so you can match your egg case to an appropriate species.
But what happens if it feels a bit… full? The first thing you should do is check whether the eggcase is actually empty. Hold it up to the light and check if anything is inside. See something wriggling around? The egg should be submerged back into the water, wedged between rocks or coral or seaweed.
Speaking of, you can also hunt for eggs underwater! “As well as documenting empty eggcases, we’re keen to receive records of eggcases developing in-situ. Often they’re extremely well camouflaged and can have marine organisms such as algae growing on them. If you do spot one make a note of the location and, if possible, take a photo. Then record your finding as normal,” The Shark Trust says. “Underwater records help us pin-point exactly where sharks and skates are laying and can be linked to beach records. Learning the depth and substrate that they lay on also helps us to better understand the species.”
