This week, our class delved into the captivating world of tide pools and the enchanting story of Pagoo, a children’s book about a hermit crab’s adventures. Our eager learners arrived well-prepared, having completed the assigned reading, which detailed Pagoo’s quest for a perfect shell. They also expanded their vocabulary by solving an online crossword puzzle related to the chapter. The result was a lively class full of cross-curricular connections and enthusiasm.
Before the class, Ben and I embarked on a seaside treasure hunt to collect an array of shells. Our journey to Anclote Key beach yielded an unexpected gem: the egg casing of a lightning whelk!
We kicked off the class by placing a few shells in a vinegar-filled bottle, topped with a balloon. The students observed as bubbles formed on the shells, a reaction between the calcium carbonate shell and the vinegar. This produced carbon dioxide, filling the balloon and gradually dissolving the shells until they vanished by day’s end. This exploration also sparked an insightful discussion about ocean acidification and its impact on marine life. Our learners were captivated by the implications of this environmental issue on the delicate shells that they had just witnessed dissolving in the vinegar. By connecting hands-on activities with real-world concerns, the students gained a deeper understanding of the vital need to protect our ocean ecosystems. Next, we introduced the mysterious egg casing, challenging our young scholars to identify its origin. While their creative hypotheses were quite impressive, none could guess the casing belonged to a lightning whelk.
The lightning whelk (Busycon perversum) is a fascinating marine gastropod adorned with a uniquely patterned shell that features lightning-like streaks. As predators, these whelks primarily feed on bivalves, such as clams and oysters. Notably, they exhibit sinistral (left-handed) shell coiling, capturing the interest of marine biologists.
The lightning whelk is also remarkable for its intricate egg casings. Females lay eggs in lengthy strings called “egg cases” or “egg collars,” which can measure up to 3 feet (1 meter) long and house hundreds to thousands of individual eggs. Secured in sandy or muddy seabeds, these cases ensure the safety and stability of the developing embryos. Although each capsule contains multiple eggs, usually only one or two embryos per capsule reach the larval stage, while the rest nourish their siblings.
In 4 to 6 weeks, minuscule yet fully-formed juvenile whelks emerge from the capsules, embarking on their oceanic journey. These tiny creatures resemble their adult counterparts and continue to grow until they reach maturity, adding to the allure of the lightning whelk’s life cycle.
Our students reveled in the opportunity to dissect individual segments of the egg casing, releasing the myriad tiny whelks inside. Despite the casing’s potent odor, they were enthralled by the experience and were thrilled to take home transparent boxes containing their very own lightning whelks.
Hands-on learning provides an irreplaceable educational experience. While books hold a special place in our hearts, the knowledge and memories formed through tangible activities are truly priceless.
