Kaltura Share to Google Classroom Naturalist Rudy Mancke examines a whelk shell which became trapped in a reef and has recrystallized. Grades: 3 4 5 6 7 8 9 10 11 12 Subjects: Science Collection: ETV StreamlineSCAbout KnowItAllAudio DescriptionsRudy Mancke Collection Series: Short Takes with Naturalist Rudy Mancke