Coastal Habitats & Species—Growing Up in the Ocean

Summary: Most students are aware that plants and animals come in all shapes and sizes and many undergo metamorphosis during their life cycle. Marine invertebrates like sea stars, crabs and sea urchins have microscopic pelagic larval stages that are very different from their familiar adult forms. This activity explores the complex life cycles of marine invertebrates by learning about the life cycle of crab through observation, asking and answering questions as well as learning how to use microscopes. While learning about the life cycle, students are able to explore unique adaptations of marine invertebrates often seen in tidepools of Oregon.

Concepts to teach: Life stages, adaptations and survival

Goals: Students will explore and describe the life stages of crab and the similarities and differences between each body form.

3.1L.1, 3.2L.1, 3.3S, 4.2L.1, 4.3S, 5.2L.1, 5.3S

Specific Objectives:

  1. Students will be able to define “larva” and “metamorphosis” and give 3 examples of marine larva found in Oregon’s ocean.
  2. Students will describe an adaptation of a young and adult crab and why that feature is suited to the habitat it lives in at that time as well as the function of that feature.
  3. Students will find and identify at least one similarity and one difference between the 3 different life stages of a crab.

Activity Links and Resources:

  • Growing up in the Ocean lesson plan from the Oregon Institute of Marine Biology
  • The Planet Plankton lesson from the NOAA Estuary Education website offers estuary-based middle school curriculum, but includes general lessons about the importance of plankton in marine invertebrate life cycles, including:
  • The Oregon Coast Aquarium in Newport offers has a variety of on-site lab classes, outreach programs, and classroom lesson plans for Grades 3-5, including:
    • Plankton Investigation (Gr 3 and 4)—Students discover the world of plankton by using scientific tools to collect microscopic life from the Yaquina Bay, examine the external structures of plankton, and complete the life cycle of a local mystery plankton.
  • The Center for Microbial Oceanography: Research and Education (C-MORE) has Plankton educational kits available in some areas in Oregon, including Lincoln County. Download complete lesson plans and resources, and/or check out a kit through the C-MORE website.


  • Worksheets included in the Growing up in the Ocean and The Great Plankton Race lesson plans.