MARINE INVERTEBRATES 
LESSON PLAN
Objective
Ocean Literacy
Standards
Students will be able to identify common marine
invertebrates found in the U.S. Virgin Islands.
5. The ocean supports a great diversity of life
and ecosystems.
LS4.D: Biodiversity and Humans - There are many
different kinds of living things in any area, and they
exist in different places on land and in water.
NGSS Standards
Background - What are invertebrates?
Invertebrates are animals that lack a vertebra
also known as a backbone. They also account
for most of the macroscopic life found in our
oceans. These invertebrates exhibit a variety
of different body plans; some allowing them to
thrive in habitats where other animals could
not. There are 6 major phyla that most marine
invertebrates can be grouped into. 
Overview
This lesson will provide students with an
introduction to the taxonomic classification of
marine invertebrates. Students will engage in a
shoreline walk activity to observe marine
invertebrates such as sea urchins and brittle
stars.
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Arthropoda 
1.
 
Animals in the phyla Arthropoda have
these defining features:
Possess an exoskeleton 
Have jointed appendages 
Examples of Arthropods include crabs,
lobsters, shrimp, and barnacles. 
2. Annelida 
Annelids are segmented worms which
can be found on land and underwater.
Most marine worms are classified as
polychaetes (having many hairs per
segment). Examples of annelids include
fireworms, christmas tree worms, and
featherduster worms. 
3. Cnidaria
Animals in the phyla Cnidaria are
primarily found in both freshwater and
marine environments. Cnidarians
typically possess cnidocytes, which are
specialized stinging cells used to capture
prey. Examples of cnidarians include
jellyfish, corals, anemones, and hydroids.
(Greek) Arthron = Joint / Pous = foot
(Latin) Annelus = Little ring
(Greek) Cnidos = Stinging nettle
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4. Echinodermata
Echinoderms are animals that posses
body symmetry (usually 5-point / like a
star) and may also have spiky or bumpy
skin. Most are also able to regenerate
lost appendages or organs. Examples of
echinoderms include sea stars, brittle
stars, sea urchins, sand dollars, and sea
cucumbers.  
5. Mollusca
Molluscs can be found on land,
freshwater, and marine environments.
Defining features of molluscs include a
mantle which resembles a cape, a radula 
used for feeding, and the presence of a
nervous system. Examples of moluscs
include snails, octopus, clams, squid,
and chiton.
6. Porifera
Sponges belong to the phyla Porifera;
they are multicellular and contain
numerous pores which allows water to
flow through them, thus aiding in filter
feeding.
Greek - Ekhinos = Hedgehog / Derma = skin
Latin - Mollis = Soft
Latin - Porifera = Pore bearer
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Overview of the Shoreline Walk
Page 4
Safety
The following precautions will be taken during
the shoreline walk to ensure safety of all
participants:
Safety briefing administered prior to the
start of activity.
Gloves will be worn when overturning rocks
to avoid being injured by fire worms. 
Water shoes are worn by all participants to
avoid injury.
Equipment
During the shoreline walk, the following
equipment will be used/needed:
Viewfinder buckets 
Gloves 
Laminated animal identification cards 
Notebook and pencil
Drinking water
Explore
Examples of students using the Viewfinder
buckets are provided below.
Attire
Students should have the following:
Clothing they don’t mind getting wet (No
long pants)
Water shoes
Hat
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While on the shoreline walk, use these
prompts to encourage further discussion:
What are the defining features of (insert
invertebrate phyla here)?
Which marine invertebrate did you
observe most frequently?
 What are potential impacts to this
ecosystem and the animals it supports?
Evaluation Rubric:
Can identify at least 1 representative
animal from each of the 6 marine
invertebrate phyla.
Can identify defining features for each of the
marine invertebrate phyla.
EVALUATION:
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Overview
For the Shoreline Walk Activity, students will:
Be organize into small groups and provided
their equipment.
Receive the safety briefing.
Use the Viewfinder buckets to observe
marine invertebrates in their natural habitat. 
Document what they find and categorize
based on phyla. 
Duration
Approximately 1 - hour 
Critical Thinking
Great
Excellent
Needs work