Introductory Set:
1. Introduce this activity by
explaining that oysters begin life as microscopic lifeforms called
larvae and that they are way too small to see with your eyes. Explain
that as a larva (singular) grows and develops, it passes through
distinct "stages" (just as people change from infants, to babies, to
small children, to teenagers...etc).
2. Students will
learn the names and characteristics of these stages.
If computer video projection equipment is available, show 10 second
clips-- "Swarming video clip" (showing larvae moving amongst grains of
sand) and "Settling video clip" (showing a "pediveliger" stage larva
using its foot to attach)--from the
http://www.hpl.umces.edu/facilities/oysters.html, Horn Point
Laboratory-UMCES web site, to give a clear visual idea of what larvae
look like.
Flow Chart:
1. Have students review the activity handout ("The Oyster’s Lifecycle")and carefully read the background information.
2.
Distribute two cut-out pages, scissors, and glue stick. From the
cut-out pages, students remove the diagrams and labels by cutting along
the black lines.
3. Allow students devise their own
methods for arranging the information in the proper order on the Flow
Chart. (See Teacher Key for notes and an organized table of lifecycle
information).
4. All informational pieces should be
"dry fit" before being permanently glued down.
The instructor could adjust the difficulty of the activity by adding or
removing 'set' information from the Flow Chart. (Lesson Time: 30 to 45
minutes).
Alternative Lesson:
If
time is extremely limited [Lesson Time: 15 minutes], use the
Introductory Set above but substitute "An Oyster's Life", a Maryland
Sea Grant activity published by the Maryland Department of Natural
Resources (download from Lesson Resources). Answers: (1)Egg,
(2)Spermatazoa, (3)Fertilized egg, (4)Embryo, (5)Free-swimming larvae,
(6)Cilia, (7)Pseudopod, (8)Spat, (9)Adult oysters, (10)Bonus:"clutch." |