External Anatomy of a Crayfish

screenshotStudents examine the external anatomy of a crayfish in order to gain an appreciation for differences between vertebrates and invertebrates.   In this activity, the focus is on the mandible and maxillipeds of the head.  Students can remove the mouthparts to get a view of how the mandible opens from side to side.   Students also locate the eyes and manipulate the chelipeds (claws).

Students count the segments of the crayfish and compare to other specimens and determine whether they have a male of female based on the appearance of the first pair of swimmerets.   You can follow up with the “Internal Anatomy of the Crayfish,” though beginning students often have a difficult time identifying internal structures.

Crayfish Specimens can be ordered from Amazon, or alternatively students can view a plastinated model.

See also:  Crayfish Photo Album

Grade Level: 7-9 | Time Required:  45 min



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