Crayfish and lobsters look the same other than their size.  Are they related to each other?

-     Greg Gough
       8th grade
       South Middle School
 

Professor Science Replies:

That is a great question, Greg.  Unfortunately, I am not really all that familiar with crayfish or lobsters.  But, like any good scientist, I decided to try to find  more information.  One of my good friends, Gary M. Lange, who is an Associate Professor of Biology at Saginaw Valley State University, was able to help me out with this question.  Here is what he said...

"Greg... the answer to your question is.... the lobsters we eat and the crayfish we find in our creeks and ditches ARE indeed very similar.  Both of these organisms belong to the same Order, Astacidea.  The primary differences between them are found in their ecology.  The lobster is a marine organism, meaning it inhabits salt water environments (such as the oceans).  The crayfish, on the otherhand, lives in freshwater creeks, ditches, or lakes.  Another very distinct difference is of course seen in their size.... the lobster is much larger than the crayfish.  However, both species have nearly identical anatomy and physiology.  You may not be aware of this, but many people enjoy eating crayfish, and they will prepare them in the same way that lobster is prepared.  People I have met who have eaten both species, say they taste nearly the same."

Question:

What is the difference between a shamrock and a clover?

- Beth Moeller's 7th Grade Class
   Thurston Middle School

Professor Science Replies:

Thank you for writing in with such a great question!  I decided to ask my very good friend and botanist, Kathleen Pelkki to help me with your question.  Kathleen Pelkki is the laboratory technician in  the Department of Biology at Saginaw Valley State University.  Here is what she said:
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"The shamrock is a common name of a number of plants with leaves that are divided into three leaflets.  Every once in a while in any of these plants, a leaf will be produced that has four leaflets.  So you would be lucky to find one with four leaflets."

Kathleen continues:

"White clover (Trifolium repens) is considered by many to be the original Irish shamrock.  However, the black medic (Medicago lupina), the wood sorrel (Oxalis acetosella), and the hop clover (Trifolium minus) are also called shamrocks.  The names in parentheses are the scientific names that scientists use to identify specific plants.  Every scientist would know exactly which plant Trifolium repens is, but as you can see, if someone talks about a shamrock, we really do not know exactly which plant is being referred to."

"The Irish word "seamrog," from which shamrock comes, means "little clover."  These plants are native to Britain and have been brought to North America often to be grown as food for livestock."

"St. Patrick is said to have used the three leaflets of the clover to represent the Holy Trinity.  Before St. Patrick, the Celts of Wales believed that the white clover was a charm against evil spirits.  So, the shamrock has been thought of as a special plant for a long time."
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Again, an excellent question!  And, again, I decided I needed help in discovering the answer to your question.  This time, I asked my good friend, Richard Trdan to explain this complex process.  Dr. Trdan is both Professor and the Chairperson of the Department of Biology at Saginaw Valley State University.  Here is how he explained this process:
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