Tuesday, September 18, 2012

first field trip of the term

Our field trip yesterday to Otter Cliffs, my favorite intertidal site to explore on MDI, was blessed with gorgeous weather and a good low tide (-1.1 feet).  The goal was to see high diversity of higher taxa, and we focused our attention on phyla and classes, generating a fairly respectable list.

Phylum Porifera, Class Demospongiae
Phylum Cnidaria, Classes Hydrozoa and Anthozoa
Phylum Mollusca, Classes Gastropoda and Bivalvia
Phylum Annelida, Class Polychaeta
Phylum Arthropoda, Classes Insecta and Crustacea
Phylum Bryozoa, Classes Cheilostomata, Ctenostomata
Phylum Echinodermata, Classes Asteroidea, Ophiuroidea, and Echinoidea

Photo of springtails by Adam M
We could have expanded this list by aggressively tracking down flatworms (Platyhelminthes) and ribbonworms (Nemertea), both of which I've seen at Otter Cliffs in the past. As it was, we still had plenty to look at to provide tangible examples of those many branches of the phylogenetic trees that form the underlying conceptual structure for this course. 
The sponge was surprisingly hard to track down!  Virtually everywhere I expected to see it, in tidepools alongside coralline red algae, I found only bare rock.  I don't know what's happened to all the Halichondria that used to be so common there.
My students who are also taking entomology this term were thrilled to find springtails in the upper tidepools.

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