Thursday, April 24, 2014

Interesting creatures abound in Narragansett Bay

Jen Kelly
Education Specialist


With temperatures warming and spring right around the corner, it’s almost that time of year again - marine science cruises on the Providence River and upper Narragansett Bay! A few weeks ago we were aboard our education vessel, M/V Alletta Morris, with students and three professors from Brown University's oceanography program. 

We've been running this unique program with Brown University for the past eight years. Students rotate through four stations on the vessel. They measure salinity, dissolved oxygen, temperature, and chlorophyll fluorescence at various depths in the water column using a CTD-fluorometer. They also research light detection, conduct a sediment grab, and identify plankton.

On our most recent trip, I came upon something I had never seen before, wiggling and squirming around in the jar. Then I noticed a second, larger one. Placing it on a slide and under the microscope, I saw that it resembled the bell of a jelly. This organism had four tentacles stemming off of the bell. Interestingly, it had a long tube that extended down the center of the bell and past the tentacles. It resembled a siphon because it seemed to be pushing the jelly around. This was something I had never seen before and I was excited to find out what it was.

I opened the Atlantic Seashore Peterson Field Guide and determined that a clapper hydromedusa. The long siphon-like part is actually called a pendulous manubrium and contains the mouth at the end. The clapper can grow up to 0.25 inches long. As I continued to read about it, I learned that they are found as far south as the Chesapeake Bay.

It’s always exciting to stumble upon something new while on educational programs and to share such moments with others about Narragansett Bay.

- Jen

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