Friday, July 27, 2012

Lovells: Finding on my favorite Island in the Boston Harbor

Yesterday, we started on our trip to Lovells Island. First we went to Georges Island until the DCR's Abigail too us to Lovells! Thank you so much!!! We examines the tide pools at Lovells as well as the tree life on the Island. We found similar species to what we have seen at Peddock's, Castle Island, and Under the Docks at the tide pools, such as Periwikles, Blue Mussels, and all sorts of tunicates. There were much less tunicates than we have seen on our other adventures. Although it was a rocky beach like Peddock, there were huge accessible tide pools. 

According to my guidebook, there a are two types of periwinkles that could be found in the region we were exploring, these include the Rough Periwinkle and the Common Periwinkle! Here are three periwinkles I found that looked much different than the common periwinkles that were scattered all over the tide pools. Although there form of the shells were similar to the common periwinkle, the color variation was quite different. Also, I held a few of the common periwinkles in my hand, and as i held my hand steady they came out of their shells, and bodies were blackish-blue in color with two antennas. The periwinkle shell closest to the bottom in the photo had a hermit crab living in it, but the two others did have snails. When i turned these over the color of the snail was white and orangey/red. Those two were much more timid about coming out of their shells. I tried holding my hand still, as well as trying to position them so they were touching the outside of another shell but although the moved slightly, they would not come out. After looking at my guide book, I think these are Atlantic Dogwinkles.

According to the Article "The Land Snails of New England", the land snails we saw were mostly likely Helix Supressa or Helix Concava. The reason we might have found the there terrestrial snails on a rock on the beach from from predators. The article "Differences in predatory pressure on terrestrial snails by birds and mammals" confirmed that snails that were broken on the beach, possible by bird species or rats. The birds use the rock to crack the snail's shell and eat the inside. 

 Akshat Jain's blog post from 2010 concluded that that I was most likely wrong on in my identification of the land snails. He said, "The land snails that we saw on the Lovell's Island had white colored lobes and black - brown colored lobes. Thus, they most closely resembled the white-lipped snails (Helix albolabris) as well as the brown-lipped snails or grove snails (Cepaea nemoralis). The shells colors and the rings do not seems to classify them in different groups. The colors are merely a way of adapting to the surroundings. However, the color of their lobes are important in determining the kind of snails they are and the group they belong to." I thought this was very informative, thats Akshat!

Rosin, Olborska and Surmacki. (2011). Differences in predatory pressure on terrestrial snails by birds and mammals. Journal of Biosciences. September 2011, 691–699.

The Land Snails of New England (Continued)
Edward S. Morse
The American Naturalist , Vol. 1, No. 8 (Oct., 1867), pp. 411-414
Published by: The University of Chicago Press for The American Society of Naturalists

Hermit Crab coming out of it's shell

Club Tunicated cover in seaweed and small periwinkles. I found a few of these attached to rocks.

Shell of Sea Urchin

Bone, most likely from a bird.

Asian Shore Crab

A Boy I think?


Worm on it's back

Green Crab

Crab Holding a Shell. It has a pretty strong grip! Although it was the size of the asian shore crab its colors were much different.

-Liza Zipursky

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