Monday, August 2, 2010

Ahoy!

Day 4:

On day four of our snails to whales class adventure, we ventured to Lovells Island. The day was beautiful with clear skies and low humidity. We arrived at Lovells at low tide, which was perfect for our class assignment. Splitting into partners our class was to identify different species in the tidal pools. The water was clear and it was a lot of fun to observe the conditions of the tidal pool as well as its inhabitants. Different from the previous fieldwork we did as a class, we had a lot more accessibility to the species that inhabited our environment at Lovells. Also, we were exposed to a greater variety of species in the tidal pools as opposed to the docks at the Barking Crab.

While exploring the tidal pools at Lovells, our group discovered many exciting species. Some of these species include, a northern lobster, a green crab, long-clawed hermit crabs, tunicates, sea squirts, and periwinkles.

After our lunch break, the class was shown different shells with holes in them.

After researching, I came to the conclusion that this was due to whelks. http://www.weichtiere.at/Mollusks/Schnecken/meer/wellhorn.html

“Whelks; a group of marine snails use their radula to drill a hole through the side of other mollusks, then kill them so that they relax and the shell can then be opened and the contents eaten. “ ( answers.com)

Our next activity was to observe the different kinds of snails on the island. Our assignment was to tell the difference between the snails we found in the water and the snails we found on land.

The snails we observed in the water I identified as a periwinkle. ( Britannica Online; Wikipedia)

The snails we observed on land I identified as a Grove Snail (wikipedia).

The two types of snails had both similarities and differences:

The Grove snail can be found in a range of habitats including grasslands and woodlands where as periwinkles are usually found in intertidal zones in the water. Grove snails were introduced from Europe and are closely related to the white-lipped snail. In addition, “apart from the band at the lip of the shell, grove snails are highly polymorphic” (absolute astronomy). Grove snails are also thought to use their shells to camouflage against predators.

http://www.absoluteastronomy.com/topics/Grove_snail

Contrastingly, periwinkles live in the water and feed on invertebrates in their habitat, but are also an invasive species introduced in the 1800s.

It was a great experience to research and observe the species of the tidal pool!

For the first time, I feel I really made a connection with the Boston Harbor and I am so excited to explore further.

Ciao Everyone,

Hilary Katulak


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