Saturday, July 31, 2010

Class #3

Today we observed both the urban coastline of Boston Harbor and got a brief glimpse of the organisms that live out of view under the harbor piers. Though we only saw the intertidal zone of Long Wharf from afar, I have a feeling that what we saw from land are related to the organisms that we found underneath the pier, and that they may be species related to each other in some way or another. Before I researched the actual identities of the different things I saw today, reading even the description of the Hitchhikers Guide made me think twice about everything I had seen. My judgment of everything I saw immediately shifted from wonder to skepticism, as I wondered if any of the creatures I had seen today were actually invasive and disturbing the existence of the indigenous creatures.

Starting with the plants we saw while standing at the Wharf, I noticed the two most obvious species to the naked eye. Both species were visible at low tide and because some lived submerged and some lived exposed to open air, they must both be able to survive a change in habitat. One species existed both in patches and large stretches, was green in color and resembled moss that you would find on a rock. In fact, some of this moss-like green substance, which I can assume is a plant because of its appearance, lived on rocks submerged in the water. I am guessing that the green plant found both in the water and on the wall are the same species because high tide would submerge the plants on the wall like the ones already in the water, but I cannot know for sure. After researching “mossy seaweed” online, the closest match I could find in appearance and habitat description is the seaweed Cladophora and is found in intertidal zones just like the one we saw. A second plant species in this same area was brownish, resembled long thin leaves, and lived along with the green plants both in the water and on the wall. Again, I am only guessing that the species in the water and above the water are the same because of the change in tide levels, but I cannot be sure. After researching “brown seaweed Massachusetts” online, the seaweed I found that most accurately matches what I saw in the water and on the wall is the Fucus gardneri, which is described as thriving both on land and in protected areas.

Moving on to the pier at the Barking Crab, I found myself looking at many green, lettuce-like leaves attached to the floats underneath the pier. They stretched the length of the pier, were close to the surface and were therefore exposed to a lot of sunlight, and dried up like a dead leaf would once on the pier for awhile. After researching lettuce-like seaweed, I found that in fact there is a seaweed called “Sea Lettuce” or Ulva lactuca. The appearance is very similar to that which I saw in the water, is observed in the Northeast, and can apparently even be used in salads.

This piece had a jelly-like brown substance on it, which I will talk about later.

Moving on to the animals I saw today, the most interesting one to me was an orange, stick-like creature that dwelled on the seaweed attached to the pier. It was about a half inch long, had 6 prong-like feelers at one and two legs in the middle. It seemed to have no backbone as it squirmed in every direction when touched. From my guidebook, looking at the picture and description of the Long-Horn Skeleton Shrimp and noting that its habitat is well within the reaches of where I found it, I believe that the creature I saw is atleast related to this Skeleton shrimp.

A second animal I saw today lived on the seaweed just as the Skeleton Shrimp did and looked to me like a tiny, grey or colorless shrimp with too many antennae for me to count. They moved very quickly, covered almost the entire surface of the seaweed, and curled up when they died. Looking at my guidebook, I thought that I may have either seen a Red-eyed amphipod, a Scud, or a Mottled Tube-maker but the description of the latter two led me to believe that neither of them were what I saw. The closest match was the Red-eyed amphipod, similar in length, color, and habitat. A third animal I saw was a large shellfish creature clinging to the seaweed under the pier. Brownish in color and covered with the small shrimp-like creature I described earlier, the shell was about one inch in width and two inches in length. I thought that there might be an animal living inside the shell that wasn’t exposed, but didn’t want to disturb it. The shape of the shell looked most like the California Mussel from my guidebook, but since the location didn’t match the location of the shell I found, I turned to the Blue Mussel instead. Matching in habitat, description, and location, I believe what I saw may have been a Blue Mussel. A fourth animal I saw was a small grey crab, with eight legs (including two pinchers) and about an inch in size. The closest match I could find in the guide book was the Flat Mud Crab which lives among oysters and in bays. Because I didn’t get the chance to look at the crab for very long, I may be way off on this one but from what I can remember and wrote down, this looks to be the closest.

Looking at the Hitchhiker’s Guide before researching the identity of the daisy-patterned creature online, I thought that the first image of Diplosoma Tunicate looked like it could be related. When I typed in the name online to find more pictures, I found a link to the government of Massachusetts’ advisory on this invasive species. I found on this site that the Diplosoma Tunicate was most likely not the same substance because it looks more porous and more like a coral-type creature than a jelly-like creature. I did find on this site though the Botryllus schlosseri which is described as a gelatinous colony with a star-like pattern and is mostly translucent. This matched part of the description of the substance we found, and the pattern in the pictures are definitely related to the pattern of what we found. I can’t be sure that this is exactly what we found, but the similarities in appearance and description of the habitat of the creature and the typical colors make me think that this is either the creature, or is something closely related. In any case, I now believe that what we found under the pier was an invasive tunicate made up of zooids. So there you have it, and from this further research I now think even more that what we saw was related to the Botryllus scholosseri. The other jelly-like creature, almost completely orange in color and just as gooey-looking, though upon closer look seems to be almost spongey. Looking in the guidebook, the closest match I can find is the Orange Sheath Turnicate. Just as the daisy-like substance is a turnicate, so is the orange substance, but I wonder if they are related?

-Lydia T

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