May 22 2006, 07:22 PM
Group: TREC Team
Joined: 12-April 06
Member No.: 23
Critters from the vanVeen and otter trawl on May 16, 2006: A Sea Star, formerly known as a starfish. This isnít really a fish at all. Fish are vertebrates. That means they have a backbone. A sea star is an invertebrate. It doesnít even have bones! It is in the phylum of invertebrates called echinoderms and in the class called asteroidea. It has 5 arms, radial symmetry, tube feet, and its mouth is under its body. They often eat clams and mussels for dinner and they can also regenerate an arm if it gets cut off.
Critters from the vanVeen and otter trawl on May 16, 2006: Snow Crab. This is a very small specimen compared to legs of these crabs that are served in restaurants. A snow crab is an arthropod in the class of crustaceans. Crabs are closely related to shrimp, lobsters, and insects.
Critters from the vanVeen and otter trawl on May 16, 2006: Hermit Crab. Hermit crabs donít have a hard shell over their soft abdomen like most other crabs do, so they find the empty shells from long-gone snails to occupy. When they outgrow a snail shell, they move into a bigger one. Itís a good thing that they donít have much packing to do!
Critters from the vanVeen and otter trawl on May 16, 2006: Brittle Star. A brittle star is an invertebrate animal in the phylum of echinoderms like sea stars, but they are in a class called stelleroidea and a sub class called ophiuroidea. They are called brittle stars because their arms easily break off when handled or disturbed. Our trawls sometimes pull up brittle stars by the thousands. They are very abundant in parts of our sampling area south of St. Lawrence Island in the Bering Sea.
Critters from the vanVeen and otter trawl on May 16, 2006: A Basket Star. This invertebrate is related to a sea star, but it is in the class of echinoderms called stelleroidea and the subclass ophiuroidea just like brittle stars. Basket stars have arms with many branches. The arms of this basket star are all curled up, but they use them for moving and for grasping food since they are scavengers.
Critters from the vanVeen and otter trawl on May 16, 2006: Mussels. Mollusks like mussels form their own shell as they grow. Mussels are like clams and scallops in that they have a hinged shell with two halves. Mussels are different from clams and scallops because they actually attach themselves to surfaces using little hairs called abyssal threads. Mussels are actually closely related to snails except snails are in a class of mollusks called gastropods and mussels, clams, and scallops are in a class called bivalves. They are filter feeders.
Critters from the vanVeen and otter trawl on May 16, 2006: Sea Strawberries. No, these are definitely not like the yummy fruit that we put on shortcake with whipped cream! These are actually a type of soft coral. Sea strawberries are invertebrate animals even though they might look more like a plant. They are in a phylum called cnidaria with jellyfish, but in a different class than jellyfish called anthozoa with sea anemones. This sea strawberry actually has little polyps that swell up when they are undisturbed in the water and it makes them look even more like a strawberry. They are also filter feeders.
Critters from the vanVeen on May 20, 2006: Worm. Did you know that some types of worms live in the ocean? This worm is in the same phylum as earthworms called annelida, but it is in a class of worms with many segments and feet-like appendages called polychaetes. If you look at the end of the worm in the center of the coil you will see two tiny little black tooth-like things. These are the wormís powerful jaws that help it eat other worms. It only sticks out its jaws when disturbed or eating. The rest of the time, it keeps them inside of its mouth opening. Worms like this have a good sense of smell and can smell their prey from quite a distance Ė for a worm!
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