Friday, October 24, 2008

Deep Sea Treasures!

I have been quite busy these last couple of days, but I have an exciting new treasure to share with you!!! On Wednesday, Diego (my partner) and I went over to our friends' place for some wine and cheese. Jon work for Fisheries and Oceans and goes out on cruises identifying species and collecting data for the government. This time around he brought home some delightful shells that he shared with me!


These are called tusk shells. They are a small group of molluscs that are found throughout the world and generally at depths of 30m (100 feet) or more! They are in the same class as snails (Gastropoda) except that the foot (see diagram) is reduced and adapted for digging. They live partially buried in the sand or mud (pointy part up) and they draw in water so they can absorb the oxygen and eliminate wastes through their skin of their mantle where the water then exits through a small hole at the apex (tip of the point).

From Wikipedia Commons: Snail Diagram

Also the head has no eyes or tentacles but it has appendages (anything that sticks out from the core of the body of any animal, like our arms) that look like threads around its mouth that it uses to capture tiny bivalves (means 2 valves - like clams) and forameniferans.

Photo from Image Quest 3-Dhttp://www.imagequest3d.com/pages/shop/Posters/plankton.htm

Forameniferans (forams for short) are microscopic organisms that live everywhere in the ocean, they can be floating in the water as plankton or crawling on the bottom (ie: benthic forams). They are composed of one cell that lives inside a hard shell of calcium. These are increadibly important, not only as food for other species but when they die their shells sink to the bottom of the ocean and remain there. Much of the mud of the ocean is almost entirely composed of shells of forams, as well as some of the rocks which constitute the earth's surface. These rocks are made of forams from thousands or even millions of years ago that were once mud then because of intense pressure and/or heat the mud became rock (this is known as the Earth's rock cycle - http://en.wikipedia.org/wiki/Rock_cycle) !

I have only ever read about tusk shells and admired the shells in my books, so I am very happy to add them to my collection. Although, they are quite stinky, so they will stay outside for a while to dry out. I don't want the shells to crack if they freeze so they might get a bleach bath when outside temperatures start to dip near zero!

2 comments:

  1. OUuuuu! that's super cool! It must have felt amazing to hold such a unique part of our earth's amazing cycle! Are Forameniferans the organisms that have been attempting to eat the microscopic plastic spheres that are being broken down in the ocean from pollution?
    Anyhoo- This Blog is fantastic and I look forward to reading and learning more about our beautiful ocean!
    Lisa

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  2. I haven't heard of these plastic spheres...please tell me more!

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