Friday, September 28, 2012

Gastropods

Gastropod means "stomach foot" and includes all snails and anything else that makes one shell. Gastropods have one foot, one shell, and one siphon.

Some shells are spiral and have an operculum to act as a door for when they hide inside. The snail lives in the entire shell (all the way up into the top and retreats inside to hide when it feels threatened or exposed. The operculum blocks any would-be attackers and is made of a material similar to fingernails. These types of molluscs include whelks and moon snails.

Other shells are not spiral and the snail has good suction power so that predators have a difficult time pulling the snail off the rocks. These types of molluscs include slipper snails, abalones, and limpets.

Nudibranch (naked-gills) are sea slugs that have lost the ability to make a shell over evolutionary history. They are still classified as gastropods.

Even though they don't have a shell, they do however have some interesting adaptations to keep from getting eaten. Most nudibranch exhibit warning coloration because they are poisonous or have stingers - none that they make - they acquire them from the prey that they eat!

National Geographic did a great article a few years ago full of lovely photos. Both are linked here. Watch the video for a full-range spectrum of photos.


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Computer Lab Etiquette

You are in the computer lab to do work for this class. If you are not doing work, then we will have problems.

Do not pack up early. Work until the bell or until MsJ says.

SAVE OFTEN. And if you save to a key, also save it to your number. If you lose it, you will have to do it again.

If MsJ asks for your attention, stop what you are doing and listen to what she has to say.

You may watch videos about your organism through reliable websites.

You may listen to music through the computer if you have your own headphones. Rule1 MsJ cannot hear it. You get one warning. Rule2 Turn it on and listen – no million clicks and constant changing. Take both ear phones out when MsJ is talking.