Marine gastropods and bivalves (aka 'seashells')

The Mollusca is a huge phylum and encompasses a great diversity of forms (there are 85,000 living marine species!). They include strange favourites of mine like cuttlefish, scaphopods and nudibranchs. But for this assignment you'll have to let those swim away free, and concentrate on collecting what we think of as marine snails and bivalves. It's an interesting group to pick (and necessitates trips to the seaside - what's not to like?)

Molluscs from the North Wales coast. CC image by Manfred Heyde.
This is definitely a group about which students and their collections have really opened my eyes and sparked a new interest for me in the last year or two. Perhaps it's previously been 'familiarity breeds contempt' - we've probably all collected seashells as children, without giving much thought to the habits of the animals that used to live in them. But I'm finding myself increasingly drawn to them, and wanting to find out about their varied ways of life. Perhaps you too will be inspired by a fresh look at something apparently familiar?

Most species you find will be Gastropods - the usually spiral-shelled group that have terrestrial, freshwater and marine representatives. They might be herbivorous or carnivorous. Others you find will be Bivalves. All bivalves are aquatic, and most species are marine.  Bivalves are all dependent on filter feeding - the amount of seawater they filter means they collect and accumulate whatever pollution ends up in the sea (an interesting environmental connection).

Chrysomallon squamiferum. CC image Kentaro Nakamura
Did you know, molluscs are a major component of the hardcore community living in the extreme conditions at hydrothermal vents? I thought you might like to see the weird Scaly-foot snail from a site in the Indian Ocean (above). You probably won't get anywhere so exotic (and besides, your species have to be native to UK waters), but by consciously investigating different habitats you'll be able to amass a good number of specimens. Different species live in sand, gravel and on rocky shores. Some live beneath the waves, others in the intertidal zone. If you keep your eye out you may find empty shells that have washed up from further out to sea than you as a land mammal can visit - which makes you start wondering about these creatures' hidden life histories.

If you're interested in animals but don't want to kill any, then this is a perfectly good option to choose, because (as you know), vacated shells can be picked up quite easily.

Here are some ideas on collecting marine molluscs.
I also have some advice on resources for identifying them.
You can read about how you might display them.  There have been some great collections made in recent years so I have some examples of how people have presented their work here and here.
 
This link will bring up all posts tagged with 'marine molluscs' (including any extra thoughts I've had or links I've found recently).

The Guggenheim museum in New York. Its architect (Frank Lloyd Wright) was inspired by a Thatcheria shell. CC image by blink+.

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