Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Make it Lady on 21/02/2009 22:38:00

Title: Are barnacle feet, really feet ?
Post by: Make it Lady on 21/02/2009 22:38:00
I've been doing a bit of research on barnacles for my latest magazine article for creative steps. The kids will be making filters and learning about filter feeders. In most things I have read they say that the barnacles wave their feet, through the hole in the roof of their protective crust, and filter out plankton from the sea. Their feet look like feathers. They are fastened to the rock by their heads. My question is that if they don't walk anywhere and they use these "feet" as food catchers, surely they are not feet. Can anyone enlighten me on these little crustaceans.   
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 21/02/2009 22:46:47
I know nothing about barnacles except that they hurt if you tread on them barefoot.
Title: Are barnacle feet, really feet ?
Post by: Chemistry4me on 21/02/2009 23:00:25
Inside, there are six parts of forked limbs that are fringed with stiff hais, or setae. These limbs, or cirri, equivalent to the limbs used for walking or swimming by other crustaceans, beat in unison, flicking out through a gap between the plates then with-drawing again, in a grasping action. So you're right, they are not "feet".
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 21/02/2009 23:07:20
If a barnacle had a foot it would be grossly out of proportion  [:D]
Title: Are barnacle feet, really feet ?
Post by: Chemistry4me on 21/02/2009 23:09:42
It would probably freak me out! A walking barnacle! [:D]
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 21/02/2009 23:24:13
Barnacle Bill the Sailor. I shan't post the lyrics (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Fnono%2F2.gif&hash=708eb4525d4d44241694d95f05e08b73)
Title: Are barnacle feet, really feet ?
Post by: Make it Lady on 21/02/2009 23:37:05
If you are freaked out about the feet then you will be shocked to know that they have the biggest sexual organ, compared to body size, of any animal.
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 21/02/2009 23:38:12
If you are freaked out about the feet then you will be shocked to know that they have the biggest sexual organ, compared to body size, of any animal.

Apart from beavers
Title: Are barnacle feet, really feet ?
Post by: Chemistry4me on 22/02/2009 01:19:43
If you are freaked out about the feet then you will be shocked to know that they have the biggest sexual organ, compared to body size, of any animal.
Yeah, perhaps, but I already knew that [:)]
Title: Are barnacle feet, really feet ?
Post by: dentstudent on 22/02/2009 10:07:44
MIL - Have you checked what Darwin wrote  (http://darwin-online.org.uk/EditorialIntroductions/Richmond_cirripedia.html) about barnacles? I think that he produced 4 volumes about them....Fun guy!
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 22/02/2009 10:18:00
Darwin also liked worms

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fliveindavis.files.wordpress.com%2F2008%2F05%2Fworm_cartoon.gif&hash=e250a5e142ccec3be5a1ad7f8f06c693)
Title: Are barnacle feet, really feet ?
Post by: dentstudent on 22/02/2009 10:20:23
Darwin also liked worms

That's right. I have one of his books on the matter: "Vegetable Mould and Earthworms". My copy is from 1904.
Title: Are barnacle feet, really feet ?
Post by: DoctorBeaver on 22/02/2009 10:22:16
Darwin also liked worms

That's right. I have one of his books on the matter: "Vegetable Mould and Earthworms". My copy is from 1904.

Gawd, that'll cost you a lot when you take it back to the library!
Title: Are barnacle feet, really feet ?
Post by: blakestyger on 22/02/2009 13:14:27

It all depends on what you see a foot as. The barnacle's foot is its point of contact with the ground, or rock, which is what ours does too - although we are conditioned to think of feet as something at the end of a vertebrate limb. The fact that the barnacle's foot also serves to waft plankton into its feeding system needn't detract from its essential 'footiness'.

What I find extraordinary is that they are in the class Arthropoda, along with spiders and crabs - though when you look closely at their anatomy it's less remarkable.