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Beaks

olgacguven

Hatchling
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Joined
Oct 31, 2005
Messages
5
In some of the scientific journals about the beak analysis I have found some terms about beak measurements such as Lower rostral length (LRL) and upper rostral length (URL). I will be very grateful if someone can explain me these terms. If its possible with figures. thanks....
 

Graeme

Vampyroteuthis
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Sep 26, 2005
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352
Gaagh! Mouthpart Terminology!! erm..... Right, I'm guessing that'd be the upper and lower half of the beak. I'm not toally clued up on Ceph mouthpart morphology, but that would be my best guess! There's so many words describing different parts of mouthparts, which in Arthropods in very easy since all the mouthparts are practically seperate. But when you start getting into animals with "2" mouthparts then it starts to become hazy.

Graeme
 

Jean

Colossal Squid
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Joined
Nov 19, 2002
Messages
4,218
:welcome: Olac

Are you measuring beaks???? What species??? I've measured a wee few Nototodarus sloanii beaks and the odd Moroteuthis ingens ones........................what fun :roll: One wee bit of advice use digital calipers if you can.........so much easier on the eyes!

Cheers

J
 

olgacguven

Hatchling
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Oct 31, 2005
Messages
5
I am planing to measure three difrent species in Antalya Bay TURKEY (S. officinalis, L. vulgaris, E. cirrosa)
 

Jean

Colossal Squid
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Nov 19, 2002
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4,218
olgacguven said:
I am planing to measure three difrent species in Antalya Bay TURKEY (S. officinalis, L. vulgaris, E. cirrosa)

That sounds interesting. Are you doing RL to mantle length regressions? It's nice to hear someone else measuring gazillions of beaks!!!!!
:lol:

J
 

Steve O'Shea

TONMO Supporter
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Nov 19, 2002
Messages
4,671
You'll have a bit of 'fun' measuring rostral length of the lower beak in an octopod, given the lack of a clearly defined 'jaw angle'. Prepare to pull your hair out; differentiating beaks can be tremendous fun (and equally frustrating). When doing so, especially when comparing closely related taxa, keep in mind that the differences between them might not be obviously mathematical (especially if you limit yourself to a few basic measurements), but in some other less-easy-to-define character state.

Take a good look at those beaks ... throw your ruler away .... and understand how they are put together. Differences are remarkably subtle, but once familiar with beak construction they are as distinct as apples and oranges (or pears as those in the UK might say).
 

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