Reply
 
Thread Tools Display Modes
  #1  
Old 08-12-2018, 04:49 PM
Contemplation Contemplation is offline
Guest
 
Join Date: Sep 2014
Posts: 218
Do blue-black dogs actually have blue pigments?

Do dogs with blue-black coats actually have blue pigments in their coats?
I know humans don't but it isn't too far-fetched for another mammal to have blue fur pigments. There are already mandrills that have blue butts and dogs that have blue eyes, so are their dogs with actual blue coats?
__________________
The best ability of the mortal mind is its inability to correlate all of its contents.
  #2  
Old 08-12-2018, 05:37 PM
Colibri's Avatar
Colibri Colibri is offline
SD Curator of Critters
Moderator
 
Join Date: Oct 2000
Location: Panama
Posts: 39,431
No. Like other dogs, they have melanin, a dark pigment, in their hair.

Blue coloration in vertebrates (and most other animals) is not due to pigments, but to structural colors. That is, the color is produced by characteristics of the skin, scales, or feathers that scatter blue wavelengths of light.
  #3  
Old 08-12-2018, 05:48 PM
Contemplation Contemplation is offline
Guest
 
Join Date: Sep 2014
Posts: 218
Quote:
Originally Posted by Colibri View Post
No. Like other dogs, they have melanin, a dark pigment, in their hair.

Blue coloration in vertebrates (and most other animals) is not due to pigments, but to structural colors. That is, the color is produced by characteristics of the skin, scales, or feathers that scatter blue wavelengths of light.
Interesting that thats actually true. I guess the blue-ish look is just the blue sky reflecting off a black shiny coat.
__________________
The best ability of the mortal mind is its inability to correlate all of its contents.
  #4  
Old 08-12-2018, 08:33 PM
Pork Rind's Avatar
Pork Rind Pork Rind is offline
Charter Member
 
Join Date: Jan 2001
Location: Santa Barbara
Posts: 2,306
Quote:
Originally Posted by Contemplation View Post
Interesting that thats actually true. I guess the blue-ish look is just the blue sky reflecting off a black shiny coat.
Similarly, blue eyes arenít actually blue from a pigment perspective.
  #5  
Old 08-13-2018, 07:10 AM
ftg's Avatar
ftg ftg is offline
Guest
 
Join Date: Feb 2001
Location: Not the PNW :-(
Posts: 17,096
A dramatic example of structural color is the blue jay. No blue pigment, just the way the light refracts in the feathers.

With a dog a good way to see this is to brush your hand with the grain of the fur and notice how some colorings appear and disappear as the angle of light changes.

Last edited by ftg; 08-13-2018 at 07:12 AM.
  #6  
Old 08-13-2018, 09:21 AM
Colibri's Avatar
Colibri Colibri is offline
SD Curator of Critters
Moderator
 
Join Date: Oct 2000
Location: Panama
Posts: 39,431
Quote:
Originally Posted by ftg View Post
A dramatic example of structural color is the blue jay. No blue pigment, just the way the light refracts in the feathers.
The fact that the feathers are not actually blue can be seen when they are wet, when they appear black, their actual color. The water prevents the scattering of blue light.
  #7  
Old 08-13-2018, 10:00 AM
dtilque dtilque is offline
Charter Member
 
Join Date: Jan 2000
Location: My own private Nogero
Posts: 6,047
Our former master did a column on this. At the time he wrote it, there was some dispute about whether the blue came from scattering or interference. But it's definitely not blue pigments
  #8  
Old 08-13-2018, 10:05 AM
Jasmine's Avatar
Jasmine Jasmine is offline
Member
 
Join Date: Jul 1999
Location: Chicagoland
Posts: 1,027
I've never in life seen a blue or even a partially blue dog.

Is this real?
__________________
"The greatest obstacle to discovery is not ignorance -- it is the illusion of knowledge."
--Daniel J Boorstin
  #9  
Old 08-13-2018, 10:19 AM
Tom Tildrum Tom Tildrum is offline
Charter Member
 
Join Date: Apr 2002
Location: Falls Church, Va.
Posts: 13,771
Quote:
Originally Posted by Jasmine View Post
I've never in life seen a blue or even a partially blue dog.
Maybe it's like with that dress; some people see them as yellow and black.
  #10  
Old 08-13-2018, 10:49 AM
Colibri's Avatar
Colibri Colibri is offline
SD Curator of Critters
Moderator
 
Join Date: Oct 2000
Location: Panama
Posts: 39,431
Quote:
Originally Posted by Jasmine View Post
I've never in life seen a blue or even a partially blue dog.

Is this real?
Obviously not. The dog has either been dyed or the image photoshopped.
  #11  
Old 08-13-2018, 03:10 PM
ftg's Avatar
ftg ftg is offline
Guest
 
Join Date: Feb 2001
Location: Not the PNW :-(
Posts: 17,096
Quote:
Originally Posted by Colibri View Post
The fact that the feathers are not actually blue can be seen when they are wet, when they appear black, their actual color. The water prevents the scattering of blue light.
Jays are annoying enough dry. I'd hate to think of the ruckus they'd make if I tried to get them wet!

Anyway ..., I come across a jay feather once in a while in the yard. I'll have to try this.
  #12  
Old 08-13-2018, 03:36 PM
scr4 scr4 is offline
Member
 
Join Date: Aug 1999
Location: Alabama
Posts: 14,646
Are we saying blue dogs have structural coloring that make their fur blue?? I don't think so. The "blue" dogs like the blue heeler aren't actually blue. I'm pretty sure the "blue" patches are just light gray patches that look blue when contrasted against the pale brown fur.
  #13  
Old 08-13-2018, 04:16 PM
Colibri's Avatar
Colibri Colibri is offline
SD Curator of Critters
Moderator
 
Join Date: Oct 2000
Location: Panama
Posts: 39,431
Quote:
Originally Posted by scr4 View Post
Are we saying blue dogs have structural coloring that make their fur blue?? I don't think so. The "blue" dogs like the blue heeler aren't actually blue. I'm pretty sure the "blue" patches are just light gray patches that look blue when contrasted against the pale brown fur.
That's not the kind of "blue" that the OP is talking about, which is blue-black. As you say, blue heelers and blue tick hounds are not blue, but a shade of gray that we refer to as blue gray. This kind of "blue" is due to pigment.

Very deep black glossy hair can appear to have blue highlights due to the reflection of light. That's an effect of the light, not pigment (although not due to reflection of the sky, as speculated in the third post).

Last edited by Colibri; 08-13-2018 at 04:25 PM.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:05 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@straightdope.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Copyright © 2018 STM Reader, LLC.

 
Copyright © 2017