Blue/green lingcod article

[Sitkaspruce]

Good read

Why are some ling cod electric blue? - BC News

Five years ago, marine ecologist Aaron Galloway surfaced with a ling cod he had spearfished off the coast of Oregon and proceeded to freak out.

www.castanet.net

Cheers

SS

 

[tubber]

No answers there. Protection against the sun in shallow water? Nutritional stress? Cabezon turn blue too.
No mention of Octopus ink sac.

 

[Dogbreath]

Cabezon turn blue too.

That's right I forgot that.

 

[agentaqua]

It's an interesting question, thanks for posting. My own favourite theory is that they get it from eating abalone.

In support of that theory:
1/ I have a commercial ZN fisher friend that used to tell me when they caught cabazon (didn't think to ask at that time what proportion were blue) often abalone would spill out from their guts. As an aside - I believe they had to throw the cabezon back as they were targeting rockfish. Removing competition of the cabezon while not harvesting a predator of abalone likely has not helped the abalone stocks recover;
2/ the smaller lings are often found shallower (where abalone are found) than the larger lings and this study found higher prevalence's of blue coloured lings in the smaller sizes esp the smaller females (the larger female lings are fecund and more often found deeper where I am assuming they deposit egg masses); and finally
3/ many years ago there was an abalone hatchery in Bamfield where the colour of the abalone shells changed as they fed them different types of algae, and different types of algae have different pigments. I'm not sure how they would test for the pigments from blue-green algae in fish flesh - but that's the connection I would look for. Another angle to research would be to look at the home ranges of the blue cabezon verses non-blue cabezon and see how the abalone densities compare.

The actual study referenced in this news article can be found at:

Assessing prevalence and correlates of blue-colored flesh in lingcod (Ophiodon elongatus) across their geographic range - Marine Biology

Intraspecific variation in external and internal pigmentation is common among fishes and explained by a variety of biological and ecological factors. Blue-colored flesh in fishes is relatively rare but has been documented in some species of the sculpin, greenling, and perch families. Diet...

link.springer.com

 

[CBsqrd]

Thanks for posting the original article. They made reference to the sportfishingbc.com forum near the end of the discussion!

 

[renier]

A Friend of mine has observed that the gall bladders in the blue lingcod seem to be smaller or not present compared to the white flesh ones
We caught quite a few recently off the west coast and it seem his observation was spot on
Maybe the gallbladders are underdeveloped at an early stage of life in some of them
The bile is the same tinge of blue than the flesh
Wondering if the bile is tainting the flesh

Just a thought and a thing to look for when cleaning them.

 

[Dogbreath]

Freshwater fish occasionally have blue flesh too I remember my Dad catching a 'Blue Pike' which for whatever reason is now called a 'Silver Pike' because Walleye can have blue flesh too (I know that sounds stupid).