Interesting Info On Copper In Shrimp Diets

[KCB]

I was looking up the ingredients of Hikari Shrimp Cuisine as it said it contains copper and I thought it was odd as I had heard copper is toxic to invertebrates. I came across this post from ThePlantedTank and thought it was quite interesting.

"[background=rgb(245, 245, 255)]To be a stickler for terminology, shrimp don't have blood or a closed circulatory system as in vertebrates; instead, a fluid called hemolymph sloshes about within the body cavity. The oxygen-carrying molecule in their hemolymph is hemocyanin, a respiratory protein which binds oxygen using [/background]two copper atoms[background=rgb(245, 245, 255)]. [/background]

[background=rgb(245, 245, 255)]According to [/background]this paper[background=rgb(245, 245, 255)], decapod crustaceans (like shrimp) need around 31.3 to 38.1 μg (1 μg = 1/1,000,000 of a gram) of copper per gram of body mass "to meet the requirements of both copper-associated enzymes and the copper bearing respiratory pigment haemocyanin". [/background]

[background=rgb(245, 245, 255)]The line between need and toxicity [/background]can[background=rgb(245, 245, 255)] be fine ([/background]source[background=rgb(245, 245, 255)]), but copper is an [/background]essential trace metal[background=rgb(245, 245, 255)] required for copper-dependent enzymes in energy production, pigmentation, and so on.[/background]

[background=rgb(245, 245, 255)]We should distinguish this dietary requirement from the effects of the cupric ion (Cu+2). This is copper's major toxic species -- doing much damage to crustacean gills by inhibiting osmoregulation -- and results when [/background]copper sulfate medications[background=rgb(245, 245, 255)] are added to water ([/background]source[background=rgb(245, 245, 255)])."[/background]

 

[Chad]

Copper is an odd thing. They require micro amounts of it but larger amounts kill.

Now keep in mind when I say micro amounts I mean it...amounts that our best test kits wouldn't even read.

My guess...and this is just a guess...the PPM in the Hikari is probably so tiny they only list it because people would cry foul if they didn't.

Just a guess...

Anyway...thanks for sharing that is an interesting read.

 

[Tuxyu3]

Good find. I suppose it's only like how humans require certain heavy metals in their bodies.

 

[KCB]

Yeh I guess it's the equivalent of us needing iron. A little is good for haemoglobin and oxygen transportation, but too much can cause serious health deterioration.

Here's an e-mail from the Hikari company which also explains why they have copper in their shrimp food (e-mail taken from ThePlantedTank forum):

[background=rgb(245, 245, 255)]"Here is a more in depth response from our research staff.[/background]

[background=rgb(245, 245, 255)]Yes, too much copper in the diet will kill the shrimp. But, shrimp need a very small amount of copper in their food for good health.[/background]

[background=rgb(245, 245, 255)]Not like us(humans), animals or fish, most shrimp use copper to deliver oxygen[/background]
[background=rgb(245, 245, 255)]inside of their body. For example, we (humans) have red blood cells which[/background]
[background=rgb(245, 245, 255)]contain [/background]hemoglobin[background=rgb(245, 245, 255)]. [/background][background=rgb(245, 245, 255)]Hemoglobin[/background][background=rgb(245, 245, 255)] contains iron metal (Fe), and this iron[/background]
[background=rgb(245, 245, 255)]actually absorbs oxygen at large and delivers this oxygen to every part of[/background]
[background=rgb(245, 245, 255)]body and organs.[/background]

[background=rgb(245, 245, 255)]However, in the case of Shrimp, they have Hemocyanin in their blood cells, with[/background]
[background=rgb(245, 245, 255)]copper metal. They use copper to deliver oxygen to their vital organs and circulatory system.[/background]
[background=rgb(245, 245, 255)]That is why their blood is clear or green color rather than red color like ours (humans).[/background]

[background=rgb(245, 245, 255)]We hope this additional information helps!"[/background]

 

[Chad]

Good info. I knew they needed the copper now its nice to know why. it's in their blood...

 

[raptorrex]

Most Crabs, Shrimp, Octopus, Cuttlefish and Crayfish are the same.

Its shared with some arachnids and insects too.
 
Their blood is either clear or slightly blue.
 
Hemocyanin is their version or our Haemoglobin.