Calcium in exoskeleton

[viridisornatus]

Hello,

I was wondering about the calcium in the chitin of shrimp in low KH environments. It is calcium carbonate in most crustaceans, is it the same in these shrimp? Tigers and cherries can adjust to low KH so I would guess it is, although apparently some crustaceans use calcium phosphate. Since the water contains no carbonates, are they getting it all from their diet as calcium carbonate, or are they able to absorb calcium sulfate/chloride/phosphate etc from water/food and combine it with metabolic carbonates? This is synthetically possible, and I got the impression that plants/algae can do it, as can bacteria. It seems like it should be possible since calcium ions can be transported dissociated in tissues. Does anyone know?

Thanks :)

[NoGi]

@jayc?

[jayc]

@viridisornatus @NoGi I'm pretty sure the shrimps we keep have the bulk of their exoskeletons made up of calcium carbonates. Although some structures in crustaceans are made up of a calcium phosphate and carbonate mix. The possible use of the two forms of calcium on different parts of their body is for hardness and elasticity. For example, their mandibles need to be harder, so you'd find more phosphates there. While carbonates are more elastic for easier moulting.

 

Shrimps, like fish, can absorb calcium from the water. If calcium is abundant enough in the water, the shrimps will obtain the majority of their calcium through their gills.  Calcium in diet makes up the remaining source. 

It doesn't matter if the calcium is in the form of sulphate, chloride, nitrate or phosphate. The key is a balance with Magnesium. Magnesium keeps the calcium in a dissolved state. Magnesium also converts Vitamin D into its active form so that it can help calcium absorption.

 

 

Edited December 31, 2016 by jayc

[viridisornatus]

Fascinating, thanks Jayc and NoGi!