[reefjitsu]

Who uses iodine: Shrimp

As one moves up the food chain to more sophisticated organisms, data on their ability to take up iodine from the water column becomes very sparse. Shrimp are known to have a need for iodine to grow, but that is only known in terms of a dietary requirement. The shrimp, Penaeus chinensis O'sbeck, for example, grows optimally when the diet contains 0.003% iodine.56

Shrimp apparently incorporate substantial amounts of iodoorganics into their bodies. The shrimp Pandalus borealis, for example, incorporates between 0.04 and 2 ppm iodine as iodoorganic compounds depending on the particular body tissues examined. Their roe were somewhat higher, up to 4 ppm iodine as iodoorganic compounds.57 Shrimp shells and other parts can contain up to 17 ppm by dry weight iodine, the majority of which is iodoorganic compounds58, but the values are still far lower than for other inverts like macroalgae, sponges, or gorgonia.

Still, the amount contained says nothing about whether iodine is an important requirement. I could find no scientific studies that showed that shrimp need iodine from the water column, but neither could I find any that demonstrates that they do not.

Chemistry and the Aquarium