Nutritional basis for coloring

annopia · Post by **annopia** » Thu Mar 01, 2007 2:38 pm

this is a topic that has been confounding me for some time now. i know that it is generally accepted that (with PPs) darker coloring indicates either nutrition consumption or age/size. but what is going on with the crabs that do not follow this rule? i will give two examples, Sassy and Lila. they are both medium PPs, both have had molts with me (Lila at least four, Sassy one). they are in the same tank and recieve the exact same nutrition (an expansive list i draw from, with one fresh protein, nut, fruit, veggie, grain, and flower a day; meats/nuts etc are rotated out and served only 1 or 2 times a month for each specific type).

Sassy:

Lila:

yet Lila's coloring (and i've had her for over a year) is no where near as dark as Sassy's, and they have the same diet and size. have you guys experienced this? i know that straws are a bit of a different issue with light and other things, so i am talking strictly PPs here. i'd like to hear your thoughts.

Caroline

Guest · Post by **Guest** » Thu Mar 01, 2007 2:54 pm

I agree 100 percent!!! It's confounded me for quite some time also. With my osbervations there MUST be other factors that effect coloring.

Guest · Post by **Guest** » Thu Mar 01, 2007 4:08 pm

Yes its happened to me too..

Even though they were only in my care for maybe a month before they molted..

When they didn the 2 pp's, One name Oxymaroon(So dark he was maroon), and the other Light pink/orange/purple Still unnamed...

Both ate the same kibble and fresh foods... Im not nearly as therou with the fresh food as i should be but im workn on it.

Guest · Post by **Guest** » Thu Mar 01, 2007 6:32 pm

I am almost positive that there is a genetic component to their coloring. According to what I have learned in my invertebrate biology course, genetics has a factor in other crustacean's coloring in combination with diet and environmental conditions at the time of the molt, so I see no reason why it wouldn't apply to hermit crabs as well.

For example, my crayfish has bright oranges and reds with dark purple shadings after her latest molt. This is different from her previous molt because she ate lots of red cabbage and carrots. This shows the dietary components.

Her babies however vary widely widely in coloring from black, blue, brown, tan, and even white. They have been in the exact same conditions and been fed the exact same diet since they hatched so diet and environment cannot be the cause of their coloring differences. Their varying colors are due to genes.

Since certain genes only "activate" for a short time or every week few weeks, etc. this could at least partially account for the unexplainable gains and losses in colors which vary between crabs in the same tank. If sibling crayfish colors can vary so widely, why shouldn't crabs from different areas with different gene pools vary?

annopia · Post by **annopia** » Sat Mar 03, 2007 11:50 am

that is very interesting, Kaep. i wish that my own college major was more applicable (chemistry). as much as i would love to do something hermie-centered for my independent studies, i just cant figure out a way to relate it to organic chemistry!

could you explain a little more about certain genes only activating for specific times?

Caroline

Guest · Post by **Guest** » Sat Mar 03, 2007 5:37 pm

Yeah, unforunately I have to do organic chemistry and this. (I don't mind it that much just hate reaction mechanisms...)

With the genes activating:

Some genes are only active at certain times, for example the genes that control organ development would only be active before birth because after that point there is no need for them. Genes that control reproduction is certain animals would only activate in the spring during their breeding season.

There are sections of your DNA that are used to make proteins and these proteins direct body functions (basically the sections that make noticeable changes). Other sections of the DNA are like timers, these sections control when another section of DNA is turned into protein. These "timers" are affected by the environment, hormones, and passage of time.

I hope that made sense... if you need any clarification or want to know anything else feel free to ask.