Last update: April 24, 2010, Reader ideas added towards the end. Yay!
My crayfish recently molted successfully. If your crayfish has been established and is healthy, it is OK to take out his molt sometimes. Usually it is best to leave it in for a day or so and let the crayfish eat it (if he bothers) to get the materials back in his system. If you remove this one, let him have the next one.
Here is something to do with that molt should you like this sort of thing–set the molt!
If the molt has not been sitting around getting gross or nibbled on, remove it gently from the water using your hand or a small net. They are fragile so do not squeeze or swish it around too much.
Do this when you have time. Once it starts to dry, you cannot move the parts around. Also, lets hope your crayfish does not decide to molt when you have had too much coffee on an empty stomach. This is not the best set I have ever done. I was jittery and impatient. But I had to finish it before it dried.
The picture above shows a molt in the foreground and the crayfish recovering in the background.
- Intact crayfish molt (clean with no flesh left)
- toothpick or something similar to work in a small place. Here I used an old pokey thing you use to hold legs together when roasting a chicken. I forget what they are called. I am not much of a cook. ;)
- paper towels
- safe location for it to dry away from pets and other sources of damage
- protective spray (optional)
- WD-40 oil (optional)
Fold a paper towel and lay the molt onto it.
Get the crayfish molt to sit on its ventral (belly) side with the legs out on their correct side (none folded over under the belly, 5 on each side).
The picture above shows the molt laid out on its side.The back is up, exposing the gill area. The picture below shows the back up from behind. You can see right inside. This part needs to be pushed back down. The picture below, right shows the leg positioning by using a narrow device such as a toothpick.
Push the back of the crayfish down into place. This is where the crayfish backs out of its shell. Reminds me of an open hood of a car. ;) The white stuff under the “hood” is where the gills are located.
Position the tail into a more natural position up against the back rather than laying flat. There should not be a gap between the tail and the back. Take a pinch of paper towel and roll it tight until it is the right thickness to place under the tail to keep the shape you want. Use bits of twisted paper towel throughout to position the body parts. You can try cotton or something else as well. I like the towels because I can keep tearing off what I need until I get what I want. It is also possible to make wedges as well.
Spread the tail fins if you wish.
Use a toothpick or similar item to move the legs to where you want. This part is tedious because they will want to fold back. I try to hook the feet into the paper towel that it is sitting on. I then wedge paper towel bits between the legs to help hold them. You may need to place another piece along the side to keep the animal from looking like it is about to tip.
If you want him sitting up a bit, place one under the front. Do not forget the little “arms” by the mouth and position those.
The claws will need several bits of paper towel, especially if you wish to have them raised. Use the toothpick to open the claws if you wish. You may need to stuff towel between the claws to get them open.
Wad a large piece of towel to place in front of the animal. Tease apart the 4 antennae. The two long ones can be placed on the large piece.
Keep adding paper towel bits to prop the animal how you would like it to stay. Once it dries, that is the way it will stay. Be careful on claw positioning so the animal does not tip forward when the towels are removed.
Let it sit out in a well ventilated area so it does not mold. Be sure it will not get bumped and broken.
You can spray a protective coating to prolong the life of the animal once it is dry. They do tend to lose color over time though regardless. You may wish to experiment with WD-40 to prolong color and life before adding a protective coating. This helps prevent the shell from getting even more brittle from drying out. It is limited and you may want to spread the oil with a cotton swab to prevent flooding it. I used to do this years ago and I forgot how well it worked over time. I think I remember it doing pretty good. Polyurethane may cause the animal to turn red so you may want to try alternatives. I would love any suggestions. I tend to just leave the coating off these days after I add some oil (if any). So far my blue molts do turn more white over time.
You may want to keep it in a clear container for protection. These are fragile but very neat. Good for show and education. I prefer to keep mine this way.
This works on most crustaceans. I have also set crabs and lobsters this way for people. You can get creative with poses, but work fast.
If the molt you have found smells, I suggest not keeping it. Likely there is still tissue inside from a bad molt or predation (if you found it on a beach) and it will rot and stink horribly. Bad crustaceans stink! The final set molt should not smell at all.
Where did I get this idea? I just thought it would be neat to do one day and did it. I am sure others have done something similar. Or maybe I am just strange. Don’t answer that!
Here (above) is one picture of the finished molt set from above. I hope to have a few more pictures soon along with any old molts I can find that I still have.
The post about my live, blue crayfish is located at https://virtuallyamy.wordpress.com/2008/09/04/crayfish-as-pets-my-electric-blue-boy/
I also have a knitted crayfish at https://virtuallyamy.wordpress.com/2008/09/30/knitting-blue-crayfish/
Here I am setting up a new one. He did not want to eat this one so I decided to give it a try. I am experimenting with having the weighty claws up in the air. I am not sure how well this will work. I will post an update showing the results. Here, in addition to wadded paper towels (good for pulling out some moisture), I also used aluminum foil I wadded into support structures for the pinchers. This turned out to be handy to mold the foil in a way to hold stubborn limbs that do not want to stay or to hold heavy ones up hight that the paper was not up to. It is currently drying for a few days as I type this.
In these two pictures (left and right) the molt is about buried in support material. I will be amazed if it is not overbalanced when finished but I had to experiment.
After forgetting about the molt sitting around, I finally took a picture of the final product. I forgot to spray with oil when it dried so it is looking a little rough as far as color. It also got bumped, breaking an antenna off. But the main point of doing this one worked out. The claws stay up fine without tipping the molt over. The pictures are not great, sorry about that. But at least you can see enough to maybe give you ideas for your own. :)
Here is a message from a reader, Julie, who did this with a bamboo shrimp:
“I recently tried this with my Bamboo shrimp’s molt. It’s been sitting around for a month now (I really need to find a case for it). I used your method, but I also sprayed it with Krylon brand matte finish. It’s usually used for stuff like charcoal drawings but can also be used on painted sculptures. Since coating it with this, I didn’t notice any heating up of the color– however, my shrimp is naturally orange. But the colors didn’t change at all from when it initially dried, so I think this coating works pretty well. I don’t know the longevity for sure, but it’s been a month and still looks the same. Here’s a photo of it (this molt is about 3 to 4 inches long):”
You can see this message in the comments as well.
Additionally, Anthony Mills mentioned putting a molt in resin for a neat paper weight. Also see the comments section for full details.