Tag Archive for rot

An Argument for Isolating Hermit Crabs

Hermit crab with black spot shell disease

Hermit crab with black spot shell disease

When adding newly purchased or acquired crabs to an existing colony, for the long-term health of all, we at CSJ recommend the use of an isolation tank. Placing newly purchased or adopted hermit crabs into an existing healthy colony without a quarantine period risks the unnecessary exposure of your healthy hermits to shell disease or parasites.

If you are just starting out with hermit crabs and do not have an existing colony or crabitat in place, use of the PPS Reduction Method will allow you to monitor your new crabs for 30 days and bring them slowly up to ideal environmental conditions.

The PPS Reduction Method should be used with all newly purchased crabs unless you have visually confirmed that they are from a setup with sufficient heat and humidity. This is a 30-day process, allowing sufficient time to identify signs of illness or parasites, and reduces the number of hermit crab deaths due to PPS, most of which occur within the first month but can occur up to eighteen months post-purchase. The first molt for a hermit crab in your care is the biggest hurdle in overcoming Post-Purchase Syndrome.

For adoptive hermits coming from an ideal environment, quarantine conditions should be set at recommended heat and humidity levels for an established crabitat. However we still recommend the use of shallow substrate to allow for easy visual inspection. If you prefer to allow them to dig down, plan to quarantine for 60 days instead.

If the hermit crabs are coming from an unknown environment, the PPS Reduction Method provides the needed quarantine time not only for combating PPS but also for shell disease or parasites.

Shell Disease Syndrome includes a number of exoskeleton-related bacterial infections that are easily transmitted to healthy animals. Most infections are external-only and do not affect underlying tissue unless there is cross-exposure and re-contamination while molting. (There is, however, one variant that causes the exoskeleton to fuse with underlying tissue, preventing a successful shed and resulting in death or deformity.) Crustacean shell disease is highly contagious and spreads rapidly in an artificial environment. Wild-harvested hermit crabs are warehoused in dirty, overcrowded conditions and then shipped to pet stores. One crab could expose many other crabs, particularly those made vulnerable from physical stress or injury. New crabs should always be inspected for damaged exoskeletons both at the time of purchase and prior to adding to an existing colony. When purchasing a hermit crab with visible damage, said crab should be kept in quarantine until successive molts have repaired all signs of damage or disease. At the time of writing this article, it is unclear if the bacteria that causes shell disease can survive in the substrate, so it may prove beneficial to give the hermit crab a gentle bath in ocean water before placing in the main crabitat. As a rule we do not recommend forced bathing but in this instance you do not want to risk carrying contaminated substrate into the main crabitat, thereby placing your entire colony at risk.

Mites or other parasites can hide in the shell of newly purchased hermit crabs. This is especially true of hermit crabs purchased from filthy conditions where dead hermits are present. Before selecting new hermit crabs, check them over carefully for mites or other bugs, both on the body and the shell—exterior and interior. Red mites attached to the leg joints or gills are parasitic and harmful. In rare cases there may be fly larvae inside the shell where you are unable to see it. If the store habitat is especially dirty there is a higher likelihood of phorid flies and other fly larvae being present. You may not be able to easily see mites or parasites so visual inspection does not mean it is safe to place them in the main crabitat with your healthy colony. Quarantine for 30 days and check daily for signs of mites.

If shell disease appears in an existing colony, the scenario is more complicated due to the possible contamination of substrate coupled with molters still underground. Infected crabs should be moved immediately to a quarantine tank with minimal substrate until they have molted and show no signs of infection. This may precipitate a surface molt, but that is preferable to re-infection from digging into contaminated substrate. For the main crabitat, consider replacing the substrate and sanitizing items in the tank once all molters are above ground. This may be exercising an abundance of caution, but I do believe that an episode of contaminated substrate (ten years ago) is what killed my colony of Coenobita compressus (as well as some of the other species), halting their molts and trapping them in their exoskeletons.

We do have a recipe for a hermit crab medicinal bath that may be beneficial in treating shell disease.

Medicinal Bath for treating bacterial infections, shell rot and black spots.

This recipe can be modified, made stronger for use with very sick crabs, although this strength is fine for more minor cases!

Medicinal Bath created by Gertrude Snickelgrove and updated by Sue Latell of CoenobitaResearch and CSJ

Ingredients for Medicinal Bath for Hermit Crabs created by Gertrude Snickelgrove and updated by Sue Latell of CoenobitaResearch and CSJ

General wash for injured crabs:
1 Tbsp. Marshmallow root shaved
1 Tbsp. myrrh powder
1 Tbsp. calendula (marigold)
1 Tbsp. whole chamomile flowers (not powdered)

First, you’ll need to make a decoction. Take one quart of water, and heat it over the stove to near boiling. Add one tablespoon marshmallow root, and one tablespoon myrrh. Cover, and simmer for thirty minutes. Remove from heat. Add one tablespoon calendula flowers (marigold) and one tablespoon whole chamomile flowers. Cover immediately again. Let sit until cool, then strain herbs out and refrigerate. It will last a max of 48 hours. The herbs are all safe, they can even be fed to the crabs. I routinely feed calendula and chamomile to mine.

When bathing the crabs, bathe the affected parts only. I don’t see any need to get the stuff on the gills, unless there is an infection of the abdomen. The reason I say this, the marshmallow root makes a slime coat, which is sort of thick, and is not beneficial in the shell unless you’re fighting an infection in that area. If the infection is in on gills or soft tissue you can leave out the marshmallow root.

These are some of the general benefits of these herbs:

So marshmallow root draws out infections, draws out splinters, and makes a thick slime coat layer that helps prevent infection and aids in healing.

Myrrh powder (like what was given to Baby Jesus), is a powerful anti-bacterial, yet unlike antibiotics, is completely safe for crustaceans.

Calendula flowers (marigold), gently stimulates the immune system, is a mild anti-bacterial and anti-fungal, and cuts down on healing time.

Chamomile flowers, reduces inflammation, helps to speed healing, and reduces swelling when it is present.

A few words of caution: do not use powdered herbs; you really need to find the bulk medicinal herbs, because too many properties evaporate when the herbs are crushed. If you drink chamomile tea, and do not find it that relaxing, you should try a cup made from the whole flowers. There is a noticeable difference.

And second, all the properties of chamomile (the essential oils) evaporate with the steam. That’s why, when cooking herbs that have any essential oils, you must trap all the steam and let it cool, so the medicinal contents will remain in the formula.


Specific Wash for Bacterial Infection (including shell rot if caught in early stage):

2 cups dechlorinated water
1 Tbsp. myrrh powder
2-3 Tbsp. calendula (marigold)
1 Tbsp. whole chamomile flowers (not powdered)

Veterinarian recommendation: place the crab in clean sand, increase light exposure and bring humidity down to 70% and maintain there. Lower humidity retards the metabolic rate of the bacteria but 70% is the lowest a crab can tolerate while being treated. This must be done in isolation. Bacterial shell diseases are highly contagious but can be shed with a good molt.

This concoction should be steeped after the water is boiled. Let it sit for about 20 minutes, strain out petals. Wash should be applied 2 times a day for 3 days, let the crab sit in it as there may be lesions on his shield and abdomen. It will benefit him if he retains it as shell water. After the first few days if you notice more lesions forming or see more discolored depressions in his chitin, you may not be able to stop the progression of the disease.

If you do notice that there is no more formations, change out the substrate for new and watch him in ISO for at least another week. You can repeat the process again if you see reformation occurring. I think it would be up to you if you want to continue, but remember to keep this crab separate until you are sure that he has no active growth of the bacteria on him. With my indo BOB, he remained in a 2.5 gal ISO until he molted.

Here are his pictures:

Bob came up from his molt like this. This spot was suspected shell rot. The deformation of the claw is from an unidentified toxic substance, or even from the bacteria being present when he molted the first time.

 

Bob

Bob


This was after his molt and after the bath treatment. I think it contributed to him molting again so soon, and while his claw still is undercut, there was no spot or depression in his chitin.

 

Bob

Bob


Sorry for the poor quality of the pictures, I lost the originals when I had a hard drive crash.

Photos from Daethian:

 

Hermit crab with black spot shell disease

Hermit crab with black spot shell disease

 

Hermit crab with black spot shell disease

Hermit crab with black spot shell disease

 

Hermit crab with black spot shell disease

Hermit crab with black spot shell disease

 

Hermit crab with black spot shell disease

Hermit crab with black spot shell disease


Credits:

The main recipe was given to Daethian(Stacy Griffith) via email from Gert Snicklegrove in 2005. The best of our knowledge she is the creator of this recipe along with Summer Michaelson.

The second portion is an adaptation created by Sue Latell of Coenobita Research after speaking with her vet in 2006.