What is this odd white film growing on our Fiddler Crab?

  1. aquilusdomini Initiate Member

    Hello everyone,

    Our fiddler crab Bob has lived with us for only a couple weeks but his tank is well established. He has a good percentage of land (i'll provide pictures) and roughly 1 gallon of water in a 10 gallon tank. The water/salt ratio was 2tsp (teaspoon) Instant Ocean salt to one gallon of de-chlorinated water. There are three different types of sand: bio-sand (CaribSea AragAlive), general play sand, and then standard clean non-bio aquarium sand. I added the sands in layers with the bio-sand being the top layer, play sand the second and of course the general aquarium sand the third. As of right now he has an old glass mug in the water for hiding, an aquarium lighthouse decoration on the land and a makeshift plastic tube cave for land hiding. In all other respects aside from one missing leg (i believe he came that way but cannot remember for sure) and this weird white film he is jolly and healthy. He scavenges in the water and on the land for food bits and he regularly shoves the bio and play sand bits in his mouth and then spits them out. He eats well (baby shrimp, plankton, seaweed/algae, bloodworms) and seems to enjoy his plankton most of all. Everything in his tank he enjoys climbing on. There is one odd thing about him, he does not like to spend much time on the land. Every now and then he'll come out but he prefers scavenging and running about in the water for the majority of the day. I fear he may not be drying himself off enough. Also last week i noticed when he did finally come onto the land he was producing bubbles and appeared to be cleaning himself with those bubbles, is that normal? This white film he's acquired he tries to pick off and eat but doesn't appear very successful at picking it off, what could the film be?

    Now Bob didn't come from an aquarium store, the poor dear came from a Wal-mart where they had him and a bunch of other fiddler crabs in tiny plastic dishes with rocks, a couple drops of water and no food. They were listed as freshwater creatures, which is horribly erroneous and i plan on speaking to and thoroughly educating the manager today when i go there to hopefully rescue another one of these (if they haven't all been killed from starvation or lack of basic needs). But before i put female in the tank, i'd really like to know if what Bob has is mold, disease, or if it's something simple like he's going to molt soon? Maybe it's a lack of a certain protein or mineral? Or is he spending too much time in the water and if so how do you keep him out of it?

    Pictures:

    bobaquariumviewa.jpg
    bobclaw.jpg
    bobfilm.jpg
    bobfilm2.jpg
    bobfoodclearer.jpg
     
  2. Wendy Lubianetsky Well Known Member Member

    I salute you for trying to save the fiddler crabs. I did not know they were salt wter creatures until I killed them in my aquarium. They are very interesting creatures. I could not see the film you were talking about in the pictures, however, I would assume it is some sort of bacteria. Can you pick him up and simply wipe it off? You have me at a loss because I have had fiddlers but, they never had a white film. I even googled it and could not find anything on it.
     

  3. Mike Fishlore Admin Moderator Member

    Just guessing here about the white film... but is it starting to molt maybe?
     

  4. catsma_97504 Fishlore Legend Member

    I am thinking the same thing!
     

  5. Wendy Lubianetsky Well Known Member Member

    By the way, Welcome to Fishlore.
     
  6. aquilusdomini Initiate Member

    Many thanks to all for the welcoming :)

    We've noticed the white film seems to come and go depending on how long Bob stays out of the water, so it probably is a bacteria or maybe a fungus that's water dependent. He doesn't show any signs of molting any time soon and other than a few colour changes that depend on the temperature and light, he doesn't appear to have changed in any way at all. I'm keeping my fingers crossed for him and hope that the tank set up is sufficient for his needs. It would be really fantastic if he could live to the average captive lifespan of 3 years or beyond.
     
  7. Stang Man Well Known Member Member

    The first thing that comes to mind and I can not see from your pictures what you are talking about but it sounds to me that it could be an algae that is fading possibly from the water and not sure how much lighting you provide per day. I have also seen this with soft shell brackish turtles and was due to not enough water changes and also by using tap water we started using R/O water and it went away.
     
  8. aquilusdomini Initiate Member

    thanks to all who replied :D bob's film may have been an algae but the good news is...
    the film seemed to disappear on its own with the addition of more salt to the water. salinity may have been the issue all along as it leaned more toward fresh than it did toward marine. bob molted the other day and is doing good, no film and he has regular night and day colour changes (light at night, dark during the day). we got him a friend and...well...that's for a new thread. let's just say his friend needs her own tank now...
     
  9. ryanr Moderator Moderator Member

    Thanks for the update. Glad Bob is doing great :D