Dr. Octopus - Young mercatoris

Discussion in 'Cephalopod Journals' started by Icabod169, Feb 25, 2009.

  1. Icabod169

    Icabod169 Cuttlefish Registered

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    Hey guys,
    My name is Alex and i just received a new young mercatoris "dwarf" octopus from Sea Life inc. His new home is a 7g desk tank that i decorated with live rock, old barnacles, a couple greek pillars, and some shaving brush plants. Although i know it might be bad, I added a couple tanksmates to the aquarium. There's a sure to be eaten green chromis (which helped the cycle process), a couple of nano pencil urchins, and a horseshoe crab that i made a separate sandy bottom for. The tank has 2 filters with foam guarding the intakes. I will keep everyone posted on recent developments!

    Here are some pics i took while acclimating.
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  2. Icabod169

    Icabod169 Cuttlefish Registered

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    BTW The little guy's name is Dr. Octopus. Doc for short.
     
  3. sedna

    sedna Larger Pacific Striped Octopus Supporter Registered

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    Super cute little friend! I would encourage you to ditch the chromis, though!!! Fish that are aggressive enough to not get eaten are aggressive enough to damage your pus- most especially by biting at their eyes which can cause life threatening infections. I've seen chromis that were pretty docile, then again I've had some that would hold their own against triggers, even start the fight.

    I'll wait to let others chime in about the urchins, and as you said the crab might be food but then again might be ignored by your octo.
     
  4. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Alex,
    The tank is likely to be OK for a few months but 7 gallons is too small for the life of the octo. I would recommend changing a gallon a day as part of your feeding routine even now.

    Please take the chromis out and see if you can trade it for something useful (pair of plastic tweesers for feeding maybe). Be sure your octo has a place to hide where the fish can't peck at it but you should not have both in the tank at all. NO FISH in this sized tank with merc, NONE! The tank can't handle the wasted even if the fish does not get a hold of your dwarf.

    The horseshoe is fine but will either die or out grow the tank quickly. A larger octo might try to eat it but I don't think there is an issue with the merc, certainly not at this size but check that it is alive EVERY day and don't let it stay dead in the tank overnight if it dies. At 7 gallons you have very little biologic (if any) filtration and water can go bad overnight.

    The pencil urch should be fine but it will become a meat eater. They will eat plant (seaweed and algae) and a little meat naturally but become soley meat eaters - which includes some corals - if there is not enough algae and they don't seem to revert once they start so you will need to provide some dead shrimp or something similar and then be sure any remains are removed before the water quality is effected. I have used dried seaweed but it often has aptasia that will spread when hydrated and can start a problem.

    I would encourage you to start a tank twice that size now so that it can be cycling.
     
  5. Icabod169

    Icabod169 Cuttlefish Registered

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    Thanks for the pointers! First of all I didn't know that chromis could be aggressive. I just thought he'd be a snack or something. I just got off work and took a look inside the tank. Doc has made a home inside the bottom section of the old barnacles and i gave him a shell to use ass a door. Hopefully I can get him to eat a minthrax tonight. I was also wondering if I could use a blue led instead of red to see him at night cause I had one of those lying around. I know the tank is kinda small but it was first cycled to house cuddlefish but the eggs never hatched :sad:
     
  6. forever27

    forever27 GPO Registered

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    A lot of times chromis aren't too aggressive towards other fish and inverts, but I'm sure the one you have is too big for your octo to eat. Therefore, as D and Sedna have already stated, it'll probably nip at or attack him/her. Especially in such a small aquarium. Be sure the crab is small enough for him to eat as well. I use a blue light to view my O. luteus at night, also a nocturnal species. Just make sure it stays pretty dim or he won't even bother coming out.
     
  7. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    The reason for using a red light is based upon studies that indicate octopues cannot see red. In theory, using the right frequency of red, you could have the tank fully lit and the octo would think it was dark (sometimes you will see zoos use this for bat houses and infrared light). I am not 100% sold on them not detecting the light (LED seems more detectable than red velum filtering but both seem to work well enough to be able to observe nocturnal octos). One of our New Zealand members (Dr. Jean, University of Otago, Portobello Aquarium) has noted problems with a large daytime octopus and blue lighting (like actinics) but none of the smaller animals have been reported as objecting. One of the things I do is to leave the red light on 24/7 so that there is no "darker" period. I have raised two generations of mercs (one group captive raised, the other captive bred) using this kind of lighting scheme without known problems (the oldest of each group lived over 12 months and the original wc lived 11 weeks post hatch). However, it does not mean that it provides any benefit :hmm:

    The barnacles were a good choice for a den option. Several of my mercs have chosen them and I had much higher visibility than the ones (with the exception of Sisturus) that chose to live in the live rock.
     
  8. Icabod169

    Icabod169 Cuttlefish Registered

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    Doc just took his first feeding! I just lured a small thawed krill in the "Hinges" of his shell door and i saw a small shadow then something snatched the krill. I'll make sure tomorrow morning that he ate the whole thing. I put the blue led up until i get a red one but it's real dim and i dont think he will notice. I'm keeping my eyes open...:cyclops:
     
  9. Icabod169

    Icabod169 Cuttlefish Registered

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    BTW
    The horseshoe crab seems to crawl around alot. He might have to go...
     
  10. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    As long as the horseshoe does not die, he will make a good scavenger. He cannot bite the octo (if you gently pick it up and place it in your hand you will see that it has no ability to bite :rolleyes:) and there is little chance of the telson doing any damage (it steers and rights itself with it). My concern is for the crab's survival in the tiny environment.
     
  11. Icabod169

    Icabod169 Cuttlefish Registered

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    I have to say, the blue light worked pretty well but I'm still goin to switch it out with a red one. As for what I thought was a feeding last night, I found the shrimp still in the tank. A little chewed up, but there none to less. I also thought he might have ate one of the minthrax crabs but i just found both of them:neutral:. My next try is going to be blue legs.
     
  12. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I am glad you reported the krill as not being eaten. It does appear that frozen krill are not accepted almost universally so when someone reports consumption a follow-up is desired to determine if there is a difference in brands or, as in your case, a sampling and rejection.
     
  13. sedna

    sedna Larger Pacific Striped Octopus Supporter Registered

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    I have one merc that loves hermits, and another one that so far will only eat fiddler crabs that are cut in half! Keep trying different stuff, you'll hit on something he'll eat.
     
  14. Icabod169

    Icabod169 Cuttlefish Registered

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    As I'm sitting here on my computer next to the tank, I keep looking over and Doc has moved to inside the top barnacle and is poking out with his head staring at me. I love it. It's like he's keeping post. The tank's lights are off and the blue light is on. There's a little light in the room.
     
  15. Icabod169

    Icabod169 Cuttlefish Registered

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    FIRST FEEDING

    WOW! So I went to the LPS today and bought 4 hermits. I threw them all in when i got home and relaxed for a while. I came back into my room and realized Doc was in a weird position like he was wrapped around something. I counted all the hermits and still had all 4. Checked the mithraxes and the red one was missing.
    After I observed him for about 10 minutes he brought his whole body out with his left overs, couple legs and a shell ripped open and empty. :octorun:Should I remove this stuff immediately? I really hope he accepts the hermits or my krill. Mithrax crab is too expensive for Doc to have.
     
  16. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Sometimes I feel like a broken record, fiddler crabs will be the most universal live food to feed an octopus. They are far cheaper than mithrax and you can reliably, legally and ethically purchase them here: http://www.aquaculturestore.com/swinverts.html

    If you order from Paul, request the smaller ones. If he can get them (he collects them weekly) he will (it does depend on availability). The male has a wickedly large claw and I always disable it by breaking off one tip. Often the fiddler will drop the arm when I do this so be sure you have the crab over the tank when you prepare it.
     
  17. Icabod169

    Icabod169 Cuttlefish Registered

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    How long will the crab survive under saltwater? What if Doc doesn't see it or doesn't have interest?
     
  18. Icabod169

    Icabod169 Cuttlefish Registered

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    Hey D,
    What time do mercs usualy come out at night? What can I put in the tank that can give me evidence that he comes out at night. I don't know if he ever comes out of his barnacle at all. Doc has also chosen a barnacle facing upward towards the light. Isn't this unusual? Everytime I view him he is just curled up in his den.
     
  19. gholland

    gholland Haliphron Atlanticus Supporter

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    Most of these questions have been asked (and answered) many, many times. A little use of the "search" option will reveal much info: http://www.tonmo.com/community/index.php?threads/8884/

    The dimmer your red light and the quieter the room, the sooner a new mercatoris will come out. After many nights of feeding and socializing, they will start to peek out as soon as it is "dark" and they see you. Mine often occupy upward facing barnacles, so I wouldn't worry.
     
  20. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Mercs are like the bigger guys, they all have their own personalities and sense of timing.

    Tapper (original wc female) was only seen rarely in her 45 gallon tank until I put in a barnacle and she chose it for brooding. Then she was visible on a 24 hour basis if she did not have her door in place.

    My wonderful Sisturus (captive raised) would come to the top of the tank every night at 11:00 and expect to be fed. It was so regular that Neal would check on him before going to bed and call me down from my office saying, "Someone is calling you". Medusa (his tank mate) learned from Sisty about feeding time but did not come out until I arrived with the goodies.

    Wiley (captive bred) could not be relocated to the smaller tank (he was born in a large tank and continually escapted the net). He was assumed dead over and over again for weeks at a time. I eventually quit feeding octo food to the tank and found him in the front looking for food. I captured him and put him in the smaller tank but he never took an interest in humans and denned at the back of the tank. He did learn to take shrimp from my fingers but he would not leave his den in my presence. He lived to be over 13 months old.

    Here is my "go by" for merc:

    If it is eating its health can be considered acceptable. If it closes itself up and won't eat, it is likely a brooding female. If it stays out of a den during the day and is overly friendly, it is dying, likely of old age. Old age can also be detected by the richness of color and the ability to hold color on a regular basis (not just once), but color is hard to determine with the nocturnals. I could tell more from the flash photos than by looking at them under a red light (where they are almost always white and rarely show red).

    It does seem to help to keep them in a well trafficed area, especially an eating room where people are regularly there but not running around (no help with this for Wiley though). You can encourage early night time appearances by turning off all ambient light around 9:00 PM. I think (subjective analysis) that leaving a red light on over the tank 24/7 is helpful for regulating their out and about time.

    There are no hard and fast rules with anything related to behavior, that is part of their attraction and curiosity.
     

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