Autophagy in Octopods

Discussion in 'Physiology and Biology' started by Euprymna, Nov 17, 2005.

  1. Euprymna

    Euprymna O. vulgaris Registered

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    Hi all,

    I'm currently doing some work aiming to evaluate the potential of ongrowing O.vulgaris on a commercial scale. This, as you surely know implies minimizing costs, hence providing them with the cheapest food possible i.e. not crust nor molluscs! For that reason we are giving them mackerel (S. japonicus) once a day (about 20% of their body weight day-1). Of course they never eat everything we give them but they are still showing reasonnable growth rates.
    However, the problem is: a major part of the isolated individuals miss an arm or a part (interestingly always the third right arm, hectocotylus in males!!) which they definitely had when they arrived from the sea 'cause we had to sex them. This means that they eat their own arms. I presume they do so to compensate for a lack of a certain nutrient in their diet.
    I've had a look in the literature and Bernd Budelman wrote a paper on this topic in 1998.

    BUDELMANN B.U. 1998. Autophagy in Octopus. S. Afr. J. Mar. Sci 20:101-108.

    which of course my librairy doesn't have! Does any body have a copy??
    We are currently designing an experiment to try understand this.
    Does any body knows if autophagy has been reported for wild octopuses?
    Any thoughts on this would be appreciated?
    I attached a picture showing clearly a part of the third right arm missing.

    cheers,

    Eups
     

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  2. Jean

    Jean Colossal Squid Supporter

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    Hi Eups,

    Pm me a snail mail addy, I have that ref. It may be the weekend before I can send it tho' and no promises about how long it will take to get to you what with Christmas mail and all!

    To be honest that doesn't entirely look like the autophagy we've observed (although I'm sure there are different expressions of this nasty bug!) We've had it a couple of times in the aq :mad: in all cases more than one arm was involved and they tended to bite it off at the base...quite close to the web, colour and skin "tone" was off too.

    Kinda weird how they're going for the hectocotylus :confused:

    All of our octis are wild caught and one came in with arms already chomped. There is a theory that the disease is a prion (like mad cow) which is present in many individuals and it can be triggered by stress. This is of course unproven. Colin has an article in the database about diseases and autophagy. I would hazard a guess that your diet is a major contributing factor. Octopus just don't do well on a fish only diet there is something in the crustaceans that they need and although yours were growing well I would say they were missing an essential nutrient. Our octopus rarely eat fish in any way shape or form!.....their choice!

    Word of advice if this is autophagy it is incredibly contagious. Anything that can be thrown away, must be, other stuff has to be sterilised in Sodium hypochlorite for at least a week, then neutralised for a week, then soaked in freshwater for a week, then left dry for a week.........then you can use it again. This is the only way we were able to prevent a reoccurrance....miss out a step and the next octi gets it too.

    I'll look out that ref!

    jean
     
  3. Feelers

    Feelers Vampyroteuthis Registered

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    I wouldnt know anything about autophahgy but if that pic is what they are raised in maybe an old pot or something for a den might help. I know that octo's feel alot safer with a den. Might help lower stress a little.

    An article Righty on this board found - http://www.advancedaquarist.com/issues/jan2004/invert.htm
    Might have some good info for you in regards to the nutritional value of some foods.
    Possibly of interest is that fresh water crustaceans are actually very similar in nutritional value, and lower in some saturated fats than their marine counter parts. I would imagine they would be quite a lot cheaper too!

    Have you tried supplimenting their diet with mussles or something? I would imagine that one mussle a week is much better than none at all, especially when lack of certain nutrients is a problem.
     
  4. bigGdelta

    bigGdelta Vampyroteuthis Supporter

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    autophagy is common enough they had to have a word for it?
    (curls up in corner rocking) yeeecchhh
     
  5. Feelers

    Feelers Vampyroteuthis Registered

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    Who could blame them? Octopus does taste good! :grin:
     
  6. Euprymna

    Euprymna O. vulgaris Registered

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    Feelers, we are not growing them in these sort of boxes. They are all in large tanks (~3200 Litres) with a den (large PVC pipes) for each individual. The box in the picture is a transitional tank were we put them, just before being weighed.

    As for supplementing the diet with higher quality food such as mussels. We haven't done this because previous data have shown that if you start giving them "tastier" food, octos will get more picky and will refuse to feed on the main diet. If you know there is caviar around, you will not be interested in eating corned beef!! It's like my cat! He almost doesn't accept anything else than fresh food now!
     
  7. Euprymna

    Euprymna O. vulgaris Registered

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    Wow, wasn't aware it was actually caused by a some sort of pathogen :shock: Our system is opened, so I guess sterilising everything will not secure things for a long time!

    It's true thatn it is quite frequent to have indivduals arriving from the sea with arms missing, but I attributed to predators.

    Eups
     
  8. valter

    valter Pygmy Octopus Registered

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    That is very interesting! Is it a pathogen common to all cephalopods? or only octopus?

    valter
     
  9. Jean

    Jean Colossal Squid Supporter

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    So's ours! the worst thing about an open system is that if you have more than one octi connected they will ALL get the disease....nasty! That's the situation Budelmann reported.

    Not all of the missing arms will be autophagy. Autotomy is quite common too. And yours actually looks more like that. The arm in the pic that is missing is quite far up and I notice that arm II is showing signs of narrowing at about the same level. The octopus doesn't chew the arms off it bites right through, so that narrowing wouldn't be seen in autophagy. Is there any chance they're getting arms caught somewhere or in something?

    j
     
  10. bigGdelta

    bigGdelta Vampyroteuthis Supporter

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    I thought prions had to be eaten ie kuru, mad cow and the new one killing elk here in the US.
     
  11. Jean

    Jean Colossal Squid Supporter

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    Octopus are cannibalistic!

    But there is a school of thought that Prions can be resident in cells and just need the right trigger to set them off. Much to learn about such things!!!!

    J
     
  12. Euprymna

    Euprymna O. vulgaris Registered

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    luckily, it doesn't seem to spread too fast. We have about 15 octopuses with all their arms and they have been in our system for about 17 days. Only :roll: a third of the individuals have an arm problem.
    Hopefully they will stay intact until ready to end up on a plate! :sad:
    God I hate saying that!

    eups
     
  13. Jean

    Jean Colossal Squid Supporter

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    Which also suggests that it's not autophagy! That spreads FAST!!!!

    J
     

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