I've heard that an hungry octopus when lacking food can eat its own arm or two . Is that true? I know that when they lose an arm a new one grows back, so how long does it take to grow back to full size? if it goes back to full size that is.
Interesting question! Lady TTF (Tintenfish, aka Kat) went for a dive several days ago and saw something like 5 octopus; she (and our jolly good cobber from Kelly Tarlton's, Nik) collected one of them; it has 3 arms missing (I didn't think it appropriate to ask questions).
The animal was collected 2 days ago and is doing fine; I'll tell you how long it takes to regenerate the missing arms.
Eating oneself (in octopus speak) is called autophagy; it is, as far as i can ascertain, not uncommon practice in stressed animals.
True, but there is some thought that it is a disease! we had one which had settled in very nicely, was eating and behaving normally and it suddenly started eating it's own arms, shortly after that the skin began to peel and we euthanised it. Problem is the disease version appears to be incredibly infectious. We had it this year, so drained the tank and let it stand dry for a week or so then refilled and restocked, in less than a week the new octi was eating it's arms. So we sterilised with bleach for a week, then neutralised it, replaced pipes and nets etc and we seem to be OK now (fingers crossed!). Budelmann has a paper on it where he reports it passing from tank to tank in a research situation. While he thought stress played a part, he was also wondering about disease, at one stage there was some discussion that it may be a prion (like mad cow disease). I don't think any further work's been done on it though. I was discussing it with James Wood and he doesn't think any more work's been done either. Research project there maybe???????
Beautiful and what a great memorial for a mate......wish I could find a new spp. I know who I'd name it for (had a dear friend killed this year, she'd have thought having an octi named after her the best......!)
I've just returned from feeding him; there's certainly a very fine, long piece of arm developing from one of the arm stumps; will try and get a pic morrow. Just fed him a pile of crabs ... literally ... the thing devoured the lot in about 2 seconds. Took me ages to collect them too!
autophagy is a physiological process by which enzymes within a cell digest its parts. research (albeit in relative infancy) suggests a correlation exists between autophagy malfunction and diseases, such as cancer. this would make it sorta the opposite of apoptosis. jmo.. a.f.
Skin biting/chewing exists in some humans, part of the self-injury syndrome which is on the same neuropsychological spectrum as obsessive-compulsive disorder. It is classified as an "impulse control" disorder, and is often the result of abuse (either physical, emotional, or sexual) in childhood.
This form of self-injury (which can also include skin-cutting or skin-tearing behavior) is NOT a form of masochism, nor an attempt at suicide; rather, it creates a trancelike dissociative state which enables the person to escape environmental stressors or severe anxiety.
I am neither a psychologist nor a marine biologist, but IMHO there may be some relation between such behavior in cephs and in humans. (It has also been observed in non-human primates, and I believe certain other species.) I think stressors which do not allow an individual organism to lash out at the actual source, may turn the aggression inward to self-destructive behavior, which in turn releases endorphins that enable the organism to "cope" -- albeit in a very counterproductive way -- with the situation.
Do cephs produce endorphins? Steve-O, Jean, or Kat, perhaps one of you can answer that, as I don't know. I recently read that fish which have been caught on hooks were found to produce endorphins, presumably to counteract the pain of being pierced.
The neuropsychology of stress -- in both humans and animals -- is of great personal interest to me, so any further info on the subject of autophagy in cephs would be most appreciated.
I am neither a psychologist nor a marine biologist..I think stressors which do not allow an individual organism to lash out at the actual source, may turn the aggression inward to self-destructive behavior, which in turn releases endorphins that enable the organism to "cope" -- albeit in a very counterproductive way -- with the situation.
IMHO your assessment is excellent. The only point with which I disagree is your inference that all coping mechanisms are counterproductive. Stress (apart from that which is life-threatening) inspires coping. Rather than self-destruction, it is self-preservation. JMO.. a.f. :)