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View Full Version : why don't octopus and other cephlapods live very long?


shrimphead
06/06/2011, 12:26 PM
as the title says whats the reason biologically speaking why they don't live very long? i know they die after they breed. and also why do the cold water species live longer?

jimmy_beaner
06/06/2011, 12:32 PM
In general, colder temps mean slower metabolism. Less energy available typically in colder environments so it pays to live longer rather than reproduce rapidly. In ecology, there tends to be two ways to "win" evolutionarily. Either reproduce quickly (and often) with shorter life spans or reproduce slowly, invest more energy into offspring and live longer.

I'd assume they would have rather large clutch sizes (typically "one and done" species have very large numbers of possible offspring in that one clutch). If you find this is the case, you have your answer. They have been evolutionarily geared toward one massive reproduction event.

bradleym
06/07/2011, 12:33 PM
Cephalapods do breed in large clutches, but I wonder why there aren't any that raise their young or live longer, like fish for instance.

malac0da13
06/07/2011, 10:28 PM
I think jimmy nailed it. They reach sexual maturity quick breed. Take care of the eggs then die not long after. They do seem to put a lot of effort into protecting and nutting the eggs until they hatch.

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shrimphead
06/08/2011, 07:39 AM
thanks for the intelligent reply's, so if the metabolism is higher in the warm water species is it effecting their hearts and thats why they die quicker. just trying to understand what part of their anatomy fails quicker for whatever reason it may be (faster metabolism ect)
weird question i know.

bradleym
06/08/2011, 07:46 AM
Cold-blooded animals respond to their environmental temperature. Like snakes getting lazy at night because it's cold. The lower metabolism slows down their growth as well as their death. Additionally, many species in deep cold water will live longer, and get bigger. A good example is the giant and colossal squid species.

jimmy_beaner
06/08/2011, 07:50 AM
thanks for the intelligent reply's, so if the metabolism is higher in the warm water species is it effecting their hearts and thats why they die quicker. just trying to understand what part of their anatomy fails quicker for whatever reason it may be (faster metabolism ect)
weird question i know.

There are a couple possible things. I doubt if it's the heart giving out. There's an advantage to growing quickly if your reproduction rate is off the charts. What this means is that you complete your life cycle faster. In warmer waters, there is more energy available for growth. I would assume there tends to be more biomass at lower trophic levels and therefore can support more animals in these warmer regions. Also, many enzymes tend to be more efficient at elevated temperatures, which means they can process chemicals/molecules faster. When you combine faster processing with more available energy/food you get faster growth. These animals can then use that to reproduce faster but carry the onus of dying after reproduction so they end up with shorter lives.

If you wanted to go with the "bodies giving out" argument, they could have rather reduced ability to process metabolic breakdown products (some of which can be toxic) and over time, these biproducts damage the body... though I don't think I would buy this as easily as the first argument. For whatever it's worth, animals with very short life spans don't need to have requirements for excellent DNA repair pathways (as they likely won't be alive long enough to develop a cancer/tumor that would kill them).

cadre
06/09/2011, 01:31 PM
I'm sorry but I have a hard time believing the 'slow metabolism means they live longer' argument. Evolution would suggest that these animals and their metabolisms are adjusted to their environments. Maybe the food sources or predators in cooler waters make larger body sizes necessary and longer lifespans allow for that growth?

I would think that when brooding, a female octopus puts out a lot of energy without taking much in and that may lead to her death. I know that in humans, the mother's wellbeing will be second to the child during pregnancy (meaning, energy will go to the baby first and the mother second). I'm still learning about Cephalopods though so I'm definitely not sure what happens.

JothamTheSlayer
06/10/2011, 02:14 PM
They live life in the fast lane.

Opcn
06/30/2011, 02:54 AM
Their cells turn over molecules more quickly, metabolizing sugars and fats and proteins in order to grow quickly. All of that rapid action leads to the production of free radicals and oxidative damage. Their bodies pull some tricks to keep them going in the end as they care for their nests, but then they die. If you are a one and done breeder it make no sense to hold anything back to live off of after the spawn. Additionally the food that the young need to eat is food that the parent is incapable of catching for them. Any kind of teamwork would just attract predators that would eat the young and be counterproductive as a result. One step further the young probably need to be learning to catch food on their own. the skills they develop hunting on their own doubtlessly come in handy as they grow.

cadre
06/30/2011, 11:57 AM
Their cells turn over molecules more quickly, metabolizing sugars and fats and proteins in order to grow quickly. All of that rapid action leads to the production of free radicals and oxidative damage. Their bodies pull some tricks to keep them going in the end as they care for their nests, but then they die. If you are a one and done breeder it make no sense to hold anything back to live off of after the spawn. Additionally the food that the young need to eat is food that the parent is incapable of catching for them. Any kind of teamwork would just attract predators that would eat the young and be counterproductive as a result. One step further the young probably need to be learning to catch food on their own. the skills they develop hunting on their own doubtlessly come in handy as they grow.

This makes sense but since octopuses are so smart, and they can learn from each other, it seems it would be beneficial if the parents lived longer and taught their young. I guess it would attract predators but wouldn't be what the parents are for? Protection and such I mean.

Opcn
07/01/2011, 08:08 AM
It's very difficult to protect a swarm of 5000 babies, and there is a problem of scale as well. A relatively mature octopus can learn off of another octo, but with the babies we are talking about something the size of your thumb at the biggest! Those babies wouldn't be able to follow mom on a shrimp or a crab hunt, and they wouldn't be able to mimic her feats of strength catching fish or opening clams. I think there's kind of a one way valve so far as size is concerned.

derekdelisi
07/01/2011, 12:18 PM
I would think that when brooding, a female octopus puts out a lot of energy without taking much in and that may lead to her death. I know that in humans, the mother's wellbeing will be second to the child during pregnancy (meaning, energy will go to the baby first and the mother second). I'm still learning about Cephalopods though so I'm definitely not sure what happens.

x2

An octopus not given the chance to reproduce will live longer. Like many animals.

Why this is the case is a whole other question.

asid61
07/08/2011, 11:14 PM
it's very difficult to protect a swarm of 5000 babies, and there is a problem of scale as well. A relatively mature octopus can learn off of another octo, but with the babies we are talking about something the size of your thumb at the biggest! Those babies wouldn't be able to follow mom on a shrimp or a crab hunt, and they wouldn't be able to mimic her feats of strength catching fish or opening clams. I think there's kind of a one way valve so far as size is concerned.

+1

Opcn
07/10/2011, 04:20 PM
It also just occurred to me that cephalopods haven't got an adaptive immune system. As vertebrates our immune systems detect foreign substances (called antigens) and then custom build proteins (called antibodies) to latch onto them and do functions (like killing what ever it is attached to, or binding up working surfaces) and constantly tailor those antibodies to fit better. This enables us to live much longer because parasites and infecting organisms cannot adapt to the stable chemical environment of one individual or population because each of us are constantly changing our antibodies to match them. If an adult ceph. were to stick around and hang out with its offspring it would probably be just colonizing them with the same organisms that it has working to kill it, and giving those organisms a head start. The short generational time of the cephalopods probably gives them better adaptive advantage against parasites.

capecoral
08/16/2011, 12:18 AM
Maybe some of these ideas can be used to help them live longer in our tanks.

Opcn
08/16/2011, 05:12 AM
I think that is unlikely. If we knew how to arrest the programmed aging process or to half oxidative damage the holder of that knowledge would literally make billions of dollars off of selling it for use on humans. I think the standard cool water tank and hand feeding the infirm older ceph are probably the most effective ways to keep them alive a long time.

Opcn
08/16/2011, 05:13 AM
I should mention that I had the same thought when I first learned about aging as an undergrad, given my extreme vanity I must therefor conclude that it is a smart thought, not a dumb thing to ask, just the laws of nature conspiring against our interests :)