Changing sex?

[Nancy]

Hi Steve,

Just watched the webcast from the British Museum. The question came up from the audience whether cephs (here they were talking about octopuses) could change sex, like some snails can. The answer given was "Possibly". Have you ever encountered instances of this? Somehow it doesn't seem likely.

Nancy

 

[Steve O'Shea]

Hmmmmmmm. I've looked at 'a few cephs' in my time and have never encountered anything remotely hermaphrodite, nor in the process of, or apparently having changed sex; neither have I read anything that any ceph is capable of this feat. This may well be yet another attempt to sensationalise the lives of octopus and/or squid (they're pretty interesting anyway without this sort of thing being said/implied). Unfortunately I missed the broadcast too - was counting sheep.

The only reason that I'm not saying 'no, this does not happen' outright is that there's always the remote possibility something will come out tomorrow about sex changes in octopus under environmental variables A, B and C, or some new, weird and wonderful species is discovered that morphs between male and female. I'm just not aware of anything at this point in time.
Cheers, O

 

[ceph]

Re: Changing sex?

Hi Steve,

Just watched the webcast from the British Museum. The question came up from the audience whether cephs (here they were talking about octopuses) could change sex, like some snails can. The answer given was "Possibly". Have you ever encountered instances of this? Somehow it doesn't seem likely.

Nancy

Well, the mollusks do it in jut about every way you can imagine but the cepahlopods have seperate and perminate sexes. Steve is right, this one of the few statements about cephalopods that I can think of that doens#t have an exception!

 

[Armstrong]

No no no no no wherever you heard this its PURE false. Iv studies Cephalopods for a LONG time and Octopus, Squids, and even cuttlefish cannot change there sex at all. Male Octopuses have a sperm like arm that delivers sperm in the mantle cavity of an Octopus while a female just has the ovum inside the cavity for the sperm to enter. They produce over 6,000 and even more eggs a year but sadly almost all of them get eaten as they are each as small as a grain of rice. Only 6 out of that 6,000 would survive.

 

[Steve O'Shea]

This is true Armstrong, but some of the deeper-water octopus species probably don't produce 6000 eggs, and the eggs of many of them, when actually deposited upon the substratum and encased within a capsule, might be as large as 22mm in greatest dimension. What you say certainly applies to the majority of pelagic squid and shallow-water species of octopus, but there are always exceptions to generalisations (bentho-pelagic squid like Sepioloidea spp. that deposit ~ 50 spherical eggs to 10mm diameter in a cluster and are pretty much exhausted (egg wise) afterwards; and octopus in the genera Benthoctopus, Bathypolypus, Graneledone, Thaumeledone, ... in fact many genera with an ..eledone end, and all cirrate (finned) octopus with which I am familiar).
Cheers
Me