dtodd wrote:A few months back I came across an octo denned in Cove 2 and shot this picture of what, based on Greg's comment in this thread, I now believe to be a spermatophore being blown out of the siphon. Does anyone know how long the females hold on to the spermatophore before ejecting it or just what is going down there? Calling Roland Anderson, are you out there?
As I mentioned to Greg, this is a very rare photograph to get so treasure it.
I don't believe anyone has any documented evidence as to how long the female can store the sperm but reports from aquaria where they have brought in a female GPO and then had her lay fertile eggs suggests that 5 to 6 months is about the limit.
The spermatophore is a very interesting object in that it has one tube enclosed in another tube. The inside tube is where the sperm is. The outside tube contains a substance that absorbs water and increases in size. If you ever get the chance to have a close look at the male's hectocotylus (3rd right arm tip) you will see a groove there. The spermatophore has a string or tail on the end that fits into the groove of the hectocotylus. When the spermatophore is passed to the female the string is broken off allowing water to access the fluid in the outer tube. This fluid now swells and because the outer tube is harder than the inner tube the inner tube is crushed. Imagine holding a toothpaste tube by the end and running your hand down it while you squeeze. All the toothpaste would be pushed out the end and so is the sperm in the inner tube of the spermatophore.
Once the female has stored the sperm the spermatophore is discarded and I think that is what your photo has captured.
edofleini wrote:
The male is tasting the water with his suckers and in particular he is tasting for a chemical that is produced by a female who is ready to mate. I should say, at this point, that I has not been proven that female GPO's produce pheromones but most of us are convinced it is true. Anybody want a M.Sc. project?
Jim Cosgrove
Co-author of SUPER SUCKERS - The Giant Pacific Octopus and other Cephalopods of the North Pacific.
Hi Jim! Welcome to Northwest Dive Club !
So how would you prove that? Taking samples of water nearby a female, a male who faces the current with his mantle spread out or where a bunch of males hang around near the den of a female?
Can you tell from the color of the octopuses that I saw whether they were mating or not?
edofleini wrote:
The male is tasting the water with his suckers and in particular he is tasting for a chemical that is produced by a female who is ready to mate. I should say, at this point, that I has not been proven that female GPO's produce pheromones but most of us are convinced it is true. Anybody want a M.Sc. project?
Jim Cosgrove
Co-author of SUPER SUCKERS - The Giant Pacific Octopus and other Cephalopods of the North Pacific.
Hi Jim! Welcome to Northwest Dive Club !
So how would you prove that? Taking samples of water nearby a female, a male who faces the current with his mantle spread out or where a bunch of males hang around near the den of a female?
Can you tell from the color of the octopuses that I saw whether they were mating or not?
Hi Betty:
I am not an organic chemist but I suspect that ocean water samples would have so many chemicals in it from so many species that no one would be able to separate out the octopus. To my mind it would be best to build a large version of an apparatus that is used for smaller species and that is a kind of maze.
Usually it is Y-shaped. You put the suspected gravid female at one horn of the Y and the mature male at the bottom of the Y with water running from the top of the Y down both horns towards the male. If he moves up the Y to the female on repeated tries then it is assumed there is an attractant involved. Random chance would say that the male should move up the horn without the female as many times as he goes to the female.
Once you are sure that the male is moving to the female then perhaps a water sample run through a gas chromatograph may isolate the pheromone. The really difficult part of the project would be constructing the apparatus in a place large enough to house it and then obtaining a series of mature females to test.
I am not able to say conclusively about your photos because I cannot see where the arms are but if they are not mating then it is very odd to have two mature animals that close to each other.
edofleini wrote:
I am not able to say conclusively about your photos because I cannot see where the arms are but if they are not mating then it is very odd to have two mature animals that close to each other.
Jim
The octopus #1 had a couple of arms coiled around its mantle and the rest underneath a structure that looked like a pile of rocks with a concrete slab stuck between them. Octopus #2 had most of its arms hidden either by rocks or underneath the mentioned structure. Now I am thinking that maybe there was female underneath the structure and those two octopuses were males going after her but I cannot be certain because I could not see anything. I tried to find the same spot two weeks later to see if there was a den there but I could not find it.
!