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Male or female??

It's quite difficult to tell on a bimac. As a result, each of our bimac owners just decided on one sex or another and chose a name. I thought that Ollie was a male until I saw her with a string of eggs! Same was true for Carol's Ink. And it looks like Roxy, who was given a female name, is actually a male.

So Otis is a fine name - just go with it!

I have never managed to visually sex an octopus while it is still alive! You may get lucky and spot the groove running along an arm called the hectocotylus which is a modified arm the male uses for passing sperm to a female.

In that case you have a male, if you dont see it, it may be a female or a male whose hectocotylus you cant see!!! :smile:
O. bimaculatus sexing

I forget where I found the information, but when I first got my bimac, Andy, I read that for this particular species, bimaculatus, males do not possess the modified tentacle or hectocotylus, but instead have obviously enlarged suckers on the 2,3 and 6,7 arms. This feature is only noticeable in mature animals. Species where there is a hectocotylus, it is usually on the third arm. The pacific octopus at the Long Beach Aquarium is very easy to sex as a male when he comes out because of this feature.
ok, maybe a stupid question, but I'm gonna ask it anyway.

you say a male is recognized by the hectocotylus (and I thought mary poppins had long difficult words :P ) on the third arm.

but how do you know what the third arm is? an octo's arms are in a circle around his mouth. which arm is first, second,... ?

or do you just look at all the arms and hope to see a hectostuffthing?

another stupid question while I'm at it.

if octo's are so difficult to sex. how come the bimac is bred? do you just throw 2 animals together and hope they turn out to be male/female or is there another trick involved?

:notworth: thanks for the patience and attempts to make me smarter :notworth:
The breeding I'm guessing is random, either that or they really keep an eye out for the hectocotylus.

I know where the third right arm is but I'm not exactly sure how to put this in words. Anyone have a better explanation?
The arms are numbered in pairs (1st left arm, 1st right arm, etc). Pair 1 is the pair of arms that is most dorsally located, i.e. the furthest away from the funnel (the 'front' pair in an octopus). The ventral pair, nearest the funnel, is pair 4 (at the 'back').

You should also check this out. (Note figure 2) Very useful.

Gotta go to work now.

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