idea for breeder

[Brock Fluharty]

Ok. I guess that is a relief if I want to breed, but there is the obvious downside of not knowing what species it is...I know how to tell if it's a bimac though. It will show it's eyespots sooner or later. Are bimacs large eggs types? Is Bali a warm temperature area? It sounds like it. Thank you guys so much for not flaming me for wanting an octo!!!

 

[DHyslop]

My guess is that eggs are laid in the late Spring/early Summer, and the new generation of bimacs are too small to be found by collection divers until close to fall, when they're about the size of a lime.

This is merely an anecdotal observation and hasn't been tested. If anyone has done a formal study, I'd love to hear about it.

Hi Jim,

I have just a study in my hand right now.

During the spring of 1984 at Santa Barbara (which represents the northern range limit of this species), egg-laying took place from at least December through May, with hatching in May through September. In the southern range (San Quintin), spawning occured from October 1984 through January 1985, with hatching from January through May 1985. These estimates by no means represent time limits of spawning, but they do inidcate a broader spawning season for this species than reported previously (Hochburg & Fields, 1980). Caution is advisable in viewing these estimates because the 1983/84 "El Nino" conditions may have affected the normal spawning season.

Anyway, Jim's right about aquaculture. It won't be profitable. The only way it will happen is by folks like us who are interested in raising hatchlings from eggs as a hobby in itself on the occasion that eggs are available. That isn't a good or a bad thing, it just is a sign that this is a hobby in its infancy. Any one of us could become (and some here are already on their way!) the cephalopod equivalent of Anthony Calfo.

Dan

 

[cephjedi]

Thanks for posting the hard facts Dan! Interesting stuff, and it's good to know I was at least in the ballpark, ha!

For Brock: Bimac 101! There's two flavors of "Bimac:" Octopus bimaculoides and O. bimaculatus. Here's how to tell em apart:

`latus:
-Larger overall (head is grapefruit sized)
-Striking flattened out display
-blue ocelli in jagged radiating pattern
-black ink
-small eggs

`loides:
-Smaller (head gets orange-sized)
-Generally darker complexion
-Blue ocelli in a ring-shaped chain
-Brown ink
-large eggs

News! We had our first small egg hatchling today! Named him "squirt" He's about a millimeter across and blows the cute scale as he attempts to jet around the nursery tank. More info as it comes in.

Tonight we acclimate benthic and pelagic copepods!

Cheers! CephJedi

 

[Brock Fluharty]

So I want the bimaculoid for breeding.

 

[DHyslop]

Thanks for posting the hard facts Dan! Interesting stuff, and it's good to know I was at least in the ballpark, ha!

Hehehe, Jim now I'm really going to pick on you! In that article and another in the same volume (Malacologia v29) individuals from different populations of O. bimaculoides are reported to grow larger than O. bimaculatus!

Discussion on it here: Bicamculoides vs bimaculatus[sic]

The caveat is neither study's main goal was to look at size, so the comparisons may not be fair: it is possible that the global average 'latus is indeed larger than the average 'loides; however in those particular samples it seemed the other way around!

As hobbyists I think we've been passing on a few myths without truly understanding the sources. I've been spending time in the peer-reviewed literature (preparing to someday hatch some bimacs, hopefully) and have been surprised at the number of things I've found contrary to previous understanding--the size differential being a good example.

I don't know about the other characters used to distinguish the two bimacs--I haven't found mention of them in the literature. It would appear that most scientists differentiate the two based on egg size or gut bacteria. If you have a good email for Forsythe you might email him, given that you know him and I'm sure he would know (and the NRCC addy I have for him is bouncing!).

Dan

 

[Nancy]

I've also heard that there's a bimac in Asian waters, maybe Indonesia. I was told that some of our bimacs come from there. Don't know whether it's true, but I heard it from an LFS.

I was very determined that my first octopus be O. bimaculoides, but when the tiny octo arrived, I found that her eye spot was even smaller and no way was she going to hold still for inspection!! So it was a while before I could determine that she was a bimaculoides.

John Forsythe has retired, but we might be able to reach him.

Congratulations, cephjedi, on your hatchlings!

Nancy