[Octopus]: Maya - O. hummelincki

[DWhatley]

Roy,
Do the eggs look round to the naked eye? Maya's definitely look/looked round and not oval. Also, hers are totally opaque.

 

[Neogonodactylus]

Nope. They are your basic two mm jelly bean. I don't know if these are fertile. The other female that laid this week mated in the lab, but if this one is carrying sperm, she got them before we received her.

Roy

 

[DWhatley]

I wish I had a better judgement of size on Maya's eggs. From my view and estimation, her's are half that size, totally opaque and definitely round from the viewing angle I have/had (she has really closed down the den now and I can barely see her and nothing behind her). This would suggest that the eggs are infertile (if the ones on the glass are fertile, then this might suggest a reason for the difference) or these are different species. I am sadly thinking the later (both, of course, could apply).

 

[DWhatley]

Maya is still with me and has not left her den. She keeps the inside tightly covered from view now but based upon the last chance I did get to look inside, most of the eggs are gone. I keep expecting her to exit any time (I have given up on any hope on any viable eggs) but she stays firmly routed with one eye peering out. Serendipity never came back out of her underground den and just disappeared but Beldar and Trapper both wandered the tank for awhile (Trapper for 11 more weeks and would eat Cyclopeeze) before dying so I am hoping to have a least a last week with her.

 

[DWhatley]

Brooding - 5 weeks

I am pretty sure the eggs are all gone now. I never saw any hatchlings but the few times I could see into the den, the numbers seemed to decline and for over a week I have not seen any (she keeps the den heavily blocked with her arms now but when I see her gill openings, there are no eggs). I did not change the filter or clean the tank last week and when I did so today, I found a gooey, jelly substance on the bag of charcoal and on the outside of the filter sock as if it had oozed through. I think this is egg material and hopefully was not living young that all went through the overflow during the night. So sad.

I have tried and tried to get her to eat but she totally refuses. I put a tiny live crab in with her yesterday and this morning the rock it was on (the decorators don't move around much) along with several other of her den door materials were pushed a good 10 inches away from her den. I don't think she could have moved them this far away without leaving the den but we have not seen her out since the day or two after she put the eggs on the wall. In the last two days she has changed position so that her mouth is always pointing outwards. I tried putting a piece of shrimp with my fingers directly onto the suckers at the mouth. She grabbed my fingers with more strength than I would have expected but still refused the shrimp no matter how insistent I was. After she decided my fingers were not a danger, she just ignored me and pushed the shrimp away repeatedly once I removed my hand from the tank.

I also noticed that the starfish keep approaching her den. She picks them up easily and throws them out but I suspect they know the end is near. The serpents, however, are not pestering her at all.

 

[Neogonodactylus]

These are day 15. Eyespots are well developed.

 

[DWhatley]

Maya still has not left her den but the eggs are definitely gone as I can now see the strands where they were attached. I hope the goo I found in the filter bag was egg and not octo but I will never know. It deterorated while sitting in a bucket and produced a vile smell so it worries me that ther may have been live young that went through the overflow directly after hatching. Maya is not ready to give up yet and is still defending her den successfully but the starfish has been continuously approaching for the last couple of days. I am not sure what it is detecting since her flesh seems firm but it is unusual for it to pester her. I have a short video I will put up on YouTube but here are a series of photos.

 

[Neogonodactylus]

Our first female to lay produced infertile eggs. They began to disappear at around day 10 and by day 15 were all gone. I assume she was picking them off. Day 16 she moved off the egg site. She is now about half her size when she laid. The end is near.

On the other hand, the second female to lay has developing larvae that now have active chromatophores (day 19). I'll post a picture later. Of all the female octopus I have had lay eggs, this female's defense of her brood is by far the most fierce. When I try to use a large pair of forceps to take a few developing eggs to photograph, she initially gathers the eggs under her and directs the mouth at the forceps assuming the typical aggressive posture with the first pair of arms folded back over her head. When I persisted, she attacked coming about a body length off the eggs, grabbing the forceps and repeatedly biting. You could literally hear the beak striking the metal forceps. She also made a couple of grabs for my hand, but fortunately I got out of the way in time. This behavior was interspersed with her shooting jets of water at me. All in all, a most impressive performance.

Roy

 

[Neogonodactylus]

O. filosis eggs - day 19 Here are a few eggs from the O. filosis brood at day 19. The chromatophores are functional.

 

[DWhatley]

The behavior matches Maya's as well as the timing on the infertile eggs (when I first noticed I could not see them) so I feel better that it is unlikely they all went live to the overflow. The stalks are bare but she will not come out and maintains the guarding post. She looks good and can still color (evidenced by her short attacks on anything coming in front of her den, including occassion quick attacks when she sees my magnifying lens outside the tank). Her breathing is heavy though and I have added an air stone near her den to encourage the CO2 out more rapidly in her immediate area. I am not sure the idea has a lot of merit but it hurts nothing and I feel like I am trying to do something to make her more comfortable (ie the crude attempt is more likely to make ME feel better than anything it does for her).

I "let" (as in she grabbed and I just left my hand there) her grab my hand once while I was cleaning the tank in front of her den. She grabbed fiercely but did not bite so I wonder it is the fact that you were obviously going for the eggs or that the object was hard (vs a soft hand) that brought about the biting. I am glad she did not try to bite after reading your description though.

I am assuming the infertile eggs were the ones on the glass and the in-tank mating produced the fertile ones since you said you had to go past her to retrieve the ones you photographed but please do qualify. It is interesting that they seem to lay eggs so quickly when placed in an aquarium even if they have not mated. I have wondered if the environment somehow queues the egg release or if it is just the stress. Both Maya and Serendipity were very small (compared to my two males) and should have (I think) grown much larger before brooding.

Roy, on another note. You (and James and Crissy) still use the term filosis and I have read varying reasons for keeping or disguarding the name. I know you use mercatoris even though they were originally classified joubini and that there are two distinct octos in this case but only one in the hummelincki/filosis naming and that the older name was dropped because of a very poor written description that was thown out without reading the backup information. Sooo which name should we be using and briefly (unless I can get you to pontificate), why?

 

[Neogonodactylus]

I poked around trying to find a revision that would change the name to hummelincki from filosis, but could not find anything definitive. As far as I can tell, filosis has precedence, so I will use it until I see that there is a formal revision. The mercatoris mess is easier. The type O. joubini is a small egg species and O. mercatoris was described as large egged species. They aren't easy to tell apart from preserved specimens (without eggs), but live material is obvious. However, there is at least one other similar species (Belize) that remains to be named.

Roy

 

[DWhatley]

Maya has Died

Maya died on Dec 21 (I think ). I had hoped she would spend her last week out in the tank (as some of my females have done) but she did not come out even after the eggs were long gone except on her last day. I found her on top of the LR barely alive and placed her in a breeder net to die unmolested. The night before, I noticed that her arms were swollen as if she was retaining water so I suspect her main heart had stopped functioning even though it appeared the two gill hearts were active (or at least the gills were both moving). She had retained color and ability to pattern up until the day I saw the swelling and showed nothing but dead grey coloration on the last day. When her gills had stopped moving and she stopped reacting, I put her in formalin and the chromataphores triggered a complete brown color slowly over her body (no movement as if I had not waited long enough though).

She had appeared so healthy (but weak) all during the time she guarded the den, I was really hoping she would live on for awhile. I am thinking she went into brooding prematurely and still puzzle over what may trigger this in a captive environment and how we might delay it.

Roy, Mucktopus, Steve, biology majors...

The swelling brought up a major question about hydration. It is my understanding that all marine animals need fresh water for hydration and that most (if not all) get it from the food they eat. A brooding octopus ceases eating so how it is that they don't rapidly dehydrate?

 

[sedna]

Sorry, D. It's so hard to watch them die, knowing it's coming doesn't make it easier. Thanks for the great journal, though. Roy, I hope you continue to post entries and pics of your octo eggs and their development. Thanks to both of you for such interesting stuff!

 

[CaptFish]

So sorry to hear, I dread the day I have to go through the same, but I guess thats the price of the coolest creature on the planet.

 

[DWhatley]

Maya's last photo I don't remember if Maya was still breathing when I took this or not but I am posting it to show the odd swelling that I noticed in her arms just before she died. Note that the arms have wrinkles. I am wondering if this is a sign of heart failure and thus water retention from poor circulation, similar to problems humans have when the heart no longer pumps well.