How to set my lights for octopus tank?

[DWhatley]

Your octopus will decide which areas it likes for a den but it will pick somewhere that you cannot see in. Typically, we try to aquascape for our own esthetics and often the octo will reject the area we have made, ie there is no known ideal setting, but will find or make a hiding place somewhere in the rockwork. You can provide a few loose ping pong ball and smaller sized rocks and shells that the octopus can easily move around to fashion doors,

Looking through the journals should help with ideas but here is a link to Maya's journal and a video of her moving a gorgonian to the front of her den. Just before doing this she had changed dens to an opening in the live rock across the tank. She decided she liked her original den better but wanted the "plant" that was in front of the abandoned new home. Sadly, all this effort was to establish a den to lay eggs but it was fascinating to watch.

 

[sensei]

Thanks DWhatly,

you were right, the octopus has rearranged some rocks in these 2 days.
I should not touch the rock work and let him do what ever he wants correct??

I programed my radiums with a 20K spectrum and I have noticed that he is not always hiding.
does this mean that he is not 100% nocturnal?
or should I wait the first month after he would be fully aclimated?


thanks again

 

[DWhatley]

In general, you cannot count on any behaviors to have lasting meaning until after about a month of aquarium life.

Yes, providing rock and shells to do her/his own decorating is advisable. It is unclear whether disrupting a den (even accidentally during cleaning) provides enrichment or stress. It is pretty clear that they don't "like" disruption that is not of their own making but if it is beneficial or stressful has not been studied.

If you are seeing hunting behavior under a daylight condition, it may mean that the animal is diurnal, crepuscular (early AM, early PM foraging) or getting close to laying eggs (obviously, only if female), Sadly, it is not at all uncommon for the later behavior to be observed in a new arrival. What is not clear is if the stress of capture and rehoming accelerates the time to brood or if the animal was more easily caught because she was out foraging in preparation for egg laying and a long starvation period.

 

[sensei]

DWhatly,

is there a way to know if my octo is male or female?
Octo has been eating everyday though.
I understand that they stop eating when about to lay eggs?

Thanks

 

[DWhatley]

Both sexes stop eating when they enter their end of life phase. Sometimes females will eat a bit during egg tending.

It is only possible to positively identify a male without dissection, Here is a brief and photos to help sexing an octopus (you may want to check out all the links in the Posts with Info for New Octo Keepers thread.

 

[sensei]

Thanks DWhatley,
I just noticed a lot of holes in the photos of the octopus tank cover you posted. can I know why?

the acrilic cover I placed in my octopus tank does not have any holes, I have 3 covers over my tank and there are litle spaces between them. there is some condensation in the covers inside the tank but I never thought that could affect??

thanks again

 

[DWhatley]

The holes (we used a peg board as a template to get them evenly spaced) are to help with temperature control and air circulation. I believe it helps as we don't see condensation and the acrylic has warped only marginally over several years but all my octo tanks have similar venting so I don't have a comparison.

 

[sensei]

DWhatley,

today I found lots of what I think are eggs in octopus tank
please look at photo attached.
does this mean octo will die soon?
only female lay eggs correct?
can you confirm if these are eggs and if so will some hatch??

 

[tonmo]

They look pretty clear but let's see what D or others say.

Yes, only females lay eggs.

 

[DWhatley]

Yes, I am pretty sure those are octopus eggs and not eggs of some other animal. Yes, all octopuses have two distinct sexes and do not change sexual orientation. Sadly, yes, this means the female will die shortly after the eggs would hatch if they were fertile (fertility has nothing to do with her longevity). The length of time varies considerably even within species and does seem to be associated with whether or not she can be convinced to consume food. Since she has only been in an aquarium for a short time, there is a good chance the eggs are fertile.

The female should try to tend her eggs and keep them from predators and algae even if they are not fertile. You can watch for two black spots to appear on the eggs over the next couple of weeks. If eyes are detected, you will have hatchlings. If the mother dies before the eggs hatch or she abandons them (both are rare) keeping water flowing over them and removing any predators (including starfish/serpent stars, urchins) will likely get them through hatching. Unfortunately, I believe your female is a small egg animal and the chances of being able to raise any of the hatchlings for more than a few days is dismally small. Small egg hatchlings don't actually morph but are born as immature pelagic swimmer/floaters that continue to mature in the plankton (something akin to natural premature birth) and we have not figured out how to raise them to settlement.