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Dwarf Octo eggs/setup recommendation

aquagrrl

Pygmy Octopus
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Jun 23, 2010
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7
A friend of mine has what I believe are O. joubini eggs and mum that we are assuming are fertile as they haven't had her for very long. I've dabbled in the cephalopod world, and even raised a few unknown ones from a fish store that had eggs (more on that later). They were just laid a couple days ago, so I think we have a few weeks to plan. I'm going to design the setup for both of us, and we're going to split the babies.

Last time I raised babies it was a crap setup because we weren't expecting any. And while it worked, it didn't work well. For starters, even though 3 of the octopuses lived normal lifespans, they were much smaller than mom, the mantle being about the size of a quarter. I think it was a feeding issue. I've been reading more about raising them and I was feeding too little too infrequently, and only feeding live mysis. As they got bigger, fed ghost shrimp, but possibly not frequently enough. From what i've been reading, i should be feeding amphipods at the very least, and small crabs if I can get them. Fortunately I have a surplus of amphipods from my algae scrubber I think I can use consistently. (I've been harvesting them regularly to supplement the diet of seahorses).

I used betta cups, obtained from my local petsmart, and cut holes in the side, gluing mesh webing to it. Then cut holes in the top that were big enough for airline tubes. I used one of these Amazon.com and hooked the airline to it, so each cup had it's own water supply. The cups were suspended on a makeshift egg crate shelf in a 20 gallon seahorse tank because it was the best option I had at the time.

It "worked" but it wasn't the greatest setup. The netting would get clogged, and I lost at least one to the water flow getting plugged up. Feeding was difficult because we had to take them out, get the cover off, drop the food in, then cover again, so you couldn't go very fast.

I'm looking for ideas for what has worked for other people. My husband and I are learning to work acryrlic but aren't very good yet. Like we don't have a blade for cutting, but we have a local plastic company we buy scrap from to experiment on. We do have a router, but can only do basic trimming with it. Any suggestions would be greatly appreciated.
 
:welcome: aquagirl!

First, you probably have O. mercatoris and not O. joubini. For many years the two were thought to be the same and the mercs were tagged that way. O. joubini is a small egged species and are impossible at this point to raise. There have been minor successes (4 out of 10,000 or more eggs and the hatchlings did not survive to full adult with vulgaris, a couple of O. joubini, again making it past the pelagic stage but not adult survival and one Alaskan species I don't recall are all I know about). Large egg species are a viable consideration but not an easy task. We have had several successful O. mercatoris generations on TONMO. In 2006 I started with Trapper, raised 5 of her 6 hatchlings and ended with the hatchlings from one of her offspring. GHolland journaled his adventure with Varys, her offspring and grand offspring in 2008. Both links have forward links to each generation and should be somewhat helpful in configuring a system and rearing. Do note that in all cases only 5 hatchlings survived through adulthood.

One food I would suggest would be frozen Cyclop-eze. I also recommend providing shells in a netting and hand feeding with a pipette daily. We have found that merc brought up this way can live together if the tank is not over crowded. I have a not ready for prime time paper I wrote about raising mercs that I would be glad to send if you will PM me your email address (attachments are not allowed through the TONMO email system).

It has been awhile since we have had hatchlings so PLEASE journal the experience!!!
 
I just looked at the aquarium mini filter you posted. That spray bar option is a magical find!!!!! THANK YOU! If you set up nets inside a larger tank, I think this will be great for pushing water inside the net but with the filter outside. I wish I had found something like this before and will definitely get one (or two) now to have on hand.
 
What do you mean by nets - like breeder nets? Or just plain fish nets? Growing them in groups would be so much easier! And cycopeeze is doable, I have one of those giant bars, but would frozen be adequate? I'd assume live would be better. Plus, I've noticed with seahorses that dead food breeds bacteria like nobodies business, so even if they'll take cyclopeeze, I skip it. I do grow a few species of copepods; if that's better I can feed that. And I really think I will be able to collect more than enough amphipods.

I've also been wondering about this. I know people have tried live brine shrimp and even though eaten, they haven't done well. But what about enriched brine shrimp? I use some serious enrichments with my adult brine shrimp for seahorses when they are transitioning to mysis. Would it be a bad idea to try it (mixing with amphipods?). I do also have mysis, but I don't really have them in a productive set up, they're more for emergencies.

If you like that spraybar, look what else I found: Multi-Outlet Air Manifolds at the best price
It's supposed to be for airline but I suspect it could be used the same way, maybe even chaining some together.

Thanks for the correction on the species. I was going off what I found online as the atlantic dwarf octopus. I'm not sure of the species, but it's small, and from the Atlantic . . . :smile:
 
Take a look at the links above marked Trapper and Varys. You should be able to get an idea if your female is similar (very likely as it is the only large egg Atlantic that we see. There may be others, of course but ...).

The breeder nets I like are about twice the size of the most commonly seen in pet stores. These (I am not vouching for the vendor, just the product but that is a good price) have a grate that can be placed about 1/3 of the way to the top/bottom and work really well for providing a surface for denning shells (the "room" divider is useless). IF you can get them to stay in the net (I had one that refused but still survived) as they get a bit bigger, they can hunt live food in the bottom. The suction cups work for about one use but I find that the mag cleaners are a successful alternative.

Live food is a bit more problematic for the little ones. Keep in mind that these are benthic animals at birth so any live food should crawl more than swim. If you plan to release them into live rock (not my recommendation until they can hunt shore shrimp), amphipods will probably nutritionally sustain them but mysis are pelagic. With the Cyclop-eeze and a pipette, I could ensure I was offering food each day to each individual (harder at first because they are the size of a hungry tick).

Even supplemented, new hatched brine (less than 24 hours old) has failed to provide cuttlefish with enough nutrition to let them survive. Newly hatched cuttles have been known to eat it but they die. I have not tried brine with octopuses but since brine does not crawl, newly hatched octos may not be able to find it for food.

The manifold is a nice DIY find (I bookmarked it) but I like the whole idea of the spray bar set up with a pump that can be placed outside the containing breeder.
 
The netting is fine enough for them not to go out through the holes so that part is not a problem. Any hole in the netting does need to be stitched (the suction cups pegs on the nets I like will leave large enough openings for escape if not realigned with the pegs. The holes are located along the brace bar and easy for the crawling octos to find.

I find that even with adults if the sides continue up to an overhead canopy, this goes a long way towards keeping them in the tank as well as placing the top of the net slightly above the waterline, I did have one to crawl up the side of the tank and die before it found its way back to the water but I don't recall if the netting was properly placed at that point (this was my first experience with hatchlings and it may have been a standard breeder net to start). They don't crawl much on the netting but will crawl on the posts and get into corners and crevices. Initially it is very hard to count them each day and if you read my journals you will see that I was only successful in finding all of them about once a week. There were only 6 hatchlings in my first group so counting was not as difficult as the second set where there were over 50 but in both groups only 5 survived.

If the tank does not have a sump (ie, changing the water will lower the water line) I would recommend adding new tank water before removing it rather than lowering the water level. Thales reported that their biggest loss while experimenting with trying to raise the chierchiae hatchlings was during weighing so any out of water experience should be avoided. Careful flooding and a quick return to normal levels will not likely see many escapes if the net comes up over the edges for an inch or more.

Be sure to offer individual dens to each octo in the net with a couple of spares so they don't argue over housing. As they grow they seem to become a little aggressive and I split them into groups of two and three when I saw arm interaction over a period of about a week. I don't know that this was necessary but at this stage all survived.

Catching the hatchlings was a trick in itself. Look for a GOOD (one that you can control the bulb easily) turkey baster with a large opening. Sucking them in is only half the battle. If you can flush them back out of the baster before they adhere to the sides, you will be doing well. I had a harder time getting them out of the baster without letting them be exposed to air than catching them. Sometimes you can catch them "between hopps" with a cup but generally speaking the turkey baster approach was the most successful.
 
About how big are they when first born? They must be just tiny.

So, do you think the reason you only had a few survive out of 50 had anything to do with cannibalism? I'm wondering if success rates wouldn't have been higher if they were kept separately. Any ideas?
 
I have absolutely no idea why 5 out of varying numbers seemed to be magic. Here is the beginning of the journal recording Miss Broody's hatching. If you scroll down to #56 you will see my frustration with trying to determine hatchling count. If I failed to mention it before, it appears that 10 days (based on this, memory :roll: and GHolland's journals) for all merc eggs to hatch. It seems that the second day/night (also based upon O. briareus hatchings and one recorded by Thales for O. vulgaris) produces the highest number of little critters. I began to suspect somewhere along the line that the male adult(s) in the tank may have been snacking on some of the little ones but could never be sure that they were not just eating the Cyclop-eeze.

If you imagine a tick (you may need to live in the South to envision this correctly) that has not eaten and then color it white you will be able to identify them on the glass when they hatch. So small, yes but much larger than the pelagic cephs. The survivors lived between 10 and 14+ months for both the wild fertilized and the in-bred group.

I also wanted to mention that we have another member with a female merc and eggs that are showing eyes and chromatophoress. You may want to subscribe to iAlex, O. mercatoris journal to compare notes.
 

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