Raising hatchling bimac

[Dr. Lizz]

I need some advice on raising a bimac

 

[ISpeakForTheSeas]

Which species of bimac - Octopus bimaculoides or Octopus bimaculatus? I ask because, to my understanding, O. bimaculoides is a large egg species (relatively easy to rear the young), and O. bimaculatus is a small egg species (very difficult to rear the young at this point).

Also, is it actually a hatchling (i.e. just hatched), or is it just a young specimen (i.e. hatched a while ago but is still quite small)?

 

[Dr. Lizz]

It is o bimaculoides. Large egg form. The eggs started hatching eight days ago. We now have. 42 hatchlings. So far just one death and one escapee from the tiny holes drilled in it”s 8 oz container. All hatchlings are housed separately. Each container has a small black hide tube. We are feeding the hatchlings live mysids and feeding the mysids hatchling brine shrimp. All live food have bubblers. All containers are in chilled water to 68 degrees. The oldest appear to be growing. Any additional advice would be appreciated. We are uncertain what to do with most of the hatchlings should they survive.

 

[ISpeakForTheSeas]

It is o bimaculoides. Large egg form. The eggs started hatching eight days ago. We now have. 42 hatchlings. So far just one death and one escapee from the tiny holes drilled in it”s 8 oz container. All hatchlings are housed separately. Each container has a small black hide tube. We are feeding the hatchlings live mysids and feeding the mysids hatchling brine shrimp. All live food have bubblers. All containers are in chilled water to 68 degrees. The oldest appear to be growing. Any additional advice would be appreciated. We are uncertain what to do with most of the hatchlings should they survive.

Well, it sounds like you're doing well so far. How often are you feeding the hatchlings?

The only advice I have at the moment is as follows:

1 ) In order to be able to get rid of any surviving hatchlings you don't want to keep, start offering the hatchlings (in addition to the live mysis) a good-quality pellet feed that's readily available for hobbyists on the market (something like Otohime or TDO Chroma Boost pellets would be my suggestion, preferably supplemented with something with a higher algae content like NLS Marine Fish pellets) - if a large number survive, then having them prepped and eating a pellet feed would make it a lot easier to be able to give them away; a premade diet vs a diet of live mysis will be a lot more appealing to the average saltwater aquarist/fish store.

A number of different octopus species have been fed pellets without issue before, so I'd guess O. bimaculoides would take them without issue as well.

2 ) "Enrich" the hatchlings' environments - the quotes below deal specifically with O. vulgaris, but I'd imagine they would prove fairly generalizable:

"In this study, we evaluated how different environmental conditions affect subjects of Octopus vulgaris maintained in an aquaculture system through the observation of major body patterns. The results showed that octopuses kept in an enriched environment showed significantly more body patterns and gained significantly more weight than the subjects kept in a basic environment. The body patterns manifested by the octopuses maintained in a basic environment were similar to those exhibited under situations of hostility and inter/intra-specific conflict."

"Enriched (ENR) environment, with the presence of physical enrichment: substrate (sand), wall color (the walls were “naturalized” with beige-colored polypropylene panels); cognitive enrichment: the presence of seashells, stones, and plastic toys; social enrichment (contact with conspecifics and the operator) and food (ad libitum feeding and live food)."

Source:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10251970/

For what to do with the hatchlings, I'd suggest offering them to local saltwater aquarists, local fish stores with saltwater sections, local public aquariums, local colleges/schools with saltwater tanks/marine biology classes, etc. and if needed posting them on forums like Tonmo, Reef2Reef, Humble.Fish, etc. - if you end up with a lot of survivors and you really need to get rid of them, offering them to other hobbyists for just the cost of shipping may help.

 

[Dr. Lizz]

Thank you for your prompt reply and suggestions. The female bimac is not mine, but I have been helping out. I have two bimacs I bought them as very small and baby about six weeks ago. The larger is in a 220 gallon custom built thank with one HP chiller, etc. The baby, now larger is currently in a temporary 55 gallon tank while a new custom 120 gallon tank cycles. I agreed to take some of the hatchlings and plan to place them in their individual containers in a 55 gallon tank.

 

[Dr. Lizz]

In answer to your question regarding how often the hatchlings are being feed, I am currently not personally taking care of any (until this coming Wednesday), but I believe each is currently being fed 2-3 live Mydsis shrimp twice daily.

 

[tonmo]

...and just to pile on, here are a few threads for you to peruse:

[Featured]: - Octopus Hatching in the Lab!

Hello All! While I focus 92% of my time on the nautilus, the other 8% of my time is on their cousins! Haha. Over the last couple of weeks, we have had Octopus bimaculoides eggs hatching in our lab at Central Campus in Des Moines, Iowa. The female came in after having laid eggs in a "unique"...

tonmo.com

tank size for hatchlings?

Hello! I'm working with Octopus bimaculoides and looking at trying to rear some fertilized eggs. I would like to raise them in different tanks than the adults are housed in for logistical reasons (mostly to prevent them from going into the filtration system, but also to better track their...

tonmo.com

and as D had shared in that last thread, here's a list of resources:

Raising Octopus Hatchlings Links

I did a non-exhaustive search for journals that contained either extensive reporting or significant references on rearing young. EDIT: Additional articles included below the initial list. Food Performance of raw material thermal treatment on formulated feeds for common octopus (Octopus...

tonmo.com

There are many results in our Search for bimaculoides hatchlings as well.

 

[Elessar333]

Which species of bimac - Octopus bimaculoides or Octopus bimaculatus? I ask because, to my understanding, O. bimaculoides is a large egg species (relatively easy to rear the young), and O. bimaculatus is a small egg species (very difficult to rear the young at this point).

Also, is it actually a hatchling (i.e. just hatched), or is it just a young specimen (i.e. hatched a while ago but is still quite small)?

I assume O. bimaculoides, since this was a relatively large mother. She has kept the eggs well-hidden with her body in her "cave", but the hatchlings are 4-7 mm as fully formed, mostly white kids.