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Bimac culture


Haliphron Atlanticus
Staff member
Moderator (Staff)
Mar 17, 2003
It has been almost a year since we started culturing a number of O. bimaculoides hatchlings. We started with a couple of dozen and still have 16, so I have to consider our techniques successful. The hatchlings were initially held individually in 100 cc plastic cups and were fed live brine shrimp (enriched). They were fed and the water changed daily. The entire operation is in a cold room kept at 15 C.

After about a month, they were moved to 1 L plastic containers, given small pvc tubes and were fed brine as well as pieces of live grass shrimp. (A really good food has been to strip off clumps of eggs from brooding grass shrimp.) They were fed and the water changed at least every other day.

Once the animals got to about 1 cm mantle length, we started to experience some mortality. Suspecting low oxygen levels, we added gentle airstones to each container. This is against the advice of most people who keep octopus, but it worked cutting mortality and improving growth.

When the juveniles reach a size of about 3 cm mantle length, they were placed in 2 L plastic jars with numerous 3 mm holes drilled in them. They were given larger pieces of pvc and a few pieces of coral rubble. The jars were submerged in larger closed circuit aquaria (but with airstones). The animals are fed live grass shrimp every other day. They are now reaching 4-5 cm mantle length and will be transferred to individual aquaria.

Note that these animals are growing very slowly, but they are active and appear healthy. I've posted a picture of one of the juveniles that I took this morning.

Hey Dr. Roy, Very informative post.

Do you think that Live mysis could be used in stead of brine?
Bimac Culture

Nice information. I would also recommend live mysid as the staple diet of hatchling bimac and I think you should have better success. Is there any reason why you chose to feed the grass shrimp every other day rather than every day??

Mysids work fine if you have a supply. I have also been using amphipods with our O. mercatoris juveniles.

Two reasons for the feeding schedule. 1) It is a lot of work and takes a lot of lab personnel. 2). If fed as much as they wanted one day, often they would take, but not eat food the next day. Some individuals would eat every day, but most not.

My merc had only 6 babies. Five have survived for 12 weeks with a diet of frozen Cyclop-eeze and grass shrimp (bb's, unenriched but less than 12 hours old were also fed the first month). The mother stayed alive until Wednesday (11 weeks and 5 days from the first hatching) living solely on the Cyclop-eeze for the last month. From what I can find (almost nothing), this is longer than normal. There may be many inter-related reasons to the extended longevity and the success so far with the hatchlings but I think the Cyclop-eeze is a contributing factor.
I use the frozen, NOT the dried. I can see bits of shrimp in the mix but I am not sure what else. I am seeing better feeding from my abdominalis when I soak their frozen mysis in it as well as fat little cuttles that get live shore shrimp once and two feedings of the cyclop-eeze daily.

I would really like to see someone try feeding it during the final stages of life to see if my one experience is repeatable.
Roy, your container-farming sounds similar to what I did when I raised the bimac hatchlings last fall. Highly oxygenated water seems to be important, and in that vein, colder temps are definitely an advantage in terms of morbidity and mortality; that adds up to a longer lifespan. I still have 25 of the original 100 that survived the first month. 95% of the rest have been sent to hobbyists. Zyan