This article appeared in Volume 3, Number 2, 1995 of The Breeder's Registry, Journal of Maquariculture. The article is reproduced with the acknowledgment and permission of the author. All rights reserved, 2005 The Cephalopod Page
Notes on Raising Octopus briarius
by James B. Wood
Note: This is the original article as submitted to The Breeder's Registry. A slightly different version appeared in Volume 3, Number 2, 1995 of the Journal of MaquaCulture. Printed by permission. All rights reserved.
The Story
This work was done while I was an undergraduate at the University of Florida and marks my first attempt to raise octopuses from eggs. Many mistakes were made. I have since become deeply interested in cephalopods and am studying the deep sea octopus Bathypolypus articus at graduate school (Dalhousie University, Nova Scotia, Canada).
On November 28, 1992 a female reef octopus O. briarius was captured in the Florida Keys. She laid eggs in the front upper corner of her 20 gallon tank on January 12, 1993. This tank was maintained at 26 - 26 degrees Celcius. Some of the egg festoons were carefully removed from the mother; that was fun - mom's eight arms versus my two! The ends of the festoons were placed between two microscope slides which had rubberbands holding them together. These were suspended in one gallon mason jars. These jars were placed in an environmental control room and kept at 20 degrees Celcius. An airstone was used to circulate the water and mimic mom's care.
The first eggs to hatch were the ones left in the twenty gallon tank. At this time, I only had a little information, which is dangerous. Since I had read that octopuses are cannabalistic, especially O. briarius, a lot of rocks, PVC, and glass jars were added to the tank in hopes that interspecific contact would be minimized. Due to all the cover, I could not tell how many octopuses I had, if they were eating, etc. The other mistake I made was in feeding them Artemia. They were observed to capture adult brine shrimp but would usually discard them after several minutes. A further complication was that food density needs to be high since young octopuses seem to wait till food items bump into them instead of actively seeking dinner. This is hard to do in a twenty gallon tank. Additionally, the return tube from the filter tank had to be bypassed at night when food was offered. Massive mortalities occurred 4 days after hatching; I did not see a live octopus after the sixth day (likely this is when their yolk reserve was exhausted).
Luckily, I still had the eggs that had been placed in the environmental chamber. They were taking much longer to develop in the cooler water so I had time to locate more information. I had planned to rear octopus in smaller containers and use mysid shrimp and amphipods as food instead of Artemia. By this time I had read more of the scientific literature and felt that I could rear the young. Unfortunately, an air pump failed and killed all of these eggs just before hatching. Very annoying! However, all was not lost as I had given 15 of the eggs to a friend (Kate Cullison) before the disaster (don't keep all of your eggs...). The octopuses in these eggs were not hatching; they were using up their yolk reserves and dying. By the 88th day only four of the fifteen eggs were still alive. At this point we decided to cut, yes cut, the babies out. Two died within a few days but the other two survived for six weeks. They were fed mysid shrimp and occasionally amphipods. After six weeks the school year was over and I went to the University of Hawaii for a summer internship and Kate went to the Smithsonian for an internship. We left the babies with a well intentioned friend. They were both dead within a week.
Tips
* Don't handle the eggs too much - I have read that this may cause problems in hatching and may be why we had problems with the remaining fifteen eggs. (In addition to moving them from different systems I was also manipulating them in order to photograph and film them.
* D not use Artemia. I tried using newly hatched Artemia as well as adults pumped with Selco with the first batch and lost all of them. Yes, O. briarius has a great feeding response and will capture Artemia but no one has documented positive growth using this food (Boletzky, 1983).
* Use mysid shrimp, amphipods, crustacean larvae, crustacean appendages, little kids (just joking), and small crabs for food.
* Food size should be from 1/3 to 2 times the mantle length (Hanlon, 1985 ).
* Almost all female octopuses will stop eating when the eggs are laid and die shortly after the eggs hatch.
* An unfertilized female octopus may lay eggs in your tank. Then she will likely guard them for a while, then eat them, and then die (personal experience).
* When the octopus and the yolk "flip" inside the egg, so that the octopus is under the yolk sac, they are approximately 3/4 of the wat to hatching.
* O. briarius is a "large egged" octopus. "Large egged" refers to the life history strategy of the juvenile as well as the egg size. Large egged young are benthic upon hatching. "Small egged" young are planktonic and are significantly harder to raise.
Encouragement
Keep in mind that I was rather green when I did this experiment. Raising large egged octopuses should be relatively easy compared to the young of most marine critters, especially those that spend a portion of their life in the plankton. Good luck!
I Want MORE
If you are interested in maintaining octopuses and would like more information please read the two part TFH article that appeared in the summer of 1993 co-authored by John Forsythe, as well as "Don't Fear the Raptor; An Octopus in the Home Aquarium" FAMA April 1994 written by yours truly. If you are seriously interested in rearing juvenile octopuses and have access to a university library, the work of Dr. Hanlon and John Forsythe is excellent. If you need further guidance, please visit The Cephalopd Page or feel free to contact me by e-mail at: jamesbwood2000(at)yahoo.com.
References
Boletzky Sv, Hanlon RT. A Rieview of the laboratory maintenance, rearing and culture of cephalopod molluscs. Mem Natl Mus Victoria 1983; 44:147-87
Hanlon RT, Forsythe JW. Advances in the laboratory culture of octopuses for biomedical research. Lab Anim Sci 1989; 39:306-12
Wood, J. B. 1994. Don't Fear the Raptor; an Octopus in the Home Aquarium. Freshwater and Marine Aquarium Magazine. 17(4).
