Combat Karl O. Hummelincki


Mar 15, 2009
Octopus: Combat Karl O. Hummelincki
Location Captured: Daytona Beach Shores, FL Halifax River
Size at Capture: Mantle apprx 3-3.5"
Age: Unknown, but full grown
Identifiers: Missing half of #2 tentacle, but has regrown a substatial portion of it
Temperament: Playful/Curious has not showed aggressive tendancies towards people
Diet in order of most chosen: Stone crabs, small blue crab, large hermit crabs, shrimp, snails
Tank: 125 gal 72x18x22 with 40 gal refugium/sump ASM G3 skimmer 3" sandbed, apprx 200#s rock, multiple cave structures
Lighting: 2 4' VHO total 220 watts, low lighting


This first entry will be a summarization of the last several months Karl has been in the tank. The biggest changes have been behaviorly and eating habits. When first introduced to tank, Karl stayed in the rock with frequent exploratory excursions around the tank. Karl stayed in a ball and "glided" around the tank rarely crossing the sandbed without being able to touch a rock. Feeding during this time period was opportunistic, as anything that went into the tank was killed within 20 mins. This covers approximately the first 3 weeks. The second and current stage is characterized by no fear of being in the open and shows a keen interest in what is happening outside of the tank. Radomly running up and down the glass and swimming in the corner of the glass is also typical. Feeding has become more discriminate, as hermit crabs now live in the tank for days to weeks before he shows interest. The variable is Karls availibility of crabs. Karl will bypass all other food for a crab, and will attack with force. Handfeeding is no problem, and Karl will come to your hand if put into the tank. Karl shows signs of play behavior with a hand, and seems to enjoy his/her mantle being rubbed. Food is also sometimes poked and proded before consumption. This is very typical with shrimp. The undirected behavior of swimming and glass wandering is worrisome, but hopefully it is typical for Karl. He has also bitten and killed crabs without consuming them.
Thank you for such a detailed and interesting introducton to your journal!

I'll add Combat Karl to the List of Our Octopuses soon - temporary delay because I have to move entries to create more room.

Your welcome Nancy, and i will be posting some pictures soon. Hopefully i can figure out how to get them onto here. I do have a question; how do you sex an octopus?

Karl also ate a suprisingly large shrimp today.
If Karl is Karl and not Karleen, you will notice that the third arm to the right (clockwise) will be almost always curled and the end is never used for anything requiring dexterity (like wall climbing or looking for food in the LR). This should be very obvious (unless it is the missing one).

I have a theory that octos see crabs as a theat and may kill them to avoid having them wondering the tank when they sleep. :roll:

Do get some pictures up as I miss OhToo even though I am keeping with two other species. I have not changed my desktop so whenever I don't have a fully cluttered screen (almost never), there is a smile in front of me but it would be nice to have a vicarious hummelincki about.
Yup.... its Karla and not Karl. Even the arm that is regrowing is used for tactile functions. I read your journal on OhToo, and there are many similarities. I know he passed awhile ago, but I'm sorry for your loss as my wife and i both dread the day Karla passes. Your theory about crabs is very interesting, im going to keep my eyes open and see if she does it before sleeping.

Todays entry


Karla was awake and active when i got up at 6:30 a.m. During the night, she ate a large hermit crab, and i cannot find one of the two small stone crabs. I came home at 11:30 a.m., and Karla was exhibiting foraging behavior. She was canvassing the rocks reaching into every hole and crack. I offered her a small stone crab, and she took it from my hand. She began consuming the crab while on the glass where i could see her subdue and begin to dismember it.... Insanely cool:cool2: Later in the evening Karla exhibited foraging behavior again. I offered a crab, but she was much more interested in "playing" with my hand and getting her mantle rubbed. Showed no interest in the crab so i put it back in the refugium. My wife then put her hand in and Karla whited out with black streaks and the eyespots became very dark blue/purple. Was extremely reluctant to do anything with her hand there and actually swam to the other end of the tank. I then put my hand in and it was play time all over again. I don't know if she can distinguish b/t my wife and I but possibly. She glass wandered in the corner by where we were and then went into the cave to presumably sleep.
No question in any octo owners mind that they can recognize people. I did find it interesting the Octane (OhToo's predecessor) came up to be petted immediately when my mother (we do favor greatly) put her hand into the tank. Octane seemed to know male from female and preferred females. It may have been something as simple of long hair (or dark and light hair) or hand size that gave this impression but he definitely showed a difference when a hand was offered. The immediate play with my mother never happened with anyone other than myself. Neal (who was primary feeder) would often teasingly pout that Octane just did not like him.

The white color and spectacular show of rings (only caught it once and not a great shot) is a show of surprise/fear and nothing to do with aging (they actually seem to color less as they age or possibly don't fear anything in their environment). While looking for that picture, I found a post in Octane's thread of a video AM found showing their ability to flash. I did not find the photo I was thinking of but here is a page in Octane's journal that has a couple of interesting color change patterns, one being a not so frightened/surprised white (the color rings are not vivid).

I keep an open tank for a hummelincki hoping my collector will come across one. This is the only octo he can identify :biggrin2: but he has done well when he lets me know he found one so I am hoping for another in a couple of months.
I am pretty convinced she can distinguish us now. I have been the primary feeder/attention giver as my wife has been reluctant to put her hand in the tank, but I have large hands and my wife has very small hands. I would feel my hands would look much more imposing, but Karla is not exactly predictable. She definetly seeks out attention, there is no question to this. My first approximation at mantle size is inaccurate as well. I tried to measure last night and it is definetly under 3". She also seems to have a malicious streak as she will randomly pull snails off the glass for entertainment it would seem. She shows little to no interest in the small astria snails in the tank and has only killed a couple.

All of this leads me to question whether or not the wandering and swimming are undirected behaviors or attempts to draw attention to herself in hopes of interaction. Maybe this is just wishful thinking. She doesn't exhibit the whited out fear coloration often, and most of the time it only comes out when you come around the corner and startle her. It lasts even shorter as immediately as it appears she returns to her go-to camo coloration. The tank is also in a high traffic area, and we have put a couch and coffee table in front of the tank. I would say we eat dinner there and watch her more than we watch tv at this point.

Regarding your open tank, i am currently about to make a bunch (not sure how many yet) of octo traps and am going to put them around this area. If i do get hummelincki, you are more than welcome to it. I have a crab trap out that i am letting grow over, and all sorts of animals are moving in. I figure it is only a matter of time before a curious octo makes it their base of operations. I do not know how well they ship, but if anyone knows information on this it would be helpful. Oh, and i will be getting some pictures up soon. I'm still not sure how to get them on here but i am dedicating some time to this tonight.
negative on the Karla....... its Karl. #3 tentacle stays wound up all the time, and he only uses the base of it occasionally on the glass.
So, my ignorance aside, i have figured out the picture situation.
Yea on the successful picture posts (and your new avitar)!

Take a good look at that first right arm (clockwise). OhToo's same arm was smaller and deformed (missing suckers for most of the arm, likely from multiple amputations) and it appears that Karl has a smaller (thinner) arm in the same location. If this is the case, try to get a good photo showing the difference. Relatively recently there was a mass participation experiement done by untrained observers to try to determine if octopuses were right or left handed so to speak. The study showed no coorelation but did observe that the back arms seem to be used more as legs and the front more as arms. If we should see that many hummelinckis have regrown this particular arm, it would suggest a different result (most of the observed octos were vulgaris).

I went back and looked at some of Octane's pictures after making this post because I remembered he had an arm injury on arrival. It appears to have been the first right arm as well. How cool is that? It is an observation that would be interesting to remember to make for new keepers to see if it is consistent. :biggrin2:

If you capture a young male (now that you know how to tell :sagrin:) I would be estatic to keep another. You might consider leaving any captured females in situ. Females of all species seem to go into brooding shortly after being placed in an aquarium and will die shortly after the hatching (this is true in the wild and is the case for most species - there a very few know species that have multiple broods). The observation may be due to capture age or something in the environment that triggers the need to lay eggs. Only a very few public aquariums have had any success with the small egged species. Large egged species have had some success, the mercatoris being the most successful within the TONMO journals. Hummelincki, unfortunately is a small egged species or I would be all over trying to raise them :hmm:

I found that the hummelinckis (and am seeing something similar with Beldar, macropus complex of undetermined species) that they become very possessive about their homes and do not like things out of place or in places that are deemed unsuitable. Both Octane and OhToo would put a warning arm on my hand while I cleaned their tanks. One member had to QT his hummelincki for tank cleaning because the octopus would not allow the process. Nancy has mentioned that her bimac, Ollie, would need to be distracted by a second person during tank cleaning. Beldar also put a warning arm on my hand when I was working on his pump (usually he is sleeping when I clean his tank) and several days later dashed to the pump and wrapped all his arms around the piece I had removed and replace. The agressive removal of snails may be Karl's house cleaning to keep his environment orderly rather than an attack on the snails themselves.:wink:
When you have time, would you mind reviewing some of Tuvalu's pictures and see if you notice a difference in the first right arm (note my second and third paragraphs on post #9)?

dwhatley;135171 said:
When you have time, would you mind reviewing some of Tuvalu's pictures and see if you notice a difference in the first right arm (note my second and third paragraphs on post #9)?


I never got any really good pics of Tuvalu, her time was before the nice camera.
When i got Karl that tentacle was a recent amputee and had not even begun to heal. Thats crazy that it is the same arm!!:biggrin2: In that photo he has the tip wound up a little. The first photo is a little fuzzy but i put it up because it was such a good shot of the eye spot. When Karl plays with my hand he usually uses the front arms for grabbing me and the back arms for holding onto the glass..... very similar to what you are describing. I haven't noticed any preference of the left or right, but then i haven't been looking either.

Thank you for the information about females! If i catch any i will definetly let them go, as I don't want to be responsible for needless octo death. I am a relatively new ceph caregiver so information like this is both appreciated and humbling :notworth:

The traps I am thinking about making will either be made from 4" corrugated pipe or some terracotta pots i have seen that have narrowing mouths. I am leaning towards the terra cotta as i can easily get a rope around them and if I happen to forget where one is (which is pretty much going to happen :smile:) or the float somehow disappears it will deteriorate on its own. If anyone has made any before please let me know. If i get a young male he is yours.
That would be stellar! Might even talk Neal into a trip to FL to get it :wink: (my sister is in Tampa and has been bugging us to come down).

One thing to clarify. You would not be killing the female. Death very shortly after hatching is the way of it. Very few of the hatchlings will survive in the wild but NONE will survive in our current setups so it is for the next generation that I suggest leaving the females. The males will die at about the same age (perhaps slightly older depending upon when the female "decides" to brood) but there is no parental care given by the male and he will mate with multiple females (number of sperm packets per male is not yet known so how many matings are possible for a single male has yet to be determined). Octopuses do not take mates. They are only one night stand companions :sly:. Even with the large egged species, we have not seen success with the limited number of attempts to mate any octos that have not been raised together. Of the successes, only merc sibbling pairings are journaled here in the past 3 years (I don't know about journaling prior).

Putting a self decomposing pot made from earthen materials would seem to be best but I don't know what kinds of treatments are used in making terra cotta today or from what country the soil is taken :roll:. If you can find locally made ones there may be less of a chance for undesirable additions. I do know that terra cotta is a preferred substrate for breeding with some of the more brackish freshwater fish and that octos have been noted by Jacques Cousteau to like clay pots (the ancient ones from ship recks). How useful those thoughts are, I don't know :razz:
I remember reading about the clay pots when I was working on our Cephalopods book. I found a paragraph about using pots in ancient and modern times in Peter Boyle and Paul Rodhouse's book, Cephalopods: Ecology and Fisheries :

"Earthenware pots and jars of various sizes, made to contain wine, oil, and other commodities throughout the Mediterranean, were probabluy the most widely used methods of catching octopuses. Laid on a rock bottom and lifted at regular intervals, they are an effective fishing method just in the same way as pots are used today almost everywhere in coastal regions."

There is a photo of commercial pots used for octopus trapping, and they seem to be clay, with handles, and have a wide mouth.

Octopuses never seem to leave the jars as they are being raised.


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