meeting a local - Situ(O.gibbsi or O.tetricus)

[DWhatley]

Difficult decision. They are a lot of work and time in an aquarium and the tidal pool takes care of all the maintenance tasks and expenses but you already have the tank and a maintenance routine. Raising one from tiny would mean not being able to release it back to the wild to breed I would think since it would not have learned to protect itself or find food but fortunately, this species is extremely common and exists in healthy numbers. You already have some idea of life span in situ since you mentioned that a photo review showed roughly 2 years before they disappeared. The ability to observe the difference between one in an aquarium and similarly aged ones in the wild would be too tempting for me to avoid though (in addition to the fact that they can make terrific pets).

 

[haggs]

Yesterday I went back yet again to visit the pools, I took some fish for enticements... I found Situ, still in the same den. #3 (the baby) of them all was also in the same place, where as #2 occy had moved.

It's only been a couple of days but it seems to have grown the most. After taking the piece of fish it moved out into the open and hung upside down, quite content to hang there and eat. Each occy had different colourings as they ate, Situ's body colour had lightened a little. #2 went greenish, and #3 went quite dark, for being in a sandy area.

I then went to another pool and found #4, it too seems to be of the same sort. It also allowed me to set the focal distance of the camera to 10cm and was quite content to sit there.

 

[DWhatley]

Do you often see starfish near their dens?

For our biologists: I see on #2 and #3 photos a pair of white spots at roughly mid mantle. These spots seem to be very common in a multitude of species (prior examination of Norman's book shows them on the majority of species, all in about the same place proportionately and I have seen them on my hummelincki). Any clue what they may be?

 

[haggs]

D, a few answers for you.

I went over to the island this morning to check out the Chitons. I was there well before sunrise (5:10am) with my trusty little torch to see if the "light" affected their movements. As I hopped into the pool I thought "all in the name of research", it didnt make the water any warmer though. The water temp was about 21 and the air temp was 17 degrees, and to make it even better I couldn't find any chitons... not one. Usually there are quite a few there, so I guess I cannot answer that question yet.

Sea stars near octopus dens...

Out of the 6 dens that I have looked at there, is only the one den that has sea stars right at the enterance. The others are at least half a metre away.

The white spot on the mid mantle...

This morning Situ was the only occy home, and she too has the marking on her mantle, but in two places. Directly behind each eye. (mental note) .. check the rest next time.

1st Image is of Situ's 2 spots
2nd Image is of the sunrise from in the water

 

[DWhatley]

Haggs,

The only times I see 5:30 AM is from the night side and you won't find me in the water when it is much below 80 degrees F (27 ish), not even for that terrific shot (you should have posted it in the monthly contest and called it octo hunting - I am already pushing the open topic for this month !)

The white spots are always parallel and always come in pairs (you can't always see them though). If you go back to your other photos, you will find the second one in each. I spent the better part of an hour one night going through my copy of Cephalopods, A World Guide and found them on the majority of the photos. Because they are so common in most species (I never saw them on the mercs), I am surprised no one has commented on what they are or what they mark.

 

[haggs]

D, The largest of my chitons died over the weekend and I had to dismantle some of the LR to remove the decaying body. It had been living on the bare bottom of the tank, what it has done is actually "rasped" away the polished surface of the glass leaving a "matt" finished area.

 

[DWhatley]

Interesting and a bit scary for those of us with acrylic tanks. I did notice with my longer term survivor that he totally avoided the clear surfaces (as did the ones that died after a short time as I had tried to get them to "stick) on the clear acrylic/glass). The bottom may be clear but is likely to be dark and so might have the same effect. In the reef, mine stayed on the black walls and piping and I would not be able to tell if the surface changed. If it does rasp at glass or acrylic, that might be a problem for the digestive system but as simple as it is, maybe not.

What of Situ?

 

[haggs]

Situ is still in the same pool but has moved to a bigger den and after putting my hand just outside I found the reason why. She has grown so much, as I put my hand outside her den, out came an arm gently wrapping around my finger, then letting go and doing the same a little further up the hand. A second arm then came out and did the same ... touching and feeling. It was then I realized how much she had grown and the strenght that they have, her arm could easily reach my wrist and get a firm grip. Not life threatening or anything like that, but if it was someone that had no idea about their strength I think there may have been a bit of a panic attack. She didnt come right out so I don't have a picture with anything to campare her size to.

#2 is also still in the pool, she too has grown but not as much as Situ and appears to accept the fact that I keep returning and invading her privacy. Her den is very obvious with the amount of "dead" shells right outside her door you can't help but see her.

#3 the baby. Also needed bigger accomodation, she (I think) has moved into a narrow crevasse instead of a small hole where I think there will be space for a long time. When I first stepped into the pool I actually placed my foot right outside her den without realising that she had moved there.

#4 Has moved on... I only saw this octopus for a couple of visits, then there was a shift in the sand and the den got covered for a couple of days and it hasn't been back since.


Image of.. Situ's new den, with room to move

 

[DWhatley]

 

[haggs]

For a number of reasons I have not been able to get across to the island until yesterday, I was very surprised to see the terrible state of the normally clean and clear pool. I even had thoughts of not getting in, but I had to .... just to check on the octopus. The pool looked as though it hadn't been flushed for weeks, there were "pillows" of brown algae ballooning everywhere, with cobweb like strands of air bubbles reaching for the surface. The normal amount of sand had more than doubled, thus allowing the water to heat up much more than normal I assume producing the huge algae bloom.

I was able to find several fresh looking emptied scallop shells but not in the usual places, and not a single octopus anywhere to been seen. I couldn't blame them for leaving as it was not a very "pretty pool" anymore.

I went back for a quick check this afternoon, .. but still no Occies

 

[DWhatley]

I was excited to see a new post and sad for what you found. Did you think to look outside the pool or is there no proper shelter on the perimeter?

You hinted at a project (was it squid?) that you might be getting involved with, anything interesting?

 

[haggs]

it would have been interesting, but it has fallen through.

 

[haggs]

sorry D, I didnt answer the first question........

No, there are no other pools close to this one that they can move to, maybe they will come back when the sand has been flushed out.

 

[haggs]

Well I snuck off from work a little earlier this afternoon, and went down the pool to see how things were going there. The water was nice and clean with just a few algae bubbles, however the amount of sand is still creating a problem I think for the occies.

There was some signs which indicated that there has been an octopus there but not enough empty shells and crab carcasses for the 3 that were there before. The majority of the shells were only small, making me think the larger octopus have moved out and maybe a new smaller one has moved in.

After spending nearly an hour in the water …. Watching… watching…. with rain falling down and making the water all “blurry” I decided that I was cold enough to go home and have a warm shower, seeing that I couldn’t find anyone home in the pool.

Maybe next time.

 

[DWhatley]

Thanks for shivering for us! SOOO envious of your drive from dive to hot shower, might even get me into colder water on occassion