GPO: Tank size.

[neurobadger]

No, I am not planning on keeping a GPO. I am not insane.

However, the GPO where I volunteer is kept in a very, very dinky tank (because I don't want to get fired, I'm not going to tell you where it is). From the estimate of a similar-sized tank that the director gave me, she is kept in a 400 gallon tank. How big a tank should a GPO exist in?

When she was smaller, she was just fine, but she's bigger and now paces around the tank. Her pupils are never open when I see her, which is twice a week. She is somewhat listless. She's only two to three years old!

She gets fed adequately, but I don't know if she gets consistent enrichment.

I worry about her sometimes.

 

[iAlex]

In another thread, skywindsurfer said:

We keep them in a rectangular exhibit aproximately 1,000 gallons. Which in my opinion is far too small.

 

[DWhatley]

Are you sure that equivalent tank is really equivalent? 400 gallons is excessively small considering a large Mediteranian vulgaris has a recommended tank size of roughly 365 gallons.

 

[CaptFish]

What are the dimensions of the tank. We can math it up and figure out how big it is.

 

[Joe-Ceph]

There are 231 cubic inches in a gallon, so using interior dimensions of a tank in inches, you can get its capacity in gallons with:
L x W x H / 231

So 400 gallons would be about 36" x 36" x 72"
and 1000 gallons would be about 48" x 50" x 96"

 

[neurobadger]

This is only a visual estimate, but the dimensions, I am sure, are almost the same size, within one foot in each dimension. Actually, the GPO's tank may be a little smaller. I estimate the front of the tank is about five feet long, and the height of the tank is about three feet; the depth is probably about three to four feet.

She cannot stretch out her arms completely in the tank.

 

[neurobadger]

This is at an AZA-registered aquarium, mind you, and one that would be recognizable by name.

 

[neurobadger]

Are you sure that equivalent tank is really equivalent? 400 gallons is excessively small considering a large Mediteranian vulgaris has a recommended tank size of roughly 365 gallons.

This assumes, though, that they actually are keeping her in an adequately sized tank. I am taller than that tank on all dimensions, and I'm about five and a half feet tall.

 

[skywindsurfer]

Most aquarist both professional and hobbiest will agree that the ideal lenght of an aquarium should be 4x the lenght of the animal, and the width 2x the lenght of the animal. This is to say that you are keeping them in a rectangular tank. So for an animal that full grown can reach a lenght of over 10' arm tip to arm tip, yes this exhibit is TOO small.

 

[skywindsurfer]

Now if this aquarium did catch and release with their animals. The Seattle aquarium keeps Rossia Pacifica on a catch and release basis. They keep them for a few months and then release them so they can bread. If they did this and exchanged animals as they outgrew the exhibit, than that would be ok.

 

[neurobadger]

Most aquarist both professional and hobbiest will agree that the ideal lenght of an aquarium should be 4x the lenght of the animal, and the width 2x the lenght of the animal. This is to say that you are keeping them in a rectangular tank. So for an animal that full grown can reach a lenght of over 10' arm tip to arm tip, yes this exhibit is TOO small.

I actually emailed Dr. James Wood about this, and he said that his recommendation for Octopus vulgaris is 55 gallons, though he did not specify dimensions. 55 gallons does not seem as if it would satisfy these conditions for a full-grown Octopus vulgaris. However, it is possible for the animal to stretch itself entirely in that tank. In this tank, the GPO will never be able to stretch herself out entirely. I don't know what size to extrapolate from Dr. Wood's recommendation - since the armspan is 1-2 feet on Octopus vulgaris and the armspan on the GPO is about 10-15 feet, would one multiply all dimensions by 7? Using those numbers, I get a tank size of 21000 gallons, which is 100 times larger; by comparison, this GPO's tank size is only 4 times larger.

 

[neurobadger]

Now if this aquarium did catch and release with their animals. The Seattle aquarium keeps Rossia Pacifica on a catch and release basis. They keep them for a few months and then release them so they can bread. If they did this and exchanged animals as they outgrew the exhibit, than that would be ok.

They don't.

It's upsetting that this wonderful octopus is going to spend the rest of her life in a tank that is too small. I'd even organize a campaign for funds to release her back into the Pacific when she's started eating more in preparation for laying eggs and obtain a new one, but somehow I don't think that'd go over too well with the staff.

 

[neurobadger]

Depressingly, there are no standards for keeping invertebrates, and in fact, Dr. Wood emailed me and said he was publishing a paper recommending standards for invertebrates. At the very least, cephalopods should have standards, since they have complex brains. I'm in favor of requiring standards for all animal classes. Even our friggin' starfish have excellent living conditions; she's the only animal that doesn't.

 

[skywindsurfer]

Well I'm not sure where these all of these numbers are coming from, or what you are multiplying what by, but like I said, the animal just needs room to turn and room to stoll down the lenght of the tank. Gallons can be manipulated to be more or less depending on what you need and can afford.

 

[CaptFish]

Just a quick FYI Dr. Woods, is a staff member here on TONMO, his ID is Ceph. send him a quick PM and inform him about this thread and I'm sure he would put in his two cents.

Too see what other awesome staff members are on here check this link out.
http://www.tonmo.com/forums/content.php?117-Meet-the-Staff