Any idea what this might be?


Blue Ring
Oct 4, 2006
This is Proteus, an octopus I've had for the past year.

He only has two colors, white and a dark rusty color. He is nocturnal and he is very tiny--a mantle length of just under an inch. He is very well-behaved and never tried to escape his tank. I bought an octopus field guide, but could not find a species that matched these characteristics. I think he's actually be female, but it's hard to get a good look at him to check, since he hides so much!

He is dying now, so I know his lifespan since I bought him, which is roughly one year. He was very tiny when I first got him, so he must have been very young then. About halfway through his lifespan, he stopped venturing out to hunt and instead waited at the entrance to his den for a crab to scuttle by.

Thanks for any help!
Forgot to mention...

One thing about Proteus that I forgot to mention, I ordered a bimaculoid from the fish store originally, but instead I got him! So presumably (if the fish store people aren't lying) Proteus is native to the same waters as the bimaculoid.
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With the warning that I'm pretty amateurish and will probably be wrong, I'm guessing Octopus digueti if it's from really from bimac territory. It sounds too small to be Octopus rubescens although it does look a bit like one. The only other possibility I can think of is Octopus micropyrsus which I know only from the picture in Norman's book, but it looks very smooth, shiny, and purple in that picture, unlike yours.
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Its definitely not an O. rubescens. the white around the eye and white on the dorsal mantle papillae are not right for rubescens. It doesn't quite look right for Octopus digueti to me either . It does look like you may have gotten an O. mercatoris to me.
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I'm with Taollan on this one but I have not seen other dwarfs so my comparison my well fit other dwarfs as well. The patterning, nocturnal habit, ability to turn only two colors, quickly tapering legs with little webbing, acceptance of tank limits (don't tell but my Mercs tanks are not octoproofed - there are special tank considerations and one can be but my guys live without secured tops) are all things exhibited by my Mercs. Also, my bood of 5 are all different sizes, my most active male being the smallest and about the size of Proteus.

On the other hand, the location and the white dots on the mantle (vs lines I see in the Mercs) seem to favor the digueti. Dollars to doughnuts it is one of the two. Try and examine the photos of both the Mercatoris (or Joubini) and then at the Digueti. The differences I see are in mantle shape (may not be a true difference) and in the white patterning on the body (the arms seem similar). The Digueti would be the Pacific equivalent of the Atlantic dwarf.
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Thank you for the help, all posters. The Joubini on cephbase certainly looks similar, except that Proteus has shown much wider variations in his body patterns than the caption with the pictures on cephbase says that a Joubini is capable of. So I think that perhaps the Mercatoris is the best match.
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It looks much too bulky to be a digueti to me...but species differences can occur. None of the ones I have ever seen evidenced that much white colour either...I should think mercatoris is the most likely.

Of course, all of the digueti I have seen have come from one localized area in northern Mexico, and they may vary.
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I can't speak for Dwhatley's Mercatoris', but mine never showed the white, star-like appendages around the eyes... he had tiny white spikes on his mantle during his younger days though.
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Tonight I noticed a similar eye marking on Sistrurus. With the red lighting it is harder to detect but there were two white marks below the eye. It is the body dots vs lines and the less than one inch mantle that still keep me from feeling certain.
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