It is true that all octopi have venom is it not? If so then what is the potency of the Great Pacific Octopus' venom?

the short and approximate answer is that cephalotoxin is a neurotoxin for crustaceans but doesn't have much impact on vertebrates, although injecting any random protein into yourself risks allergic reactions or infections from the wound.

The standard reference seems to be this one:

http://www.ncbi.nlm.nih.gov/pubmed/4853965

Toxicon. 1974 Mar;12(2):109-15.Click here to read Links
Purification and composition of a toxin from the posterior salivary gland of Octopus dofleini.
Songdahl JH, Shapiro BI.

which I don't have. It's summarized in this paper:

http://www.cephbase.utmb.edu/refdb/pdf/7298.pdf

which says:

A toxin purified from the PSG of Octopus dofleini (Songdahl and Shapiro, 1974) gave a single constituent toxic to crustaceans. Its molecular weight indicated by SDS-polyacrylamide gel electrophoresis, was 23,000 ^ 1000 Da.

In general, coleoids that aren't blue-rings or Eledone cirrhosa have a variant of cephalotoxin, which is neurotoxic to arthropods and probably other invertebrates (it causes tonic paralysis like many insecticides do) but not toxic to vertebrates.

Thanks, monty, for the links. They are helpful.:smile:

Thanks, monty, for the links. They are helpful.:smile:

glad to help. If you get a copy of the 1974 paper, it'd be awesome if you posted a summary of the details.

If I get a chance I will. I wont be online for the weekend, so it'll have to wait.

I would not want to be bitten by O. mototi either.

From personal experience, a bite by O. rubescens and O. fitchi seems worse (more inflamation) than those of other species that have bitten me.

Roy

Has mototi been confirmed toxic? That's the one that the local natives say is poisonous, right? I can't find any refs in google scholar that describe its toxin, but rumors of toxicity seem like a good reason to avoid bites, of course.

there's an article about rubescens bites here:
http://www.thecephalopodpage.org/octobite.php

its name means "poison octopus" in the natives' tongue....check out Normans Cephalopods: A World Guide