Photographer: Ann Buster

Photographer: Alexander Semenov.

Hawaiian Octopus

Blue-ringed octopus.

But like a windowpane, a transparent animal reflects light at depths below about 800 meters (2,600 feet), where hiding places are scarce and predators lurk with bioluminescent flashlights that shine in the blue wavelengths. In that environment, it is wisest to be red or black, as those colors absorb blue light rather than reflect it – creating a different kind of invisibility.

(source.)

biomedicalephemera:

Octopus, octopus, squid, squid, squid!

Report on Cephalopoda from the Voyage of the H.M.S. Challenger. 1873.

Photographer: Rohan Holt

via BBM Explorer on Flickr.

Blanket octopus in action!

Fun (/kinda creepy) facts about the Tremoctopus:

• They are commonly known as blanket octopuses, in reference to the long transparent webs that connect the dorsal and dorsolateral arms of the adult females. The other arms are much shorter and lack webbing.
• These species exhibit an extreme degree of sexual dimorphism. Females may grow to over 2 metres in length whereas the tiny males are at most a few centimeters long. The males have a specially modified third right arm which stores sperm, known as a hectocotylus. During mating, this arm detaches itself and crawls into the mantle of the female to fertilize her eggs.
• The male dies shortly after mating. The females carry over 100,000 tiny eggs that are attached to a sausage-shaped calcareous secretion held at the base of the dorsal arms and carried by the female until hatching.
• They have evolved an unusual defense mechanism: blanket octopuses are immune to the poisonous Portugese man o’ war, whose tentacles the male and immature females rip off and use for defensive purposes.
• Unlike many other octopuses, the blanket octopus does not use ink to intimidate potential predators. When threatened, the female unfurls her large net-like membranes that spread out and billow in the water, greatly increasing her apparent size.

(via Wiki)

HAPPY BIRTHDAY, OCTOPODA!

Thanks so much to all of you for re-blogging, sending in lots of great submissions, & following this blog! I appreciate all of yr sweet notes & comments very much. Two years, thousands of followers, & one giant octopus tattoo later… It has been, & continues to be, a whole lot of fun to curate Octopoda. While we’re here, I want to highlight some favorite cephalopod & general sea life-related Tumblrs (in no particular order):

01. http://cephalolove.tumblr.com
02. http://rhamphotheca.tumblr.com
03. http://fuckyeahoctopus.tumblr.com
04. http://octopuswatch.tumblr.com
05. http://adventures-of-the-blackgang.tumblr.com
06. http://beneaththeseas.tumblr.com
07. http://fyeahoctopodes.tumblr.com
08. http://iheartoctopus.tumblr.com
09. http://fyeah-seacreatures.tumblr.com
10. http://the-ocean-is-not-silent.tumblr.com

Also, if you’d like to follow me elsewhere, my non-octopus Tumblrs are here (all sorts of misc. stuff) & here (strictly poetry & writing-related content).

xo, Alina