The Bioluminescent Octopus, or Stauroteuthis syrtensis, is a deep sea species that has been relatively little studied. Some have been described on the basis of a single, poorly preserved specimen, and this makes deducing their relationships difficult.
The length of the mantle of Stauroteuthis syrtensis is about 2 to 4 in. (5-10 cm), and its width about 1.6 in. (4 cm). The fins are roughly 1.6 to 2.4 in. (4-6 cm) wide. The eight tentacles are of unequal length, the longest extending to about 14 in. (35 cm). These are joined for two-thirds of their length by two webs, a dorsal complete membrane and a ventral partial one. That gives the animal a beautiful and fascinating umbrella-like shape.
Bioluminescent Octopus Physical Characteristics
A total of about 60 adhesive suckers exist on each arm. Twenty-five of these are larger and extend to the edge of the web. In the male, the first eight suckers are smaller and the rest large and conical, but in the female, they are of an even size. Between suckers 8 to 25 there are conspicuous cirri. These are elongated, fleshy tendrils borne on the sides of the oral surface of the arms, the longest at sucker 20. A further 30 to 40 smaller, closely packed suckers are on the arm extensions and tips.
The general texture is gelatinous and the animal is reddish-brown and translucent, with the internal organs visible through the skin.
The Bioluminescent Octopus lives in the North Atlantic Ocean at an extreme depth range of 500 to 4,000 m (1,600 to 13,100 ft). Further, it is most frequently present a few hundred yards from the bottom of the ocean at depths between 4,900-8,200 ft. (1,500-2,500 m.).
It seems to be fairly common off the edge of the continental shelf on the eastern coast of the United States, and is also present at similar depths off the British Isles.
Bioluminescent Octopus Glow
The Bioluminescent Octopus emits a blue-green light from about 40 modified suckers, photophores, present in a single row between the pairs of cirri on the underside of the arms. The distance between these decreases towards the ends of the arms with the light becoming fainter.
Interestingly, the animal does not emit light continuously. It could do so for a period of five minutes after suitable stimulation. Some of the photophores emit a continuous stream of faint light, while others are much brighter and switch on and off in a cyclical pattern, producing a twinkling effect.
Finally, the function of the bioluminescence is perhaps for defense. That would be to scare off potential predators, and also as a lure for the small crustaceans that form its primary diet.
Todd Sain Sr.