This species of octopus is only one of a few to exhibit bioluminescence, making it an incredible sight and a very interesting marine animal to research. But, little research has actually been done on the lives of these types of octopuses due to the depths at which they dwell.

They are a type of cirrate octopus, named for the small cilia-like strands on their arms that they use around their suckers. This interesting creature is only one of two genera of octopuses known to glow in the dark. It emits a blue-green light from its suckers for short periods of time, around five minutes. 


Appearance 

These small octopuses have a mantle of around 2 to 4 inches or 5 to 10 cm. The width is around 1.6 inches or 4 cm. The octopuses have eight arms of different lengths, with the longest reaching around 14 inches or 35 cm. The eight arms are joined together, approximately two-thirds of the way towards their tip, by webs. These octopuses have a soft body, common to their kind.

Bioluminescent Octopus on the ocean floor
Bioluminescent Octopus on the ocean floor

Credit: shellmuseum.org

The octopuses have two webs that join their arms, a dorsal complete membrane and a ventral partial one. The double webbing allows them to move their arms towards their mouths without compromising the primary web, a critical feature for hunting and eating. The octopuses also have a U-shaped internal shell, one of the primary features of the species of citrate octopods.

Their most alluring feature is their ability to glow in the dark, or bioluminescence. Their forty-five to fifty-five suckers do not function as those that other octopuses utilize. Instead, they have become light-producing organs. Scientists believe that they are used in a number of different ways. Perhaps, for luring prey or for scaring off predators. 

Interestingly, males have differently shaped suckers than females. The first eight suckers, according to Animal Diversity, are barrel-shaped. The following are enlarged and more pointed in shape. Males of the species also have their suckers at different distances from one another than females. But, both males and females have three types—proximal, mid-arm, and distal, terms that indicate how close the suckers are to the mantel. 

Illustration of bioluminescent squid
Illustration of bioluminescent squid, similar to the bioluminescent octopus


Habitat 

These octopuses are fairly common around the eastern coast of the United States, towards the edge of the continental shelf. Octopuses are usually found near the bottom of the ocean up to depths around 500 to 4000 m or .3 to 2. 4 miles. This incredible range is based on the temperature of the water. They prefer temperatures of 3 to 3.3°C or around 37.5-38°F. 

Diet 

Little is known about the diet of these small octopuses. But, research into preserved specimens has indicated that they eat small crustaceans, such as copepods. It’s also been suggested that their bell-shaped web can be used to capture zooplankton. The use of bioluminescence to attract prey, as mentioned above, has been suggested but not confirmed.

Different types of crustaceans
Different types of crustaceans


Reproduction 

Unfortunately, a juvenile specimen of the species has never been found or studied. This means that little is known about the developmental process of the species or their lifespan. Additionally, nothing is known about the mating behavior of the species. But, examinations of the known specimens have revealed some information about the male and female genital systems. For example, the majority of eggs found in the female genitalia were quite small, less than one millimeter, and the largest up to eleven millimeters, according to Collins and Henriques, 2000.  

These octopuses are believed to lay around 900 eggs at a time. 

Threats 

Natural predators of the species of bioluminescent octopus have not been observed. Due to the depths at which reside, they are at little risk from human-caused threats, such as climate change and pollution. But, this does not mean that they are completely safe. In fact, various studies have indicated that these animals are often damaged by trawls by fishing boats.

It’s also likely that these animals do have specific predators they have to avoid within their deep-sea habitats, they just have yet to be observed by scientists. 

Facts about the Bioluminescent Octopus

  • Their suckers glow in the dark and are incapable of sucking. 
  • These octopuses are small, around 2 to 4 inches, or 5 to 10 cm. 
  • The octopuses have eight arms of different lengths.
  • The octopuses have two webs that join their arms. 
  • Their natural predators are unknown. 
  • The bioluminescent octopus likely eats small crustaceans. 


FAQs 

What is the bioluminescent octopus? 

The bioluminescent octopus, or Stauroteuthis syrtensis, is a small octopus species with forty-five to fifty-five suckers that glow in the dark rather than suck. Little is known about this species. 

What is the rarest octopus?

Dumbo octopuses are some of the rarest octopuses in the world. Other rare species include the blanket octopus and the glass octopus. Many of the sightings of these species are regarded as “once in a lifetime.” They are rare due to the fact that they live at incredible depths, towards the bottom of the ocean, and sometimes due to detrimental effects of climate change and human encroachment or natural habitats, driving the species towards extinction.

Are Dumbo octopuses bioluminescent?

No, Dumbo octopuses are not bioluminescent. They are small compared to other octopods, averaging between 20 and 30 centimeters. They are known for their ability to camouflage themselves. 

Featured image credit: shellmuseum.org