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Vitreledonella is a genus of mesopelagic octopods from the family Amphitretidae which contains two species, one of which is the glass octopus.

These octopods have the sucker on their arms arranged in a single series with the suckers widely separated from each other. The third left arm is hectocotylised with a spherical vesicle at the distal end and in males the other arms have suckers which are enlarged beyond the web. The eye has strong lateral compression with a near rectangular shape in lateral view and with the width equal to the diameter of the lens. There is a ventral, blunt rostrum-like extension on the eye which contains iridescent tissue above the eye. The opening to the mantle is broad, the radula is multicuspid and linear in form with the first and second lateral tooth each being unicuspid, which means that this species has a heteroglossan radula. The long and slender digestive gland is spindle-shaped and the stomach is positioned dorsally to the digestive gland.

Amphitretus and Bolitaena are two other transparent, gelatinous pelagic incirrate octopods. Both of these genera differ from Vitreledonella in that the right third arm is hectocotylized and the radula is ctenodont (with comb-like individual teeth).

List of species
According to the EOL:

Diet
Vitreledonella preys upon various types of crustaceans. This could include crabs, shrimp, etc. They also feed on various types of small fishes, clams, and snails. Studies have found that the glass octopus has teeth, during the paralarvae stage, to help function in digestion. However, after a period of maturation, a faint development of a beak forms. Due to the beak of the glass octopus being less developed than other octopus species, it could indicate consumption of soft-bodied prey as well.

Behavior
Throughout the period of this species' evolution, cephalopods have become intelligent individuals. One of the largest advances in its evolution that the octopus has seen, in general, has been its large nervous system, including large brain. Just to provide a sense of how big their nervous systems are, the common octopus, Octopus vulgaris, has an approximate 500 million neurons in its body. Due to their expansive nervous systems and connective neurons throughout the body, all octopus species have the ability to navigate the best possible route for themselves. They are notorious for being able to escape simple and challenging mazes - especially in the laboratory. Octopus, like the glass octopus itself, utilizes visual cues to help distinguish between two environments, then take the best route. Like many other species of octopus, Vitreledonella richardi, uses its eight long tentacles to sense and control its surrounding environment. With their tentacles, they also have the ability to sense chemicals (smell or taste). This species of octopus is especially sensitive to its external environment due to the fact that it resides within deep-sea areas, which causes a lack of light for vision purposes. It is always ready to quickly propel itself through the water, using its tentacles to create jet-stream propulsions of water. Many aspects of the glass octopus' behavior, as well as the behavior of other octopus species, is solely driven by different strategies to evade predators.

Predators
Scavengers and other organisms often attempt to prey on octopus eggs, even when the female is present to protect them. However, studies have shown that remains of Vitreledonella have been found within the stomach contents of northern bottlenose whales, Hyperoodon ampullatus, within the northeast Atlantic ocean. This was found by sampling stranded northern bottlenose whales. In all four samples, the food remains consisted mainly of all cephalopod beaks. Through various testing methods, the species, Vitreledonella richardi, was identified. This proves that this type of octopus is preyed upon by other larger marine animals. Furthermore, studies performed within the Ecuadorian Pacific area have indicated the presence of the glass octopus within the stomach contents of three different shark species. Multiple sharks from the species groups of Carcharhinus falciformis, Carcharhinus limbatus and Nasolamia velox were sampled from. Amongst the presence of the glass octopus, their prey included bony fishes, elasmobranchs, molluscs, crustaceans, and turtles. Moreover, it is important to note that because the glass octopus is practically almost transparent, this feature works to its advantage, when avoiding predation by other marine organisms.