Glass Octopus
Encyclopedia
Vitreledonella richardi, also known as the Glass Octopus, is an incirrate octopus
. It is the sole representative of the genus
Vitreledonella and of the family
Vitreledonellidae.
Vitreledonella is a transparent, gelatinous, and almost colorless meso-
to bathypelagic octopod found worldwide in tropical and subtropical seas with a mantle
length (ML) of up to 11 cm and a total length of up to 45 cm in adults. The upper three pairs of arms are subequal in length; in juveniles about as long as the mantle, in adults 2–3 times ML. The fourth, ventral pair is slightly shorter. Suckers are small, widely separated, and in a single series. In males, the left arm III is hectocotylized
, with a spherical vesicle near the tip, but is not detachable. Eyes are nearly rectangular in shape as seen from the side. The radula
is heterodont, also known as heteroglossan, in which the middle or rhachidian tooth is each array has mutlitple cusps and the lateral teeth are unicuspid.
Vitreledonella is ovoviviparous. The female broods her eggs, of which there are hundreds, within the mantle cavity. Each egg measures about 4 mm in length. Newborn larvae have a ML of approximately 2.2 mm.
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.
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
. It is the sole representative of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Vitreledonella and of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Vitreledonellidae.
Vitreledonella is a transparent, gelatinous, and almost colorless meso-
Mesopelagic
The mesopelagic is that part of the pelagic zone that extends from a depth of 200 to 1000 metres below the ocean surface. It lies between the photic epipelagic above and the aphotic bathypelagic below, where there is no light at all...
to bathypelagic octopod found worldwide in tropical and subtropical seas with a mantle
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
length (ML) of up to 11 cm and a total length of up to 45 cm in adults. The upper three pairs of arms are subequal in length; in juveniles about as long as the mantle, in adults 2–3 times ML. The fourth, ventral pair is slightly shorter. Suckers are small, widely separated, and in a single series. In males, the left arm III is hectocotylized
Hectocotylus
A hectocotylus is one of the arms of the male of most kinds of cephalopods that is modified in various ways to effect the fertilization of the female's eggs. It is a specialized, extended muscular hydrostat used to store spermatophores, the male gametophore...
, with a spherical vesicle near the tip, but is not detachable. Eyes are nearly rectangular in shape as seen from the side. The radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
is heterodont, also known as heteroglossan, in which the middle or rhachidian tooth is each array has mutlitple cusps and the lateral teeth are unicuspid.
Vitreledonella is ovoviviparous. The female broods her eggs, of which there are hundreds, within the mantle cavity. Each egg measures about 4 mm in length. Newborn larvae have a ML of approximately 2.2 mm.
Amphitretus
Amphitretus
Amphitretus is a genus of pelagic gelatinous octopuses. It is the sole genus of family Amphitretidae and consists of 2 species. Some authorities consider Amphitretus thielei as a subspecies of Amphitretus pelagicus, making this family monotypic.-External links:*...
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.