Amphioctopus

Amphioctopus
Veined Octopus, Amphioctopus marginatus
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Octopoda
Family:	Octopodidae
Subfamily:	Octopodinae
Genus:	Amphioctopus Fischer, 1882
Species
See text
Synonyms
Schizoctopus Hoyle, 1886 “Sub-group of Octopus aegina” sensu Robson, 1929 “aegina species group” sensu Norman, 1993

A. marginatus using two different bivalve shells for shelter

Amphioctopus is a genus of octopuses comprising around 16 species.

Description

Members of the genus Amphioctopus reside in tropical and subtropical waters. These octopuses are found primarily in the Pacific and Indian Oceans but representatives can also be found in the Atlantic. They are characterized by arms that are about two or three times their mantle length with deep lateral webs and very shallow dorsal webs.^[1] This genus can be further divided into two subgroups, one group with ocellate octopuses, the other with non-ocellate octopuses.^[2]

Taxonomic status

Historically, members of this genus were placed within the genus Octopus, but recognized as forming a distinct group and referred to as the Octopus aegina species complex.^[3] The genus was originally described by Fischer in 1882. He assigned to it the already described species, Octopus membranaceus (Quoy and Gaimard, 1832), as the type species (not to be confused with Enteroctopus membranaceus (Rochebrune and Mabille, 1889), the original types species of the genus Enteroctopus). Robson in his review of octopus taxonomy in 1929 regarded Amphioctopus membranaceus as a nomen dubium, referring it to his newly named "aegina species complex", a group of octopuses forming a distinct constellation characterized by Octopus aegina. The genus Amphioctopus was subsequently considered invalid. In 2002, Gleadall suggested that the aegina species group represents a distinct genus with Amphioctopus being the senior name. In 2004, Gleadall resurrected the genus Schizoctopus and assigned Octopus fangsiao as the type species.^[4] In 2005, Huffard and Hochberg, arguing that Robson's designation of Octopus membranaceus as a nomen dubium was premature and considering it a valid name, resurrected the genus name Amphioctopus for the Octopus aegina species complex. Huffard and Hochberg also found Schizoctopus to be a junior synonym for Amphioctopus.^[3]

Species

• Amphioctopus aegina
• Amphioctopus arenicola
• Amphioctopus burryi
• Amphioctopus exannulatus
• Amphioctopus fangsiao
• Amphioctopus granulatus *
• Amphioctopus kagoshimensis
• Amphioctopus marginatus, veined octopus
• Amphioctopus membranaceus *
• Amphioctopus mototi
• Amphioctopus neglectus
• Amphioctopus polyzenia
• Amphioctopus rex
• Amphioctopus robsoni
• Amphioctopus siamensis
• Amphioctopus varunae

Species marked with an asterisk (*) remain unresolved.

References

1. Norman, M.D. & F.G. Hochberg (2005). The current state of octopus taxonomy. Phuket Marine Biological Center Research Bulletin 66: 127–154.
2. Norman, M. (2003). Cephalopods: A World Guide. Hackenheim, ConchBooks, p. 214.
3. Huffard, C.L. & F.G. Hochberg (2005). Description of a new species of the genus Amphioctopus (Mollusca: Octopodidae) from the Hawaiian Islands. PDF Molluscan Research 25(3): 113–128.
4. Gleadall, I.G. (2004). Some Old and New Genera of Octopus. Interdisciplinary Information Sciences. 10(2): 99–112.