Cirrothauma

Cirrothauma is a genus of deep water octopuses from the cirrate family Cirroteuthidae. The species of Cirrothauma are fragile, gelatinous deep-sea octopods with a large 'butterfly-shaped' shell.

Cirrothauma
Cirrothauma murrayi
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Octopoda
Family:	Cirroteuthidae
Genus:	Cirrothauma Chun, 1911[1]
Type species
Cirrothauma murrayi Chun, 1911

They are unique in the Octopoda in being blind, with eyes lacking lenes and being imbedded/covered in head tissues. The genus contains a single species Cirrothauma murrayi.^[2][3]

Species and taxonomy

Two other species have formerly been included in Cirrothauma,^[4] but have recently been allocated to their own genus (Inopinoteuthis): Inopinoteuthis magna (Hoyle, 1885) and Inopinoteuthis hoylei (Robson, 1932).^[2][5]

Both Cirrothauma and Inopinoteuthis have butterfly-shaped shells, and much longer arms than the related Cirroteuthis. Genera Cirrothauma and Inopinoteuthis can be separated given the presence of well-developed eyes on Inopinoteuthis (vs. vestigial eyes) as well as the presence of functional suckers with suction chambers on Inopinoteuthis (Cirrothauma have minute vestigial suckers atop elongate fleshy stalks across the mid-distal arm regions).^[2]

Range

The single recognized species Cirrothauma murrayi has been reported from various locations across the Atlantic, Arctic, and Pacific Oceans, but seemingly not the Southern Ocean.^[6][7]

Species

There is a single currently recognized species within the genus Cirrothauma, though a second (as yet undescribed taxon) is indicated in molecular data.^[1][2]

• Cirrothauma murrayi Chun, 1911