Cirroteuthidae Explained

Cirroteuthidae is a family of pelagic cirrate octopuses comprising at least three species in two genera.

Description

The cirrate octopods have a unique internal shell, positioned dorsally above the viscera and with a 'saddle-like' shape (or 'butterfly-like' in Cirrothauma due to the anterior corners being more drawn out). The lateral faces of the 'saddle' acting as large attachment sites for fin muscles, supporting proportionally large and powerful fins. The arms are elongate and have both a primary web, forming most of the webbing, and a secondary web connecting the primary webbing to the aboral (outer) faces of each arm. The cirri, pairs of small finger-like projections between each sucker, are very elongate. Both the elongate cirri and secondary web are features shared with Stauroteuthidae, but no other cirrate family.^[1]

Taxonomy

The family Cirroteuthidae contains two generally accepted genera containing at least four species, but also some possibly undescribed taxa.^[2]

• Genus Cirroteuthis Eschricht, 1838: this genus contains an additional undescribed species from around Australia and New Zealand.^[3]
  • Cirroteuthis muelleri Eschricht, 1838
• Genus Cirrothauma Chun, 1911
  • Cirrothauma magna (Hoyle, 1885)
  • Cirrothauma murrayi Chun, 1911: often known as the blind cirrate.
  • Cirrothauma hoylei (Robson, 1932): originally described in genus Cirroteuthis, but almost certainly a Cirrothauma and possibly synonym of C. magna.

There are also two genera of uncertain affinity placed in this family, but both are in need of critical assessment.

• Laetmoteuthis Berry, 1913
• Froekenia Hoyle, 1904: One described species (Froekenia clara) and an undescribed species, quite likely synonymous with Stauroteuthis given shell form.^[4]

External links

• Tree of Life website gives information about the classification of cephalopod groups
• Cirroteuthidae discussion forum at TONMO.com

Notes and References

1. Collins . Martin . Villanueva . Roger . 2006 . Taxonomy, Ecology And Behaviour Of The Cirrate Octopods . Oceanography and Marine Biology . 44 . 277–322.
2. Web site: WoRMS - World Register of Marine Species - Cirroteuthidae W. Keferstein, 1866 . 2023-09-21 . www.marinespecies.org . en.
3. Verhoeff . Tristan Joseph . 2022-07-03 . Finned octopus Cirroteuthis Eschricht, 1836 (Cephalopoda: Cirrata: Cirroteuthidae) confirmed from Australian waters . Molluscan Research . en . 42 . 3 . 205–211 . 10.1080/13235818.2022.2087143 . 249837870 . 1323-5818.
4. Verhoeff . Tristan Joseph . 2023-07-20 . A new species of Stauroteuthis (Octopoda: Cirrata) and further novel cirrate octopods from Australian waters . Molluscan Research . en . 1–20 . 10.1080/13235818.2023.2232534 . 260017318 . 1323-5818.