Luteuthis
{{Short description|Genus of octopuses}}
{{Automatic taxobox
| taxon = Luteuthis
| authority = O'Shea, 1999{{cite web | url = http://www.marinespecies.org/aphia.php?p=taxdetails&id=390702 | title = Luteuthis O'Shea, 1999 | accessdate = 7 February 2018 | publisher = Flanders Marine Institute | author = Philippe Bouchet | year = 2018 | work = World Register of Marine Species}}
| type_species = Luteuthis dentatus
| type_species_authority = O'Shea, 1999
| subdivision_ranks = Species
| subdivision = Luteuthis dentatus
Luteuthis shuishi
}}
Luteuthis is a small genus of cirrate octopuses currently placed in the family Grimpoteuthidae. There are two species classified in this genus one from waters west of New Zealand and the other from the South China Sea.
Taxonomy
Luteuthis are characterized by several unique features. The body is relatively elongate, extensively gelatinous and lacking areolar spots. The paired fins are laterally placed, and supported by a W-shaped internal shell with the shell wings bearing in-rolled margins and tapering to acute points. The arms are narrow and connected by simple webbing, there is no web nodule acting as a web attachment point. The suckers are crenulated (around the aperture opening) and are flanked by rows of short cirri (cirri about half as long as the sucker diameter). The gills resemble a "half-orange" and have seven lamellae. Luteuthis species have a well developed radula as well as palatine teeth on the palps flanking the radula, and the digestive gland is bilobed.{{Cite book |last1=Collins |first1=Martin |last2=Villanueva |first2=Roger |date=2006 |title=Taxonomy, Ecology And Behaviour Of The Cirrate Octopods |url=http://dx.doi.org/10.1201/9781420006391.ch6 |journal=Oceanography and Marine Biology |series=Oceanography and Marine Biology - an Annual Review |volume=44 |pages=277–322|doi=10.1201/9781420006391.ch6 |doi-broken-date=12 July 2025 |isbn=978-0-8493-7044-1 }}{{Cite journal |last1=O’Shea |first1=Steve |last2=Lu |first2=Chung Cheng |date=2002 |title=A New Species of Luteuthis (Mollusca: Cephalopoda: Octopoda: Cirrata) from the South China Sea |url=http://zoolstud.sinica.edu.tw/Journals/41.2/119.pdf |journal=Zoological Studies |volume=41 |issue=2 |pages=119–126}} As with other cirrate octopods, the ink sac is missing.
The genus was originally placed within its own family, Luteuthidae (O'Shea, 1999), as the presence of a radula was deemed very distinctive. However, it later became apparent that species of Grimpoteuthis also often have a radula and the two genera share other distinctive features (such as the optic nerves forming a single bundle each side of the head), with molecular data further supporting placement of Luteuthis, Grimpoteuthis and Cryptoteuthis in the family Grimpoteuthidae.{{Cite journal |last1=Piertney |first1=Stuart B. |last2=Hudelot |first2=Cendrine |last3=Hochberg |first3=F.G. |last4=Collins |first4=Martin A. |year=2003 |title=Phylogenetic relationships among cirrate octopods (Mollusca: Cephalopoda) resolved using mitochondrial 16S ribosomal DNA sequences |url=http://dx.doi.org/10.1016/S1055-7903(02)00420-7 |journal=Molecular Phylogenetics and Evolution |volume=27 |issue=2 |pages=348–353 |doi=10.1016/s1055-7903(02)00420-7 |pmid=12695097 |issn=1055-7903|url-access=subscription }}