Luteuthis spp. are very fragile, gelatinous, presumably pelagic cirrate octopods whose affinities are uncertain (see Nomenclature) The two species in this genus are known from only three specimens.
An opisthoteuthid ...
- with distinctive broad, W-shaped shell.
- Presence of a radula.
- W-shaped shell.
- Suckers with tooth-like margins.
- Linear arrangement of accessory glands in the male.
The presence of a radula is now known be we widely distributed in the Grimpoteuthis. The W-shaped shell is unusual but an intermediate condition is seen in Grimpoteuthis tuftsiGrimpoteuthis). (O'Shea and Lu, 2002, consider this species to be in the Luteuthidae but Collins, in press, considers it a typical The peculiar suckers appears to be a unique feature. The arrangement of accessory glands needs further evaluation. The arrangement of glands is unknown in many species and where known the clear arrangement of the parts and, indeed, their proper identification is often unclear.
We suggest that placing Luteuthis in its own family is premature at present.
- Shell W-shaped.
- Shell with basal shelf deflected beneath saddle.
- Shell with lateral wings keeled, in some species, inrolled margins.
- Arms and web
- Sucker enlargement in males undetermined.
- Sucker apperature crenulate with tooth-like structures.
- First cirri between suckers 4 and 6.
- Cirri short; maximum length comparable to half of largest sucker diameter.
- Web nodules absent.
Figure. Side and oral view of cut suckers showing tooth-like structures of L. dentatus. Drawing from O'Shea, 1999.
- No areolar spots.
- Gills with half-orange appearance.
- Digestive system
- Intestine shorter than or approximately equal to esophagus (including crop) in length.
- Digestive gland bilobed.
- Radula present.
Figure. Side view of the digestive system of L. dentatus. Drawing from O'Shea, 1999.
- Reproductive system
- Male with linear arrangement of accessory glands.
- Penis well developed.
- Optic lobe
- Circular in cross-section
- Single optic bundle penetrates the white body.
Figure. Digestive system of L. dentatus. Drawing from O'Shea, 1999.
The two distinctive features of Luteuthis are the tooth-like structures on the suckers and the shape of the shell.