Funnel–mantle locking apparatus

Structure found in many cephalopods

The funnel–mantle locking apparatus is a structure found in many cephalopods that connects the mantle and hyponome (funnel) and restricts their movement relative to each other.^[1] It consists of two interlocking components: one located on the mantle (often fibrous) and the other on the funnel (often cartilaginous).^[1] The apparatus may permit some anterior–posterior displacement or prevent movement altogether.^[1]

Function

Variability

Funnel component

Six major forms of the funnel locking apparatus are recognised among teuthids (lazy-T shape, inverted-T shape, straight shape, triangular shape, oval with tragus and/or antitragus, and oval shape) and several more are found in the sepioids (including the boomerang shape and keyhole shape).^[2]

Shape of funnel locking apparatus	Species	Family
	Idioteuthis cordiformis	Mastigoteuthidae
	Magnapinna talismani	Magnapinnidae
	Mastigoteuthis flammea	Mastigoteuthidae
	Mastigoteuthis glaukopis	Mastigoteuthidae
	Mastigoteuthis grimaldii	Mastigoteuthidae
	Mastigoteuthis magna	Mastigoteuthidae

Mantle component

Shape of mantle locking apparatus	Species	Family
	Mastigoteuthis grimaldii	Mastigoteuthidae

References

^ ^a ^b ^c Young, R.E., M. Vecchione & K.M. Mangold (1999). Cephalopoda Glossary. Tree of Life Web Project.
^ Young, R.E., M. Vecchione & K.M. Mangold (1997). Cephalopod Funnel Locking-Apparatus. Tree of Life Web Project.

Cephalopod anatomy

Shell

Types

External	Ammonoid shell Argonautid eggcase Nautiloid shell Orthocone
Internal	Belemnoid guard Cirrate shell Cuttlebone Gladius (pen) Spirula shell Stylet

Features

External	Aperture Apex Callus Lirae Periostracum Sculpture Spire Sutures Umbilicus
Internal	Body chamber Camerae Nacre Phragmocone Septa Siphuncle Whorls

Mantle &
funnel

External anatomy	Dermal structures Fins (wings) Flotation devices ("secondary fins") Funnel–mantle locking apparatus Tail
Internal anatomy	Branchial hearts Ctenidia (gills) Hepatopancreas (digestive gland) Ink sac and ink Needham's sac Nephridia ("kidneys") Nidamental glands Osphradium Pericardial glands

Head &
limbs

Brachial crown	Arms Hectocotylus Tentacles Carpus Dactylus Manus Suckers and hooks
Buccal region	Aptychus Beak Odontophore Radula Spadix and antispadix
Occipital region	Nuchal crest (occipital crest) Nuchal folds (occipital folds) Occipital membrane Olfactory organ Nuchal organ
Other parts	Eyes Statocysts