Terminology Description
Terminology Description
Anal flaps A pair of fleshy papillae that arise at the sides of the anus.
Anterior Toward the head end or toward the arm tips of cephalopods.
Arm formula Comparative length of the arms expressed numerically in decreasing order, e.g., or
Armature Refers to the presence and arrangement of suckers and/or hooks on the arms and tentacular clubs of cephalopods.
Beak The chitonous like structure at the mouth of a cephalopod. The beak is similar in structure to a parrot's beak and can give a nasty bite.
Bifurcated arm tip The division of the arm tip into 2 branches.
Biochemistry The study of the chemistry of living organisms
Brachial Pertaining to the arms.
Branchial Pertaining to the gills or gill region.
Buccal lappet Small, subtriangular flap at tip of muscular band that supports the buccal membrane; may bear suckers.
Buccal membrane Thin web of tissue that encircles the mouth, reinforced by 6 to 8 buccal supports.
Buccal membrane connectives Muscular bands that connect the supports of the buccal membrane to the bases of the arms.
Buccal suckers Small suckers on the buccal lappets/membrane.
Calcified Chalky, calcareous by deposition of calcium salts (calcium carbonate).
Calimus The conical papilla or projection on the hectocotylus of octopods at the proximal terminus of the sperm groove, distal to the last sucker
Carpal cluster A usually distinct group of suckers and knobs on the carpus of the tentacular club.
Carpal knobs Small, rounded, hemispherical protuberances on the carpus to which carpal suckers from the opposite club adhere during the locking of the clubs.
Carpal suckers Small suckers on the carpus of the club that usually adhere to knobs on the opposite carpus during the locking of the clubs.
Carpus The proximal zone of (small) suckers (and knobs) on the tentacular club.
Cartilaginous scales Cartilage like structures in the skin of certain squids; may be overlapping and scale like, or mutlifaceted knobs or papillae.
Cephalopod A class of Molluscs that are known for the reduction, internalization or loss of their shell (exception: Nautilus), active life styles and advanced behavior. Cephalopods are jet powered, many can produce ink and they can rapidly change color, shape and texture.
Chitin(ous) A horny polysaccharide substance (fingernail like) that forms the sucker rings, hooks and beaks.
Chromatophores Pigment filled muscular sacs in the skin under individual nervous control that collectively provide the background colour, colour patterns, and colour play of cephalopods.
Circumoral appendages The eight arms (squids, cuttlefishes and octopuses) and two tentacles (squids and cuttlefishes) or the very numerous arms (Nautilus) that arise from the h ead and encircle the mouth of cephalopods.
Cirri Arm: elongate, fleshy, finger like papillae along the lateral edges of the oral surface of the arms, especially in cirrate octopods. Body: fleshy protuberances of the skin that can be erected as papillae, usually over the eyes.
Class Any of the taxonomic groups into which a phylum is divided and which consists of one or more orders.
Cones, conus The spoon like or cup like conical posterior terminus of the gladius or cuttlebone; homologous to the phragmacone of fossil teuthoids.
Corneal membrane The very thin, transparent skin that covers the eyes of myopsid and sepioid cephalopods.
Cuttlebone The calcareous (chalky) oblong, supporting plate in the dorsal part of the mantle of cuttlefishes.
Dactylus The distal, terminal section of the tentacular club, often characterized by suckers of reduced size.
Distal Away from the body or point of origin; toward the peripheral parts (opposite of proximal).
Dorsal The uppermost or back surface of a cephalopod, opposite the ventral surface where the funnel is located.
Enzyme A protein made within a living organism which accelerates specific chemical reactions (a catalyst).
Epidermis The outer layer of cells.
Family Any of the taxonomic groups into which an order is divided and which consists of one or more genera.
Fast Moll A list server for people interested in cephalopods. Most members are scientists and traffic is very low.
Fin angle The angle between the longitudinal axis of the mantle and the posterior border of one fin.
Fin lobe The portion of each fin that protrudes anteriorly from the anterior point of attachment of the fin to the mantle.
Fins The pair of muscular flaps that arise along the dorsolateral surface of the mantle of sepioids, teuthoids, and cirrate octopods; used for locomotion, steering and stabilization.
Fixing apparatus The mechanism of suckers and knobs on the carpal region of the tentacular club that permits the two clubs to be locked together during capture of prey
Foveola Transverse, membranous fold of skin that forms a pocket in the funnel groove of some oegopsids
Funnel / Siphon The ventral, subconical tube through which water is expelled from the mantle cavity during locomotion and respiration (reproductive and waste products and the ink also pass through the funnel). Archaic term siphon.
Funnel groove The depression in the posteroventral surface of the head in which lies the anterior portion of the funnel.
Funnel locking Cartilage The cartilaginous groove, pit, pocket, on depression on each ventrolateral side of the posterior part of the funnel that joins with the mantle component to lock the funnel and mantle together during locomotion, so water is expelled only through the funnel and not around the mantle opening (see Mantle locking cartilage).
Funnel organ The glandular structure fused to the internal surface of the funnel, generally a single W shaped form in octopods and a dorsal inverted V shaped component with opposed ventral oblong components in decapods.
Funnel valve The semilunar muscular flap in the dorsal surface of the distal opening of the funnel.
Ganglia Knot like masses of the cell bodies of neurons located outside of the central nervous system (CNS); includes the swellings of the CNS in invertebrates.
Gill lamellae The leaf like convoluted individual components of the gill through which gas exchange occurs.
Gills Structures used by cephalopods and many other marine animals like fish for respiration.
Gladius The feather or rod shaped chitinous supporting structure in the dorsal midline of teuthoids and non sepiid sepioids; the homolog of the shell of ancestral forms.
Hectocotylus One (or more) arm(s) of male cephalopods modified for transferring spermatophores to the female; modifications may involve suckers, sucker stalks, protective membranes, trabeculae
Hooks Chitinous, claw like structures ontogenetically derived from the suckers on the arms and/or clubs of some oegopsids.
Ink sac The structure that manufactures and stores the ink of cephalopods; it lies along the intestine and empties via a duct into the rectum.
Iridescent Shimmering and changing colours.
Keel A flattened, muscular extension along the aboral surface of some arms to render them more hydrodynamic; (2) 1 or 2 expanded muscular membranes on the tentacular
Light organ A simple or complex structure that produces bioluminescence by intrinsic (self generated) or extrinsic (bacterial) means (also termed photophore).
Ligula The spatulate to spoon shaped, terminal structure of the hectocotylus of octopods, that contains the calimus basally (proximally) and usually a series of transverse ridges and grooves on the oral surface
Mantle The fleshy (muscular) tubular or sac Iike body of cephalopods; provides propulsion through jet Iike expulsion of water; contains the viscera.
Mantle locking cartilage The cartilaginous ridge, knob or swelling on each side of the ventrolateral, internal surface of mantle that locks into the funnel component of the apparatus during locomotion
Manus Central or "hand" portion of club between the dactylus distally and the carpus proximally.
Medial (n) Pertaining to a structure located towards, on, or along the midline.
Needhams' sac The elongate, membraneous container at the terminus of the male reproductive tract that stores completed spermatophores (=spermatophore sac).
Ocellus A pigmented spot or patch usually consisting of a central locus of concentrated chromatophores with one or more concentric rings of chromatophores. Ocellae occur on some octopuses, and their normally vivid pigmentation make them stand out against the background colouration.
Oesophagus (Esophagus) The region of animal gut which transports food from mouth or pharynx.
Olfactory papilla A bump Iike to finger like protuberance on the posterolateral surface of each side of the head; of presumed olfactory function.
Orbital pore Minute pore in the anterior part of the transparent tissue that covers the eyes of sepioids and myopsids
Orbital sinus An anteriorly directed indentation in the eyelid of oegopsids
Pedicel Short, tubular stalk that supports a sucker in sepioids and teuthoids.
Photophore An organ of greater or lesser complexity that produces and distributes bioluminescence, either intrinsically through biochemical reaction or extrinsically through luminescent bacteria
Ploidy (in ref to algae) Indicating a specific multiple of a single set of Diploidy.
Pocket An open depression in the anteroventral surface of the head of sepioids into which the feeding tentacles are retracted when not in use.
Protective membrane Thin web like integument along the lateral angles of the oral surface of the arms and clubs lateral to the suckers, supported by muscular rods called trabeculae
Proximal Toward the body or nearest or next to the point of origin or attachment; (opposite of distal).
Rachis The thickened central axis that usually extends the entire length of the gladius. Free rachis is the portion that does not support vanes
Radula The chitinous, ribbon like band in the mouth of cephalopods containing several transverse rows of teeth.
Retinal Pertaining to the light sensitive membrane lining the posterior wall of the eyeball.
Senescent Growing old.
Sepion The calcareous dorsal supporting structure in the mantle of cuttlefishes.
Side pockets Small membranous folds of the integument that form pockets lateral to the foveola
Sperm recepticle A bulbous structure in the buccal region of some female cephalopods, e.g., loliginids, for the retention of viable sperm until they are required for fertilization. A tubular structure manufactured by male cephalopods for packaging sperm; capable of holding millions of sperm, being transferred intact, and attaching to the female until fertilization begins.
Spermatophore A fleshy patch of tissue, usually in the mantle cavity of some female cephalopods (e.g. loliginids), to which spermatophores adhere after mating until fertilization occurs.
Spine The sharp spike Iike extension on the posterior tip of the gladius or cuttlebone
Statocyst The 'ear bone' of cephalopods. Statocysts of some species can be used to age them.
Sucker ring Chitinous, often serrated or denticulate ring that encircles the opening of suckers of squids and cuttlefishes.
Suckers Muscular, suction cup structures on the arms and tentacles (rarely on the buccal membrane) of cephalopods; some are stalked, placed on muscular rods that contract (squids and cuttlefishes); some are sessile, embedded without stalks on the oral surface of the arms (octopuses). They are usually counted either in longitudinal or in transverse (oblique) rows.
Tail The posterior extension of the mantle, frequently elongate. Fins or tapered terminations of fins may extend posteriorly along the tail.
Tentacles Elongate, stalked circumoral appendages of cuttlefishes and squids used for prey capture; distal ends contain clubs with suckers (or hooks); stalks usually devoid of suckers. Tentacles can retract into pockets on the head of cuttlefishes, or merely contract, in squids.
Tentacular club Terminal portion of a tentacle; armed with suckers (or suckers and/or hooks), used for capturing prey
Trabeculae Muscular rods that support the protective membranes on the arms and clubs of cephalopods; occasionally membranes are reduced and/or trabeculae are elongated, so they extend beyond the edge of the membrane, papilla like.
Umbilicus The central core of the chambered Nautilus shell, representing the juvenile shell with its initial coils.
Vane Thin lateral expansion of the gladius that arises from the rachis.
Ventral The lowermost or belly surface of a cephalopod; the surface on which the funnel is located; opposite the dorsal surface.
Viscera The 'guts' of an animal.
Water pores Small orifaces at base of the web of some pelagic octopuses
Web A membranous sheet of greater or lesser extent that extends between the arms of many octopuses, giving an umbrella like appearance when the arms are spread out, e.g., on cirroteuthids