This web site was created within Arctic Ocean Diversity (ArcOD) project
and was financially supported by Polish Ministry of Science (project number: DPN/AD/1881/09 and 396/N-EOL-ENC/2009/0)


Abdomen - posterior region of the body.
Acicula (aciculae) - internal chitinous rod supporting a parapodium.
Acicular lobe - parapodial lobe supported by the acicula. Anal cirrus - elongated projectionsfrom the pygidium.
Antenna (antennae) - sensory appendage on the anterior or dorsal surface of prostomium.
Apodus - without parapodia.
Arborescent branchiae - branchiae like a tree.
Bayoned chaetae - compound chaetae with very thin blades.
Bidentate chaeta - chaeta with two tips.
Biramous - with two aciculae and both noto- and neuropodium well-developed.
Branchia (branchiae), gill - extension of the body wall which aids respiration.
Buccal segment - segment pertaining to the mouth.
Capillary chaetae - long slender chaetae gradually tapering to a fine point.
Caruncle - projection from the posterior end of the prostomium carrying nuchal organs..
Cephalic plate - plate-like antero-dorsal surface of the head region in some Maldanidae and Pectinariidae.
Cephalic rim - flange encircling the head.
Chaeta (chaetae), seta - chitinous bristles protruding from pockets in the body wall.
Chaetiger, setiger -segment bearing chaetae.
Cirrus (cirri) - sensory appendage which is usually slender and cylindrical.
Collar - encircling fold covering the base of the crown in Serpulidae and Sabellidae.
Compound chaetae - articulated chaetae consisting of blades and shafts.
Dorsum - dorsal (back) surface of body.
Dorsal cirrus - cirrus situated dorsally on the parapodium.
Epidermis - outer cellular layer of the body wall.
Eyespot - heavily pigmented region that apparently functions in light reception.
Facial tubercle - projection from prostomium, dorsal to mouth but ventral to median antenna.
Forked chaetae - fork like chaetae.
Genital hook - modified notopodial chaeta used in mating in some Capitellidae.
Genital pore - modified nephridial opening.
Gill, branchia (branchiae) - extension of the body wall which aids respiration.
Harpoon chaetae - stout pointed seta with recurved barbs near the tip.
Hooded hook - hook distally covered by a delicate chitinous envelope or guard.
Hook - stout-shafted simple chaetae which may be distally curved or toothed.
Interramal cirrus - cirrus situated on the ventral side of the notopodium, projecting into the space between the notopodium and the neuropodium.
Jaws - hardened, opposable parts in the pharynx.
Lamella (lamellae) - fleshy, flattened or plate-like structure.
Lobe - conical process of a parapodium.
Macrotubercles - large knob-like protuberance.
Mandible - ventral jaw plate.
Maxillae - dorsal jaw plates.
Microtubercles - small knob-like protuberance.
Mouth - anterior opening of the alimentary canal, usually anterior opening of fully everted pharynx.
Neurochaeta - chaeta from neuropodium.
Neuropodium (neuropodia) - ventral branch of a parapodium.
Notochaeta - chaeta from notopodium.
Notopodium (notopodia) - dorsal branch of a parapodium.
Nuchal organs - paired chemosensory structure situated posterolaterally on the prostomium.
Ocellus (ocelli) - small eyespot.
Operculum - kind of lid used to close the tube.
Paleae - stout, long anterior chaetae with pointed tips directed anteriorly.
Palp - elongate or cushion-like sensory or feeding structures on the head.
Papilla (papillae) - small, nipple-like projection.
Paragnaths - small hardened teeth on the proboscis of species of the family Nereididae.
Parapodial lobe - well developed, fleshy parapodium.
Parapodium - lateral lobe of a body segment, often reduced, usually bearing chaetae.
Peduncule - attachment stalk of the operculum in Serpulidae.
Peristomium - presegmental region of the body surrounding the mouth.
Pharynx - anterior muscular part of the alimentary canal, including the eversible proboscis.
Postbranchial segments - segments posterior to the branchiae.
Postchaetal lamellae - lamellae located posterior to the chaetae in each parapodium.
Prechaetal lamellae - lamellae located anterior to the chaetae in each parapodium.
Proboscis - eversible, non-muscular part of the pharynx, often used interchangeably with pharynx.
Prostomial peaks - antero-lateral projections, often chitinised, of the prostomium in some scale-worms.
Prostomium - anteriormost region of the body, anterior to mouth.
Pygidium - terminal part of the body, surrounding the anus.
Pygidial cirri - cirri projecting from the pygidium.
Radioli - main tentacles in the crown of Sabellidae and Serpulidae.
Scales (elytra) - dorsal scales found in the Aphroditoidae.
Scaphe - flattened posterior body region of Pectinaridae.
Seta, chaeta (chaetae) -chitinous bristles protruding from pockets in the body wall.
Setiger, chaetiger - segment bearing chaetae.
Sickle chaeta - simple chaeta with a sickle-shaped blade in some Spirorbinae.
Simple chaeta - unjointed chaeta.
Spatulate chaeta, pseudospatulate chaeta - simple chaeta with a broadly expanded distal margin, like a spatula, spoon-shaped.
Spine - thick acicular or spear-shaped chaeta, may be straight or slightly curved.
Subbiramous - parapodia with two aciculae but with the notopodial lobe reduced, often represented by the acicula only.
Talon - proximal process of opercular plate.
Tentacles - long, paired or multiple food-gathering appendages, most are grooved and/or have a longitudinal row of cilia.
Tentacular cirri - cirri situated on cephalized segments, or any anterior dorsal cirri that are better developed than the other dorsal cirri.
Thorax - anterior region of the body.
Torus (tori) - welt or ridge-like parapodial ramus, often with hooks or uncini.
Tubercle - knob-like protuberance.
Uncini - deeply embedded chaetae with multidentate heads.
Uncinigerous - bearing uncini (in tori).
Unidentate chaeta - chaeta with one tip.
Uniramous - parapodial lobe with only 1 branch present, usually the neuropodium.
Ventral cirri - cirri situated on the ventral surface of the parapodia.
Venter (ventrum) - lower body surface.
Winged capillary chaeta, limbate chaeta - simple chaeta with a flattened wing projecting from one side along much of its distal half.