Back to: Projects

Taxonomic information across the Internet

Glossary

Below is a list of terms used in these pages. This glossary is taken from Day 1967. A monograph on the Polychaeta of Southern Africa.

Abdomen
The region of the body posterior to the thorax and sometimes followed by a caudal region or tail.
achaetous
without setae
acicular setae
a very stout projecting seta homologous with other setae but similar in thickness to an internal aciculum
aciculum, acicula, aciculae
a stout internal chitinous rod which supports one of the two lobes of a parapodium
anal cirrus
projection from the pygidium or terminal segment on which the anus opens
antenna
a sensory projection arising from the anterior or dorsal surface of the prostomium
apodous segment
a segment without a foot or parapodium
arborescent
branching like a tree
aristate seta
a stout seta with a smooth shaft and a tuft of fine hairs at the end
biarticulate
two-jointed
bidentate (seta)
with two teeth
bifurcate (seta)
ending in two prongs
bilabiate
with two lips
bilimbate
a pointed seta with wings or flattened margins on both sides, like a feather
bipinnate
a structure such as a feather with a main axis and two rows of side branches
biramous
having notopodia and neuropodia
biramous parapodium
a foot or parapodium with two bundles of setae, one in the notopodium and one in the neuropodium
branchia
a gill, usually a outgrowth from the body which pocesses elements of the blood system
buccal
pertaining to the mouth
calicinate
like the calyx of a flower
canaliculate
with fine canals
capillary
hair-like
capillary seta
strictly a hair-like bristle but often used to cover all long slender tapering setae
caruncle
a sensory lobe extending behind the prostomium
ceratostyle
the distal joint of an antenna
ceratophore
the basal joint of an antenna
cirriform
shaped like a cirrus
cirrigerous
a segment bearing a cirrus
cirrophore
a basal projection on which a cirrus is mounted
cirrostyle
the distal part of a cirrus
cirrus
a sensory projection (usually tapered) derived from the superior part of the notopodium (dorsal cirrus) or the inferior part of the neuropodium (ventral cirrus)
clavate
club-shaped
compound seta
a jointed seta
compressed
flattened in the lateral plane
cordate or cordiform
heart-shaped
crenulate (seta)
with a series of small cusps
crotchet
a long-shafted seta with a hooked or curved end
ctenidium(a)
a branchia or respiratory organ
cultriform
shaped like a knife
deciduous
liable to fall of like a leaf
dentate
toothed
dentate-crested hooks
setae with the apex of the shaft toothed
denticle
a structure like a minute tooth
denticulate
with minute teeth or denticles
depressed
flattened in the dorso-ventral plane
detritus
particles of organic origin on the sea bed
digitiform
finger-shaped
distal
the part of a structure towards the end
dorsum
the dorsal surface of the body
echinulate
prickly like a sea-urchin
eversible (proboscis)
capable of being extended by turning the inner part outwards
falciform
hook-shaped
falciger
seta having a stout, hooked blade or apex
filamentous
shaped like a filament or fine thread
filiform
thread-like, very slender
flanged (seta)
an elongate seta with a flattened edge or margin
foliaceous
leaf-like
fusiform
spindle-shaped or cigar-shaped
geniculate
bent like a knee
genital papilla
projection below the neuropodium on which a reproductive duct opens
glabrous
smooth and glistening
harpoon seta
a stout pointed seta with recurved barbs near the apex
hastate
shaped like the blade of a spear
heterogomph
a compound seta with a slanting or asymmetrical joint between shaft and blade
hispid
minutely furry
homogomph
a compound seta with transverse or symmetrical joint between shaft
hooded hook
a stout, blunt or apically toothed seta with the apex protected by a delicate chitinous envelope or guard
hook
a broad term used to cover a wide range of simple setae which have stout shafts and blunt or toothed apices
imbricating
overlapping like tiles
inferior
the more ventral of two structures
intermediate cirrus
a cirriform projection between the notopodium and the neuropodium
intersegmental
between segments
lamella
a flattened or plate-like structure
lanceolate
pointed and shaped like a lance
ligule
a compressed conical lobe of a parapodium
limbate (seta)
a seta with a flattened margin to the blade
lobe
projection from parapodium
mammiliform
shaped like a breast
medial
on the side nearer the median or mid-line of the body
median
in the mid-line
membraneous
thin and flattened like a membrane
moniliform
like a string of beads
neuropodium
the lower or ventral part of a parapodium
neurosetae
a seta arising from the neuropodium
notopodium
the upper or dorsal part of a biramous parapodium
notoseta
a seta arising from the notopodium
nuchal organ
a sensory organ on the prostomium or extending back from it usually in the form of a groove or ciliated ridge
occipital
pertaining to the posterior part of the prostomium
occipital antennae
antennae on the posterior part of the prostomium
ovoid
egg-shaped
palea
a broad flattened type of seta
palmate
like the fronds of a palm
palps or palpi
paired projections growing out from the sides of the head. In errant polychaetes they arise from the ventral surface of the prostomium and have a gustatory function but in sedentary polychaetes they arise from the peristome and are usually grooved and ad
palpode
a tapering anterior projection of the prostomium
palpophore
the basal parts of a jointed palp
paragnaths
horny or chitinous granules in the pharyngeal cavity of the Nereidae which help to grip the prey
parapodium
segmental, projections bearing setae
pectinate
with a series of projections arranged like the teeth of a comb
penicillate
like a little paint brush
peristomium
the segment behind the prostomium, which is modified to form part of the head and surrounds the mouth. Only the first segment forms the true peristomium but in the families Nereidae, Hesionidae and others the possession of more than two pairs of tentacles shows that two or more segments have fused
pharynx
the posterior part of the mouth cavity leading on to the oesophagus
pilose
velvety; covered with very short hairs
pinnate
feather-like; with a main axis and lateral branches
pinnules
a series of side branches of some feather-shaped organ
piriform
with a broad bulbous base and tapered tip; onion-shaped
postsetal
posterior to the setae
presetal
anterior to the setae
proboscis
the anterior part of the alimentary canal derived from the stomadaeum which can be everted to project forwards
prostomium
the anterior lobe in front of the mouth bearing eyes and antennae
proximal
part of a structure nearer to the base or main body; cf. distal
pygidial
pertaining to the anal segment or pygidium
pygidium
the anal segment or terminal part of the body
ramose
branched
ramus
a branch or prong; the notopodium and neuropodium which form the two parts of a parapodium are often termed the two rami
reniform
kidney-shaped
rhomboidal
irregularly four-sided
rugose
rough or lumpy
sabre seta
a seta with a broad curved blade
secondary tooth
the second of two teeth, the first being the apical or terminal one
segmental organ
organs occurring in segmental arrangement. In the Alciopidae they are swellings (often pigmented) at the bases of the parapodia
sessile
without a stalk
setal
pertaining to setae of bristles
setiger
a segment with setae
setigerous lobe
that projection or part of the notopodium or neuropodium which bears the setae
simple seta
an unjointed seta
spindle-shaped
elipsoid; cigar-shaped with pointed ends
spiniger (seta)
a compound seta whose blade tapers to a fine point
spinule
a small spine
spinulose
provided with spinules
spirally serrulate
a seta whose blade is encircled with spirally arranged serrations
striated
very fine parallel marks or lines - striae
stylet
a small pointed, tooth-like structure
stylode
a botanical term here used to mean a finger-like projection usually on a parapodium
sub-biramous
a parapodium which is neither completely uniramous nor biramous
subequal
approximately equal
subspiral
approximately spiral
subterminal
almost at the end
subtriangular
approximately triangular
superior
the more dorsal of two structures
tentacle
a slender outgrowth from the head
tentacular cirrus
a cirrus arising from the peristome which is elongated to act as a tactile organ
tentaculophore
a basal projection on which a tentacle is mounted
tessellated
a surface with a network of grooves like a tiled wall
thorax
the anterior region of the body
tori of parapodia
ridges from which the setae arise
truncate
with the end cut-off; not tapering
uniramous
with a single lobe or prong where two might be expected; the opposite of biramous. (Uniramous parapodia lack one of the two setigerous lobes)
ventrum
the ventral surface of the body
winged capillary seta
a simple, unjointed seta whose blade has an axial rib but the margins are flattened and tapering

Back to the help menu.