Glossary L-Z
Abbreviations and Terms
L
LL, Llat: lateral line.
LTAR: lateral tail ridge.
LTR: lateral trunk ridge .
labial: pertaining to the lips.
lacrymal: foremost circumorbital bone immediately in front of each eye (see ‘preorbital').
lamella (pl. lamellae): thin plate, layer or film, especially of bone or tissue.
lamina (pl. laminae): lamella, often with a stratified structure.
lanceolate: spear- or lance-shaped.
lappet: lobe-like structure, often associated with the iris in the eye.
larva (pl. larvae, adj. larval): immature stage of a fish, which differs greatly in appearance from the adult.
lateral(ly) (comb. latero-) adj.: referring to the side, away from the centre.
lateral line (scales): row or rows of pored scales or sensory pores in the skin along the side of the body; counted as the number of pore bearing scales from the upper end of the gill opening to the base of the caudal fin.
lateral midline: lengthwise centre of the side.
lateralis: laterosensory.
lateral tail ridge: in the Syngnathidae, the longitudinal ridge laterally on the tail rings, abbreviated ‘LTAR'.
lateral trunk ridge: in the Syngnathidae, the longitudinal ridge laterally on the trunk rings, abbreviated ‘LTR'.
laterosensory: sensory system comprising regularly arranged surface pores opening from a subcutaneous system of canals with receptors capable of detecting low frequency vibrations (movements).
lath-like: similar to thin strips of sawn or split timber for use as internal support for hard plaster.
latitude: angular distance from the equator North or South measured in degrees, minutes and seconds.
lectotype: one of several type-specimens designated after the publication of a species-group name, as the type-specimen of the taxon bearing that name; designated only where there was no original holotype.
lens: transparent substance with curved sides for the concentration or dispersal of light.
leptocephalus (pl. leptocephali): transparent leaf-like pelagic larval form of eels and their close relatives.
light organ, light-producing organ: structure that produces light by a chemical reaction (bioluminescence), either directly by special body cells or through luminescent bacteria cultured in body tissues.
limb: appendage, such as a leg, arm or wing, or section of a continuous structure, like a gill arch.
lingual: of the tongue.
litter: offspring produced at the same time.
live-bearing: retention of eggs within the body cavity of the mother, releasing free-swimming young at birth.
lobe (adj. lobate): roundish and flattish projection or pendulous part.
long-based: having a long base.
longitude: angular distance on the Earth's surface, measured East or West from the prime meridian at Greenwich, England, to the meridian passing through a position, expressed in degrees, minutes, and seconds.
longitudinal: along the length.
longitudinal series: number of scales in a longitudinal row along the length of the body.
longline: fishing gear comprising a line of considerable length off which hang many shorter lines with baited hooks, the main line usually set horizontally in the water column.
luminescent, luminescence: producing light.
luminous infracaudal organ: light organ on underside of caudal peduncle.
luminous organ: light organ; specialised part of the body that produces light, usually without a lens.
luminous supracaudal organ: light organ on top of caudal peduncle.
lunate: shaped like a crescent moon, pertaining to the tail fin.
lure: structure used to entice potential food items within striking distance of its predatory owner.
M
m: metre(s).
mm: millimetre(s)
MP: mandibular pores.
MPAs: marine protected areas
mail-cheeked: having horizontal spiny ridge or other protective covering on the side of the head beneath the eye.
malar: pertaining to the forward portion of the upper surface of the pectoral fins (fused with head) in rays.
mandible (adj. mandibular): lower jaw.
mandibular pores: pores of the cephalic lateralis canal system laterally on the lower jaw.
maori-like: having markings like the tattoos of the Maori people of New Zealand.
marbled: having mottled or streaked colouration like marble limestone.
mature: fully developed and capable of reproduction.
maxilla (pl. maxillae, maxillaries, adj. maxillary): hindmost of two pairs of bones forming the lateral margin of the upper jaw.
medial(ly): towards the middle of the body (towards the vertical plane).
median: pertaining to the middle (vertical plane).
medusae: sea jellies (jellyfish).
melanophore: black pigment cell or chromatophore.
membrane: thin layer of connective tissue.
meristic: countable.
mesial(ly) (comb. meso-) adj.: towards the middle or medial plane.
mesopelagic: free swimming in the open ocean at depths from 200m to 1000m.
mesopterygoid: bone in the suspensorium that forms part of the roof of the mouth on either side behind the palatines.
metabolism: chemical processes within living tissue or organisms necessary for the maintenance of life, involving the breaking down of substances to yield energy for vital processes and the synthesis of others, necessary for life.
metalarval stage: stage of larval development at the point of changing to the adult configuration.
metamorphosis: the marked changes in body form during growth, most frequently from the larval to the adult stages.
microhabitat: natural home and immediate surroundings (fine scale perspective).
micronekton: microscopic component of free swimming animals in a body of water.
mid (adverbial prefix): halfway or at the centre, as in midcaudal - at the centre of the caudal.
midline: longitudinal centre.
midpoint: centre.
midside: central part of the side laterally.
midventral: centre of the underside.
mid-water: occurring in the open ocean well above the bottom and well away from the ocean surface, usually at greatly reduced light levels or in darkness.
minute: tiny.
mode: way in which things are done; prevailing fashion.
molar (adj. molariform): blunt, rounded tooth, adapted for grinding.
mollusc: member of a major invertebrate group typically having a soft unsegmented body, a mantle and usually a protective calcareous shell or shells; includes snails, slugs, bivalves, octopus, squid, etc.
monophyletic: sharing a common ancestor.
monospecific: having only a single species.
monospondylous: having a single vertebra in each body segment, as in the trunk of certain fishes; in cartilaginous fishes, vertebral centra larger than diplospondylous vertebral centra.
monotypic: having only a single species.
morphology (adj. morphological): the anatomical form and structure of organisms.
morphometrics, morphometry: measurements of body structures.
mosaic: made up of many small non-uniformly coloured or textured parts.
mouth width: transverse distance between corners of mouth.
mouthbrooding: retaining eggs within the mouth, usually by the male, while they develop, thus improving their chance of survival.
mucous, mucus: slimy substance produced by cells in the skin of fishes.
multicuspid: having many points or projections.
multifid: divided into many parts or lobes.
multilobed, multilobate: having many lobes.
multiserial: having more than one series or row.
myomere, myotome: segment of body muscle (muscle block).
N
naked: skin that is smooth and without scales.
nape: upper surface in front of the dorsal fin, just behind the head.
nares (adj. narial): nostrils.
nasal: relating to the nose or nostril.
nasal curtain: internasal flap; fleshy flap extending between the nostrils and partly covering the mouth of some rays and sharks.
nasal organ: sensory organ for detecting smell.
nasal rosette: nasal organ, having prominent fan-like laminae equipped with numerous olfactory sensory organs to enhance smell capability.
nasal tentacle: thick fleshy filament near the nostril.
nasal valve: nasal opening.
nasoral groove: furrow connecting the mouth to the nasal organ, usually concealed beneath internasal flap.
neotype: a single specimen designated as the type-specimen of a nominal species-group taxon of which the holotype (or lectotype), and all other type specimens are lost or destroyed or suppressed by the International Commission on Zoological Nomenclature.
neurocranium: the part of the skull that surrounds the brain.
neuromast: free nerve endings having a sensory function.
nictitating membrane: clear membrane at the front of the eye that can be pulled over the surface of the eye for protection.
nocturnal: active at night.
non-serial photophore: isolated photophore not part of a photophore series.
nostril: pore-like opening of the nasal organ; many species having two pairs, an anterior nostril and a posterior nostril.
notch: indentation.
notochord: rudimentary or embryonic spinal cord or spinal column appearing as a clear, stiffened rod.
nuchal: pertaining to the nape.
nuptial tubercles: small abnormal horny outgrowths that become evident just before spawning and disappear shortly afterwards under the influence of hormonal secretions.
nursery: space where offspring are raised.
O
OA: lateral series of photophores.
Op: ‘cheek' photophores on opercle.
OP: opercular photophores.
ORB 1: photophore anterior to eye.
OV: lateral series of photophores, subdivided into anterior OVA & posterior OVB.
oblique: slanting or declining from the vertical or horizontal; not at right angle.
oblique scale rows: diagonal scale rows; regular arrangement of scales in slanted rows along the side of a fish's body usually counted above the lateral line, if present, from the edge of the operculum to the posterior edge of the hypurals.
obsolescence: no longer of use.
obtuse: not pointed; with a blunt end, forming a broad angle.
occipital (n. occiput): pertaining to the back part of the top of the head (or the occipital bones of the skull).
oceanic: of the open ocean.
ocellus (pl. ocellae, adj. occellated): an eye-like spot with a marginal ring (often a dark spot with a pale marginal ring).
ocular: pertaining to the eye.
olfactory: pertaining to the nasal organs or the sense of smell.
olfactory organ: organ for the sense of smell.
opercle: large, posterior bone of the gill cover.
opercular: pertaining to the operculum or gill cover.
operculum (pl. opercula): bony flap (supported by several individual bones), which covers the gills.
oophagous: feeding on eggs.
ooze: mud; very fine soft sediment.
opercular membrane: membrane around the free edge of the gill cover providing a seal across the gill opening when water is drawn into the mouth for respiration.
oral disc: circular mouth of lampreys.
orbit (adj. orbital): bony eye socket.
orbital tentacle: filamentous fleshy outgrowth, usually above the eye.
orbital thorns: enlarged spine-like denticles partially encircling medial side of orbit in some skates.
order (adj. ordinal): commonly used major grouping in classification falling between class and family.
origin: the most anterior point of the base of a fin, a spine, or a ray.
osmosis (adj. osmotic): tendency of a fluid to move through a selective barrier into a more concentrated solution.
ossicle: plate of bone-like material.
ossify (n. ossification): to turn into bone.
ostracitoxin: tetrodotoxin; virulent poison, capable of causing death, present in certain body tissues of pufferfishes and some of their relatives.
ostracod: small crustacean with a pair of clam shell-like valves for protection.
ostracoderm: extinct group of fishes best known for its outer bony covering or exoskeleton.
otolith: oval-shaped calcareous structures in the ear capsules of bony fishes (earbones).
ovate, ovoid: oval-shaped.
oviparous: eggs that hatch outside the body of the female parent.
oviphagous: method of embryonic nutrition where the embryo feeds on unfertilised eggs or other embryos with the uterus.
ovoviviparous: producing eggs with a definite shell that hatch within the body of the female parent.
ovulate: to release eggs from the ovary.
P
P: number of elements in each pectoral fin, usually comprising just soft rays (Arabic numerals).
PC: pyloric caecae
PLO: photophore above pectoral-fin base.
PO: ventral series of photophores in front of ventral fin.
Po: postorbital photophore posteroventral to eye.
Pol: lateral photophore(s) between adipose fin and posterior part of anal fin.
POP: preopercular pores.
Prc: ventral series of photophores just in front of caudal-fin base.
PV: ventral series of photophores between bases of pectoral and ventral fins.
PVO: lateral photophores ventral, opposite, and/or dorsal to pectoral-fin base.
palate: roof of the mouth.
palatine: one of a pair of elongated bones on the palate just lateral to and behind the vomer; the anteriormost bone of the suspensorium.
palatoquadrate: that portion of the suspensorium extending from the jaw hinge to the front of the neurocranium.
papilla (pl. papillae, adj. papillate, papillose): small fleshy projection.
parasitic: living for some period of time, to its own benefit, in or on another organism (the host) to the host's detriment.
particulate: in the form of separate particles.
pectoral: pertaining to the breast region.
pectoral disc: flattened disc-like body of skates and rays formed from the union of the pectoral fins with the head and body.
pectoral fin: usually the most anterior of the paired fins, situated in the breast region or midlaterally on the side just behind the head (corresponding to forelimbs in terrestrial vertebrates).
pectoral girdle: skeletal support for the pectoral fin.
pedicel: stalk-like structure.
peduncle: narrow stalk-like structure (most frequently referring to the caudal peduncle).
pelagic: free swimming in the open ocean and seas.
pelvic bone: see ‘pelvis'.
pelvic fin: ventral fin; each of the paired fins situated ventrally and usually below or behind the pectoral fins (corresponding to hind limbs in terrestrial vertebrates).
pelvic girdle: skeletal support for the ventral fin.
pelvis: basal bony support for the ventral or pelvic fins.
periphery (adj. peripheral): outer margin.
periproct: scaleless area surrounding anus.
peritoneum: thin membrane that lines the abdominal cavity.
pharynx (adj. pharyngeal): gullet or back part of the throat into which the gills slits open.
phosphorescent: emission of light without combustion or perceptible heat.
photophore: small, circular light-producing organ on the surface of the body.
phylogeny (adj. phylogenetic): pertaining to interrelationships based on ancestry.
piebald: of two colours irregularly arranged, especially black and white.
pinnacles: natural peak ending in a pyramid- or crown-like form.
pit: indentation or hollow in a surface.
placenta: flattened circular spongy vascular tissue in the uterus that helps to nourish a developing foetus in live-bearing individuals.
planktivorous: feeding on plankton.
plankton (adj. planktonic): small animals or plants that drift passively with the ocean currents.
platelets: small discs, often with slightly concave centres.
pleural rib: slender paired bones based on the vertebral column that provide the structural support for the membrane surrounding the body cavity in which the swim bladder and major digestive and reproductive organs are contained.
plicate: pertaining to skin arranged in pleat-like folds.
polychaete: bristle worm; major group of annelid worms, particularly diverse in the marine world.
polygonal: referring to an enclosed shape with many (usually more than four) sides and angles.
polyp: individual member of a coelenterate colony, usually consisting of a tubular body with an oral opening surrounded by a circle of tentacles at the distal end.
pore: small opening or pit, as in the lateral-line pores.
Posidonia: genus of marine flowering plants or ‘seagrass' with moderately broad flat leaves.
post (adverbial prefix): coming after or behind, such as postorbital - behind the orbit or eye.
posterior(ly) (comb. postero-) adj.: relating to the hind region.
posterolateral: hind region along the side.
post-larvae (adj. postlarval): newly settled larvae that have not yet acquired the juvenile configuration.
postocular: behind the eye.
postorbital: behind the orbit.
posttemporal: portion of the head or skull on either side behind the orbits.
posttemporal bone: superficial bone suspending the upper end of the pectoral girdle from the cranium on either side behind the orbits, and enclosing a section of the laterosensory canal.
pouch: bag-like cavity.
pre (adverbial prefix): coming before or in front of, such as preorbital - in front of the orbit or eye.
preanal-fin chambers: series of lymph compartments within the finfold on the ventral side of the body in advance of the anus.
prebranchial length: distance from the front of the rostrum to front of first gill aperture.
prebranchial slime pores: slime pores from the anteriormost to the last pore before the first gill aperture.
precaudal: anterior to the tail region.
precaudal length: length from snout tip to upper caudal-fin origin.
precaudal pit: notch on the caudal peduncle just before the caudal fin.
precaudal vertebra: vertebra associated with the abdominal cavity, lacking a haemal spine.
precloacal length: length from snout tip to anterior extent of the cloacal opening.
predorsal: anterior to the origin of the first dorsal fin.
prehensile: adapted for holding, as in the tails of monkeys or the snout of elephants.
prejuvenile: early life stage just prior to acquisition of juvenile characteristics.
pre-mature: not yet capable of reproduction.
premaxilla (pl. premaxillae, adj. premaxillary): one of the paired bones forming the front of the upper jaw, usually bearing teeth.
preocular: in front of the eye.
preopercle (adj. preopercular): the bone situated behind and below the eye and in front of the opercle.
preoral: pertaining to the area in front of the mouth.
preoral groove: (preoral cleft) groove before the mouth.
preoral length: shortest distance from the snout tip to the mouth.
preorbital: in front of the orbit.
preorbital bone: lacrymal; anteriormost (first) suborbital bone.
preorbital length: shortest distance from the snout tip to the orbit.
prepelvic claspers: small, retractable appendages on each side just forward of the ventral fins of mature male chimaeroid fishes; concealed with a slit when retracted; prepelvic tentacula.
preural: pertaining to the next to the last vertebral element of the vertebral column.
primary photophores: those photophores occurring in the majority of the species, including serial photophores and recurring isolated photophores.
principal ray: one of the major segmented and often branched rays supporting the caudal fin and articulating with the hypural bones basally (in most fishes the number of principal rays equals the number of branched rays + 2 unbranched rays).
proboscis: elongated, flexible extension of the snout.
process: natural appendage, outgrowth or protuberance.
procurrent ray: each of the small unbranched and often unsegmented rays in the tail of many fishes situated on the dorsal and ventral margins of the caudal peduncle in front of the principal rays.
protolarval stage: earliest larval stage.
protractile: capable of being extended forwards; protrusible.
protruding (adj. protrusible): thrusting forth, projecting, often pertaining to the jaws of fishes.
protuberance: bulge, prominence.
province: major area of natural distribution in a biogeographical sense.
proximal: part of a structure nearest the base or point of attachment.
pseudobranch: remnant of the hyoid gill arch attached to the inner surface of the gill cover; covered by skin in some fishes.
pterotic: each of a pair of bones on either side forming a portion of the neurocranium (brain case) behind and slightly above the eye.
pterygiophore: three-part internal skeletal support at the base of each of the dorsal- and anal-fin spines and rays.
pterygoid: ectopterygoid; a bone in the suspensorium on the posterior part of the palate.
pungent: stiff and sharply pointed, as in some spines.
pupil: circular opening in the centre of the iris of the eye.
purgative: having the effect of a strong laxative; causing evacuation of the stomach and bowels.
pyloric caecum (pl. pyloric caecae): tubular sac attached to the stomach.
Q
quadrangular: with four angles and edges.
quadrate: bone in the suspensorium with which the lower jaw is hinged.
R
radials: series of column shaped bones in the pectoral girdle providing a base distally for the pectoral-fin spines and rays and articulating with the coracoid and scapula proximally.
raker: see ‘gill raker'.
rapacious: grasping; predatory.
ray: flexible, usually segmented structure that supports a fin.
receptors: organs of sensory reception.
recurved: curved backwards or inwards.
reflector: surface causing light waves to rebound.
regressed: having gone backwards.
resorbed: absorbed again.
retia: rete mirable; highly vascularised organ within the gas bladder responsible for gas secretion.
reticular (reticulate, n. reticulation): divided into a network; arranged in small squares or with intersecting lines.
rhomboid (adj, rhomboidal): having a 4-sided (quadrilateral) shape with only the opposite sides and angles equal.
riverine: of or on a river, or its banks.
rostrum (adj. rostral): projecting snout or beak.
rudimentary (n. rudiment): very small and poorly formed; undeveloped; imperfectly developed.
rugose: with a rough surface.
S
SAO: lateral series of photophores above anus.
SDR: subdorsal rings.
SL: standard length.
So: photophore just below eye.
SO: paired photophores near symphysis of lower jaw.
SOP: supraoccipital pores.
Sor: suborbital photophore anteroventral to eye.
STAR: superior tail ridge.
STR: superior trunk ridge.
Suo: light organ dorsoposterior to eye.
sac: bag-like membrane-enclosed cavity.
saddle: marking on the back resembling a horse's saddle.
salp: barrel-shaped free-floating tunicate that moves by pumping water through its gelatinous body by means of contraction, and strains the water, feeding on phytoplankton.
sashimi: Japanese food consisting of raw fish.
scales above lateral line: regular arrangement of scales in slanted rows between the dorsal margin of a fish's body to, but not including the lateral line, counted downward and backward from the base of the first dorsal-fin spine (or ray if spines are absent) unless otherwise stipulated.
scales below lateral line: regular arrangement of scales in slanted rows between the ventral margin of a fish's body to but not including the lateral line, counted upward and forward from the base of the first anal-fin spine (or ray if spines are absent) unless otherwise stipulated.
scale rows between dorsal-fin base and lateral line: scales above lateral line (see above).
scale rows between lateral line and ventralfin base: scales below lateral line (see above).
scaled: having scales.
scalloped: with a series of rounded projections along the margin or edge, like the outer margin of a scallop shell.
scavenger: feeding on carrion.
schooling: forming a shoal or aggregation.
scribbling: resembling hurried or careless writing.
scull: propel by moving oar-like structure from side to side in a twisting fashion.
scute: bony plate or ridged scale.
scutellum (pl. scutella): shield-lie scale.
sea jelly: jellyfish; marine invertebrates of the phylum Cnideria, whose adult body is composed of a bell-shaped, jellylike substance enclosing its internal structure, with tentacles suspended beneath.
sea urchins: members of the phylum Echinodermata, with globular, usually rigid body having a five-part symmetry, covered by spines and moving by means of hundreds of tiny, transparent, adhesive ‘tube feet'.
seagrass: marine flowering plants with grass-like form.
seamount: underwater mountain.
seaweed: any of a large number of marine benthic algae.
secondary photophores: photophores occurring in a relatively few number of species, other than regular serial photophores and recurring isolated photophores.
secrete (n. secretion): excrete substance, separated from blood, to the exterior.
sedentary: characterised by little movement or swimming.
segmented ray: fin ray divided into segments along its length.
seine: fishing net with floats at the top and weights at the bottom used to encircle fish, and usually hauled ashore.
semi-detached: partly connected and partly free.
sensory canal/pore: canal or pore associated with the electrosensory or laterosensory systems.
serial(ly): of, in or part of a series.
serrae (adj. serrated): notches, like those of a saw.
sessile: fixed in one position, immobile.
sexual dimorphism (adj. sexually dimorphic): difference in physical appearance between males and females.
shelf: see ‘continental shelf'.
shovelnose: having a spatulate snout.
siltation: the act of having sediment deposited by water.
simple: not divided into branches.
skin fold: area where skin is bent over upon itself, forming a flesh ridge.
slime pores: series of pores along the flank of hagfishes that produce large amounts of slime used in defense or in suffocating other fishes.
slope: see ‘continental slope'.
snout: upper part of the head in front of the eyes.
soft dorsal: dorsal fin supported entirely or almost entirely of soft rays.
soft ray: fin ray that is bilaterally paired and often segmented and branched.
spatulate: with a broad, flat and rounded shape.
specific: pertaining to species.
speciose: composed of many species.
sperm: male sex cell.
sphenotic: each of a pair of bones on either side forming a portion of the neurocranium (brain case) immediately behind and slightly above the eye, just below the frontal bone.
spheroid: sphere-like but not a perfectly spherical body.
spinal column: vertebral spine.
spine: sharp pointed projection, often supporting a fin; in reference to fin spines, each element being undivided and unsegmented.
spiniform, spinoid: having the shape of a spine.
spinoid scale: cycloid scale with a serrated margin; superficially similar to ctenoid scales but with spines as outgrowths of the scale, as opposed to true ctenii.
spinous: composed of spines or spine-like.
spinule (adj. spinular, spinulate, spinulous): a small spine.
spiracle: opening behind the eye in sharks and rays with an open passage to the pharynx, used in respiration.
spiral valve: spiral or helical fold in the midgut of primitive fishes that increases the surface area for processing food without lengthening the intestine.
splint bone: modified first ventral-fin ray that is unsegmented and not bilaterally paired.
spur: hard, pointed projection.
squalene: oil produced in the liver of some sharks.
stalked: on a peduncle or stem-like structure.
standard length: length of a fish measured from the tip of the snout to the end of the posterior edge of the hypurals, abbreviated 'SL'.
stellate: star shaped.
striae: striations.
striated (n. striation): having a series of linear marks on the surface.
stripe: lengthwise strip of colour.
sub (prefix): below, as in ‘subrostral', or almost but not quite, as in ‘subterminal mouth'.
subadult: maturing individual that is almost capable of reproduction.
subarctic: region well away from the equator but not close enough to the North Pole to be regarded as arctic.
subantarctic: biogeographic region of the Southern Ocean in the vicinity of 50°S latitude.
subcircular: nearly circular.
subclass: division of classification immediately below class, between it and the level order.
subcontinuous: slightly interrupted.
subcutaneous: below the skin.
subcylindrical: not quite cylindrical.
subdermal: below the skin.
subdorsal rings: in the Syngnathidae, the number of trunk rings beneath the dorsalfin base + the number of tail rings beneath the dorsalfin base, abbreviated ‘SDR'.
subequal: almost equal.
subfamily: division of classification immediately below family, between it and the level genus.
subgenus (pl. subgenera): grouping of closely related species with a common ancestry below the generic level; only recognised if there are at least two such groupings in the genus.
subinferior: extremely inferior, as in subinferior mouth - a mouth on the underside of the head well away from the tip of the snout.
subopercle: bone forming a portion of the operculum immediately below the opercle.
suborbital: referring to below the orbit or eye.
suborbital bones: infraorbital bones, ventral series of circumorbital bones not fused with the neurocranium.
suborbital stay: bony ridge beneath the eye extending from the suborbital bone across the cheek to the preopercle, or almost to the preopercle.
suborder: division of classification between the levels of order and family.
subphylum (pl. subphyla): division of classification below the level of phylum composed of one or more classes containing species that have a common ancestry.
subrhombic: almost diamond-shaped; nearly an oblique equilateral parallelogram.
subrostral: referring to below the snout.
subspecies (adj. subspecific): population confined to a particular geographic area within the overall range of a species that differs in a consistent way from populations elsewhere in the range.
substrate, substratum: underlying layer or substance; foundation.
subtemperate: on the polar side of a temperate region.
subterminal mouth: mouth opening on the underside of the head almost at the anterior end.
subtidal(ly): below the low tide mark.
subtriangular: nearly triangular.
subtropical: at the periphery of the tropical region, almost temperate.
subvertical: approaching the vertical.
sucking disc (suction disc): disc-like structure on the head of Echeneidae comprised of a series of thin movable plates called laminae; or ventral disc formed, in part, from united ventral fins of Gobiesocidae used to attach fish to rocks or vegetation.
suctorial: capable of sucking; having a sucker for adhering to an object.
suffused, suffusion: an overspreading of colour.
superior tail rings: in the Syngnathidae, the longitudinal ridge on the dorsal margin of the tail rings, abbreviated ‘STAR'.
superior trunk rings: in the Syngnathidae, the longitudinal ridge on the dorsal margin of the trunk rings, abbreviated ‘STR'.
super (prefix): situated directly over, or more than.
superclass: division of classification immediately above class, between it and the level phylum.
superorder: division of classification immediately above order, between it and the level class.
superspecies: division of classification immediately above species, made up of two or more very similar species.
supra (prefix): above, as in supraorbital - pertaining to the region above the orbit (eye).
suprabranchial pores: posteriormost pores above the gill opening in the temporal pore series of cephalic sensory pores.
supracaudal: on top of caudal peduncle.
supracarinalis anterior: lengthwise muscle connecting the rear of the skull dorsolaterally with the first pterygiophore of the dorsal fin anterordorsally.
supracleithrum: paired dermal bone of the secondary pectoral girdle above the cleithrum and below the posttemporal.
supramaxilla, supramaxillary (also as adj.): one or two dermal bones on the upper side of the posterior end of the maxilla in more primitive fishes.
supraneural: one of a median series of detached, usually ossified rods lying in the flesh between the head and the dorsal fin, presumably representing detached neural spines.
supraoccipital: median bone at the upper rear end of the neurocranium, often bearing a crest, and forming the top edge of the foramen magnum.
supraocular ridge: one of a pair of lengthwise bony ridges between the eyes.
supraorbital: above the eye.
supraorbital canal: cephalic sensory canal extending from above the eye to the nostrils.
suprascapula: bone or cartilage that joins the shoulder girdle to the skull.
supratemporal: above the posterolateral (temporal) region of the skull.
suspensorium: bone series on either side suspending the lower jaw from the neurocranium or braincase.
suture: ragged line of union between two bones cemented with connective tissue, allowing no movement.
swimbladder: gas-filled sac lying in the body cavity beneath the backbone that provides the fish with some buoyancy.
symbiosis (adj. symbiotic): the living together of 2 species to their mutual benefit.
sympatric: having distributions that overlap geographically.
symphysis (adj. symphysial): the junction or site of fusion between two bones or parts of the anatomy, especially in the median plane of the body, often the midline of the lower jaw.
syntypes: specimens on which a species name is based where one has not been singled out as the holotype.
T
TAR: tail ring.
Tas: Tasmania.
TL: total length.
TR: trunk ring.
tab: small flap.
tail length: distance from the origin of the cloaca to the posterior margin of the caudal fin.
tail rings: in the Syngnathidae, body rings on the tail posterior to the anal ring, abbreviated ‘TAR'.
tail slime pores: the series of slime pores that starts about over the anterior margin of the cloaca to the last pore on tail.
taxon (pl. taxa): a particular natural unit within a classification; a taxonomic unit.
taxonomy (adj. taxonomic): the science of classifying.
telescopic eye: elongated, cylindrical eye that protrudes forward or upward within an envelope of skin.
tenaculum: spiny, club-shaped organ on the head of male chimaeroids apparently used during mating.
tendril: curling filamentous projection.
tentacle (adj. tentacular): short fleshy appendage; cirrus.
terminal: towards the end; at the end.
terrestrial: living on land.
tetrapod: vertebrate animal having two pairs of limbs and feet.
tetrodotoxin: virulent poison occurring within certain tissues of some, if not all, tetraodontiform fishes.
thoracic: pertaining to the chest or region of the body near the head.
thorn: large spine or denticle.
tidal: associated with the periodic rise and fall of ocean water produced by gravitational effects of the moon and sun on the earth.
total length: body length measured from the tip of the snout to the tip of the tail, abbreviated 'TL'.
toxic: poisonous.
transverse: from side to side; extending across.
transverse scale rows: regular arrangement of scales in slanted rows between the dorsal and ventral margins of a fish's body; counted as the number of scales above the lateral line + 1 lateral-line scale + the number of scales below the lateral line.
tribe: a division of classification between the levels of family and genus.
tricuspid(ate), tridentate: having 3 cusps or points (usually in reference to teeth.
trifid: divided into three.
triradiate: having three parts or limbs that are directed outward from a central point.
trilobed: having three lobes.
truncate: with a straight margin; abruptly cut off.
trunk: that part of a fish between the posterior border of the opercular membrane and the anus.
trunk length: distance from the front of the last gill aperture to the origin of the cloaca.
trunk rings: in the Syngnathidae, body rings on the trunk anterior to and including the anal ring, abbreviated ‘TR'.
trunk slime pores: series of slime pores posterior to the gill apertures, terminating just before the cloaca; distinctly separated from the tail series.
tubercle (adj. tubercular, tuberculate): a small, usually hard protuberance on the body.
tubule: slender tube, often involved in conveying fluids.
tunicate: member of the primitive chordate subphylum Urochordata, some having an attached barrel-shaped adult stage and others being clear, gelatinous and planktonic as adults.
turbid: muddy; not clear.
U
unicuspid, unicuspidate: having a single point or cusp.
unilateral: 1-sided; done by or affecting only 1 person.
unpaired fin: singular fin on the dorsal or ventral midline of the body; dorsal, anal or caudal fin.
uniserial: in a single row.
unossified: not turned to bone.
upper jaw length: distance between the anterior and posterior extents of the upper jaw, following the line of the jaw.
upwelling: movement of water from great depths to the surface.
urea: waste product of metabolism excreted via the kidneys but also found in the blood of sharks and rays to maintain osmotic balance.
urogenital: pertaining to the urinary and reproductive organs.
urogenital papilla: genital papilla; a small fleshy projection behind the anus, through which the genital and sometimes urological system communicates with the exterior.
uterus: the organ where fertilised eggs develop.
V
V: number of elements in each ventral fin, often comprising a spine (Roman numeral) and soft rays (Arabic numerals).
VAL: lateral series of photophores from just behind ventral-fin base to just behind anal-fin origin.
VAV: ventral series of photophores between ventral-fin base and anal-fin origin.
Vert: number of vertebrae in the vertebral column, often comprising precaudal vertebrae + caudal vertebrae.
VLO: supraventral photophore above the ventral fin.
Vn: light organ anteroventral to eye.
VO: ventral series of photophores between ventral and anal fins.
variegated: marked with irregular patches of different colour.
venom: poisonous fluid injected into prey by biting or stinging.
venomous: capable of producing and injecting a toxic or poisonous substance.
vent: anus, external opening of the alimentary canal.
ventral(ly) (comb. ventro-) adj.: pertaining to the undersurface or underside.
ventral fin: pelvic fins; paired fins on the ventral surface between the head and the vent, corresponding to the hind limbs of terrestrial vertebrates.
ventral finfold: ridge of thin, fleshy tissue extending along the ventral midline of the body.
ventrolateral(ly): pertaining to the region between the ventral and lateral surfaces; the lower side of the body.
vermiculate (n. vermiculation): marked with close wavy, worm-like lines.
vertebra (pl. vertebrae, adj. vertebral): one of a series of bony or cartilaginous elements surrounding the notochord, or replacing it, and often protecting the spinal cord and caudal vein.
vertical fin: dorsal, anal and caudal fins; unpaired fins on the upper and lower midlines of the body.
vestigial: reduced to very small or undeveloped vestige.
vexillum: extremely elongated first ray in the dorsal fin of some fish larvae.
villiform tooth: small, slender tooth, set in bands.
viviparous: producing live young, the developing young nourished by the mother's body until they are released to the outside.
vomer (adj. vomerine): median bone at the front of the neurocranium, detectible at the front of the roof of the mouth, sometimes bearing teeth.
W
warm temperate: near tropical, warmer extent of a temperate region.
Y
yolk: granules of semi-crystalline phospholipoprotein used as a nutrient store during embryonic development.
yolk-sac: sac containing yolk used for nourishment in larval fish.
Z
zooplankton: small animals or larva that drift in the water.
Zostera: eelgrass; a small genus of widely distributed seagrass with long, bright green, ribbon-like leaves, about 1cm wide growing from extensive, white branching runners.