Abdomen - belly

Abdominal - pertaining to the belly

Absolute abundance - Absolute abundance is the total number of a kind of fish in the population. This is rarely known, but usually estimated from relative abundance, although other methods may be used

Absolute recruitment - The number of fish grow into the catchable size range in a unit of time (usually a year)

Actinosts - a series of bones at the base of the pectoral rays

Acuminate - tapering gradually to a point

Acute - sharp, pointed

Adelphophagous - a mode of feeding where an embryo feeds on other embryos within the uterus of the female

Adipose - fatty

Adipose fin - a small fleshy fin which lacks fin rays

Adnate - joined together

Adpressed - pressed against the body

Aestivate - to be inactive during warm dry periods

Airbladder - buoyancy organ possessed by most bony fishes and also called as swim bladder

Alimentary canal - the passage through which food passes, starting at the mouth and ending at the anus

Anal - pertaining to the anus

Anal fin - the fin on the median line behind the vent

Anal fin origin - the most anterior point of the anal fin base

Ankylosed - grown firmly together

Anterior - relating to the front portion

Antrose - turned forward

Anus - the external opening of the intestine, the vent

Artisan - someone who practices a craft as a livelihood

Artisan fishing - a small scale commercial or subsistence fishing practices

Asperity - roughness of surface

Asymetrical - without symmetry

Attenuate - tapering to a point

Axillary - process an enlarged, pointed scale projecting from the insertion of the pectoral or pelvic fin

Bait fish - are small fish caught for use as bait to attract large predatory fishes

Barbels - fleshy whisker-like extensions, usually under the mouth

Basal - pertaining to the base

Biconcave tail - outer and inner fin rays longer giving a double concave shape (same as double emarginated)

Bicuspid - having two cusps or points

Bifid - cleft in two

Bifurcate - forked or divided into two parts or branches

Blotch - pigmented spot with an indistinct outline or shape

Branchial - pertaining to the gills

Branchial aperture - the gill opening

Branchiostegals, Branchiostegal ray(s) - bony rays supporting the gill membranes behind the lower jaw

Bristle - a stiff hair-like projection

Buckler - a bony shield

Bycatch - species other than the target species that are caught incidentally in a trawl

Canines - conical teeth which are longer than other teeth

Caniniform shaped - like a canine tooth, conical in form

Carapace - a horny or bony covering encasing the body

Carinate - keeled, having a ridge along the middle line

Caruncle - a fleshy outgrowth

Catadromous - "Catadromous" species, spawn in the ocean but live part of their lives in fresh water

Caudal - pertaining to the tail

Caudal fin - the tail fin

Caudal peduncle - region of the body between end of anal fin and base of caudal fin

Choroid fissure - line of juncture of invaginating borders of the optic cup

Choroid tissue - an undifferentiated mass of unpigmented tissue adhering to the ventral surface of the eye

Chromatophore - a modified dermal cell that contains pigment and gives the fish its colour

Ciliated - fringed with eyelash-like projections

Cirri - small, thin appendages often subdivided into branches

Cleithrum - a prominent bone of pectoral girdle

Coalesced - grown together

Cohort - those individuals of a stock born in the same spawning season

Compressed - flattened laterally

Confluent - joined together

Conical - cone shaped, with a cylindrical base and a pointed tip

Corselet - a scaly covering behind the pectorals of some fishes

Countershading body - colouration which is dark above and lighter below

Crenulate - having the edge slightly scalloped

Ctenoid - rough-edged

Cusp - a pointed or rounded projection on the chewing surface of a tooth

Cutaneous - pertaining to the skin

Cycloid - smooth-edged

Deciduous - easily removed / rubbed off, temporary, falling off

Demersal - living on or near the sea bed

Demersal egg - an egg which remains on the bottom either free or attached to the substratum

Dendritic - resembling a tree or shrub

Dentate - with tooth-like projections

Depressed - flattened from top to bottom

Dermal - pertaining to the skin

Dewlap - a fold of loose skin

Diadromous - species which undertakes spawning migration from ocean to river or vice versa.

Dimorphic - body shape and colour varies between the sexes

Disc - the flattened head and body of fishes

Distal - remote from the point of attachment

Dorsal - pertaining to the back

Dorsal fin - fin on dorsal side

Dorsal fin origin - anterior most point of the dorsal fin base

Dorsum - the upper surface of the head or body

Egg survey - a systematic and scientific estimation of the abundance of eggs in an area, through sampling at the bottom or in the water column with appropriate devices

Electrocyte - a cell that generates electricity

Elongate - extended, drawn out

Emarginate - with the margin slightly hollowed

Endemic - restricted to a particular region

Epibenthic - referring to organisms living on the bottom surface

Epipelagic - referring to organisms living in the region between surface and 200 m depth

Erectile - capable of being raised or erected, often referring to spines

Esca - the lure or "bait" on the end of the illicium of some anglerfishes and relatives

Estuarine - living in estuaries

Eye diameter (ED) - horizontal distance across the midline of pigmented region of the eye

Falcate - scythe-shaped, long, narrow and curved

Falcate tail - tail fin shaped like a sickle, deeply concave, with the middle rays much shorter than the anterior or posterior rays

Falciform - curved like a scythe

Fecundity - the number of eggs a fish produces each reproductive cycle

Filament - a slender or thread-like structure

Filiform - thread-like

Fimbriate - fringed at the margin

Fin length - length of the longest soft ray of designated fin

Finfold - medial fold of integument that extends along body of developing fishes and from which medial fins arise

Finlet - a small fin, positioned behind the dorsal or anal fins, that is supported by a ray or rays

Fishery - fishery is characterised by the species caught, the fishing gear used and the area of operation. It may involve capture of wild fish or rising of fish through aquaculture

Fishing fleet - an aggregation of fishing vessels of a particular country or particular gear

Fishing vessel – a vessel (provide assistance to other fishing vessels such as supply, storage, refrigeration, transportation or processing) normally used for harvesting living aquatic resources

Fishmeal – a fish based protein-rich animal feed product

Fleshy tail – tail with fleshy knob

Flexion - bending upward of the notochord tip as part of the process of caudal-fin formation

Flexion larva - development stage beginning with flexion of notochord and ending with hypural bones assuming a vertical position

Fluviatile - living in rivers

Fork length - The length of a fish as measured from the tip of the snout to the fork of the caudal fin

Free rear tips (of fins) - the posterior tip of fin closest to the most posterior point of fin base

Frontal ridge - a ridge running along the top of the head along the midline

Furcate - forked

Fusiform - tapering towards both ends

Gametes - eggs and sperm

Gas bladder - membranous, gas filled organ located between the kidneys and alimentary canal in teleost fishes

Gill arches - the bony arches in which gills are attached

Gill cover - bony flap that covers the gills, the operculum

Gill filaments - a series of projections along the posterior edge of the gill arch, the site of gas exchange

Gill membranes - membranes covering the gill openings, attached to the branchiostegals

Gill opening - opening behind each operculum, leading to the gills

Gill rakers - a series of appendages along the anterior edges of the gill arches 

Gill - organs for breathing the air contained in water

Glossohyal - tongue bone of fish

Gonads - sexual organs which produces eggs or sperm

Gonopodium - modification of anal fin in some male fishes used to transfer reproductive products to the female

Gravid - sexually ripe

Gular - region behind the chin and between the sides of lower jaw

Head length (HL) - distance from snout tip to the most posterior point of opercular margin

Head width - transverse distance between margins at the widest area of the head

Homology - similarity of features based on common evolutionary descent

Hyaline - translucent or transparent

Hyperostosis - a condition resulting in enlargement of areas of bone

Hypural - joint the joint between the caudal fin and the last of the vertebrae

Hypural plate - the flattened bony plate at the posterior end of the vertebral column, formed from parts of the posterior vertebrae

Ichthyocide - a substance used to kill (and usually collect) fishes

Ichthyoplankton - fish eggs and larvae floating on the surface of water

Illicium - a fishing rod-like appendage on the head of frog fish

Imbricate - overlapping

Incipient fin ray - early stage in fin-ray development (unossified thickening in finfold articulating with the fin base)

Incised - with a notched margin (often referring to fin membranes)

Incisors - the front or cutting teeth

Inferior - pertaining to the lower side (usually of the head)

Interdorsal - between the dorsal fins

Interorbital - the space between the orbits

Intromittent - a structure to facilitate sperm transfer in some internally fertilizing species

Iris lappet - a fleshy flap or lobe-like structure in the eye (may be short and rounded, simple or multiply branched)

Isthmus - the fleshy projection of the body separating the gill openings

Jugostegalia - basket-like structure of over-lapping free branchiostegal rays used as support for the extended branchial region in some eels.

Jugular - pertaining to the throat

Juvenile - developmental stage from attainment of full external meristic complements and loss of temporary specializations for pelagic life to sexual maturity

Juxtaposed - placed near together

Labial - pertaining to the lips

Labial furrows - shallow grooves around the lips

Labial papillae - small fleshy projections around the lips

Lacrymal, lachrymal - anterior bone of infraorbital series (frequently overlaps the maxilla when the mouth is closed)

Lanceolate - spear-shaped, gradually tapering toward the extremity

Larva - developmental stage between hatching (or birth) and attainment of full external meristic complements (fins and scales) and loss of temporary specializations for pelagic life

Larval teeth - are little exerted spines on the premaxilla or dentary

Lateral - at or toward the side

Lateral line - a series of muciferous tubes forming a raised line along the side of body

Longitudinal series (scales) - the number of scale rows above the lateral line from the first pored lateral line scale to the caudal fin base

Lunate - shaped like a crescent moon, with long upper and lower lobes

Lyosphaera stage - a specialized pelagic juvenile stage in the genus Chilomycterus, where elongate papillae develop but these fail to form spines.

Mandible - the lower jaw

Maxilla, Maxillary - the upper jaw

Median fins - fins located on the median line of the fish (dorsal, anal and caudal fins)

Mediolateral - between the middle and the sides

Melanin - a black pigment

Melanophores - melanin bearing cells (frequently capable of expansions and contractions which change their size and shape)

Mesocoracoid - a bone of the pectoral arch or shoulder girdle

Mesopelagic - fishes that live in the mesopelagic zone

Midwater fishes - fishes that live in the midwater (well below the surface and well above the seabed)

Molars - blunt and rounded grinding teeth

Morphology - form and structure of an organism

Mouthwidth - the gape transverse distance between corners of the mouth

Muciferous - producing or containing mucous or slime

Myosepta - connective tissue partitions separating adjacent myomeres

Myotomes - serial muscle bundles of the body

Nape - upper surface of the body behind the head and before the dorsal fin

Nasal - pertaining to the nostrils

Nasoral - between the nostrils and mouth

Nictitating membrane - an inner eyelid

Notochord - longitudinal supporting axis of body which is eventually replaced as a support by the vertebral column in teleostean fishes

Notochord length - straight line distance from tip of snout to posterior tip of notochord

Nuchal - pertaining to the nape

Obsolete - faintly marked, scarcely evident

Obtuse - blunt

Occipital - pertaining to the posterior part of the skull

Ocellus - an eye-like spot

Ocular - pertaining to the eye

Oesophagus - the gullet

Olfactory organs - the organs used for smelling, commonly beneath the nostrils

Olfactory pit - a shallow depression on the snout from which olfactory organ develops

Opercular - pertaining to the operculum

Opercular spine - spine projecting from the operculum

Opercule, operculum - the bony flap that covers the gills

Orbit - the eye socket

Osseus - bony

Ossicle - a bony plate

Otic capsule - sensory anlage from which the ear develops

Otolith - calcareous structures in the ear capsules of bony fishes

Ovate - egg-shaped

Oviparous - a species that produces eggs hatched outside of the body

Palate - roof of the mouth

Palatines - bones on each side of the palate Papilla (papillae) a small fleshy projection(s)

Papillose - covered with papillae

Pectoral - pertaining to the breast

Pectoral bud - swelling at site of future pectoral fin

Pectoral fins - the anterior or uppermost of the paired fins

Pectoral girdle - the bones to which the pectoral fin attached

Pelagic - living on or in the open seas

Pelagic egg - egg which floats freely in the water column

Pelagic juvenile - pre settlement juvenile of a species that is benthic or reef associated as an adult

Pelvic bud - swelling at site of future pelvic (ventral)

Pelvic fins - paired fins behind or below the pectoral fins

Pelvic girdle - the bones to which the ventral fins are attached

Peritoneum - the membrane lining the abdominal cavity

Pharyngeal bones - bones behind the gills in the oesophagus or gullet

Pharyngeal teeth - teeth within the pharynx

Pharynx - the back part of the throat in which the gill slits open

Photophore - a circular light-producing organ on the surface of a fish

Piscivorous - an organism that feeds upon fishes

Planktivore - an animal with a diet that consists mainly of plankton

Postanal myomeres - myomeres posterior to the posterior margin of the anus

Posterior - towards the hind end of the fish

Postflexion larva - developmental stage from formation of the caudal fin to attainment of full external meristic complements and loss of temporary specializations for pelagic life

Postorbital - behind the eye

Pre dorsal fin length - distance from tip of snout along the midline to the origin of dorsal fin

Pre gas bladder length - distance from the tip of the snout along the midline to the anterior edge of gas bladder

Pre pelvic fin length - distance from the tip of snout along the midline to the origin of the pelvic fin

Preanal length (PAL) - distance from the tip of the snout along the midline to the posterior edge of the anus

Precaudal - anterior to the tail portion

Preflexion larva - developmental stage beginning at hatching and ending at the start of upward flexion of the notochord

Prehensile - adapted for holding such as the tail of a seahorse

Premaxillaries - two bones forming the front portion of the upper jaw

Preocular spine - spine positioned above and in front of the eye

Preopercle preoperculum - bone between the cheek and the gill cover

Preopercular spine - spine projecting from the preopercule

Preorbital - area under and in front of the eyes

Protractile - capable of extending forward

Protrusible - capable of extending forward often referring to the jaws of fishes

Proximal - nearest

Pseudobranchiae - small gills developed on the inner side of gill cover

Pseudoclasper - stiff ossified lobes or prongs in the tip of intromittent organ

Pterygiophore - an internal cartilage or bone that supports a median fin ray or spine

Ramus - one branch or one half of the jaw

Ray - a jointed rod which supports a fin.

Retrose - turned backward

Rostrum - a projecting snout or beak

Rugose - rough

Scalation - pertains to the pattern/ arrangement/ presence of scales

Scute - any external horny or bony plate

Serrate - notched like a saw

Setae - bristles or hairs

Sexual dimorphism - differences in physical appearance between the sexes

Snout length (SnL) - horizontal distance from the tip of snout to the anterior margin of pigmented region of the eye

Soft dorsal - posterior part of dorsal fin composed of jointed rays

Soft rays - bilaterally paired, usually segmented fin supports

Spatulate - shovel-like having a broad, flat and rounded shape

Spawning - the production or depositing of large quantities of eggs in water

Spine - a sharp projecting point

Spine length - Straight line distance of a fin or body spine from base to tip.

Spinous, spiniform, spinate - spine-like or composed of spines

Spiracles - respiratory openings behind the eyes in sharks and rays

Standard length (SL) - length of a fish measured from the tip of snout to posterior extremity of hypural plate (the expanded bones at the end of the backbone that support the caudal fin)

Submarginal - almost at the edge

Suborbital - below the eye

Suborbital stay - a bony, often spine-bearing, ridge below the eye

Superior - above or on the upper surface

Supracleithrum - bone forming a connection between back of skull and pectoral girdle

Supralateral - above the side

Supramaxillary - a supplemental bone lying along the upper edge of the maxillary

Supraocular - positioned above the eye

Supraorbital - above the eye

Supraorbital tentacle - a flap or filament of skin positioned above the eye

Suprascapular - a bone uniting the shoulder girdle with skull

Suture - line of union of two bones or plates

Swimbladder - a sac filled with gas, lying beneath the backbone

Symbiosis - used to describe any association between two organisms

Symphysis - point of junction of two sides of the jaw

Symmetrical - similarly arranged on both sides

Tail - the portion of body posterior to the anus.

Teleost - a large group containing most of the bony fishes

Terminal - at the end

Tessellated - marked with little checks or squares, like tiles

Thoracic - pertaining to the chest

Thorax - chest region, just behind the head

Total length (TL) - length from the tip of the snout to the tip of the tail

Transverse - crosswise

Tricuspid - with three cusps or points

Trilobate - with three lobes

Truncate - terminating abruptly, as if cut off square

Trunk - region between head and anus or between last gill slit and vent

Tubercle - a small, usually hard excrescence or lump

Tubiform, Tubuliform - resembling a tube

Tympanum - area of enlarged scales behind the gill opening that can be vibrated to produce sound, in triggerfishes and filefishes

Undulated - waved uniform of one colour

Urogenital papilla - a papilla through which urinary waste and gametes leave the body

Vent - the external opening of alimentary canal, the anus

Vent to anal fin length - straight line distance from posterior edge of the vent (anus) to anterior origin of the anal fin or anal fin anlage

Ventral - pertaining to the abdominal or lower surface

Ventral fins - paired fins behind or below the pectoral fins

Vertebrae - the bones of spinal column

Vestigial - reduced or very poorly developed

Villiform teeth - small, slender teeth forming velvety bands

Viviparous - species that gives birth to live young

Vomer - a bone forming the front part of the mouth roof

Vomerine teeth - teeth on the vomer  

Xanthism (xanthic, xanthochroism) - an unusual colour variety in which the normal colouration of a fish is largely replaced by yellow pigments

Yolk sac - a bag like ventral extension of the primitive gut containing the yolk

Yolk sac larva - developmental stage beginning with hatching and ending with exhaustion of yolk reserves and characterized by presence of a yolk sac