Contents: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

• Abdomen: belly
• Abdominal: pertaining to the belly
• Actinosts: a series of bones at the base of the pectoral rays.
• Acuminate: tapering gradually to a point
• Acute: sharp, pointed
• Adipose fin: a small fleshy fin which lacks fin rays.
• Adnate: joined together
• Adpressed: pressed against the body
• Anal fin: the fin on the median line behind the vent
• Anal fin origin: the most anterior point of the anal fin base
• Andropodium: a modification of the anal fin of males of certain live-bearing species in the family Goodeidae
  Goodeidae
  Splitfins, are a family, Goodeidae, of teleost fish endemic to Mexico and some areas of the United States. This family contains 40 species within 18 genera. The family is named after ichthyologist George Brown Goode.-Range and Geographic Distribution:...
  
  . It is used to transfer reproductive products to the female during mating.
• Ankylosed: grown firmly together
• Anterior: relating to the front portion
• Antrose: turned forward
• Approximate: placed close together
• Asperity: roughness of surface
• Asymmetrical: without symmetry
• Attenuate: tapering to a point, usually in reference to a tail
• Axillary: pertaining to the axilla or upper angle of the pectoral fin
• Axillary process: an enlarged, pointed scale projecting from the insertion of the pectoral or pelvic fin.)

B

• Barbel
  Barbel (anatomy)
  A barbel on a fish is a slender, whiskerlike tactile organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, sturgeon, the zebrafish and some species of shark...
  
  : an elongated fleshy projection, usually about the head
• Basal: pertaining to the base, at the base
• Base: the part of a projection, (commonly a fin), which is connected to the body
• Bathypelagic
  Pelagic zone
  Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
  
  : living at a depth between 1000 m and 4000 m, but well off the bottom
• Benthic
  Benthic zone
  The benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...
  
  : bottom-dwelling, living on the sea bed
• Benthopelagic: pertaining to fishes that swim just above the seabed at depths below about 200 m (the edge of the continental shelf)
• Bicuspid: having two cusps or points
• Bifid: cleft in two
• Bifurcate: forked, or divided into two parts or branches
• 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

C

• Caniniform: shaped like a canine tooth, conical in form
• Carapace: a horny or bony covering encasing the body
• Cardiform: small set conical outgrowths in a close set patch or band; usually refers to a band of close set small conical teeth
• Carinate: keeled, having a ridge along the middle line
• Caruncle: a fleshy outgrowth
• Caudal: pertaining to the tail
• Caudal fin: the tail fin
• Caudal peduncle
  Fish anatomy
  Fish anatomy is primarily governed by the physical characteristics of water, which is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does.- Body :...
  
  : the region of the body between the end of the anal fin and the base of the caudal fin
• Ciliated: fringed with eyelash-like projections
• Cirri: small, thin appendages, often subdivided into branches.
• Cirrus: singular of cirri (see above)
• Claspers: the external reproductive organs of male sharks, rays and chimaeras
• Coalesced: grown together
• 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
  Countershading
  Countershading, or Thayer's Law, is a form of camouflage. Countershading, in which an animal’s pigmentation is darker dorsally, is often thought to have an adaptive effect of reducing conspicuous shadows cast on the ventral region of an animal’s body...
  
  : body colouration which is dark above and lighter below
• Crenulate: having the edge slightly scalloped
• Cutaneous: pertaining to the skin
• Ctenoid: rough-edged (referring to scales)
• Cycloid: smooth-edged (referring to scales)

D

• Deciduous: temporary, falling off
• Demersal: living on or near the sea bed
• Dendritic: resembling a tree or shrub
• Denature: the "unfolding" of a protein resulting in a lessening of its biological properties. In the case of some fish toxins, denaturing with hot water can lessen painful symptoms.
• Dentate: with tooth-like projections
• Denticle, denticulate: a little tooth, having an edge with small projecting teeth, the placoid scales of cartilaginous fishes
• Depressed: flattened from top to bottom
• Dermal: pertaining to the skin
• Dewlap: a fold of loose skin
• Disc: the flattened head and body of various fishes such as stingrays, which also commonly includes the pectoral and ventral fins
• Distal: remote from the point of attachment
• Dorsal: pertaining to the back
• Dorsum: the upper (dorsal) surface of the head or body
• Dorsal fin: the fin on a fish's back
• Dorsal fin origin: the most anterior point of the dorsal fin base

E

• Elasmobranchs: cartilaginous fishes - sharks, rays and allies
• Electrocyte: a cell that generates electricity
• Elongate: extended, drawn out
• Emarginate: with the margin slightly hollowed
• Endemic: restricted to a particular region, for example endemic to Australia
• Entire: with a smooth margin
• Epibenthic: referring to organisms living on the bottom surface
• Epipelagic
  Pelagic zone
  Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
  
  : referring to organisms living in the region between the surface and 200 m depth
• Erectile: capable of being raised or erected, often referring to spines
• Esca
  Anglerfish
  Anglerfishes are members of the teleost order Lophiiformes . They are bony fishes named for their characteristic mode of predation, wherein a fleshy growth from the fish's head acts as a lure; this is considered analogous to angling.Some anglerfishes are pelagic , while others are benthic...
  
  : the lure or "bait" on the end of the illicium of some anglerfishes and relatives
• Estuarine: living in estuaries

F

• Falcate: scythe-shaped, long, narrow, and curved
• Falciform: curved like a scythe
• Filament: a slender or thread-like structure
• Filiform: thread-like
• Fimbriate: fringed at the margin
• Finfold: embryonic tissue which develops into a fin
• Finlet: a small fin, positioned behind the dorsal or anal fins, that is supported by a ray or rays
• Fluviatile: living in rivers
• Free rear tips (of fins): the posterior tip of the fin that is closest to the most posterior point of the fin base
• Frontal ridge: a ridge running along the top of the head along the midline
• Furcate: forked
• Fusiform: tapering towards both ends

G

• Ganoid scales: Armor-like scales coated with ganoin found in gars and bichirs.
• Genital papilla: a small, fleshy tube behind the anus in some fishes, from which the sperm or eggs are released; the sex of a fish often can be determined by the shape of its papilla.
• Gill arches: the bony arches to which the gills are attached
• Gill cover: or 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
  Gill
  A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
  
  s, Branchiae: organs for breathing the air contained in water
• Glossohyal: the tongue bone
• Gonopodium: a modification of the anal fin of males of certain live-bearing species in the families Anablepidae
  Anablepidae
  Anablepidae is a family of freshwater and brackish water fishes living on river estuaries from southern Mexico to southern South America. There are three genera with sixteen species: the four-eyed fishes , the onesided livebearers and the white-eye, Oxyzygonectes dovii...
  
   and Poeciliidae
  Poeciliidae
  Poeciliidae is a family of fresh-water fish which are live-bearing aquarium fish . They belong to the order Cyprinodontiformes, tooth-carps, and include well-known aquarium fish such as the guppy, molly, platy, and swordtail...
  
  . It is used to transfer reproductive products to the female during mating.
• Gravid: Sexually ripe
• Gular region: pertaining to the region behind the chin and between the sides of the lower jaw

H

• Head length: the distance from the tip of the snout (or upper lip) to the most posterior point of the opercular margin
• Homology
  Homology (biology)
  Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
  
  : similarity of features based on common evolutionary descent
• Hyperostosis: a condition resulting in enlargement of areas of bone.
• Hyaline: translucent or transparent
• 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.

I

• Ichthyoplankton: fish eggs and larvae
• Illicium
  Anglerfish
  Anglerfishes are members of the teleost order Lophiiformes . They are bony fishes named for their characteristic mode of predation, wherein a fleshy growth from the fish's head acts as a lure; this is considered analogous to angling.Some anglerfishes are pelagic , while others are benthic...
  
  : a "fishing rod-like" appendage on the head, usually a modified dorsal fin spine
• Imbricate: overlapping, like the shingles on a roof
• 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 organ: a structure to facilitate sperm transfer in some internally fertilizating species
• Iris lappet: a fleshy flap or lobe-like structure in the eye, short and rounded, simple or multiply branched.
• Isthmus: the fleshy projection of the body separating the gill openings

L

• Lanceolate: spear-shaped, gradually tapering toward the extremity
• Labial: pertaining to the lips
• Labial furrows: shallow grooves around the lips
• Labial papillae: small fleshy projections around the lips
• Lateral: at or toward the side
• Lateral line
  Lateral line
  The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
  
  : a series of muciferous tubes forming a raised line along the side of the body
• Leptocephalic: tallness and narrowness of the skull - in fish usually refers to "elongate highly compressed transparent, ribbon-like larval stage" (source FishBase glossary)
• Liver: a digestive and storage organ
• 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

M

• Maxilla, Maxillary: the upper jaw, or pertaining thereto
• Maxillae, Maxillaries: the hindmost bones of the upper jaw; preceded by the premaxillaries
• Median, medially: pertaining to the middle
• Median fins: fins located on the median line of the fish; the dorsal, anal and caudal fins
• Mediolateral: between the middle and the sides
• Mesocoracoid: a bone of the pectoral arch or shoulder girdle
• Mesopelagic
  Pelagic zone
  Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
  
  : refers to the region of the open ocean between 200 m and 1000 m in depth
• Mesopelagic fishes: fishes that live in the mesopelagic zone
• Midwater: the middle stratum of water, well below the surface and well above the seabed. See also mesopelagic.
• Midwater fishes: fishes that live in the midwater
• Molars: blunt and rounded grinding teeth
• Morphology
  Morphology (biology)
  In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
  
  : form and structure of an organism
• Muciferous: producing or containing mucous or slime
• Myotome
  Myotome
  In vertebrate embryonic development, a myotome is a group of tissues formed from somites that develop into the body wall muscle.Each myotome divides into a dorsal epaxial part and a ventral hypaxial part....
  
  s: blocks of lateral trunk muscles

N

• 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
  Notochord
  The notochord is a flexible, rod-shaped body found in embryos of all chordates. It is composed of cells derived from the mesoderm and defines the primitive axis of the embryo. In some chordates, it persists throughout life as the main axial support of the body, while in most vertebrates it becomes...
  
  : a rudimentary of embryonic spinal column
• Nuchal: pertaining to the nape

O

• 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
• Odontode
  Odontode
  Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They comprise a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to that of teeth. They generally do not have the same...
  
  : a dermal tooth
• Oesophagus: the gullet
• Opercle: the large bone which forms the upper posterior part of the operculum
• operculum
  Operculum (fish)
  The operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
  
  : the bony flap that covers the gills
• Opercular: pertaining to the operculum
• Opercular spine: spine projecting from the operculum (view the fish figure)
• Orbit
  Orbit (anatomy)
  In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...
  
  : the eye socket
• Origin: the most anterior point of a fin base
• Osseus: bony
• Ovate: egg-shaped

P

• Palate: the roof of the mouth
• Palatines: the bones on each side of the palate
• Papilla (papillae): a small fleshy projection(s)
• Papillose: covered with papillae
• Pectoral: pertaining to the breast
• Pectoral fins: the anterior or uppermost of the paired fins, which correspond to the anterior limbs of the higher vertebrates
• Pectoral girdle: the bones to which the pectoral fin is attached
• Peduncle: usually referred to as the caudal peduncle, the region of the body between the end of the anal fin and the base of the caudal fin
• Pelagic
  Pelagic zone
  Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
  
  : living on or in the open seas
• Pelvic girdle: the bones to which the ventral fins are attached
• Pelvic fins: paired fins behind or below the pectoral fins
• Pharyngeal bones: bones behind the gills in the oesophagus or gullet
• Pharyngeal teeth: teeth within the pharynx
• Pharynx: the back part of the throat, into which the gill slits open
• Photophore: a circular light-producing organ on the surface of a fish
• Placoid scales: Teeth-like scales found in sharks and rays.
• Posterior: towards the hind end of the fish
• Postorbital: behind the eye
• Precaudal: anterior to the tail portion
• Premaxillaries: two bones forming the front portion of the upper jaw
• Preocular spine: spine positioned above and in front of the eye
• Preopercle, preoperculum: the bone between the cheek and the gill cover
• Preopercular spine: spine projecting from the preopercule (see preopercle) (view the fish figure)
• Preorbital: the 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 the gill cover
• Pseudoclasper: stiff ossified lobes or prongs in the tip of the intromittent organ
• Pterygiophore: an internal cartilage or bone that supports a median fin ray or spine
• Pyloric caecae: finger-like pouches connected with the alimentary canal (the gut)

R

• Ramus: one branch or one half of the jaw
• Ray: a jointed, segmented rod which supports a fin
• Retrose: turned backward
• Rostrum: a projecting snout or beak
• Rugose: rough

S

• 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
• Soft dorsal: the posterior part of the dorsal fin which is composed of jointed rays
• Spatulate: shovel-like; having a broad, flat and rounded shape
• Spine: a sharp projecting point; an unjointed support in the anterior portions of the dorsal and anal fins
• Spinous, spiniform, spinate: spine-like or composed of spines
• Spinous dorsal: the anterior part of the dorsal fin supported by spines
• Spiracles: respiratory openings behind the eyes in sharks and rays
• Standard length (SL): the length of a fish measured from the tip of the snout to the posterior extremity of the hypurals, the expanded bones at the end of the backbone that support the caudal fin
• Submarginal: almost at the edge
• Suborbital: below the eye
• Superior: above or on the upper surface
• Supracleithrum: the bone forming a connection between the back of the skull and the 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 the skull
• Suture: the line of union of two bones or plates
• Swimbladder: a sac filled with gas, lying beneath the backbone
• Symphysis: point of junction of the two sides of the jaw
• Symmetrical: similarly arranged on both sides

T

• Teleost: a member of Teleostei, an infraclass containing most of the bony fishes
  Actinopterygii
  The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
  
  
• Terminal: at the end
• Tessellated
  Tessellation
  A tessellation or tiling of the plane is a pattern of plane figures that fills the plane with no overlaps and no gaps. One may also speak of tessellations of parts of the plane or of other surfaces. Generalizations to higher dimensions are also possible. Tessellations frequently appeared in the art...
  
  : marked with little checks or squares, like tiles
• Thoracic
  Thorax
  The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
  
  : pertaining to the chest
• Thorax
  Thorax
  The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
  
  : the chest region, just behind the head
• Total length
  Fish measurement
  Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
  
  : the length from the tip of the snout to the tip of the tail
• Transverse
  Transverse plane
  The transverse plane is an imaginary plane that divides the body into superior and inferior parts. It is perpendicular to the coronal and sagittal planes....
  
  : crosswise
• Trilobate: with three lobes
• Tricuspid: with three cusps or points
• Truncate: terminating abruptly, as if cut off square
• Trunk: the region of a fish between the head and tail, or the last gill slit and vent
• Tubercle
  Tubercle
  A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to....
  
  : a small, usually hard excrescence or lump
• Tubiform, tubuliform: resembling a tube
• Type locality: the location from which the type specimen was collected.

U

• Undulated: waved
• Urogenital papilla: a papilla through which the urinary waste and gametes leave the body

V

• Vent: the external opening of the alimentary canal, the anus
• Ventral: pertaining to the abdominal or lower surface
• Ventral fins: paired fins behind or below the pectoral fins
• Vertical fins: fins on the median line of the body; the dorsal, anal, and caudal fins
• Vestigial
  Vestigial structure
  Vestigiality describes homologous characters of organisms that have seemingly lost all or most of their original function in a species through evolution. These may take various forms such as anatomical structures, behaviors and biochemical pathways. Some of these disappear early in embryonic...
  
  : reduced, or very poorly developed
• Villiform teeth: small, slender teeth forming velvety bands
• Vomer: a bone forming the front part of the roof of the mouth
• Vomerine teeth: teeth on the vomer (see above)

W

• Weberian apparatus
  Weberian apparatus
  The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the Superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles...
  
  : An adaptation found in Ostariophysi
  Ostariophysi
  Ostariophysi is the second-largest superorder of fish. Members of this superorder are called ostariophysians. This diverse group contains almost 8,000 species, about 28% of known fish species in the world and 68% of freshwater species, and are present on all major continents except Antarctica...
  
  to improve hearing; includes the Weberian ossicles.