Glossary

Absent – A term referring to the lack of a colliculum in the sulcus of a sagitta (more information).

Acoustico-lateralis system – A sensory system in fishes for detecting sound and water motion.

Acrodont – A term applied to teeth fixed to the biting surfaces of bone by connective tissue. Most fish teeth are acrodont.

Alar process – A dorsolateral projection on either side of the mid-parasphenoid (more information).

Alveolar process – See Caudal process.

Angular – A paired bone forming the posterior section of the lower jaw and the articulation with the quadrate. In teleosts, it is typically triangular with the anterior angle fitting into the posterior bifurcation of the dentary (more information). Synonym: Articular.

Anterior crest – A forward-directed flange on the anterior margin of the hyomandibular (more information).

Anterior process – An anterior projection of the angular, fitting into the posterior bifurcation of the dentary in life (more information); also, the anterior projection of the parasphenoid joining the prevomer (more information).

Anterior wing – a small, forward-directed flange on the anterior margin of the preopercle (more information).

Ankylose – To join or consolidate; fuse.

Ankylosis – The consolidation of fusion of bones to form a single unit.

Anterior colliculum – A raised area within the ostium of a sagitta.

Antirostrum – The anterior-most projection of the sagitta dorsal to the sulcus (more information).

Aparietal – A term to describe neurocrania lacking parietals.

Apophysis – A narrow extension from the body of a bone.

Archaesulcoid – A sagitta with no clear differentiation between ostium and cauda (more information).

Articular – See Angular.

Articular process – An extension from the dorsal edge of the premaxilla, posterior to the ascending process. This process is found in most derived actinopterygians and acts as a fulcrum for the maxillary when the mouth opens (more information).

Articulation – The area of contact between two bones.

Ascending process – A vertical extension from the anterior part of the premaxillary. This process is found in most teleosts (more information).

Basapophysis – See Parapophysis.

Basal zone – The anterior part of the posterior field of ctenoid scales, consisting of the fused bases of ctenii (more information).

Basioccipital – A median bone forming the posteroventral part of the neurocranium. It borders the ventral part of the foramen magnum and articulates with the first vertebra (more information).

Basioccipital process – A posterior projection on either side of the parasphenoid joining the basioccipital (more information).

Basisphenoid – A small, Y-shaped bone at the rear of the orbit.

Biostial – See Ostio-caudal.

Caniniform – A term applied to teeth that are conical or elongated and have a sharp end. They may be straight or curved. These teeth are typical of predaceous fishes.

Cardiform – A term applied to teeth that are numerous, short, fine and pointed. The term refers to the fine-toothed card used to prepare wool. These teeth are found in many members of the Serranidae.

Cauda – The posterior portion of the sulcus of a sagitta, sometimes separated from the ostium by a collum (more information).

Caudal – A term describing the sulcus of a sagitta which opens only to posterior (or ventral) margin.

Caudal peduncle – The portion of the body between the end of the anal fin and the base of the caudal fin.

Caudal process – A posterior extension from the premaxilla (more information); also, a posteroventral projection from the main arm of the maxilla (more information). Synonym: Alveolar process (of premaxilla).

Centrum – The body of a vertebra (more information).

Collum – A raised area between the ostium and cauda of a sagitta.

Chevron – “V”-shaped. The term also applies to the ventral “V”-shaped scales of some members of the Clupeidae.

Condyle – A rounded protuberance at the end of a long bone. A condyle typically forms part of an articulation.

Coronoid process – The dorsal, posterior branch of the dentary (more information); also, a dorsal extension from the angular (more information).

Crenate – A sagitta with small, compressed humps on the margin (more information).

Crest – A long, narrow protrusion from the surface of a bone.

Crista – A prominent ridge. See also: Crista superior, Crista inferior.

Crista inferior – The ventral rim of the sulcus of a sagitta (more information).

Crista superior – The dorsal rim of the sulcus of a sagitta (more information).

Ctenii – small spines, each consiting of a base and a spine on scales (more information).

Cuneiform - A term applied to teeth shaped like a wedge or arrowhead.

Deciduous – A structure likely to be lost (as in weakly attached teeth or scales).

Dentary – A paired bone forming the anterior section of the lower jaw. Anteriorly, both dentaries meet at the mandibular symphysis. Typically there are two posterior processes, the dorsal, coronoid process and a ventral process (more information).

Dentate – A sagitta with truncate projections on the margin (more information).

Dentigerous – Bearing teeth.

Diastema – A space between teeth in the jaw.

Dorsal depression – A depression in the area dorsal to the sulcus of a sagitta (more information).

Edentulous – Without teeth.

Ectopterygoid – Paired bone of the suspensorium joining the anterior edge of the quadrate.

Endopterygoid – Paired bone of the suspensorium located between the palatine and ectopterygoid.

Entire – A sagitta with a smooth margin (more information).

Epicondyle – A projection above a condyle serving for the attachment of muscles and ligaments.

Epioccipital – See Epiotic.

Epiotic – A paired bone of the otic region joining the pterotic anteriorly, the supraoccipital dorsally and the exoccipital posteroventrally. Synonym: Epioccipital.

Ethmoid – A median bone formed in the nasal septum between the two nasal capsules (more information). In the Anguilliformes, the premaxilla is ankylosed to the ethmoid, lateral ethmoid and vomer.

Excisura – The anterior notch between rostrum and antirostrum of a sagitta (more information).

Excisura minor – See Pseudo-excisura.

Exoccipital – A paired bone bordering each side of the foramen magnum, often featuring a projecting facet that articulates with the first vertebra (more information).

External process – A ventral projection located anterolaterally on the maxilla, overlapping the lateral surface of the premaxilla in life. (more information).

External wall – The lateral boundary of the Meckelian fossa of the dentary (more information).

Face – A term applied to the surface of any bone.

Facet – A flat to slightly curved surface on a bone. A facet is typically part of an articulation.

Field – One of the four sectors of a scale, namely the anterior, posterior, dorsal and ventral (more information).

Fissure – Any naturally-occurring furrow or groove on the surface of a bone.

Focus – The center concentric ring on a scale (more information).

Foramen – Any hole in a bone through which nerves or blood vessels pass.

Foramen magnum – A hole in the posterior skull through which the spinal cord emerges. It is usually bordered by the supraoccipital dorsally, an exoccipital on each side, and the basioccipital ventrally (more information).

Fossa – A cavity, forming the articulating surface of a bone, receiving the process of another bone.

Fovea – A shallow depression or pit.

Frontal – A paired bone, meeting its partner in the midline and covering a large part of the dorsal skull. It overhangs the orbit (more information).

Head – A round process on a bone.

Hemal arch – A bony arch on the ventral surface of caudal vertebrae, enclosing the caudal vein and dorsal aorta in life (more information).

Heterodont – A term applied to teeth that vary in shape and size within the same individual.

Homodont – A term applied to teeth that are all the same shape and size within an individual.

Heteromorph – A saggita with a single colliculum in either ostium or cauda, or with two colliculi (one each in the ostium and cauda) differing in shape, the latter may be fused (more information).

Heterosulcoid – A sagitta with ostium and cauda distinguishable and differing in shape (more information).

Homomorph – A sagitta with a single colliculum spanning the ostium and cauda and undifferentiated between the two areas, or with two colliculi (one each in ostium and cauda) very similar in shape and size (more information).

Homosulcoid – A sagitta with ostium and cauda distinguishable but similar in shape (more information).

Hyomandibular – A paired bone of the suspensorium, articulating with the neurocranium dorsally and the opercular series posteriorly (more information).

Hyomandibular crest – The anterior margin of the upper arm of the preopercle articulating with the hyomandibular (more information).

Hyomandibular foramen – A hole in the hyomandibular allowing the passage of the hyomandibular branch of the facial nerve (more information).

Hyomandibular fossa – A depression in the pterotic where the hyomandibular articulates (more information).

Intercalar – A paired bone of the otic region located amid the prootic, pterotic and exoccipital.

Incisiform – A term applied to teeth used for cutting and similar in appearance to mammalian incisors.

Incisure – Any naturally-occurring notch or cleft in a bone.

Indistinct – A sagitta with colliculi not clearly defined, although the floor of the sulcus may be uneven; usually used in combination with homomorph or heteromorphy (more information).

Inferior crest – A laterally projecting ridge along the ventral margin of the angular (more information).

Infraspinal insisure – An excavation in the opercle ventral to the opercular spine (more information).

Internal process – A ventral projection located anteromedially on the maxilla, overlapping the lateral surface of the premaxilla in life. (more information).

Internal wall – The medial boundary of the Meckelian fossa of the dentary (more information).

Irregular – A sagitta with no recurring pattern on the margin (more information).

Lateral condyle – A small, round projection of the quadrate lateral to the articulating facet for the angular (more information).

Lateral ethmoid – A paired bone separating the anterior skull from the orbit. In the Anguilliformes, the premaxilla is ankylosed to the lateral ethmoid, ethmoid and vomer.

Linea – A narrow crest or ridge.

Lobed – A sagitta with large rounded humps on the margin (more information).

Mandibular symphysis – The articulation between the dentaries.

Marginal zone – The posterior-most area of the posterior field of ctenoid scales, consisting of whole cteni (more information). Synonym: Outer zone.

Meckelian fossa – A depression, located between the two posterior rami of the dentary, that holds in life a cartilaginous rod called Meckel’s cartilage (more information). The anterior process of the angular often fits into this area.

Medial – Toward the centerline of the body. See also: Medial.

Medial zone – The part of the posterior field of ctenoid scales consisting of truncated ctenii (more information).

Medioparietal – A term describing neurocrania with joined parietals and, thus, frontals separated from the supraoccipital.

Mental foramen – A hole in the dentary leading to the Meckelian fossa (more information).

Mesial – A term describing a sulcus which does not open onto any margin of a sagitta (more information). Synonym: Medial.

Mesial condyle – A small, round projection of the quadrate medial to the articulating facet for the angular (more information).

Metapterygoid – A paired bone of the suspensorium located between the endopterygoid and hyomandibular.

Maxilla – A paired bone of the upper jaw located posterior to the premaxilla. Synonym: Maxillary (more information).

Maxillar symphysis – The articulation between the premaxillae.

Maxillary – See Maxilla.

Maxillary process – A posterodorsal projection from the main arm of the maxilla (more information).

Molariform – A term applied to teeth with flat surfaces used for crushing or grinding. These teeth are similar in appearance to mammalian molars.

Mosaic – See Pavement.

Neck – A constriction of the sulcus between the ostium and cauda of a sagitta (more information).

Neural arch – A bony arch on the dorsal surface of vertebrae, enclosing the spinal cord in life (more information).

Neural canal – The space enclosed by the neural arches, containing the spinal cord in life (more information).

Neural spine – A dorsal, posteriorly directed spine on top of the neural arch (more information).

Notochord canal – A longitudinal hole through the centrum allowing the passage of the notochord in life (more information).

Occipital region – The posteriormost part of the neurocranium, enclosing a large part of the brain and connecting to the vertebral column.

Occipital crest – A dorsal-projecting flange of the supraoccipital serving as an attachment for body muscles (more information).

Opercle – A paired bone located in the dorsal part of the opercular series. It articulates with the hyomandibular and is usually the largest of the opercular series (more information).

Operculum – Gill cover.

Opercular process – A posterior projection of the hyomandibular where the opercle articulates (more information).

Opercular series – Bones of the operculum.

Opercular spine – A stout posterior projection sometimes found on the opercle (more information).

Opisthotic – See Intercalar.

Orbit – Eye socket (more information).

Orbital – Pertaining to the orbit.

Orbital shelf – The portion of the frontal overhanging the orbit (more information).

Orbitosphenoid – A bone formed in the septum that separates the orbits.

Ostial – A term describing a sulcus opening only to anterior (or dorsal) margin of a sagitta (more information).

Ostio-caudal – A term describing a sulcus opening widely onto both the anterior and posterior margins of a sagitta (more information). Synonym: Biostial.

Ostium – The anterior portion of the sulcus of a sagitta (more information).

Otoliths – Calcareous crystals housed in the auditory capsules of all Osteichthyes. Most actinopterygians have three otoliths on each side of the head: a sagitta (saccular otolith or sacculith), a lapillus (utricular otolith or utriculith), and an astericus (lagenar otolith or lagenalith). In most fishes, the sagitta is the largest of the three otolith types; the lapillus and astericus are smaller and thus rarely found in stomach contents. Exceptions are the Cypriniformes and Siluriformes in which the lapillus is largest. None of the latter orders are native to Hawaii, and thus should not be important in dietary analysis.

Otic region – The area of the skull housing the organs of hearing and equilibrium.

Outer zone – See Marginal zone.

Overlapping - As in scales.

Palatine – A paired, often toothed, bone on the roof of the mouth lateral to the prevomer.

Palatine sulcus – A groove on the anterodorsal surface of the maxilla, cradling the anterior palatine in life (more information).

Parapophysis – A long, transverse process, arising from the centrum of precaudal vertebrae, serving to support epipleural ribs when present (more information). Synonyms: basapophysis, transverse process.

Para-ostial – A term describing a sulcus reduced to a narrow channel and opening onto the anterior (or dorsal) margin of a sagitta (more information).

Pararostrum – See Pseudo-antirostrum.

Parasphenoid – Median bone forming the base of the skull, joining the prevomer anteriorly and the basioccipital posteriorly (more information).

Parasphenoid process – A posterior projection of the prevomer joining the parasphenoid (more information).

Parietal – A paired bone covering the dorsal otic region of the neurocranium.

Parietolateral – A term describing neurocrania with separated parietals, allowing the frontals to join the supraoccipital.

Pavement – A term applied rows of teeth packed into large plates. Synonym: Mosaic.

Pedicel – A stalk-like supporting structure.

Pleurodont – A term applied to teeth implanted in the lateral surface of a bone. These teeth are found in some members of the Balistidae and Scaridae.

Postarticular process – A projection on the angular posterior to the quadrate facet (more information).

Posterior colliculum – A raised area within the cauda of a sagitta.

Posterior insisure – An excavation in the posterior parasphenoid (more information).

Posterior wing – The surface of the preopercle posterior to its articulation with the hyomandibular and quadrate (more information).

Postmaxillary process – An extension from the posterior half of the dorsal surface of the premaxilla. The postmaxillary process prevents the lateral dislocation of the premaxilla when the mouth opens (more information).

Postrostrum – See Pseudo-rostrum.

Prearticular fossa – A depression on the lateral surface of the angular (more information).

Precaudal vertebra – A vertebra lacking a hemal arch and located anterior to the origin of the anal fin (more information).

Prezygapophysis – An anterior projection from a centrum (more information).

Postarticular incisure – An excavation in the opercle dorsal to the articular fossa (more information).

Postzygapophysis – A posterior projection from a centrum (more information).

Premaxilla – A paired bone forming the anterior part of the upper jaw (more information). Synonym: Premaxillary.

Premaxillary – See Premaxilla.

Premaxillary sulcus – A groove on the anteroventral surface of the maxilla, fitting dorsal surface of the premaxilla in life (more information).

Preopercle – A paired, L-shaped bone of the opercular series articulating with the quadrate and hyomandibular bones of the suspensorium and housing part of the cephalic sensory canal (more information).

Preopercular process – A spine-like projection along the posterior edge of the quadrate carrying the preopercular groove (more information).

Preopercular groove – A groove on the posterior edge of the quadrate where the lower arm of the preopercle articulates (more information); also, a groove on the posterior edge of the hyomandibular where the upper arm of the preopercle articulates (more information).

Prevomer – A paired bone, frequently dentigerous, forming the anterior roof of the palate (more information). In derived actinopterygians, the pair is ankylosed to form a single bone. In the Angulliformes, the premaxilla is ankylosed with the vomer, ethmoid and lateral ethmoid. Synonym: Vomer.

Process – Any extension from the body of a bone. Processes are named according to size and shape (e.g., apophysis, condyle, head, tuberosity).

Prootic – A paired bone of the otic region joining the sphenotic and pterotic dorsally, and the exoccipital and basioccipital posteriorly.

Pseudo-antirostrum – The posterior-most projection of a sagitta dorsal to the sulcus. Synonym: Pararostrum.

Pseudo-archaesulcoid – A sagitta with ostium and cauda differentiated only by features on the floor of the sulcus, not by constriction of the cristae (more information).

Pseudo-caudal – A sulcus with the cauda close to the posterior (or ventral) margin but otherwise not opening onto any margin of a sagitta.

Pseudo-excisura – A posterior notch between the pseudo-rostrum and pseudo-antirostrum of a sagitta. Synonym: Excisura minor.

Pseudo-ostial – A sulcus with the ostium close to the anterior (or dorsal) margin but otherwise not opening onto any margin of the sagitta (more information).

Pseudo-rostrum – The posterior-most projection of the sagitta ventral to the sulcus. Synonym: Postrostrum.

Pterosphenoid – A paired bone of the orbital region.

Pterotic – A paired bone of the otic region of the neurocranium housing the horizontal semicircular canal (more information).

Pterotic spine – A stout, distal end of the pterotic forming a lateral, or sometimes ventral projection from the otic region of the neurocranium (more information).

Quadrate – A paired bone which, in most teleosts, has a triangular shape. The anteroventral angle of the quadrate articulates with the angular, acting as a pivot for the lower jaw (more information).

Quadrate crest – The anterior margin of the lower arm of the preopercle articulating with the quadrate (more information).

Quadrate facet – The surface on the posterior angular that articulates with the quadrate (more information).

Radii – Plural of radius (more information).

Radius – Grooves radiating from the center of a scale toward the margin (more information).

Retroarticular – A bone attached to the posterioventral portion of the angular. It does not form part of the mandibular articulation (more information).

Rostrum – The anterior-most projection of the sagitta ventral to the sulcus (more information).

Saccular otolith – See Sagitta.

Sacculith – See Sagitta.

Sagitta – The largest of three types of otoliths found in most Osteichtyes. Synonyms: Saccular otolith, sacculith.

Sensory canal – A tube-like structure partially enclosing the cephalic sensory system (more information).

Serrate – A sagitta with pointed projections on the margin (more information).

Sinuate – A sagitta with sine-shaped waves on the margin (more information).

Sphenotic – A paired bone of the otic region of the neurocranium found directly bordering the orbit.

Sulcus – A distinct groove on the medial face of a sagitta (more information). Synonym: Sulcus acusticus.

Sulcus acusticus – See Sulcus.

Superior angle – The dorsal-most point of the opercle (more information).

Supraoccipital – A median bone of the located at the posterodorsal neurocranium and covering the occipital region. It forms the dorsal margin of the foramen magnum (more information).

Supraspinal insisure – An excavation in the opercle dorsal to the opercular spine (more information).

Suspensorium – A “V”-shaped series of bones and cartilages suspending the jaws from the neurocranium. The anterior arm is usually formed by the palatine, endopterygoid, and ectopterygoid. The posterior arm is formed by the quadrate, symplectic, metapterygoid, and hyomandibular.

Suture – A joint composed of thin connective tissue, such that there is no movement between the two bones.

Symphysis – A joint in which the two bony surfaces are firmly united by cartilaginous tissue.

Symplectic – A small, paired bone of the suspensorium joining the hyomandibular and quadrate.

Transforming ctenii – Ctenii with truncated spines (more information).

Transverse process – See Parapophysis.

Tubercle – A protuberance or bulge for the attachment of a muscle or ligament. Synonym: Tuberosity.

Tuberosity – See Tubercle.

Upper angle – The dorsal-most point of the preopercle (more information).

Ventral depression – A depression in the area ventral to the sulcus of a sagitta.

Ventral groove – A distinct groove ventral to the sulcus of a sagitta (more information).

Ventral keel – A ventral flange projecting from the midline of the parasphenoid (more information).

Ventral process – The ventral arm of the dentary (more information).

Vertebra – A backbone (more information).

Vertebral facet – The posterior surface of the basioccipital articulating with the first vertebra (more information).

Villiform – A term applied to long, thin teeth.

Vomer – See Prevomer.

Whole ctenii – Ctenii with pointed spines (more information).