Turtle




Glossary
Terminology Description
Terminology Description
Abdominal scutes The pair of plastral scutes in nearly central position. They are in contact with the pectoral, femoral and inframarginal scutes.
Alveolar The ridges and inner grooves of the mandibles where the horny beak or tomium is implanted.
Anal scutes The rearmost pair of scutes of the plastron.
Angular bone Postventral element forming the lateral surface in each ramus of the lower mandible.
Arribazon (Arrival) Spanish word used to describe the simultaneous emergence of nesting females on a small stretch of sandy beach. It extends from several hours to several days. Also “Arribada” is used.
Axillary notch Frontal cavities on each side of the body between the carapace and plastron from which the fore flippers project.
Axillary scutes The variable number of scutes between the marginal, humeral and pectoral scutes, on the rear margin of the axillary notches.
Body pit A depression made by the female turtle on the sandy beach, during nesting. Shape and depth of the pit are generic characteristics.
Bridge bones Ventral parts of the shell that connects the peripheral bones of the carapace with the plastral bones. The contact area may be calcified or cartilaginous material.
Calipash Cartilaginous strips obtained from the edge of the carapace or extracted as jelly from the dried flippers. Generally of green colour when fresh.
Calipee Cartilage extracted from the border of the plastron, along the axillary and inguinal notches, the bridge and between the bones of the plastron. Calipee and calipash are used for the preparation of turtle soup.
Carapace length Distance either in straight line (SCL) or over the curve (CCL), between the anterior most edge to the rearmost edge of the carapace.
Carapace width Distance in straight line or over the curve across the widest part of the carapace, measured on its dorsal side.
Carapace Dorsal osseous shell of the turtle covered by horny scutes or soft skin.
Central scutes The middle scutes covering the neural plates of the carapace, in between the lateral scutes. Also named neural or vertebral scutes.
Cervical vertebrae Anterior bony elements of the vertebral column.
Choanae The internal openings of the nasal funnels through the vomerian bones on the palate.
Claw Sharp, horny nail on the anterior margin of the flippers. The claws (usually one or two on each flipper) are more strongly developed in males than in females and they are used to hold the female during copulation.
Clutch size Total number of eggs laid simultaneously to form a nest.
Coronoid bones Flat, paired, bony elements of the lower mandible.
Costal plates Expanded, ossified dermal plates fused to the axial skeleton (vertebrae and ribs), between the peripheral and neural plates of the carapace.
Crawl Symmetrical tract left by the fore and rear flippers of turtles on the sandy beach. Sizes and shapes of the crawl are considered characteristic for the species.
Cusp Sharp projection, usually on the tip of the jaws.
Dentary bone Largest element of the lower jaw, the principal support of the lower tomium.
Endemic Found only in a limited region.
Entoplastron plate Median bony plate lying between epiplastra and hyoplastra.
Epifauna Those animals living on the body of a turtle.
Epiplastron plate The foremost paired bony plates of the plastron.
Farming The culturing of sea turtles in tracts of sea water for commercial purposes. It must not rely on wild populations except initially or later occasionally, to avoid inbreeding problems and genetic degeneration.
Femoral scutes The pair of posterior plastral scutes in contact with the abdominal, inframarginal and anal scutes.
Flotilla Spanish name for a large number of migrant turtles drifting or swimming together in the open ocean.
Fontanelles Carapacial unossified areas between the peripheral and costal bones, usually disappearing with age.
Frontal bone The long bone above the orbit on each side of the skull.
Gular scutes The foremost paired scutes of the plastron.
Head length The distance between the tip of the beak and the posterior margin of the head.
Head width The distance across the widest part of the Head.
Head starting The practice of raising hatchling turtles in captivity for a few months to give them a better chance of survival when they are later released into the wild.
Humeral scutes The anterior paired scutes of the plastron, between the gular, pectoral and axillary scutes.
Hyoplastron plates The median front paired bony plates of the plastron.
Hypoplastron plates The median rear paired bony plates of the plastron.
Imprinting Theoretical procedure by which a sea turtle hatchling unconsciously “memorizes” environmental cues of its natal beach, that enables it to relocate the same beach when mature.
Incidental catch The unintentional catch of nontargetted species, such as turtles and bottom fishes during shrimp trawling.
Incubation period The time elapsed between egg laying and hatching. In sea turtles, it ranges from 45 to about 70 days, depending on species, temperature, humidity and latitude.
Indigenous An organism that originated and is living in a specified region.
Interanal scute The middle, rearmost plastron scute or scutes between the pair of anal scutes (sometimes absent).
Isotherm A theoretical warped plane or line in the water connecting points of equal temperature.
Jugal bone The long bone under the orbit, forming part of the cheek region on each side of the skull.
Kraal A pen used for holding turtles before slaughter; also an artificial beach for nesting purposes, an installation used to protect nests on a beach, or a fenced area against predation. Also called “corral”.
Lateral scutes The lateralmost scutes covering the carapace on both sides, between the central and marginal scutes. Also named pleural or costal scutes.
Lepidosis Configuration of the scales and scutes covering the body; of taxonomic value at genus level.
lmbricate Overlapping condition (like shingles on a roof) of the scutes of the carapace and plastron in the hawksbill sea turtle. Hatchlings and juveniles of other species commonly also have this condition.
lnframarginal scutes The scutes covering the bridge bones, between the ventral side of the marginal scutes and the central scutes of the plastron.
lnguinal notch The cavities on each side of the plastron from which the rear flippers project.
lntergular scute The middle, foremost plastron scute or scutes between the pair of gular scutes (sometimes absent).
Lost year The elapsed time between newborn hatchlings and growth to small plate size juveniles, during which the turtle is rarely encountered and its habits are largely unknown.
Marginal scutes The scutes covering the peripheral bones of the carapace, forming a hard edge all around it.
Maxilla The large bone extending up to the orbit and forming, with the premaxilla, the upper jaw margin.
Melanism The propensity of an organism to develop dark pigment throughout the skin.
Mentonian scute The scute under the tip of the lower Tomium.
Nares Pair of openings into the nose, the nostrils.
Nekton Free swimming organisms whose activity largely determines direction and speed of their movements, independent of water currents.
Neritic Relating to the waters over the continental shelves.
Nest The cavity where the eggs are laid by the turtles. Shape and depth differ by genus. It is also related to the clutch of eggs.
Neural plates Carapacial osseous plates fused to the vertebrae.
Niche The habits or role of an organism in a particular community. Mainly concerned with the food chain, competitors and enemies.
Nucal bones (or plates) The bones (usually two) are forming the foremost central part of the carapace.
Orbital length Longitudinal diameter of the eye socket.
Papillary projections Spine like growths presents in the throat of the sea turtles; they are more conspicuous in the leatherbacks.
Parietal bones The major elements of the skull roof between and behind the orbits.
Pectoral girdle Bones forming the support for the forelimbs or anterior flippers.
Pectoral scutes The median pair of scutes in contact with the humeral, inframarginal and abdominal scutes of the plastron.
Pelvic girdle Bones forming the support for the hindlimbs or posterior flippers.
Peripheral bones (or plates) Osseous elements forming the edge of the carapace.
Philopatry Tendency of sea turtles to nest in, or very near to, the previous nesting place, during the same or in successive breeding seasons. Also called “nesting site fixity or fidelity”.
Pigal bones (or plates) The rearmost marginal osseous plates that form the carapace.
Pigal scutes The rearmost pair of marginal scutes of the carapace. Also named postcentral, suprapigal, or supracaudal scutes.
Pivotal temperature Theoretical temperature at which incubation produces a sex ratio of 1:1.
Plastron Ventral osseous shell of the turtles, covered by horny scutes or soft skin.
Postcentral scutes The rearmost pair of marginal scutes of the carapace. Also named suprapigal, supracaudal or pigal scutes.
Postorbital bone The bone behind the orbit that forms part of each cheek of animal.
Postorbital scales The horny scales (usually 3 or 4) covering the sides of the head behind the orbits.
Precentral scute The foremost central scute of the carapace. Also named prevertebral, nucal or cervical scute.
Prefrontal bones A pair of circumorbital bones, extending anteriorly and also bordering the external nares.
Premaxilla bones The paired bones forming the front margin of the snout, supporting, together with the maxilla, the upper tomium.
Preorbital length The shortest distance between the anterior margin of the orbit and the tip of the snout. Also called preocular length.
Quadrate bone Thick bone close to the jaw articulation. Laterally, it is bound to the quadratojugal bone.
Ranching The raising of turtles from wild stock eggs or hatchlings to marketable size.
Remigrant Turtles that return to nest in a subsequent season.
Renesting Successive visits of a turtle to a nesting area, laying eggs each time.
Ribs Beneath the carapace of chelonians there are eight pairs of dorsal ribs fused to the costal or pleural and to the neural plates. The tips of the ribs are inserted in ventral pits of the peripheral bones.
Scales Thin, leathery or horny shields covering the head and flippers and forming callosities in some parts of the flippers.
Scutes Horny shields covering the carapace and plastron. The shape and size do not correspond with the underlying bony plates. The thickest and most valuable scutes are those of the hawksbill turtle.
Sexual dimorphism Morphological differences between males and females that appear at sexual maturity. Males develop stronger claws and thicker and longer tails. Females become heavier and have a deeper body shape.
Squamosal bones The principal component of the cheek region of the skull.
Supracaudal scutes The rearmost pair of marginal scutes of the carapace. Also named postcentral, pigal or suprapigal scutes.
Supraoccipital bones Paired bones of the upper part of the occiput at the back of the skull.
Suprapigal scutes The rearmost pair of marginal scutes of the carapace. Also named postcentral, pigal or supracaudal scutes.
Surangular bones The upper posterior bones of each ramus of the lower jaw.
Vomerine bone One of the pairs of osseous elements centrally placed behind the premaxillae and forming a bar between the internal nostrils or choanae.
Xiphiplastron bones The rearmost pair of bones forming the plastron.