Glossary

Adductor large muscle (or muscles) that pull the two shell valves together muscle
Algae aquatic plants that reproduce by spores
Anterior front or head

Auricle with respect to scallops, the ear or wing-like projections at the hinge of a scallop (can also refer to the chamber of heart that receives blood from the body)
Axenic culture of a single species in bacteria-free conditions
Biting condition where shell margins of two scallops become interlocked, and subsequently damage the inner soft parts
Bivalve mollusc of the Class Pelecypoda, having a shell of two valves that are joined by a hinge
Byssus thread-like filaments used by bivalves to attach themselves to a substrate
Cilia hair-like structures whose rhythmic beat induces a water current in bivalves
Ctenidia leaf-like appendages that function in respiration and filtration of food from water (used interchangeably with the term gills)
Cultch material used to collect bivalve spat
Demibranch single plate or leaf of a bivalve gill

Detritus fragmented or decomposing organic material from plant and animal remains
Diatom a single-celled alga of the Class Bacillariophyceae; cells are enclosed in a siliceous shell called a frustule, cells can form chains
Dimyarian bivalves with two adductor muscles, e.g. clams and mussels
Dioecious organisms in which male and females reproductive organs occur in different individuals
Diploid the normal number of chromosomes (2n) in cells Dorsal the back or part of an organism away from the ground
Downwelling in hatchery terminology, a growing system in which the flow of water enters at the top of a spat holding container (compare with upwelling)
D-larva the early veliger larval stage of bivalves, also known as straight-hinge larva
Embryo organism in early stages of development; in bivalves, prior to larval stage Exhalant area of bivalve where water currents have an outward direction Exotic introduced from foreign country or geographic area
Eyespot simple organ that develops near centre of mature larvae of some bivalves and is sensitive to light
Fertilization union of egg and sperm
Flagellate group of single-celled algae characterized by having a locomotory organ called a flagellum
Frustule siliceous shell-like covering of a diatom
Gamete mature, haploid, functional sex cell capable of uniting with the alternate sex cell to form a zygote
Gametogenesis process by which eggs and sperm are produced
Gill a leaf-like appendage that functions in respiration and filtration of food from water (see ctendia)
Growout the process of growing seed produced in hatcheries to market size Halocline a zone of sharp vertical salinity change
Hinge dorsal area of bivalve shell where two valves are joined together
HUFA a highly unsaturated fatty acid, referred to also as polyunsaturated fatty acid (PUFA)
Indigenous native, not imported
Inhalant area of bivalve where water current have an inward direction Larva a stage of bivalves from the embryo to metamorphosis Ligament fibrous spring-like material joining two valves of a bivalve at the hinge Mantle the soft fold enclosing the body of a bivalve which secretes the shell Mean average
Meiotic Division process in which normal number of chromosomes (2n) is reduced to the haploid (n) number
Metamorphosis in bivalves, the period of transformation from the larval to the juvenile stage
Microalgae small cell-size algae, either single celled or chain forming diatoms, cultured as foods for larvae and spat in a hatchery
Microlitre (?l) one millionth of a litre or one thousandth of a ml Micrometer (?m) one millionth of a metre or one thousandth of a mm
Monoecious organisms in which both male and female reproductive organs occur in the same individual
Monomyarian bivalves with one adductor muscle, e.g. oysters and scallops Natural Set in bivalves, obtaining spat from spawning of natural populations
Pallial Line faint circular line on inner surface of shell of bivalves showing location of attachment of mantle to shell
Palp a sensory appendage near the mouth used to assist in moving food into the mouth
Pedal pertaining to the foot
pH a measure of acidity
Plankton floating or weakly swimming aquatic organisms, can be phytoplankton (plants) or zooplankton (animals)
Planktotrophic organisms that feed on phytoplankton
Polar Body minute cells released during meiotic division of the egg after the sperm has penetrated the egg; contains excess chromosomal material to produce a haploid egg
Polyploid animals having more than the usual number of diploid (2n) chromosomes
Posterior the rear, away from the head
Pronuclei in the egg, the haploid nucleus after completion of meiosis but before infusion with the sperm nucleus
Pseudofaeces false faeces, waste material not taken into the digestive tract PSU a measure of salinity, equivalent to parts per thousand
Resilium internal portion of the ligament located centrally along the hinge of a bivalve; causes the valves to open when the adductor relaxes
Salinity the salt content of seawater usually measured in parts per thousand (ppt) or practical salinity units (PSU)
Seed a hatchery term for spat of a size ready for sale
Settlement behaviourial process when mature bivalve larvae seek a suitable substrate for attachment
Shell Height the straight line distance measured perpendicularly from the umbo to the ventral margin of the shell
Shell Length the straight line distance from the anterior to the posterior margins of the shell
Spat a newly settled or attached bivalve (also termed post larval or juvenile in bivalves)
Straight-hinge early part of larval stage, sometimes termed D-stage larva
Tentacle long, unsegmented threadlike protuberance from edge of mantle that has specialized sensory function
Tetraploid polyploid animal with twice the normal complement of chromosomes (4n)
Thermocline a zone of sharp vertical temperature change
Triploid a polyploid animal with an extra set of chromosomes (3n) Trochophore planktonic stage of bivalve embryo
Umbo beak-like projections at the dorsal part of the shell; it is the oldest part of a bivalve shell (also called the umbone)
Upwelling in hatchery terminology, a growing system in which a flow of water is induced through the base of a spat holding container (compare
with downwelling).
Urogenital system with organs concerned with excretion (kidney) and System reproduction (gonad)
Valve one of the two parts of a bivalve shell, two valves make up one shell
Veliger Larva the larval stage of most molluscs, characterized by the presence of a velum
Velum ciliated locomotory organ of the larva
Ventral pertaining to the under or lower side of an animal Zygote diploid (2n) cell resulting from union of male and female gametes