Abbreviations used;
AS       =          Anglo-Saxon
Fr        =          French
Gr        =          Greek
L          =          Latin


Aberrant  ab-er’rant (L ab=from; erro=wonder)  deviating from the usual type of its group; abnormal; wandering; straying; different

adapt: to develop and change in order to survive in a particular habitat

Adductor  ad-duc’tor  (L ad=to; ducere=to lead)  A muscle which draws a structure towards the medial line.  The major muscles (usually two in number) of the bivalves, which are used to close the shell.

Aesthete   aes’thete ((Gr aesthetes = one who perceives)   the sensory organs terminating in the tegmentum of some chitons

Anterior   an-te’ri-or (L ante=before)   situated in front, in lower animals relatively nearer the head

Aperture   ap’er-ture (L apertures=an opening)   the opening in a gastropod shell; an open passage, orifice, hole.

Apex   a’pex (L apex=the tip, summit)   the highest point of anything.  Tip, vertex, peak, the tip of the spire of a gastropod and generally consists of the embryonic shell.

Aquatic   a-quat’ic (L aqua=water)   pertaining to living in, growing in or adapted to the water

Articulated   ar-tic’u-lated (L articulatus=jointed)   the union forming a joint as the interlocking teeth of the hinge plate in bivalves

Asymmetrical   as-ym-met’ri-cal (Gr a=priv.; syn=with; metron=measure)   not even on both sides of an axis, bilaterally uneven, lack of symmetry

Beak   (L beccus=a beak)  the rounded or pointed extremity (umbo) of a bivalve shell at which it began to grow. (oldest part of the valve)

Biodiversity: the entire variety of life on earth

Bivalve   bi-valve  (L bi=two;  valva=door)   any mollusc having two valves or shells that are hinged together, as in mussels and clams.

Branchiae   (Gr Branchia=gills)  gills; respiratory organs for breathing the oxygen dissolved in water.

Branchial   (GR branchia=gills)  The ventral or inhalent aperture.  Used to take in food particles and oxygen and to release fertilized eggs.

Buccal   buc’cal  (L bucca=the cheek)   pertaining to the mouth or cheek

Buccal mass  a bulging; tongue-like object, made up of cartilage and muscle, which supports the radula

Byssal   a small opening or notch on the ventral margin for the passage of the byssus

Byssus   bys’sus (Gr Byssos=a fine flax)  The fine fibers, or bundle of silky threads secreted by a gland found in the foot of some bivalves by which they attach themselves permanently to rocks or other solid objects.

Calcareous   cal-ca’re-ous (L calyx=lime)   composed of, containing, or by the nature of limestone or calcium carbonate;  a shelly substance. Cephalic   ceph-al’ic (Gr Kephale=head)   of, pertaining to, on, in, or near the head

Cephalopoda   Ceph-a-lop’o-da  (Gr  Kaphale=head;  pous=foot)   One of the seven classes of molluscs.  (Squids, octopus, Argonaut, Spirula.)

Ceras   cer’as  (Gr Keras=horn)  a horn or horn like appendage located on nudibranchs

Chambered   cham’bered  (Gr  Kamara=anything with an arched cover)   having divisions across the hollow of the shell, separating or dividing the same into chambers.  (as in the Nautilus)

Chiton   chi’ton (Gr Chiton=tunic)   the coat-of-mail shells (Polyplacophora) .  They possess a shell made up of eight shell plates.

Cilium (plural Cilia)   (L cilium=eyelid)  A hair-like extension from the cell surface and capable of rhythmic movement.  Used to designate the filaments on the mantle, in the gills, etc.

Coelom   coe’lom (Gr Koilos=a hollow)  body cavity, that space between the viscera and the body wall.

Columella   col-u-mel’la  (L columen=column)   The thickened axial pillar around which the whorls of univalves are built.

Conch   (Lconcha=shell)  a trumpet shell; a large marine molluscs with a univalve shell

Conchiolin      con-chi’ol-in (L concha=shell)  organic compound forming the thin outer layer of Molluscan shells.

Conchology   con-chol’o-gy   (L   concha=shell)  The branch of zoology that embraces the arrangement and description of molluscs based upon a study of the hard parts.   Conchologist:  a student of conchology; a collector of shells.

Crop   (AS cropp=craw)    a widened part of the esophagus where food may be temporarily stored before being passed on to the stomach

Ctenidium   cten-id’I-um  (Gr Kteis=comb)  a gill-comb.  One of the respiratory organs found in molluscs.   Plural is ctenidia

Deforestation: the disappearance of all the trees from a particular area

Detorsion   de-tor’sion  (L de=away; torques=twist)   the act of twisting back or removing torsion;  unwinding

Detritus   de-tri’tus  (L detritus=a rubbing away)  a mass of disintegrated material composed of bits of sea weed and other organic wastes found on the ocean floor

Deviate   de’vi-ate  (L de=from;  via=away)  To turn aside from the straight or regular coarse.

Dextral   dex’tral  (L dexter=to the right)   Having the aperture on the right side of the shell when the apex is upwards and the aperture is facing you.  The whorls spiral in a clock-wise manner.

Dioecious   di-oe’cious  (Gr Di=two; oikos=house)   having the male and female present in different individuals.   ( an individual is either male or female but never both). Opposed to monoecious

Distal   dis’tal   (L  di=apart; sto=stand)  relatively remote from the center of the body or point of attachment.  Away from the center of origin, the farthest part from an object.

Dorsal   dor’sal  (L dorsum=the back)  referring to the  back edge or top of a bivalve, in the region of the hinge.  The back of a gastropod remote from the aperture;  The conical top surface of a limpet

Ectoparasite   ec-to-par’a-site  l A parasite living on the outside of another organism  (think of a flea living on a dog)

Endangered: in danger of extinction in the foreseeable future

Environment: all the living and nonliving things that surround and affect an animal or plant

Esophagus   e-soph’a-gus  (Gr  Oisophagos= the gullet)   A membranous tube or canal through which masticated food or drink passes from the pharynx to the stomach

Estivate   es’ti-vate  (L aestivare=to spend the summer)   to pass the summer in a state of topor;  the dormancy in the summer of some lank snails.

Exhalent   ex-ha’lant  (L  ex=out; halo=breathe)  having the quality of exhaling or evaporating.   Exhalent siphon   a short outlet formed of a fold of mantle through which water and other wastes are expelled.

Exotic species: foreign species that have been introduced into a new habitat

Extinct: no longer existing or living

Extinction: the complete disappearance of an animal or plant species

Feces   fe-ces  (L faex=dregs)   the alimentary refuse ejected from the anus

Foot  The muscular locomotory, undersurface of the body of a mollusc upon which the animal rests or moves.  In bivalves, the contraction and expansion of this organ is used in the burrowing, locomotion, or for anchoring the animal.  In the cephalopods, it is represented by the siphon and possibly the tentacles.

Gastropoda   gas’trop’o-da  (Gr Gaster-stomach;  pous=foot)  A class of molluscs.  Scientific term for the univalves with the stomach situated in the region of the foot, shell is in one piece and usually spirally coiled and is asymmetrical.

Gill  (ME gile=a gill)  or Ctenidium.  A large sheet-like organ used for breathing the air dissolved in the water.  In bivalves they also play the role of food collecting. The respiratory organ of molluscs.

Girdle   gir’dle  (AS gyrdel=a girdle)   A flexible, leathery, muscular integument holding the valves of chitons in place.  It is often ornamented with scales, spicules, or hairy processes.

Gizzard   giz’zard  (L gigeria=cooked entrails of poultry)   A thickened muscular stomach designed for the crushing of food.  A peculiar stomach paved with calcareous plates and strong enough to crush small shellfish.

Gonad   gon’ad  (Gr  Gonos=seed)   A generative tissue which eventually becomes a testis or ovary.  Gonoduct,  an oviduct or seminal duct.

Habitat: the environment in which a particular animal or plant species lives

Haemolymph   he’mo-lymph   (Gr  haima=blood)  Molluscan blood

Hermaphrodite   her-maph’ro-dite  (Gr Myth=Hermaphrodites, having a fabled son of Hermes and Aphrodite)  Having the sexes united in the same individual  The animal is both male and female.

Holotype   hol’o-type  (Gr  Holos=whole = type)  The original type.  The single specimen upon which a species is based

Inhalent   in-ha-lant (L in=in;  halo=breath)  to breathe in   Inhalent siphon,  a tube like fold of the mantle along which water, containing oxygen and food particles is drawn into the mantle cavity.

Labial Palps   la’bi-al  palps  (L. labium=lip   palpare=to feel)  Paired ciliated triangular flaps on either side of the mouth in bivalves.

Lamellar gills   la-mel’lar gills  (L. lamella=small plate)Enlarged, flattened plate-like gills (ctenidia) which form the feeding organs of most bivalves.

Lateral   lat’er-al (L  latus=the side0  pertaining to the side.   Lateral teeth; interlocking teeth of bivalves, not functioning as a hinge but serving to prevent valves from sliding upon each other when closed.

Left valve   Left valve of the shell where the dorsal edge or hinge is facing up and the anterior end is directed forward (away).

Malacology   mal-a-col’ogy  (Gr  malos=soft-bodied   logia=to speak)  The study of molluscs (clams and snail) based on soft anatomy.  The branch of zoology that deals with molluscs, the animal within the shell.

Mantle   man’tle  (L mantellum=a cloak, mantle)  A soft, fleshy sheet of tissue that surrounds the molluscs’s body and lines the inner surface of the shell. It secretes the materials that form the shell from the marginal glands and provides the periostracum.

Migrate: to go from one region to another with the change in seasons

Nacre   na’cre (Fr nacre=mothe-of-pearl)  The pearly or iridescent substance which lines the interior of some molluscs shells.

Neotype   ne’o-type  (Gr  Neos=new, recent + type)  A type of a species collected later, or selected to replace the original (holotype) if lost or destroyed. 

Nephridium   ne-phrid’I-um  (Gr nephros= a kidney)  one of the tubular renal organs of the molluscs.   Nephridiopore;  the duct through which liquid wastes drain from the nephridium.

Operculum   o-per’cu-lum  (L  operire=to close or shut)  A horny or shelly plate attached dorsally to the foot serving to close the aperture, wholly or partially, when the animal is retracted into its shell.  A chitinous or calcareous plate present in many molluscs.  

Operculate;  having an operculum

Osphradium   os-phr’di-um  (Gr  Osphraddion=strong scent)   An olfactory organ of some molluscs.  A collection of elongated sensory cells over each gill.

Overexploitation: wasteful killing of a species, usually by hunting or poaching

Palps (plural palpi)  (L   palpare=to feel)  Ciliated structures that surround the mouth.  Food is sorted here and moved towards the mouth.

Pelagic   pe-lag’ic  (Gr  Pelagos=the open sea)  Pertaining to or living in the open sea far from land.

Pelecypoda   pel-e-cyp’oda  (Gr  Pelekys=axe;  pous=foot)   Bivalves.  Molluscs bearing a two valved shell that is hinged along one edge.

Periostracum   per-I-os’tra-cum  (Gr peri=around;  ostracukon=shell) The outside skin or horny covering on the exterior of many shells.

Poaching: illegally taking protected animals or plants

Pollution: the dirtying or spoiling of air, land, or water

Population: the number members of a species living in a particular area

Prey: to hunt for and take by force

Propodium   pro-po’di-um  (Gr  Pro=before; pous=foot)   The foremost division of the foot of a gastropod used to push aside sediment as the animal crawls.

Protoconch   pro’to-conch  (Gr  Proto=first;  konche=shell)  The embryonic shell of a univalve.  It is frequently different in design, texture or colour of the adult shell.   The rudimentary or embryonic shell of a bivalve is called a Prodissoconch.

Radula   rad’u-la  (Lrado=to scrape or scratch)  A rasp-like organ, odontophore or lingual ribbon of armed with tooth-like processes, found in nearly all molluscs except the bivalves.  This tough chitinous ribbon of teeth obtains food particles by a rasping or licking action.

Rain forest: a thick evergreen forest with at least 100 inches (254 cm) of rainfall a year; may be tropical (e.g., Amazon) or temperate (e.g., Pacific Northwest)

Range: the geographical area naturally occupied by an animal or plant species

Regenerate: to replace lost or damaged parts by growth

Reintroduction: to place members of a species in their original habitat

Right Valve   Right half of the shell when the dorsal edge or hing is facing up the the anterior end is directed forward (away).

Scaphopoda   sca-phop’o-da  (Gr Scaphe=boat;  podos=foot)  Tusk or tooth shells  this class of molluscs possess an one-piece tapering, curved shell open at both ends and an elongated foot adapted for burrowing.

Shell  (AS scell=shell)  A hard rigid, calcareous or chitinous structure encasing an animal, or covering some part of it.  Some molluscs have an internal shell. 

Sinistral   sin’is-tral  (L  sinister=left)  Having the whorls of a spiral shell turning towards the left when a shell is held with its apex pointed up and its aperture facing the viewer.  This is a counter-clockwise whorl.

Sinus   si’nus  (L  sinus=a curve)  A depression, bend, embayment;  a recess or indentation as in the pallial line of a bivalve.

Siphon   si’phon  (Gr Siphon=siphon)  A prolongation or fold of the mantle conveying water into or out of the mantle cavity of most molluscs.  Siphonal Canal, siphonal notch   A tube-like extension or notch-like infolding of the lip of the aperture in a gastropod shell through which the inhalent siphon is extended.

Siphuncle   si’phun-cle  (L  siphunculus=a little tube)  The small tube connecting the chambers in a nautilus shell.

Slit  (AS  slite=slit0  A shallow or relatively long incision in the outer margin of the aperture of a gastropod.

Spicule   spic’ule (L spiculum=a dart)  A small, slender, hard body, sharp-pointed, often needle-like as the spiculous fringe found on the girdle of chitons.

Species: a group of animals or plants that have one or more characteristics in common

Symmetrical   sym-met’ric-al  (Gr  syn=with;  metron=measure)  Equal-sided, well balanced, having similar parts arranged in regular reverse order on both sides. 

Syntype   syn’type  (Gr  Syn=together; typos=strike)  one of several specimens of equal rank upon which a species is based. 

Terrestrial   ter-res’tri-al  (L  terra=the earth)  living in and existing on the earth.  Having its habitat on the ground as in land snails as opposed to aquatic (water dwelling) or arboreal (living in trees). 

Type species   (L typus=strike)  The species used by the author of a genus to characterize that particular genus.

Umbilicus   um-bil’I-cus  (L  umbilicus=naval    Gr  corde=string)A pit or chink in the shell next to or within the base of the Columella, occurring in gastropods in which the largest whorls are not closely wound against each other axially.

Umbo   um-bo  (L umbo=a knob or boss)  That point of a bivalve situated immediately above the hinge.  The first part formed in a bivalve around which “radial” growth has proceeded.. 

Valve  (L  valva=a leaf of a door)  One of the separate portions of a shell of a mollusc.  Univalve; one a single piece shell   Bivalve;  a two-pieced shell.   Multivalve:  more than two shell plates as in the chitons.

Veliger   vel’I-ger   (L  veliger=snail-bearing)  a larval mollusc in the stage of development where it has developed ciliated swimming menbrane or membranes.

Ventral   ven’tral  (L venter=the belly)   The edge remote from the hinge in a bivalve;  the ventral margin is opposite the umbonnes.  Opposed to dorsal.

Wildlife: wild animals and plants, especially animals living in a natural state

Whorl  (AS  hweorfa=the whorl of a spindle)  A revolution or turn of the spire of a univalve shell.  One complete spiral turn.  The largest whorl is the body whorl or the last whorl.