What is a trochophore? Look here to find a definition for this
word and other terms associated with molluscs.
Muscle(s) in bivalves attached to both shells (valves); adductor
muscles pull the two shells together (closes the shells). An
elastic hinge pushes the shells apart (opens the shells).
A mollusc with two valves, or shells, joined together by a hinge.
Members of Class Bivalvia ("two valves") can be found in freshwater
and marine environments. Examples include clams, scallops, oysters,
A mass of strong, silky filaments by which certain bivalve
mollusks, such as mussels, attach themselves to rocks and other
A marine mollusc with a well-developed head surrounded by a ring
of eight or more arms. Members of Class Cephalopoda ("head-footed")
have a well-developed nervous system and propel themselves by
jetting water through a siphon. They include pelagic and bottom
dwellers. These animals maybe shell-less such as the octopus,
possess an internal shell (squid and cuttlefish), or they may have
an external shell (chambered nautilus).
An animal that filters phytoplankton from the water for food. Most
filter-feeding molluscs pump water across their gills, which act
like fine-screen filters. A pair of siphons (inhalant and exhalent)
allows burrowing bivalves to reach the water column without leaving
the safety of their burrow.
A mollusc with well-developed foot, head, and body. Class
Gastropoda ("stomach-footed") is the largest group of molluscs and
can be found in terrestrial, freshwater, and marine habitats.
Members of this group may be shell-less (slugs and sea hares), or
typically possess a spiral-shaped shell (snails or conch).
Regions where recreational fishing is allowed (open) or prohibited
(closed) during certain times of the year.
Having both female and male reproductive organs.
A non-native species that is deliberately introduced into an area
or inadvertently brought into a region due to human activities.
An introduced species that threatens economic or environmental
harm to ecosystems, habitats, or species. Only some introduced
species become harmful.
The act of bringing an animal (fish, scallop, lobster, etc.)
A population composed of smaller, isolated populations.
A species that is not indigenous, or naturally occurring, in a
A specialized term for molluskan planktonic larvae. This stage
follows the veliger stage and the foot is well developed.
An organism that lives in open water rather than on the
Develops male reproductive organs initially and female
reproductive organs at a later time.
Juvenile bivalve. Bivalves at this stage are often attached
to other structures.
An animal that reproduces by expelling eggs or sperm (or both eggs
and sperm) into the surrounding water resulting in external
A very early larval stage of molluscs (and some worms). The body
is ringed by a band of cilia.
A specialized term for molluscan planktonic larvae. Although they
do not always have the same appearance as in adults, the shell and
most organs can be seen.