### animal | mollusc:

Bivalve
* All bivalves are aquatic, encompassing both marine and fresh-water species
  - filter-feeding organisms
  - mollusks
  - have the ability to secrete sticky threads known as byssal threads
* Have two parts to their shell and include such species as oysters and scallops.
* Many bivalves use their large foot to bury into the sediment on the ocean floor.
* Most bivalves are filter feeders and burrow into the sediment using their muscular foot
  - feeders, but some are scavengers or even predators
  - primary consumers, typically exploiting organic material
  - sedentary or slow-moving animals
  - sedentary, living in sand or mud in marine and freshwater environments
  - sessile benthic filter feeders and can be infaunal or epifaunal
  - suspension feeders
  - attach themselves to something or burrow underground
  - belong to phyla
* Most bivalves eat by filtering microscopic plants and animals from the water
  - plankton and other tiny living things, like algae
* Most bivalves have a pair of large gills which are located in their mantle cavity
  - single pair of large gills used for respiration
  - well-developed foot that is used for burrowing and creeping
  - grooves
* Most bivalves live in fresh water
  - soft sediments below the surface
  - sedentary lives, a characteristic suited to suspension feeding
  - reproduce by discharging sperm and eggs into the water where fertilization occurs
  - require water
* Most bivalves retain moisture
  - precious moisture
* Most bivalves stay in places
  - same places
  - the same place for much of their lives, but others are able to move around
* Some bivalves become predators
* Some bivalves can rapidly shut their two valves
  - swim, albeit weakly, when removed from the sediment, as can some file shells
  - collect food
  - do however live on, or most often in hard substrata such as clay, rocks and wood
  - eat prey
  - go through stages
  - has-part valves
* Some bivalves have aortas
  - eyes and sensory tentacles along the outer edge of their mantle
  - larvae
  - meals
  - septa
  - style
  - symbiotic relationships with photosynthetic organisms, providing extra nutrition
* Some bivalves live in beaches
  - colonies
  - on their sides
  - occupy habitats
  - require food
  - sit on sides
  - use gills
* also provide good examples of camouflage and mimicry.
* are a class of mollusc which have shells consisting of two hinged sides known as valves
  - mollusk that includes clams, oysters and scallops
  - group of mollusks that includes clams, mussels, oysters and scallops
  - adapted to living in a confined space and feeding by straining plankton from the water
  - animals that live in water
  - aquatic molluscs which have two-part shells
  - both marine and freshwater
  - closely related to limpets, abalone, snails, slugs, squids, and octopuses
  - common both in the sea and in fresh water today
  - composed of two shells held together by an elastic ligament
* are filter feeders and feed primarily on phytoplankton - microscopic plant life
  - found in both freshwater and marine environments
  - hermaphroditic or have separate sexes
  - hosts to parasites that can cause mortalities, particularly in the adult stage
  - mollusks with two shells, including clams, oysters, scallops and brachiopods
  - most abundant in shallow marine waters, where they burrow in soft sediment
  - organisms particularly vulnerable to climate change and ocean acidification
  - soft-bodied mollusks that have two shells hinged together by a strong muscle
  - some of the most important seafood species
  - thus filter feeders
  - two shelled aquatic molluscs, bilaterally symmetrical and laterally compressed
* are typically epifaunal and infaunal filter feeders
  - very fast moving
  - what many people think of when they think of a seashell
* can also cause economic damage
  - inhabit a variety of places depending on the species
* cling to sea whips along the deeper sections of the wall.
* consist of two shells.
* depend upon concealment and the heavy shell to keep predators at bay.
* develop methods.
* even make their own shells.
* feed on tiny bits of food found in the water or sediment.
* generally are known as creatures that almost never move
  - have a large mantle cavity with gills
* have a highly muscular organ called the foot, which muscle fibres run in all direction
  - long history
  - mouth, heart, intestine, gills, stomach and siphon but have no head, radula or jaws
* have a shell composed of more or less equal halves
  - made of two halves, which are also called valves
  - simple circulatory system, which is rather difficult to trace
  - all of the following structures except a. a radula
  - gills with mucus which trap plankton and other organisms
  - highly reduced heads and simple nervous and sensory systems
  - no distinct head, and the radula has been lost
  - small heads that consist of little more than a mouth
* have the ability to select food filtered from the water
  - simplest nervous systems among mollusks
* have two distinct shells joined by a ligament
  - shell halves that completely enclose the animal
* have two shells or valves connected by a hinge
  - sandwiched together
  - that are held together by a strong ligament
  - shells, like a clam or oyster
* have two valves and are symmetrical between the valves
  - connected by a flexible ligament
* include clams.
* includes brains
  - cell membranes
  - corpi
  - cytoplasm
  - faces
  - nuclei
  - plasma membranes
  - skulls
* lack a head, radula, and jaws.
* lead sedentary lives.
  - on the sea bed or lake bottom and are sedentary, so the head and foot are reduced
* make use of a variety of lifestyles.
* need food.
* often abound on mudflats.
* open their shell to breath,eat, or to move around.
* posses a two-valved shell that is an aragonitic concretion and bilaterally symmetrical.
* possess a bilateral and relatively simple nervous system.
* tend to be filter-feeders.
* typically have two similar hinged shells that are each asymmetrical across the midline.
* use their foot to move themselves
  - gills both for filter feeding and for gas exchange
+ Bivalve, Shell
  * Bivalves have two shells or valves connected by a hinge. They are made of a calcareous mineral, calcite or aragonite. The valves are covered by a periostracum, which is an organic horny substance. This forms the familiar coloured layer on the shell.