Flashcards in Molluscs Deck (47):
Belongs to what type of protostomes
What does the simplest body plan consist of? (3 things)
1. Foot OR head-foot portion
2. Visceral mass portion
contains feeding, cephalic sensory, and locomotor organs
contains digestive, circulatory, respiratory, and reproductive organs
Mantle Cavity does what
Two folds of skin form protective mantle or pallium
Space between mantle and body wall is the mantle cavity
Mantle cavity houses the gills (ctenidia) or a lung
Posterior to mouth is the chief what?
locomotor organ, the foot
Buccal Mass consists of what two things? And which one is unique to molluscs
Radula and Odontophore
Protruding, rasping, tongue-like organ
firm ribbon of teeth arranged in rows
Serves as a conveyor belt to move particles to digestive tract
cartilage-like supportive structure
What does the foot function as
Functions in attachment to substratum or for locomotion or for a combination of both.
What is a mantle and what does it secrete
a sheath tissue on each side of the body
Secretes the shell when present
Houses the gills or lungs that develop from the mantle
Exposed surface of the mantle also functions in gaseous
In aquatic molluscs what flows in and what flows out
Continuous flow of water brings in oxygen and food, and flushes out wastes
The products which have been excreted go to?
the empty mate cavity
What is the respiratory organ in a mollusc called?
What are the two functions of the Ciliary?
provide continuous water current in/out of cavity and modify for filter feeding bivalves
The shell is secreted by what?
What are the three layers of the shell?
Periostracum, Middle prismatic layer and Inner nacreous layer
Which shell layer is Composed of conchiolin, a tanned protein (=formation of crosslinking between proteins).
What consists of the open system?
pumping heart, blood vessels, and blood sinuses
most cephalopods have a heart, vessels, and capillaries
is what type of system
Most molluscs have a pair of what
kidneys or metanephridia
What are the four systems in a mollusk
Circulatory system, Excretory system, Nervous system
and sense organs
Gametes are exchanged how?
both internal fertilization and external fertilization
most mollusks are dioecious but some can be?
Reproduction- trochophore larva do what?
may feed, catching small plankton in prototroch,
Which one has a short life and which one has a long one: planktotrophic or lecithotrophic
Veliger larva develops from what?
In bivalves, most often develop into a second, free-swimming, larval stage
Veliger larva modification in some freshwater bivalves: fertilization is what?
microscopic non-swimming shelled larva
- initially “ectoparasitic” (10 – 30 days) on fish
- attaches to fish gills, encyst and feed by phagocytosis
Class Polyplacophora: Chitons key features
Somewhat flattened with 7- 8 dorsal plates, Most prefer rocky intertidal surfaces
Which class consists of Mussels, clams, scallops, oysters, and shipworms
Bivalves lack what
lack a head, radula, or other aspects of cephalization
Most are marine
What is the most diverse class? with over 70,000 living species
Class Gastropoda has what?
Snails, limpets, slugs, whelks, conches, periwinkles, sea slugs, sea hares, and sea butterflies
Gastropod Shells are?
Conch shells, One-piece univalve, coiled or uncoiled
Left handed and Right handed Gastropod Shells are called what?
Left handed- sinistral
Adults lack a shell but can still store
toxins from their prey
Squids, octopuses, nautiluses, devilfish, and cuttlefish
All marine predators belongs to what class?
What is the largest invertebrate?
The giant squid
Which class has sexes which are separate ?
What has the largest nerve fibers in the animal kingdom? and Can learn by reward and punishment, and by observation of others
Which brain is the largest of any invertebrate?
The sense organs are well developed but often times colour blind: which class
Cephalopods communicate using what?
chemical and visual signals to communicate
cells in the skin that contain pigment granules can also expand and cause it to change colour pattern