Lab Ex 38 Survey of the Animal Kingdom - Phyla Mollusca & Annelida Flashcards
Phyla Mollusca & Annelida
have coelomic body cavity surrounded by mesoderm; contain complex systems of organs and compartments
Protostomes
include phyla mollusca, annelida, and anthropoda; have well-developed nervous, circulatory, excretory, reproductive, and digestive systems
Deuterostomes
include phyla Echinodermata, Hemichordata, and Chordata
Mantle
mollusks such as snails, clams, octopuses, and squids are soft-bodied animals with this specialized layer of epidermal cells that secretes a shell
Open Circulatory Systems
blood pools in sinuses and bathe the organs directly; have a few large vessels and a heart, but no smaller vessels and capillaries
Visceral mass
digestive, excretory, and reproductive systems & sensory structures
Foot
ventral, muscular, often highly modified; used for locomotion
Head
some mollusks have; some don’t
Radula
horny-toothed organ in the mouth; scrapes food (algae) from rocks
Incurrent siphon & Excurrent siphon
mantles of the left and right valves join posteriorly to form a ventral ___ ___ & a dorsal ___ ___ that direct water through the clam
Mantle Cavity
the space between the mantle and visceral mass; water flows into this through the incurrent siphon, over the gills, and then dorsally into a space between the visceral mass where gills attach to the mantle; water exits this chamber posteriorly through the excurrent siphon
Hinge & umbo
on the dorsal surface of a clam; latter is toward anterior end
Labial palps
channel food to a clam’s mouth
Segmentation
most distinctive feature of phylum annelida; body of an annelid is divided into repetitive segments (AKA metameres) arranged on a longitudinal axis and divided by septa
Setae
small, bristlelike appendages often occurring in pairs on lateral and ventral surfaces