Chapter 35. Section 35.1 Video Means “soft body” Most marine, some freshwater, a few...
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Transcript of Chapter 35. Section 35.1 Video Means “soft body” Most marine, some freshwater, a few...
Chapter 35
Section 35.1
Video
Means “soft body” Most marine, some freshwater, a few
terrestrial
Body divided into 2 main section: head-foot & visceral mass:
Head-foot: head (mouth, sensory structures) and foot (locomotion)
Visceral mass: heart & digestive, excretion, and reproductive organsCovered by the mantle
Mantle: layer of epidermis that excretes a hard shell of calcium carbonate
Mantle cavity: space between mantle and visceral mass that protects the gills
Ganglia: clustered nerve cells that control locomotion & feeding
Radula: flexible, tongue-like strip of tissue covered with abrasive teeth
1. Class Gastropoda2. Class Cephalopoda 3. Class Bivalvia
Examples: clams, oysters, mussels, scallops
All have a two part shell connected by hinge closed by adductor muscles
aged by shell rings sedintary filter feeders
Video
2 siphons at the posterior end: Incurrent siphon = intake of water & foodExcurrent siphon = output of water &
wastes
Clams dig in the soil so only their siphons stick outFilters about 3 quarts an hour!
Video
Video
Calcium carbonate secretion around a foreign objectProtection of the soft visceral massMade by the mantle (just like the shell)
----------- protective outer layer ///////////// prismatic layer
----------- pearly layer
(Snails, nudibranchs, cowries, whelks)
Largest and most diverse group of mollusks Examples: snails, abalones, conchs, slugs Locomotion: wavelike muscular
contractions on mucus slime trail Can withdraw head into mantle cavity when
threatened
Video
Hemolymph: circulatory fluid
Hemocoel: fluid filled spacesA.k.a. blood cavity
tentacles- sense touch & have eyes on ends
respire with gills (aquatic) or exposed blood vessels (terrestrial) by diffusion
we eat muscular foot “escargot”
Examples: octopuses, squids, cuttlefishes, chambered nautiluses
Marine animals, free swimming Meaning “head-foot”
Tentacles have large suction cups Largest invertebrate brain Highly advanced eyes similar to humans Closed circulatory system Many release dark, inky fluid when
alarmed Many have pigment cells called
chromatophores for camouflage
Video
Squid, chambered nautilus, cuttlefish, octopus
He Was Shellfish
Body parts you MUST identify & show me during the lab:UmboValves (shells)MantleGills Incurrent & excurrent siphonsPalps & mouthDigestive gland IntestineGonadsHeart
clam
Oldest part
ANTERIOR POSTERIOR
VENTRAL
DORSAL
Section 35.2
“Few bristles”Few setae and no parapodia
Live in soil or freshwater Example: earthworms
Divided into over 100 segments Movement:
Anchor middle segments with setaeContract muscles in frontElongation of anteriorSetae of anterior grip groundPull posterior forward
Ingest soil as they burrow Digestion path: mouth esophagus
crop (temp. storage) gizzard (releases & breaks up organic matter) long intestine (absorption of nutrients) anus
Closed circulatory system Ventral (toward posterior) & dorsal
(toward anterior) vessels Aortic arches link ventral and dorsal
vessels
Respiration: diffusion of oxygen and carbon dioxide via moist skinSecretion of mucus to keep moist
Excretion: via nephridia (excretory tubules in every segment except first three)
Chain of ganglia connected by a ventral nerve cord
Each segment has a single ganglia Brain = fused ganglia Simple sensory skills
LightTouchChemicals temperature
HermaphroditesCannot fertilize own self
Mating: press ventral surfaces together, anterior ends pointed opposite directionsSetae hold worms togetherMucus secretion from clitellumEach worm injects sperm into mucusSperm going into seminal receptacles of other
wormSeveral days later chitin tube forms picking up
eggs & stored sperm fertilizationYoung worms develop inside tube and hatch 2-
3 weeks later
Examples: earthworms, leeches Annelid means “Little rings” Segmentation allows for division of labor Bilateral symmetry Live in freshwater, marine water, and
terrestrial environments
Setae: external bristles Parapodia: fleshy protrusions on outside of
body
Number of setae and parapodia divides this phylum into three class:
1. Class Polychaeta2. Class Hirudinea
3. Class Oligochaeta
“Many bristles”Number of setae and parapodia
Have anetennae & specialized mouth parts
Most are marine animalsTrochophore larvae
Predatory Largest class of annelids
Video
Smallest class of annelids Example: leeches Live in calm freshwater & moist
vegetation No setae or parapodia Most are carnivores & some are
parasiticSecrete anaestheic & anticlotting factors Ingest 10 times it own weight in blood!
Decomposers of leaves and organic matter
Recycle nutrients Release natural fertilizers (waste)
Aerates the soil
Front of Card:Phylum nameClass name Image of animalCommon name of
animal
Back of Card:SymmetryMobilityFeeding ReproductionDefenseHabitat