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Chapter 28: Invertebrates - Coggle Diagram
Chapter 28: Invertebrates
Phylum porifera
no true tissue
start of the pylogenetic tree (think of sponges)
asymmetrical, basal animals
aquatic, mostly marine
motility: sessile as adults (larval stage can move)
no cephalization
no nervous, digestive, respiratory, circulatory, or reproduction system
sponge body plan and cell types
cell is a choanocytes
generates water current and filters food
mesophyl
has lophocyte, pinacocyte, oocyte, amoebocyte, sclerocyte
lophocyte secretes collagen
pinacocyte forms outer covering, may phagocytize large food
oocyte is egg cell
porocyte controls water flow through ostia
amoebocyte dleivers nutrients to cells
sclerocyte secretes silica
choanocyte generates water current and filters
body support by spicules and protein fibers (spongin) --> like collagen
made by amoebocytes in mesohyl
reproduction
asexual: by budding or fragmentation
sexual: hermaphroditic (M/F at different times)
involves larval stage that moves
Phylum Cnidaria
jelly fish, hydra, sea anemones, coral s r
radial symmetry; diploblastic
2 body forms
sessile polyps
free-swimming medusa (jelly)
no head
sac-like body w/ gastrovascular cavity
1 opening (mouth/anus) to digestive sac
mesoglea- non cellular layers func as hydrostatic skeleton
flexible, supported by fluid pressure
nervous system- simple
coordinated by a non-centralized nerve net
sit & wait carnivores
Eumetazoans
stinging tentacles around central mouth
catch prey w/ cnidocytes
nematocyst organella insdide cnidocyte
ctenophora
comb jellies
radially symmetric & diploblastic
transparent, medusa-like bodies
moves with cilia, fused into 8-comb like plates
marine carnivores
only 2 tentacles(or none)
eject a slimy to capture prey?
Superphylum Lophotrochozoa
Ectoprocta & brachiopoda
both have the lophophore structure
(a) creeping bryozoan (ectoproct)
his baby going "more" in high chair
(b) Lambshell, a brachiopod
have pedicle, something that anchors them in sand, NOT a clam, these have a different symmetry compared to clam
most have lophophore- filter feeders
most have trochophore- a larval stage
platyhelminthes
"flat worms"
live in marine, freshwater, and damp terrestrial habitats
gold speckled flat worm
blue pseudoceros flatworm
planaria
some are PARASITES
flukes
tapeworms
parasitic in vertebrate intestine
eating undercook meat
no mouth or gastrovascular cavity, they absorb directly from hosts intestine
gas exchange and the elimination of nitrogenous watse (ammonia) can occur by diffusion across the body surface
traits
acoelomates
cephalization
gastrovascular cavity (one opening serves as mouth/anus
O2/CO2 exchange is at cell level
LACK respiratiry & circulatory system
HAVE
digestive
nervous
ganglia (clusters of nerve cell bodies
Excretory
protonephridia w/ flame cells
help remove xs water & some waste
means primitive kindey
Reproduction
synermata (rotifers)
free-living and aquatic
microscopic, cylindrical body
crown of cilia- looks like grinder thingy
pseudocoelom (not a true coelom, has gaps)
Alimentary canal: a digestive tube with two openings: mouth and anus
Parthenogenesis: a type of asexual reproduction; females produce more females from unfertilized eggs
Mollusca
most are marine, though some inhabit freshwater and some snails and slugs are terrestrial
protected by a calcium carbonate shell
true coelom
cephalization: EXCEPT for bivalves
major clades
polyplacophora (chitons)
Gastropoda (snails and slugs)
Bivalvia (clams, oysters)
Cephalopoda (squids, octopuses0
MOST with seperate sexes
most aquatic spp. w/trochophore larvae- larva disperses marine snail to new locations
body plan
1.) Muscular foot
locomotion, digging
2.) Visceral Mass
internal organs, well developed organ
Gills or simple lungs: Specialized gas exchange surface
most have open circulatory system
cephalapod ---> closed circulatory system
3.) Mantle
secretes minerals that makes shell (if present) for protection, covers visceral mass; & makes pearls!
They have
digestive system: complete with a strap like
radula to feed
excretory system
respiratory system
circulatory system
reproductive system
nervous system
Protecteing Freshwater and terrestrial mollusks
mollusks are the animal group with the largest number of documented extinctions
the most threatened groups
freshwater bivalves
terrestrial gastropods
they are threatened by habitat loss, pollution, competition or predation by non-native species and over-harvesting by humans
Annelida- segmented worms
about 16.5 k species
some marine species have trochophore larvae
earthworms, platynereis, terrestrial leech, earthworm cocoon
Segmentation (metamerism)= external & internal features are repeated
soft body- true coelom acts as hydrostatic skeleton
well-developed organ systems:
Digestive
closed circulatory system (with a heart and blood contained in vessels)
excretory systems
have pairs of metanephridia
nervous system: with ring of fused ganglia
gas exchange occurs across the moist body surface
Sedentarians
Earthworms
w/ few bristles & no parapodia
terrestrial or freshwater deposit-feeders
aerate soil
leeches
no bistles
no parapodia
most live in fresh water, some are terrestrial
anti-coagulant (hirudin)
parapodia: is unjointed limbs (look like tiny hands)
Superphylum Ecdysozoa
Ecdysozoans
species-rch animal group
ex. crayfish, lobsters, crabs, barnacles, spiders, ticks, and insects
covered in a tough coat called cuticle
cuticle is shed or molted through a process called ecdysis
the two largest
nematodes (roundworms)
No segmentation!
pseudocoelom (the big gap one)
body covered in tough cuticle (it is flexible)
model organism: C. elegans
some ate plant and animal parasites
trichinella spiralis ---> trichinosis
wuchereria bancrofti ---> elephantiasis
arthropods
1 million species described
most diverse- found in nearly all habitats
characteristics:
segmented body in 2-3 parts
highly specialized segments
head
thorax
abdomen
hard exoskeleton & jointed appendages
cuticle (exoskeleton) of polysaccharide chitin and proteins
for protection, support, & attachment of muscles; thin at joints
waterproofed with waxes in land spp.
but exoskeleton limits growth & final body size
but be shed to grow (molting = ecdysis)
hardened w/ CaCO 3 in marine spp
They have
circulatory system: open circulatory system in all spp.
hemolymph= fluid that is pumped in vessels and bathes tissues
do not have blood pigments for carrying O2
Respiratory system (like tracheal system)
Digestive system
nervous system
excretory system (malpigian tubuoles)
Reproduction system
Gas exchange varies:
aquatic spp.
hemplypmh pumped thru feathery gills (thin cuticle) in contact w/ water
terrestrial arthropods
have tracheae and book lungs as respiratory organs
tracheak system takes air directly to cells for gas exchange at cell level
spiders hemolymph flows through book lungs in contact w/ air
Chelicerates
most modern ones are arachnids
spiders, scorpions, ticks, mites
4 pairs of walking legs
feed apendages:
pedipalps
chelicerae
body play
cephalothorax + abdomen
no antennae
Myriapods
chewing mandibles for feeding
1 pair antennae, all terrestrial
millipedes: detrivores/ herbivores
2 pairs legs/segment
centipedes- predators
1 pair leg/segment with poison claw
Crustaceans
lobsters, shrimp, crayfish, krill, barnacles
mostly marine & freshwater; some live on land
predator, herbivores, scavengers, filter-feeders & few parasites
2 pairs antennae
feed with chewing manibles
Hexapods: Insects
extremely successful on land
first animals to FLY
wings derived from cuticle extensions
body in three parts
head
one pair of antennae, compound eyes, mandibles for chewing or grasping
thorax
bears 3 pairs of legs; 0-2 pairs of wings
abdomen
complex organ systems
including malpighian tubules (for excretion of metabolic waste
unique tracheal system for gas exchange
Tardigrada
"water bears"
segmented with chitinous cuticel that sheds
4 pair stubby, unjointed legs
very small
live in water films on mosses, soils
can survive extreme conditions in dehydrated dormant state
have piercing mouth parts
Superphylum Deuterostomia
Echinodermata
sea stars, sea cucumbers, sea urchins, sand dollars, and brittle stars
Pentaradial symmetry as adults (radial in multiples of 5)
echinoderm larvae have bilateral symmetry
oral/aboral sides; central mouth
no head, no brain
characteristics:
all free-living in marine habitats
contain exoskelton: internal CaCO3 plates & spines work w/ muscles to move arms
possess large coelom: distributes nutrients & help gas exchange
a unique water vasculae system, a network of hydraulic canals branching into tube feet that function in locomotion and feeding
tube foot has podium and ampulia (looks like putt putt thingy)
Invertebrates
Animals that lack a backbone
very diverse
97% of known animal species
Phylogeny of living animals
all start with metazoa
eumetazoa is the beginning of true tissues
cnidaria and ctenophora = radial symmetry and diploblastic
first 4 on phylum do NOT have coelom (body cavity)