KINGDOM ANIMALIA – Comparing Invertebrates
Name: ________________________________________________________________
Porifera
Representative
Organisms /
Classes
Unique
Features
Cnidarians
Sponges
jellyfish
anemones
corals
Very simple with
specialized cells for
functions
Cell
Tentacles with
nematocysts
Polyp or medusa form
Tissue
Asymmetrical
Platyhelminthes
Flatworms
turbuleria – aquatic
trematode – flukes
cestoda - tapeworms
Flame cells & eye spots
Nematoda
Round Worms
Sexual dimorphism
Many Parasites
Organ
Organ
Radial
Bilateral
Bilateral
None
Diploblastic
Triploblastic
Triploblastic
None
No
None
No
Acoelomates
No
Pseudoceolomates
No
NONE
Produce toxins for
Protection
NONE
Nerve Tissues = Nerve
net but no central
collection of nerves
YES
Ganglia – grouping of
nerve cells
YES
Simple several ganglia
NONE – spicule cells
make them hard
Hydrostatic skeleton
Calcarious endo or exo
None
Hydrostatic skeleton
Way of Life
Sessile
Sessile
No Muscles
Mobile & Sessile
Muscle Cells (not tissue)
Free living /parasitic
Longitudinal muscles
Free-living/parasitic,
decomposers
Habitat
Aquatic
Aquatic
Aquatic & moist
terrestrial
Aquatic & moist
terrestrial
Digestion
NONE
INCOMPLETE
COMPLETE -Two
openings: mouth and
anus joined by an
intestine = tube
Excretion
Filter feeders
Movement of water
Intracellular
Movement of water
INCOMPLETE
Mouth/Anus with
Gastrovascular cavity
=Sac
Intra & Extracellular
Diffusion
Circulation
Movement of water
Diffusion
Diffusion
Diffusion
Respiration
Movement of water
diffusion
Diffusion
Diffusion
Reproduction
Sexual or asexual
Internal fertilization
Sexual or asexual
External fertilization
Hermaphrodite: Sexually
Fission: Asexually
Able to regenerate
Dimorphic: Sexually
internal
Level of
Organization
Body
Symmetry
Germ Layers
Coelom
Segmentation
NervousCephalization
Response
Skeleton/
Movement
Mouth/Anus & intestine
=Sac
Extracellular  all rest
Diffusion aided by
Flame cells
NO SPECIALIZATION
Diffusion
Annelids
Representative Segmented Worms
Organisms /
Classes Polychaeta – many chaeta
Oligochaeta - earthworms
Hirudinea - leeches
Unique Features Segmentation
Organization
Body Symmetry
Germ Layers
Development
Segmentation
NervousCephalization
Response
Metemerism & Septa
Organ
Bilateral
Triplo-ceolomates
Protostomes
yes
Ventral nerve chord with
specialized sensory
organs in the head region
Skeleton/ Hydrostatic Pressure
Movement
Muscles and cheatae
Way of Life Free-living & Parasitic ,
decomposers
Habitat Aquatic, terrestrial
Digestion COMPLETE
Some specialization
pharynx & development
of crop & gizzard in
some species
Mollusks
Bivalves –Clam, scallop…
Gastropods – snails, slugs
Cephalopods – octopus,
squid…
Basic body plan = Foot
Mantle and visceral mass
Organ
Bilateral
Basic body plan = Foot
Mantle and visceral mass
Triplo-ceolomates
Protostomes
No
Simple in Bivalvia and
gastropoda
Complex in Cephalopods
-ventral nerve cords,
-sensory organs
Hydrostatic Pressure
Secrete mucus – gastropoda
-Jet propulsion –
cephalopods & bivales
Free living herbivores and
carnivores, also some filter
feeders
Aquatic and terrestrial but
generally moist
COMPLETE
regional specialization
many, external
fertilization & indirect
development
-Radula: a tongue-like organ
bearing rows of teeth that is
used in feeding (scraping,
drilling, etc.)
most have kidneys
(metanephridia)
-open circulatory system (in
most classes)
-closed system in
cephalopods bc large & v.
mobile
mainly gills, however
terrestrial species have
evolved lungs
monoecious and dioecious
usually internal fertilization
indirect development with
the presence of a
trochophore larva (link
to mollusks)
trochophore larva (link to
annelids)
Excretion nephridia
Circulation Closed system ***
Respiration Skin, gills, diffusion
Reproduction Sexual, hermaphroditic in
Arthropods
Crustacea – crab, crayfish
Arachnida – spiders –
Insecta - insects
Most diverse of all animal
-Jointed appendages
Organ
Bilateral
-3 parts-head, thorax,
abdomen (fused head &
thorax = cephalothorax)
Triploblastic ceolomates
Protostomes
yes
Well developed with brain
and ganglia in head
Echinoderms
Starfish – Sea Urchins –
Sea cucumbers
Believed to be closest
related to Chordates
because early development
of larva are the same &
internal skeletons
Spiny skin
Water vascular system
organ
5 part Radial
Triplo-ceolomates
Deuterostomes
yes
Simple nervous system
and no brain & no head
-ventral nerve chords
-complex sensory organs
Hard external skeleton
made of chitin – molt/shed
to grow
Nerve ring
Muscles
Water vascular System
All – free-living parasitic,
herbivore, carnivore,
detrivore, filter feeders
All aquatic and All
terrestrial
COMPLETE
regional specialization
All aquatic!!! Herbivores
Carnivores, detritus and
filter feeders
ALL aquatic
None terrestrial
COMPLETE
without specialization
Malpighiam tubules and
green glands
Open circulatory system
with a more advanced
heart and sinuses
**limits arthropods size
Internal Skeleton
Carnivore starfish flip
stomach inside out and
digest prey with enzymes
before ingesting
Solid waste via anus
Ammonia via tube feet
Open Circ. System
Tracheal Tubes(insects),
book Gills(aquatic), Book
lungs (spiders)
Separate sexes
Internal fertilization
Through tube feet or gills
Incomplete metamorphosis
= egg– nymph-adult
External fertilization
Male and female or
hermaphrodites
Can regenerate
Complete metamorphosis
= egg, larva, pupa, adult