Download NOTES: Simple Invertebrates

SYSTEMS*
Nervous (responding to environment)…brain, nerve cord, eyes…
Digestive/Excretory (food/waste processing)…stomach, intestines, kidneys…
Circulatory/Respiratory (gas/nutrient exchange/delivery)…gills, heart….
Skeletal/Muscular (movement)…cranium, backbone, muscles, tendons…
Reproductive …ovaries/testes (gonads), sexual vs asexual methods…
LINNAEAN
LINNAEAN CLASSIFICATION
CLASSIFICATION
1) ANATOMY
Is based on…
&
2)
2)
(organs/systems*)
ANIMAL
ANIMAL KINGDOM
KINGDOM
NOT zone/region/environment
PHYSIOLOGY (function of organs)
*organellescell  tissue  organ  system  organism
Marine Invertebrates (saltwater animals without a backbone)
PHYLUM (Latin)
Translation
porePORIFERA
bearing
SYMMETRY
asymmetrical
(no symmetry)
CLASS (es) / Translation(s)
Simplest
SPONGES!!
Animal
Examples and the Defining A & P
Operates like a chimney, drawing water IN through pores*,
Plankton are snagged by “amebocytes”, and the water EXITS
out through the “osculum” (hole at the top)
REPRO: 99% Asexual
NO (complex) SYSTEMS
(regeneration)
ONLY ONE LAYER OF CELLS
Why is this an animal? Multicellular Heterotroph!! *2 liters/hr!!
PHYLUM (Latin) Translation
Why am I,
the vellela,
stinging cell
a Cnidarian?
CNIDARIA
(nematocyst)
ABORAL
SYMMETRY
RADIAL
CLASS (es) / Translation(s)
ANTHOZOA
corals (hard & soft)…3700 species
& anemones
SCYPHOZOA
jellies (plankton called “neustron”
aka “floaters”)
HYDROZOA
Hydra, Portuguese Man-o-War,
& siphonophores
REPRODUCTIVE: 75%Examples
Asexual (budding)
and the Defining A & P
Sexual (larval/medusa forms change into adults/polyps)
CNIDARIANs were earth’s first animals to have SPECIALIZED cells (“tissue”);
GASTRODERMIS (first inkling of a “Digestive System”), like a primitive
“stomach”, cells that dissolve prey for-the-good-of-the-organism
STINGING CELLS, part of a NERVE “NET” (a primitive nervous
system, a de-centralized nerve cord), NO BRAIN but sensors
TWO LAYERS of cells (epidermis & gastrodermis)…no body cavity
ANEMONE
PHYLUM (Latin)
Translation
ANNELIDA
little
ring
segmented
(worms)
SYMMETRY
BILATERAL
CLASS (es) / Translation(s)
POLYCHAETA / many “bristles”
Marine worms
marine
(2 terrestrial classes)
Examples and the Defining A & P
Besides CLAMWORMS
other Annelids (polychaetes)
include GIANT TUBE WORMS*
(called Riftia) and FEATHERDUSTER WORMS
FIRST animals to have
--CEPHALIZATION (a “head” + eyespots!)
--(complete) Digestive System
--(ventral) Nerve CORD + ganglia (pre-brain)
--THREE cell layers + a body CAVITY
--excretory cells called NEPHRIDIA (kidney)
*discovered in deep sea “rift”
--(pseudo)HEARTs + blood vessels
zones, Riftia exist by CHEMO100% Sexual Reproduction (hermaphrodites)
rather than PHOTO-SYNTHESIS Respire through (moist) skin