Kingdom Animalia – Nematoda

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Kingdom Animalia Nematoda
Phylum nematoda round worms (50,000 species,
or more?) general characteristics
Very, very, very, very, very, very, common!!!
One study found 90,000 nematordes in a single
rotting apple. Maybe well check this one out for
ourselves in next weeks lab !!
Another study found 236 different species in
about 6.7 cc of coastal mud!!
Triploblastic, bilateral, vermiform,
un-segmented, pseudocoelomates
Body round in cross section and covered by a
layered cuticle growth in juveniles usually
accompanied by molting
Have complete gut
Have no specialized circulatory or gas exchange
structures, and only longitudinal muscles. Why do
you think they need a substrate to live in?
Can be free-living or parasitic
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Kingdom Animalia Nematoda
Parasitic example Heart worms cool eh?
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Kingdom Animalia Nematoda
Whereas cnidarians and platyhelminthes did not
have a body cavity (coelom), nematodes do. It is
however a pseudocoelom. All the other animals
that we discuss from now on will have true coelom
(including us!). What is the advantage of having
a coelom?
Note that in this picture, blue represents
ectoderm, yellow represents endoderm, and red
represents mesoderm. Green is the mesoglea which
is not a true tissue
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Kingdom Animalia Phylum Annelida
Phylum Annelida segmented worms (12,000
species) - general characteristics
Bilaterally symmetrical, segmented worms with a
true coelom
Digestive tract complete, usually with regional
specializaiton
Closed circulatory system
Nervous system well developed
Marine, terrestrial, and freshwater species exist
Include earthworms, marine polychaetes, and
leaches
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Kingdom Animalia
Evolution of the coelom (body cavity)
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Kingdom Animalia Phylum Annelida
Generally speaking, annelids are a very diverse
group, particularly the marine polychaetes which
may have highly developed appendages.
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Kingdom Animalia Annelid Classification
Class Polychaeta include most of the marine and
freshwater annelids these worms are often
very well developed, having specialized
appendages for feeding and/or swimming called
setae or parapodia
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Kingdom Animalia Annelid Classification
Class Oligochaeta earthworms and other similar
freshwater annelids. have no setae or
parapodia
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Kingdom Animalia Annelid Classification
Class Hirudinida leeches complex reproductive
systems, hermaphroditic, most most are
freshwater or marine (a few are
semi-terrestrial). Ectoparasitic, they can
be predaceous or scavenging
These animals have specialized suckers to help
them attach to their prey They also produce
anesthetics and anticoagulation chemicals Why
do you think this is?
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Time for a cool animal!! Phylum Tardigrada
Phylum Trdigrada (water bears) 400 500
species
Free living or symbiotic, they are found all over
Tardigrades are known for their Anabiosis state
of greatly recuced metabolic activity
during unfavorable conditions and Cryptobiosis
an extreme state of anabiosis or dormancy
where all external sings of metabolic activity
are missing!!
How tough are they? check it out
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Kingdom Animalia Phylum Tardigrada
Tartigrades have recovered from immersion in
extremely toxic compounds such as brine, ether,
absolute alcohol, and even liquid helium!!
They have survived temperature ranging from 149
C to 272 C (almost at absolute zero!!)
They have also survived high vacuums, intense
ionizing radiation, and long periods with no
environmental oxygen.
Former Soviet zoologists claim that tardigrades
survived experiments in outer space!!
In one case, a 120 year old dried moss specimen
from a museum was accidentally moistened, yieldin
g living tardigrades!!! .. You get the picture.
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Kingdom Animalia Phylum Mullusca
Phylum Mullusca snails, slugs, clams, oysters,
squids, octopus, etc. (gt 50,000 species maybe
up to 100,000??) General characteristics
Bilaterally symmetrical (or secondarily
asymmetrical), coelomate
Well developed organ systems
Have mantle with shell glands that secrete
calcareous epidermal spicules, shell plates, or
shells
Have large, well defined muscular foot, often
with a flattened creeping sole, (in squids and
octopus, the foot is modified into tentacles /
arms.
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Kingdom Animalia Phylum Mullusca
Generalized mulluscan body
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Kingdom Animalia Mullusc Diversity
Class Gastropoda slugs, snails, and nudibranchs
Not all gastropods have shell (blue). There is a
high level of variation amongst different shells
why do you think this is? How do you think
nudibranchs that do not have any Shells defend
themselves?
Most gastropods have a large, fleshy foot which
is used for locomoation (green)
Most gastropods have a unique file-like mouth
part called the radula (orange). Herbivorous
forms use it for grazing, carnivorous forms have
modified it into a drill, or a harpoon that can
inject toxins into their prey.
Most gastropods have gills for gas exchange.
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Kingdom Animalia Mullusc Diversity - Gastropods
Snail What do you think is the function of this
shell?
Nudibranch How do you think this animal defends
itself?
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Kingdom Animalia Mullusc Diversity Class
Polyplacophora - chitons
Chitons also have a large foot (green) that is
used for locomotion and clamping down on rocks
gills (yellow) for gas exchange a shell made up
of 7 or 8 individual plates (blue) and a radula
(orange) specialized for grazing on algae and
some encrusting invertebrates.
What do you think is the advantage of having
multiple (7 or 8) shell plates?
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Kingdom Animalia Mullusc DiversityClass Bivlavia
Bivalves have two shells, hinged along One edge,
with the animal in between (blue).
Most bivalves use their gills (yellow) for
both gas exchange, as well as for food capture.
How do you think this may work?
The foot (green) of some bivalves is
reduced, While in others, it is specialized for
digging.
Here is a picture of a clam. Bivalves also
include mussels, oysters, and scallops.
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Kingdom Animalia Mullusc DiversityClass
Cephalopoda
Cephalopods octopus, squids, nautilus, and
cuttlefish
Cephalopods have generally modified their foot
(green) into tentacles (arms) that allow them to
manipulate potential prey items, as well as
to move around their environments
Their shells (blue) can be complete and
external (nautilus), reduced and internal
(squid), or completely non-existent (octopus).
What is the advantage of each?
Most cephalopods use gills (yellow) for gas
exchange, and have a specialized beak (orange)
for tearing food particles.
Finally, most cephalopods use jet propulsion for
movement and swimming and they seem to be very
good at solving problems