Transcript Kingdom Animalia III - Valhalla High School

Kingdom Animalia III
Bugs, Slugs and Sea stars.
Phyla Arthropoda, Mollusca &
Echinodermata
The arthropods: The joint
legged animals.
 Of all the Kingdom Animalia, the phylum
arthropoda contains by far the greatest number of
species.
 The insects alone number over 1,000,000
identified species, more than all other animal
phyla combined.
 The beetles are the most diverse family of
organisms on earth.
Arthropod characteristics
 All arthropods have a hard outer covering called
an exoskeleton, composed of chitin.
 Specialized mouth parts
 Jointed legs
 Compound eyes
 Segmented body
 Bilateral symmetry
Metamorphosis in arthopods
 All members of the phyla arthopoda go through
some sort of metamorphosis between juvenile and
adult forms.
 A useful adaptation since this allows the juveniles
and adults to exploit 2 different resources.
 Eg. Caterpillars and butterflies.
 Caterpillars eat plant materials and butterflies feed
on nectar.
Arthropod classes
There are several important classes within the phylum
arthropoda
Crustaceans: this class consists of lobsters, crabs and
shrimp. Most have 5 pairs of legs and are called
“decapods”. Deca=10, pods=feet. Most live in water.
Arachnids: this class consists of spiders, scorpions,
sulifugae, ticks and mites. Most have 8 legs.
Insecta: the largest class. Insects have three body
segments, jaws, and six legs. The Beetles are the largest
family in this class. No insects live in salt water.
Arthropods
Phylum Mollusca
 Molluscs are muscular softbodies invertebrates.
 Most live in the oceans, but
slugs and some snails are
terrestrial.
 Some possess a hard shell to
protect their soft bodies.
Mollusca classes
 We will look at three classes
within this phylum.
 The gastropods: These are
the snails and the slugs.
 Snails have shells, slugs do
not.
 There are terrestrial,
freshwater and marine
gastropods.
Gastropod information
 Gastropods are the most
numerous of all mollusca
types. 80% of all molluscs
are gastropods.
 Some are grazers, some are
scavengers and others are
active predators.
 Gastropods reproduce
sexually, with many species
being hermaphroditic.
The bivalves
 Bivalves are molluscs
whose bodies are
protected by a strong,
hinged shell.
 Clams, mussels and
oysters are all members of
this class.
 They are an important
source of food for humans
and other animals.
Bivalve information
 Bivalves are found in both fresh and salt water,
but not on land.
 Bivalves are filter feeders who siphon water into
their gills and filter out nutrients.
 Bivalves reproduce sexually as males and females
release their gametes (sex cells) into the
surrounding water.
 Larval bivalves are swimmers which eventually
settle down and develop their shells.
The Cephalopods
 The final class of Mollusca we will consider
are the cephalopods.
 The cephalopods are the octopi, the squid
and the nautiloids.
 This class represents the most advanced
molluscs as well as the most intelligent of
all invertebrates.
Cephalopod information.
 Most cephalopods possess 8 tentacles which they
use to help capture their prey.
 All cephalopods are predators.
 Nautiloids are the only cephalopods that retain a
shell.
 Both octopi and squid are masters are camoflage.
Octopi use it to blend into their surroundings
while squid often use rapid color changes to
communicate with other members of their species.
More cephalopod information
 Cephalopods reproduce sexually with
internal fertilization.
 The male passes to the female a “sperm
packet” which the female uses for internal
fertilization.
 The female then lays eggs, sometimes
numbering in the thousands.
Cephalopods
Phylum Echinodermata
 These are referred to as the tube footed animals.
 Of all the invertebrate phyla, it is the echinoderms
that are most closely related to the chordates.
 Internally they all have a system of hydrolic tubes
which aid in their locomotion.
 Sea stars, sea urchins and sea cucumbers are all
examples of echinoderms.
Echinoderm information
 Echinoderms reproduce sexually with
external fertilization which produces a free
swimming larva.
 Many echinoderms, such as sea stars are
able to also reproduce asexually through
regeneration.
 Echinoderms may be scavengers, filter
feeders of plankton, or active predators.
Echinoderms