Download MOLLUSKS

MOLLUSKS
MOLLUSKS
Many use a soft muscular
“foot” for movement
Feed by scraping, tearing,
stabbing and cutting their food
Open circulatory system
(except cephalopods)
Some with complex, extremely
acute and sensitive eyes
Visceral mass – holds most
internal organs
Have a soft mantle that produces a
hard shell
Cephalopods
Have foot attached to their heads
Examples: squid, octopus, nautilus
and cuttle fish
Some have a radula, a tongue-like
organ that protrudes from the mouth
Some have a radula, a tongue-like
organ that protrudes from the mouth
Have a siphon that helps them move
swiftly
Gastropods
Means “stomach footed”
Muscular foot comes out of the
stomach region
Undergo torsion- the visceral mass
turns 180 degrees
Have eyes on stalks
Have a radula
Snails and slugs and conch
Single shelled
Bivalves
Have hinged- two piece shell
Name means “soft body”
Clams, oysters, and scallops
Use a siphons to suck the water to et
their food
ECHINODERMS
Examples: sea star, sea urchins, sand
dollars
All have radial symmetry: appendages
radiate around a central point
Eat by throwing their stomach onto
their food
All have a water vascular system
Move themselves around the ocean
floor by using tube feet
ARTHROPODS
All have jointed appendages (means
jointed foot)
Evolved from Annelids
All have bilateral symmetry
All have an exoskeleton
Exoskeleton is made of chitin – a type
of polysaccharide layered with proteins
All molt – shed skin to allow for growth
All have three body segments, a head,
a thorax and an abdomen (head and
thorax may be fused)
Have an open circulatory system
Word means spiny skin
5 classes
5 classes
6 pair of appendages (legs) on the
thorax
Largest class of animals in the world
(10 million species or more)
most have three body segments, a
head, thorax and abdomen
many communicate by using chemical
signals called pheromones
most have 3 simple eyes(ocelli)
between two compound eyes
most breathe through spiracles on the
thorax, little holes along the critters
side
many undergo incomplete
metamorphosis, changing from and
egg, to nymph to an adult
Some: complete metamorphosis: egg,
larvae, pupa to adult
Due to their ability to either fly or
camouflage, or mimic their
environment, these have
survived for millennium.
Without the critters in this class, most
crops could not be pollinated
Often regarded as pests because
some bite, sting, spread diseases or
compete with
humans for crop plants
Crustaceans
These critters all have a cephalothorax
(head attached to body)
These critters all have a cephalothorax
(head attached to body)
Examples are: crayfish, shrimp,
lobster, crabs
These critters have a special
appendage used for swimming called
swimmerets
Their hard outer shell is called the
carapace that protects gills and other
organs
Have an organ called a green gland:
regulates amount of salt and liquid in
blood
All have 5 pairs of appendages
Most live in aquatic habitates
Breathe through gills
Mostly scavengers
2 pair of antennae
Arachnids
All have 4 pairs of segmented legs
All have 2 pairs of mouthparts
One pair of mouth parts are fangs
used to bite prey
One pair of mouth parts are called
pedipalps used to hold and “chew”
food
Breathe using book lungs
Examples: spiders, scorpions and
mites
Horseshoe crabs are more related to
these than to crustaceans
Produce a strong elastic silk from
spinerettes to capture their prey
Have a cephalothorax (head
connected to thorax)
Only have simple eyes
Most are poison to their prey
Enzymes dissolve food, then it is
“sucked” up.
Millipedes
Have 2 pairs of legs per body segment
Body has many ( 100”s) of segments
Generally not poisonous to humans
Name means 1000 feet
Spit: hydrogen cyanide acid at prey
Centipedes
Have one pair of appendages on each
body segment
Have large poisonous fangs on their
first appendages
Name means 100 feet
Have longer antennae than other
animals in same class
Usually are carnivorous, eating other
arthropods
Antennae are sensory organ – touch
and smell
MOLLUSKS
Have a soft mantle that produces a hard shell
Many use a soft muscular “foot” for movement
Feed by scraping, tearing, stabbing and cutting their food
Open circulatory system (except cephalopods)
Some with complex, extremely acute and sensitive eyes
Name means “soft body”
Visceral mass – holds most internal organs
Cephalopods
Have foot attached to their heads
Examples: squid, octopus, nautilus and cuttle fish
Some have a radula, a tongue-like organ that protrudes from the mouth
Many have protective “ink”
Have a siphon that helps them move swiftly
Gastropods
Means “stomach footed”
Muscular foot comes out of the stomach region
Undergo torsion- the visceral mass turns 180 degrees
Have eyes on stalks
Have a radula
Snails and slugs and conch
Single shelled
Bivalves
Have hinged- two piece shell
Clams, oysters, and scallops
Use a siphons to suck the water to et their food
ECHINODERMS
Word means spiny skin
Examples: sea star, sea urchins, sand dollars
All have radial symmetry: appendages radiate around a central point
Eat by throwing their stomach onto their food
All have a water vascular system
Move themselves around the ocean floor by using tube feet
ARTHROPODS
All have jointed appendages (means jointed foot)
Evolved from Annelids
All have bilateral symmetry
All have an exoskeleton
Exoskeleton is made of chitin – a type of polysaccharide layered with proteins
All molt – shed skin to allow for growth
All have three body segments, a head, a thorax and an abdomen (head and thorax may be
fused)
Have an open circulatory system
5 classes
Insects
6 pair of appendages (legs) on the thorax
largest class of animals in the world (10 million species or more)
most have three body segments, a head, thorax and abdomen
many communicate by using chemical signals called pheromones
most have 3 simple eyes(ocelli) between two compound eyes
most breathe through spiracles on the thorax, little holes along the critters side
many undergo incomplete metamorphosis, changing from and egg, to nymph to an adult
Some: complete metamorphosis: egg, larvae, pupa to adult
Due to their ability to either fly or camouflage, or mimic their environment, these have
survived for millennium.
Without the critters in this class, most crops could not be pollinated
Often regarded as pests because some bite, sting, spread diseases or compete with
humans for crop plants
Crustaceans
These critters all have a cephalothorax (head attached to body)
Examples are: crayfish, shrimp, lobster, crabs
These critters have a special appendage used for swimming called swimmerets
Their hard outer shell is called the carapace that protects gills and other organs
Have an organ called a green gland: regulates amount of salt and liquid in blood
All have 5 pairs of appendages
Most live in aquatic habitats
Breathe through gills
Mostly scavengers
2 pair of antennae
Telson-tail
Arachnids
All have 4 pairs of segmented legs
All have 2 pairs of mouthparts
One pair of mouth parts are fangs used to bite prey
One pair of mouth parts are called pedipalps used to hole and “chew” food
Breath using book lungs
Examples: spiders, scorpions and mites
Horseshoe crabs are more related to these than to crustaceans
Malpigian tubules for kidneys
Produce a strong elastic silk from spinerettes to capture their prey
Have a cephalothorax (head connected to thorax)
Only have simple eyes
Most are poison to their prey
Enzymes dissolve food, then it is “sucked” up
Millipedes
Have 2 pairs of legs per body segment
Body has many (100’s) of segments
Generally not poisonous to humans
Name means 1000 feet
Spit: hydrogen cyanide acid at prey
Centipedes
Have one pair of appendages on each body segment
Have large poisonous fangs on their first appendages
Name means 100 feet
Have longer antennae than other animas in the same class
Usually are carnivorous, eating other arthropods
Have poison claw
Eat snails, slugs and worms
Antennae are sensory organ- touch and smell
Have poison claw
Eat snails, slugs & worms