Transcript INVERTEBRATES - WordPress.com

Contents organized by F.J. Barba Regidor. Images from various online sources (2011)
PORIFERA
-Aquatic animals.
-They have not tissues.
-They are shaped bag with the mouth
upward.
-The wall of their bodies is perforated by
pores.
- They are filtering animals.
-Water and food enter through the pores.
Waste (water) are expelled through the
mouth of the sac (osculum).
-They live attached to the foor of the see.
CNIDARIA
MAIN CHARACTERISTICS:
1. As animals they are, they have eukaryotic cells and they
are multicellular and heterotrophs.
2. Invertebrates do not have a backbone.
3. Invertebrates do not have a cranium.
ANNELIDS
-Aquatic animals.
-They present two basic forms: polyp and
medusae (jelly fish).
-They are shaped bag with the mouth
upward (polyps) or downward (medusae:
umbrella shape).
-They have a mouth and a central cavity
called the gastrovascular cavity.
- They are carnivores: to catch their prey,
they use numerous tentacles around its
mouth.
-They live attached to the foor of the see.
-Terrestrial or aquatic animals.
-Long, cylindrical and soft body
that is divided into rings.
-Each segment (ring) is similar
to the others and has the same
organs.
-No legs, but with chetae: tiny
and not articulated appendages
to move.
-They breathe through gills or
through the skin.
NEMATODES
-Soft, cylindrical bodies without
segments.
-No respiratory system.
-Male and female specimens.
-Parasites… or not.
PLATYHELMINTHES
-Symmetry: bilateral. Body
usually flattened
dorsoventrally and divided
into rings.
-Digestive system incomplete
(a mouth but no anus).
-No skeletal, ciculatory or
respiratory systems.
-The nervous system is a pair
of anterior ganglia connected
to longitudinal nerve chords.
-Hermaphrodites. The y can
fertilise themselves.
-Parasites.
ECHINODERMS
-Marine invertebrates, with an external hard skeleton,
generally with spines.
-Radial symmetry in adults (bilateral in larvae)
-Ambulacral system.
-Male and female specimens.
-No head, but there is a mouth on the underside.
GASTROPODS
-Terrestrial or aquatic animals with a
spiral shell.
-On their head there are four
tentacles.
-They have at the mouth a rasping
tongue (the radula).
-Aquatic gastropods breathe through
gills and terrestrial s do it through
lungs.
BIVALVES
MOLLUSCS:
1. Aquatic and terrestrial animals with bilateral
symmetry.
2. Soft body with three different parts: head, visceral
mass (this produces a protective shell) and muscular
foot.
3. Terrestrial molluscs breathe through lungs but aquatic
molluscs breathe through gills.
CEPHALOPODS
-Aquatic animals with a differentiated head from the
rest of their body.
-The foot surrounds the head and has the shape of
tentacles for capturing prey.
-The mantle has mobile fins for swimming..
- They are carnivorous.
-Aquatic animals.
-They have two shells, joined like a hinge.
-Their head is not differentiated from the
rest of the body.
-Their single foot has the shape of an axe
that they use to excavate.
-Most of them are filter-feeding
organisms.
INSECTS
-Most of them are terrestrial.
-Their body is divided into head,
thorax and abdomen.
-The head has two antennae.
-The thorax has six legs (three pairs).
-Many species presents four wings:
they are the only invertebrates that
can fly.
-They breathe through tracheae.
-Some of them can be carnivorous,
but many others are herbivorous.
CRUSTACEANS
ARTHROPODS:
1. Terrestrial and aquatic animals which body is divided into
assembled segments in different ways: head, thorax and
abdomen; cephalothorax and abdomen..
2. Hard articulated appendages appear from the segments in
different forms: legs, antennae, chelicerae or palps.
3. The body presents bilateral symmetry and is covered by a
thick cuticle that acts as an external skeleton..
4. They are oviparous. Fertilization is internal. Many of them
undergo metamorphosis.
CHELICERATES
Clockwise from top left: dancefly (Empis livida),
long-nosed weevil (Rhinotia hemistictus), mole
cricket (Gryllotalpa brachyptera), German wasp
(Vespula germanica), emperor gum moth
(Opodiphthera eucalypti), assassin bug
(Harpactorinae)
-Terrestrial animals which body is
divided into cephalothorax and
abdomen.
-They present mouth appendages
called chellicerae, connected to
glands that can produce venom.
-The number of legs is 8 (4 pairs).
-They breathe through tracheae.
- They are carnivorous.
-Aquatic animals: they breath through
gills.
-Their body is divided into cephalothorax
and abdomen.
-They usually have ten legs (5 pairs).
-Their body is covered by a calcareous and
hard cuticle.
MYRIAPODS
-Terrestrial animals which body is
worm-like and it is formed by a head
and numerous rings, each with a pair
of locomotor appendages (legs).
-The number of legs is greater than 10.
-They also present mouth appendages
called chellicerae.
-They are carnivorous.
-They breathe through tracheae.
Color electron micrograph scanning
of the head of a Jumping Spider
(familia Salticidae).
A color scanning electron micrograph of the
head of a human flea (Pulex irritans)
showing the mouth appendages to drill the
tissues to find the blood from which it feeds.
Color scanning electron microscope of a meal (or
flour) mites. He has long hair that extends down
her body and her large legs. This species is a
common pest of granaries, mills and kitchens, and
feed mainly on cereal grains.
Pictures from http://www.logalia.net/Fotograf%C3%ADa-miniaturarecomendado_330905.aspx
Color scanning electron
microscope of a housefly
(Musca domestica). The head
is dominated by a pair of large
compound eyes, each eye is
composed of about 4000
facets called ommatidia, which
form the image. The
mouthparts are visible
between and below the eyes.
The hairs on the head and
body act as tactile organs.
House flies tend to feed on
decaying matter, and can
collect and transmit serious
diseases to humans.
Color electron micrograph scanning of the
head of a wasp (order Hymenoptera)
showing the compound eyes (red), the
antennae and the chelicerae.