invertebrates are animals that have no backbone, or vertebral column. invertebrates make up over...
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Invertebrates are animals that have no backbone, or vertebral column.
Invertebrates make up over 95% of all animal species.
They include sea stars, worms, jellyfishes, and insects.
What Is an Invertebrate?
What is a Sponge? Sponges are the simplest and most
ancient animals in the phylum Porifera which means
“pore-bearers.” live their entire adult life as sessile
organisms; attached to a single spot.
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What is a Sponge?
◦Body Plan Sponges are asymmetrical;
they have no front or back ends, no left or right sides.
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Form and Function in Sponges
◦Feeding Sponges are filter feeders. As water moves through the sponge,
food particles are trapped and engulfed by choanocytes that line the body cavity.
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Form and Function in Sponges
◦Circulation Sponges rely on movement of water
through their bodies to carry out body functions.
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Form and Function in Sponges
What is a Cnidarian? Cnidarians are soft-bodied, carnivorous animals that have stinging tentacles arranged in circles around their mouths.
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What is a Cnidarian?
Body symmetry ◦Cnidarians are radially symmetrical. They
have a central mouth surrounded by numerous tentacles that extend outward from the body.
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Form and Function in Cnidarians
◦Feeding A cnidarian pulls its food through its
mouth and into its gastrovascular cavity, a digestive chamber with one opening.
Food enters and wastes leave the body through that same opening.
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Form and Function in Cnidarians
◦Circulation Following digestion, nutrients are
usually transported throughout the body by diffusion.
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Form and Function in Cnidarians
copyright cmassengale 23
• Colonial Hydrozoan (not a single organism
• Tentacles sting prey such as fish & humans
• Polyps in colony feed
• Has gas-filled air float
Portuguese man-of-war
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Flatworms are acoelomates, which means they have no coelom.
A coelom is a fluid-filled body cavity that is lined with tissue derived from mesoderm.
The digestive cavity is the only body cavity in a flatworm.
Flatworms have bilateral symmetry.
What Is a Flatworm?
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◦Feeding Flatworms have a digestive cavity with
a single opening through which both food and wastes pass.
Near the mouth is a muscular tube called a pharynx.
Flatworms extend the pharynx out of the mouth. The pharynx then pumps food into the digestive cavity.
Form and Function in Flatworms
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◦Circulation Flatworms do not need a circulatory
system to transport materials they rely on diffusion
Form and Function in Flatworms
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◦Roundworms are unsegmented worms that have pseudocoeloms and digestive systems with two openings—a mouth and an anus.
◦Roundworms have bilateral symmetry.
What Is a Roundworm?
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◦Feeding Many free-living roundworms use
grasping mouthparts and spines to catch and eat other small animals.
There are a variety of parasitic roundworms as well
Form and Function in Roundworms
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◦Circulation They depend on diffusion to carry nutrients
and waste through their bodies.
Form and Function in Roundworms
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What Is an Annelid?
◦Annelids are worms with segmented bodies. They have a true coelom that is lined with tissue derived from mesoderm.
◦Annelids have bilateral symmetry.
What Is an Annelid?
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◦Feeding and Digestion In carnivorous species, the pharynx
usually holds two or more sharp jaws that are used to attack prey.
Annelids that feed on decaying vegetation have a pharynx covered with sticky mucus.
Other annelids obtain nutrients by filter feeding.
Form and Function in Annelids
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◦Circulation Annelids typically have a closed
circulatory system, in which blood is contained within a network of blood vessels.
Form and Function in Annelids