Chapter 28: Invertebrates

What percentage of Kingdom Animalia are invertebrates?

97%

Invertebrates lack a ____ and _____

Backbone; cranium

Where do invertebrates live?

Land, freshwater, oceans

Name Eight Invertebrate Phyla

Porifera, Cnidaria, Platyhelminthes, Mollusca, Annelida, Nematoda, Arthropoda, Echinodermata

Most invertebrate Kingdom Animalia species are…

Arthropoda

What do porifera lack?

True gastrula, endoderm, ectoderm

Since porifera lack endoderm and ectoderm layers, what does this imply?

Cannot be diploblastic or triploblastic

What do porifera use instead of true tissues?

Specialized cells who perform said functions

While Porifera larvae are ____ and swim, they settle on a ___ and grow into an adult

Flagellated; substrate

Adult porifera are

Sessile

How do porifera obtain nutrients and oxygen?

Water (Filter feeders)

What is the porifera body plan?

Asymmetrical

What shape are sponges?

Cylindrical

(Porifera) How does water flow into spongocoel?

Using pores named ostia (tio)

How can spongocoel have direction of water flow?

Choanocyte cells line spongocoel —- contain flagellum

How is water expelled in porifera?

Through a large opening at the top (osculum)

What bodily systems do Porifera lack?

Digestive, nervous, respiratory and circulatory

How is food digested in porifera?

Absorbed by cells in spongocoel (intracellularly)

How does gas exchange occur in Porifera?

Diffusion

What kind of reproduction do Porifera have?

Sexual and asexual reproduction

What is the Cnidaria body plan?

Radial symmetry

What kind of tissue do Cnidaria have?

Diploblastic (ectoderm & endoderm)

Cnidaria have an ___ digestive system

Incomplete

In Cnidaria, what does it mean to have an incomplete digestive system?

Food enters and waste leaves in the same opening

Most Cnidaria are what kind of organisms?

Marine

What is the defining character for Cnidaria?

Cnidocyte (stinging cell)

Where is the Cnidocyte located?

Tentacles & around mouth

What are the organelles that sting in Cnidocytes?

Nematocysts

What are the two body types for Cnidaria?

Polyp and Medusa

Polyp species are ___ as adults

Sessile

Medusa species are ___

Motile

In Cnidaria, how is the epidermis obtained?

From ectoderm tissue

In Cnidaria, how is the gastrodermis obtained?

Derived from endoderm tissue

___=___ ____ tissue are found between Gastrodermis and endoderm

Non-living mesoglea

What are the organ systems in Cnidaria?

No true organ systems (only specialized, differentiated tissue cells)

How does movement occur in Cnidaria?

Using contractile epithelial cells

Cnidaria have __ nervous system

No

Instead of a nervous system, what do Cnidaria have?

Network of nerve cells throughout body

(Cnidaria) How many openings does the gastrovascular cavity have?

One opening; both mouth and anus

Cnidaria have a(n) ___ digestive system

Incomplete

How does digestion begin in Cnidaria?

Extracellularly

How are nutrients distributed in Cnidaria?

Through the mesoglea

How is oxygen absorbed and carbon dioxide released in Cnidaria?

Using cells in the gastrovascular cavity

What are the four Cnidarian classes?

Anthozoa, Scyphozoa, Cubozoa, Hydrozoa

Which Cnidarian class is the only sessile polyp species?

Class Anthozoa

What are examples of Anthozoa?

Coral, sea fans, sea anemones

What are all the Cnidarian classes that are medusa species?

Scyphozoa, Cubozoa and Hydrozoa

What is an example of Scyphozoa?

Jelly fish

What is an example of Cubozoa?

Box Jellies

What Cnidarian class is BOTH polyps and medusa species?

Hydrozoa

What are examples of Hydrozoa?

Hydra, Portuguese man o’ war

What is the difference between open circulatory system and closed circulatory system?

In open, blood isn’t fully contained within vessels while in closed, blood is fully contained within vessels

In ___ circulatory system blood mixes with interstitial fluid

Open

What is interstitial fluid called?

Hemolymph

Hemolymph is pumped from the ____ vessel into the body cavity

Dorsal

How is hemolymph returned to the heart?

Through the ostia in dorsal vessel

Open circulatory systems are found in ___ ____

Some invertebrates

Closed circulatory systems are found in….

Few invertebrates and all vertebrates

Blood is pumped out to the body through what system?

Arteries

How is blood returned to the heart?

Veins

What are capillaries?

Connection between arteries and veins

What is the body plan for platyhelminthes?

Bilateral

What tissues do Platyhelminthes have?

Triploblastic; acoelomate

Are Platyhelminthes protostomes or deuterostomes?

Protosomes

What kind of digestive system do Platyhelminthes have?

Incomplete

Do Platyhelminthes have cephalization?

Yes, simple cephalization

Can Platyhelminthes be free living or parasitic?

Yes, they can be both

What are free-living Platyhelminthes?

Predators/scavengers

What is the Platyhelminth excretory system like?

Network of tubules running along the periphery of the animal

What do Platyhelminth flame cells have to propel waste?

Cilia

What is the Platyhelminth nervous system like?

Two nerve cords running the length of the body

What are the two nerve cords Platyhelminthes have?

Cerebral ganglia

What does cerebral ganglia help with?

Sensing light and chemicals

What systems do Platyhelminthes lack?

Circulatory and respiratory

How is respiration achieved in Platyhelminthes?

Gas is exchanged through epidermis

How can nutrients be distributed in Platyhelminthes?

Through gap junctions

Are Platyhelminthes monoecious or diecious?

Monoecious

Platyhelminth fertilization is…

Internal

What is the second greatest number of species?

Mollusca

What is the Mollusca body plan?

Bilateral w/ cephalization

What tissue do Mollusca have?

Triploblastic; eucoelomate

Are Mollusca protostomes or deuteristomes?

Protostomes

What kind of digestive system do Mollusca have?

Complete

How do Mollusca do locomotion?

Using a muscular foot

What do all Mollusca have?

Muscular foot, visceral mass, mantel overlying the visceral mass

What does the mantle produce in Mollusca?

Calcium carbonate shell

In Mollusca, the shell is ___ in species like squid and octopus

Reduced

What’s the Mollusca respiratory system in aquatic species and terrestrial species?

Gills; Mantle

What systems vary in Mollusca?

Circulatory and nervous

What are the three classes to Mollusca?

Bivalvia, Gastropoda, and Cephalopoda

Bivalvia are what phylum’s class?

Mollusca

Bivalvia are what kind of species?

Marine and freshwater

Bivalvia’s body is enclosed in a ___-___ shell

Two-part

Adductor muscles ___ while Abductor muscles ___

Close; open

Do Bivalvia have cephalization?

No

How do Bivalvia respirate?

Gills

Bivalvia have what kind of circulatory system?

Open

How is metabolic waste excreted in Bivalvia?

By a pair of nephridia

How is reproduction like in Bivalvia?

Sexual with external fertilization, broadcast spawning, produce larvae

What are examples of Bivalvia?

Clams, mussels, oysters