ANIMAL KINGDOM CONTINUED Flatworms (Platyhelminthes)

Includes Planaria, tapeworms, flukesBilaterally symmetricalThree embryonic tissues = endoderm, mesoderm, and ectodermNo body cavity, mesoderm muscle inside Blind digestive track shown hereMost are parasitic and are economically important

FLATWORMS AND CNIDARIANS DIFFER IN SYMMETRY, WITH FLAT WORMS BEING ___________ AND CNIDARIANS BEING __________.

a) Radial, asymmetricalb) Radial, bilateralc) Bilateral, radiald) Asymmetrical, bilateral

FLATWORM - TAPEWORM Parasitic – 2 hosts Whitish in color Absorbs nutrients

through outer body wall

Each reproductive unit can have 100,000 eggs inside

Humans can get by eating under cooked meat

Partial or Pseudocoelom

True Coelom

ROUND WORMS (NEMATODA)

Very common – 99% of us have been hosts to some sort of round worm in our life time

Bilateral, 3 tissues Body cavity

between mesoderm & endoderm

In soil, vinegar (eels), rotting fruits & veggies, parasitic

Complete digestive track

Muscles along body wall (from mesoderm) allow for whole body movement back and forth

Range in size -1 mm to > 1 m

Body is covered by a cuticle that keeps it from desiccating

SEGMENTED WORMS - ANNELIDS

Earthworms, leeches, various marine polychaetes such as fire worm

3 tissues, true body cavity or coelom Body is segmented into repeating units,

which enable the animals to move by stretching and contracting segments

Complete digestive system, brain and nerve chord, circulatory system has 5 pumping tube rings

Polychaetes have a pair of fleshy appendages per segment

Annelid variety – parasites, filter feeders, and taking organic material from soil

MOLLUSCA

Snails, slugs, clams, scallops, oysters, octopus, squid, cuttlefish, etc. Good eating! Bilateral symmetry, 3 true tissues True coelom – totally surrounded by muscle

(mesoderm); internal organs have muscles like gut and circulatory system as well as outer body wall – complete digestive track

Body = head and foot Some of the most intelligent invertebrates

True body cavity or coelom – muscle surrounds gut, blood vessels, etc.

Brain, nerves and sensory organs

Snails – hermaphrodites – both are male to each other’s female organs when 2 mate

Terrestrial snails and slugs use mucus secretions to keep body surface moist

SOME ARE HIGHLY INTELLIGENT http://www.youtube.com/watch?feature

=player_detailpage&v=GQwJXvlTWDw

MATCH PICTURE TO GROUP

A. Nematode

B. Flatworm - Platyhelminthes

C. Cnidaria

D. Sponge - Porifera

1

2

3 4

WONDERFUL DIVERSITY IN THIS GROUP

ARTHROPODS CON’T Very large group – about ¾ of all known species 3 tissues, true body cavity or coelom Brain and ventral nerve cord tube body is consolidated into different body

regions, such as head, thorax and abdomen of insect

Appendages have become modified in different ways during course of evolution

1st 5 – head & mouthparts, next 3 thorax & legs,

last segments – abdomen, ovipositor, penis

Economically important groupDisease transmission in human, pet, livestock, cropPredators – lower pest populationsConsume our crops, but also pollinate cropsSource of food for many

Unique level of social organization in some

HONEYBEES Live in groups or

colonies Queen plus her

daughters Cells contain

stored pollen and nectar and brood

Trophallaxis and communication

Colony cycle

ECHINODERMS CON’T

3 tissues, true coelom Their embryological development sets

them apart from the other invertebrates.They develop backwards orientation from other

invertebrates – similar to vertebrate animalsSo this makes them the most similar to vertebrate animals

MATCH PICTURE TO GROUP

A. Nematode

B. Annelida – Segmented worm

C. Echinodermata

D. Sponge - Porifera

1

2

43

WHICH EMBRYONIC LAYER CREATES THE BODY CAVITY OR TRUE COELOM?

a) Mesodermb) Ectodermc) Endoderm

Tunicates

Review

Two tissues, no coelom

no coelom

partial coelom

true coelom

true coelom

3 tissues