1. Bio 2201
Invertebrates

2. The animal kingdom is divided into two main groups!
Vertebrates (have a backbone)
Invertebrates (lack a backbone)

3. Let’s take a closer look at the 8 invertebrate phyla
First, inverts are classified based on four (4) main characteristics:
1. Systems
2. Symmetry
3. Presence / absence of a coelom
4. Method of reproduction

4. Systems
For invertebrates the systems only refer to the digestive system, since no other systems are usually present.
There are two options: “one way with two openings” or “two ways with one opening”. This refers to nutrition (food) and waste.

5. Symmetry
-This is how we describe the “body plan” of an animal -Through use of an imaginary line we can divide the animal in half to determine symmetry.
There are three (3) types of symmetry: Asymmetrical Radial Bilateral

6. When an animal has bilateral symmetry the body can be divided into 5 regions:
Anterior: head region
Posterior: rear region
Dorsal: back region
Ventral: bottom region
Lateral: side region
The body symmetry of all animals is related to the necessity of them to move in order to obtain food. This is why most sensory organs are located at the anterior end of the animal (cephalization).

7. Presence or Absence of a Coelom
- This refers to an organism's “body cavity” - The coelom is filled with fluid and holds the digestive tract, as well as other organs, in place. - Not present in invertebrates (inverts) - Animals with a coelom are called coelomates. - Animals without coeloms are called acoelomates. - Some animals have a “partial” or very small coelom called a pseudocoelom.

9. There are three (3) reasons why body cavities are important:
1. Provide space for organs to be suspended and thus not be hurt by muscle pressure and body movement.
2. Provide space for internal organs to to develop and expand.
3. Contain fluids which may assist in transportation and gas/nutrient exchange.

10. Method of Reproduction
- Each invertebrate will be classified under each one of three (3) options: o asexual vs. sexual
o internal features vs. external features
o hermaphrodites vs. separate sexes
Hermaphrodite = an organism that contains both male and female reproductive organs.

11. There are 8 phyla of invertebrates we will cover in this course.
1. Porifera (sponges) think sponges have pores 2. Cnidarians (coelenterata) 3. Platyhelminthes (flat worms) plat = flat in French 4. Nematode (round worm) 5. Anelida (ring worms) 6. Mollusca 7. Arthropoda 8. Echinoderms

12. Time for...
ANOTHER TABLE!!!!

13. Porifera (Sponges) Asymmetric No coelom No digestion Reproduction:
Asexual
External Fertilization
Hermaphrodites
Example - Sponge

14. ENTRANCE (CHECK) Card:
Where do we find Sponges?
What is the Symmetry of a sponge?
Tell me three (3) things you learned in last class.
Take a peek at your notes if needed but try without first!

15. Cnidarians Radial symmetry No coelom Two way one opening digestion
Reproduction:
Asexual and sexual reproduction
External fertilization
Hermaphrodites and separate sexes
Examples: jellyfish, hydra and coral

16. Platyhelminthes (Flatworms)
Bilateral Symmetry
No coelom
Two way, one opening digestion
Reproduction:
Asexual and sexual
Internal fertilization
Hermaphrodites and separate sexes
Examples = planaria, tapeworm blood fluke
Extra:

17. Nematoda: roundworms Bilateral symmetry Coelom present
One way, two opening digestive system
Reproduction
Sexual
Internal fertilization
Separate sexes and a few hermaphrodites
Examples hookworm and pinworm

18. Annelida (ringworms) Bilateral symmetry Coelom present
One way two opening digestive system
Reproduction
Sexual
Internal fertilization
Hermaphrodites and separate sexes
Examples - earthworm, leech

19. Mollusca

20. Arthropods
- Means “jointed foot”. Arthropods have jointed appendages and hard exoskeleton - Includes Insects, Crustaceans, and Centipedes - They are bilaterally symmetrical organisms, with true coelom. - They have two body openings and one way complete digestive system. Food is digested extracellularly. - They reproduce sexually with species being either of separate sexes or some being hermaphrodites. Fertilization is internal. - Their nervous systems are advanced compared to other invertebrates with more advanced brain, ventral nerve cord and ganglia. Their sensory abilities are also advanced. Many have the ability to hear, taste, smell, touch, and see.

21. Arthropods
Excretory system made of Malpighian tubules and green glands o Malpighian tubules are a tubule network that collects liquid wastes and sends them to the hindgut in the form of nitrogenous wastes. Found in insects. o Green glands collect and excrete urine like kidneys. Found in crustacean like the crayfish

22. Echinoderms
- Means “spiny-skinned” - Includes Starfish, Sea Urchins, and Sea Cucumbers - They are radially symmetrical organisms True coelom - They have two body openings, a one way complete digestive system, and food is digested extracellularly. - They reproduce asexually via regeneration and sexual reproduction is only possible through separate sexes. Fertilization is external.

23. Can you place each of these animals into the appropriate taxa?

24. Notes 9: Arthropods have more combined species than all other phyla; there are trillions of different insects, but only 7 billion humans.
There are 4 reasons that contribute to arthropod success:
Exoskeleton
Different Body Segments
Body Systems
Diversity in Nourishment

25. Exoskeleton of Arthropods
This is composed mainly of chitin
Provides waterproof “armour”
Provides a site for muscle attachment
Sheds periodically so that juveniles may grow into adulthood

26. Body Segments of Arthropods
Allows specialized, distinct regions to be formed A. head - anterior
B. thorax - middle
C. abdomen - posterior
Jointed appendages can attach to these regions and work in sensory reception, eating, moving and reproduction.

27. Arthropod Body Systems
Digestive
Respiratory
Excretory (green glands and malpighian tubules)
Reproductive
Skeletal
Circulatory( open system)
Nervous system that is well developed with the following features: distinct brain, ventral (belly) nerve cord, sense organs such as eyes, auditory organs, sensory bristles, and antennae that touch and sense chemicals

28. Diversity in Nourishment of Arthropods
Most eat plants or plant material
Others eat animal tissues (such as blood) or full animals

29. The most successful class is class Insecta with 900,000 known species
The most successful class is class Insecta with 900,000 known species. • Nearly all are terrestrial with a few freshwater and saltwater forms • Size range is broad from 0.25 mm for some species of beetles and up to 30 cm for some tropical moths

30. The success of insects is credited to the following reasons:
They are the only invertebrates capable of flying. This allows them to move over great distances to find food, escape predators and spread to new environments.
There is tremendous variation in how they are adapted for feeding and reproduction. This allows insects to exist in all kinds of environments and to obtain nourishment from many sources
High rate of reproduction and short life cycle. This increases the ability of insects to adapt.
Small in size. This means that they do need large areas to live.
Adaptations to escape predators
Social Insects
Variations in body form

31. Modified Mouthparts of Insects
Sucking Mouthparts o Form a tube that can pierce tissues of plants and animals o i.e. Mosquitoes/Butterflies o Mandibles, maxillae, and parts of the pharynx are fused into a needle like structure
Sponging & Lapping Mouthparts o Labium has a modification at its apex o i.e. Fruit and House Flies o Have a pair of soft lobes that serve as food channels o Lap up food or liquefy with salivary secretions

32. Chewing Mouthparts o Mouthparts adapted for seizing, grasping, & crushing food o Adaptations for herbivores and carnivores o Strong mandibles, toothed plates o Enzymes are secreted from salivary glands that by way of chemical actions can liquefy food to aid in the chewing process

33. Social Behavior of Bees
“Societies” display caste differentiation; there is a clear cut division of labour
In such communities, all stages of their life cycles are present (i.e. Larvae, Pupae, and Adults)
Activities within these communities are collective, each individual works to benefit the community, they communicate with one another
Social Castes of Bees
l Queen - single sexually mature female
l Drone - sexually mature males that mate with the queen
l Workers - Sexually inactive females that care to the colony; they feed young, gather food, and care to the hive

34. Social Behavior of Bees
Castes (form of social stratification - like a hierarchy) are determined by fertilization and by what larvae are fed.
Drones develop parthenogenetically - From unfertilized eggs, they are haploid
Queens and workers develop from fertilized eggs, they are dipolid (full set of chromosomes)
Queens are fed a royal jelly produced by workers. Jelly contains enzymes that allow queen to mature sexually

37. Vertebrates! (HAVE A BACKBONE)
All members of Kingdom Animalia are not in the same phylum. (Notes 8 and Notes 9 explore different phyla)
Here we will look at one dominant phylum of Kingdom Animalia: Vertebrates
Before dividing the phylum into more specific, Classes, we should note there are three (3) common characteristics of phylum chordata. These three characteristics are distinguishing features.

38. Presence of a notochord
Rod or cartilage running along the dorsal end of the body.
Primitive backbone.
In some verts notochord is only found in embryo.

39. 2. Presence of a Dorsal hollow nerve cord
Nerves branch to all parts of the body

40. 3. Gill Slits found in the pharynx or throat
Sometimes only in the embryo

42. Vertebrates are a subphylum of Phylum Chordata Only 5% of chordates are not vertebrates They are called Tunicates. (They have no head or brain. See fig on page 191.)

43. Common Characteristics of Verts
Possess a backbone, which evolves from the notochord, and protects the nerve cord.
End of the cord develops into a brain. This process is called, cephalization .

44. 3. Body usually contains a head which contains the brain and most sense organs.
4. A tail is present at some point in development.

45. 5. Contains a jointed endoskeleton.
6. Two pairs of appendages (eg arms & legs).

46. 7. Hearts with 2 to 4 chambers in a closed circulatory system. 8
7. Hearts with 2 to 4 chambers in a closed circulatory system Use gills or lungs for gas exchange Large coelom that contains major organs Body covered in skin (other structures such as nails, hair, horns, hooves, etc can vary)

47. Respiratory systems can vary by the way a vertebrate respires, through either the lungs, gills or in rare cases the skin. Some groups will have operculum, which is a protective covering over the gills.
Circulatory systems in vertebrates are very similar with one main difference. That is the number of chambers in the heart! (2 being the minimum and 4 being the maximum) Reproductive strategy can be either internal or external. In both fertilization and / or development.

48. There are 7 main subgroups of vertebrates
There are 7 main subgroups of vertebrates. 1 is a subphylum and the other 6 are classes. Subphylum Agnatha (jawless fish) Class chondrichthyes (cartilaginous fish) Class osteichthyes (bony fish) Class amphibia Class reptilia Class aves (birds) Class mammalia