Module 2 Note - Kingdom Animalia

Most animals are

• heterotrophic, multicellular, eukaryotic 

• have motility 

• Approximately 1 million animals have been identified 

Symmetry

the shape of the animals (only the simplest animals are not)

Radial Symmetry

cylindrical in shape (like a jellyfish)

Bilateral Symmetry

May be divided into a left and right side (most complex animals)

Anterior

front

Posterior

rear

Dorsal

back

Ventral

bottom

Germ layers

embryonic tissue from which all other animal tissues arise; the endoderm, mesoderm, and ectoderm

Acoelomate (no coelom) (flatworm)

Ectoderm, mesoderm, endoderm, gut

Pseudocoelomate (roundworm)

ectoderm, mesoderm, pseudocoel, endoderm, gut 

Coelomate (earthworm)

ectoderm, mesoderm, coelom, endoderm, gut 

Gastrointestinal tract

digestive system, gut

Coelom

a true body cavity found in many animals

Exoskeleton

outer skeleton

Endoskeleton

inner skeleton

Segmentation

the subdivision of the body into a series of repeated parts

Endothermic

(warm blooded) (control body temp to a higher degree, keep temperature at a certain set point): animals that maintain a constant body temperature using heat generated by metabolism

Ectothermic

(cold-blooded) (regulate, but has to use behavioral ideas to fix it ex: laying in the sun): animals that regulate their body temperature by absorbing heat energy

Porifera

sponges

(no true tissues or organ systems, but are multicellular)

asymmetrical,

No germ layers,

No coelom

Cnidaria

jellyfish (stinging cells) and their relatives,

radial symmetry,

2 germ layers

No coelom

Nematoda

roundworms

bilateral symmetry

3 germ layers

pseudoselomate 

Protostome

Platyhelminthes

flatworms (ex: tapeworm…) no body cavity

bilateral symmetry

3 Germ Layers

Acoelomate

Protostome

Arthropado

“Jointed foot”, coruscations and insects, spiders,

bilateral symmetry

3 Germ Layers

Coelomate

Protostome

Mollusca

mollusks (snails, slugs, octopus, squid),

bilateral symmetry

3 Germ Layers

Coelomate

Protostome

Annelida

segmented worms (earthworms, leeches),

bilateral symmetry

3 Germ Layers

Coelomate

Protostome

Echinodermata

“spiney-skinned” (sea urchins, sea stars, sea cucumbers),

radial symmetry,

3 Germ Layers

Coelomate

Deuterostome

Chordata

fish, amphibians, reptiles, mammals (everything else),

bilateral symmetry,

3 Germ Layers

Coelomate

Deuterostome

Animal Phylogeny

Circulatory system

Open (pumping through a heart or heart-like structure over the oranges in the body cavity) and closed (blood stays in a continuous series of vessels)

Respiratory systems:

diffusion (gasses diffuse from highà low concentration), gills, lungs, spiracles and trachea

Excretory system:

protonephridia, nephridia (“nephron” = kidney-like organ that most likely has to do with excretion) , kidneys

Skeletal (protects/provides support):

endoskeleton (inside) and exoskeleton (outside)

Muscular system:

longitudinal (lengthwise longitudinal fibers), circular (squeeze the muscle out), oblique (angular fibers) muscle fibers

Nervous system:

nerve net (individual nerve cells that are interconnected, with no brains), ganglia (cluster of nerve cells, function like small brain), central nervous system, ventral and dorsal nerve chords (ventral is in the front, dorsal is when the spinal cord runs on the back)

Cnidaria Diversity and Classification 

1. Digestion and nutritional strategy: Waste products exit the same opening as the entrance (they are mostly predators) 

2. Circulatory system: No circulatory system. Nutrients and gases are transported by diffusion through the body and gastrovascular cavity. 

3. Respiratory system: No specialized respiratory system. Oxygen and carbon dioxide diffuse directly across the body wall. 

4. Excretory system:  No specialized excretory system. Metabolic wastes, especially ammonia, are removed by diffusion through the body wall.

5. Skeletal system: not a true skeletal system 

6. Muscular system: yes they have muscle fibers 

7. Nervous system: Yes, but very simple. They have a nerve net rather than a centralized brain.

8. Reproduction: Alternation of generation- 2 stages called Palyp stage (asexual stage): similar to how sea anemone looks, Medusa stage (sexual stage): the classic looking jellyfish 

True radial symmetry  

3 Classes of Cnidaria 

1. Scyphozoa “True Jellyfish”: Only have the medusa stage 

2. Anthozoa (sea anemones, coral): Only have the Palyp stage 

3. Hydrozoa (Obelia): Have both Paylp and Medusa stage  

Hydra:

only have one stage, but can reproduce both sexually and asexually

Platyhelminthes (flat worms) 

3 Classes-  

1. Turbellaria: free-living (not parasitic) flatworms (both male and female) 

2. Trematoda: flukes (parasitic) (female lives inside of the male) 

3. Cestoda: tapeworms (parasitic) (both male and female) 

Scyphozoa “True Jellyfish”

Only have the medusa stage 

Anthozoa (sea anemones, coral):

Only have the Palyp stage 

Hydrozoa (Obelia):

Have both Paylp and Medusa stage  

Turbellaria

free-living (not parasitic) flatworms (both male and female) 

Trematoda

flukes (parasitic) (female lives inside of the male) 

Cestoda:

tapeworms (parasitic) (both male and female) 

Platyhelminthes (flat worms) 

4. Digestion and nutritional strategy: Pharynx sucks up decomposing- gastrovascular cavity, no true digestive system (incomplete digestion) 

5. Circulatory system: no circulatory system 

6. Respiratory system: no true respiratory system 

7. Excretory system: Protonephridia (flame cell) they have cilia that keeps the water circulating 

8. Skeletal system: don’t have one 

9. Muscular system: longitudinal and circular muscles 

10. Nervous system: simple nervous system- pair of ganglia; collection of nerve cells (brain) 

11. Reproduction: Most flatworms are hermaphroditic (both male and female) but usually reproduce sexually. Flukes are an exception (the female lives inside the male and reproduces sexually), the tapeworm reproduces asexually 

Planarian Anatomy 

Pharynx, gastrovascular cavity, ovaries, testis (both male and female parts), nervous system 

Pork/beef tapeworm life cycle 

Mode of transmission: you need to ingest the worm (uncooked or undercooked pork/beef) 

Insisted: in the muscle you would be eating (the head of the tapeworm=scolix) 

Makes its way to stomach and the scolex (head of tape worm) breaks out 

Screws scolex into intestinal wall 

Produces an unlimited amount of body segments (proglottid)

Blood Fluke life cycle (Schistosomiasis) 

Areas where rice is being grown (you need to use water for rice to grow) 

The water became contaminated because of all the uses of it 

Larvae stage of this parasite is in the water, and knee deep in water allows it to burrow through your skin 

Several larvae stages occur inside the body 

Penetrates into snail

Phylum Nematoda 

1. Digestion and nutritional strategy: complete digestive tract (free living or parasitic) nutritional strategy varies 

2. Circulatory system:  None 

3. Respiratory system: None 

4. Excretory system: Excretory canal/cells (removes waste) 

5. Skeletal system: none 

6. Muscular system: a bit more advanced than flatworms (only have longitudinal muscles- move like whipping side to side) 

7. Nervous system: simple nervous system (have a nerve ring around the pharynx and longitudinal nerve chords) they have 3 nerve chords 

8. Reproduction: separate sexes and sexual reproduction 

Ascaris (parasitic roundworm)- human roundworm life cycle 

Mode of transmission: ingest fertilized eggs  

burrow through intestine 

migrate up respiratory tract and gets swallowed a second time 

pass through stomach to intestine 

then they grow into larger worms 

Hookworms (dogs) 

-eggs hatch in soil and get larval stage 

-can burrow through skin  

-dogs can ingest them accidentally  

-they can burrow into human feet 

Heartworm 

-dogs can get it 

-transmitted by mosquitos 

-lays eggs in the heart 

Elephantiasis- caused by Microfilaria worm 

-roundworm 

-transmitted by mosquitos 

-goes to lymphatic system and likes living there 

-causes swelling 

Phylum Annelida (segmented worms)

1. Digestion and nutritional strategy: complete digestive system: (earthworm) ingest soil and digest that material, (polychaeta) have fangs and can eat other worms-marine sand worms, (Hirudinea) external parasites 

2. Circulatory system: open and closed (earthworms: closed) 

3. Respiratory system: none (gas exchange across body cavity) 

4. Excretory system: yes- excretory organ, metanephridia (tiny kidneys) 

5. Skeletal system: none 

6. Muscular system: yes  - They have muscles that allow them to move their segmented bodies.

7. Nervous system: ventral nerve chord, ganglia in each segment 

8. Reproduction:  sexual or asexual, depending on the species.