mostly marine some fresh water

come in polyps (sessile) and medusae (jellyfish form) floating or free swimming

outer body wall that consists of epithelialmuscular cells,interstitial cells,gland cells, sensory cells,never cells (nerve net)

Cnidocytes-used in feeding and defense contain organelles called nematocysts

Asexual - budding in polyp forms clones and colonies

Sexual- gametes in medusae and some polyps 

1. Hydrozoa
2. Scyphozoa
3. Cubozoa
4. Anthozoa

have both polyps and medusae forms

example of colonial hydra: portuguese man of war

another example of hydrozoa is Obelia

Reproduction of Obelia is Medusae form egg and sperm that meet in water to form a zygote-blastula-planula(starts new colony through asexual budding)-new colony of polyps create medusae

class of cnidarian has little or no polyp form

example is jellyfish

another example is Aurelia

Reproduction of Aurelia is medusae mate sexually and produce planula which grounds itself to grow and produce scyphistoma-strobila-ephyra(non sessile)-medusae

class of Cnidaria

polyp reduced example is box jellies

Class of hydrozoa

have tentacles in multiples of 6

all polyps (reproduce sexually) no medusae

subclasses include:

1. Zoantharia (sea anemones and hard corals) have exoskeleton made out of calcium carbonate
2. Ceriantipartharia (tube anemones, black and thorny corals) do not secrete exoskeleton
3. Octocorallia (soft corals, orange pipe corals, sea fans, sea pens, blue corals) have tentacles in multiples of eight

coastal impacts

climate change

acidification

erosion

pollution

collection

fishing

anchors

1. Fringing Reef(youngest)-next to landmass
2. Barrier Reef (middle)-landmass and reef separated by a lagoon
3. Atoll(oldest)-reef without land mass

Tripoblastic (have three germ layers)

1. Ectoderm ( forms nervous tissue, epidermis,parts of eyes and ears)
2. Endoderm(forms digestive, respiratory,reproductive system,urinary tract,part of liver and pancreas)
3. Medoserm (forms muscle,cartilage,bone,blood kidneys)

Platyhelmenthes are acoelomate-which means they do not have a coelom,instead they have mesodermal tissue called parenchyma

A coelom is a fluid filled body cavity between outer body wall and gut that has the organs inside.

evolutionary development of a head in animals

cephalization was caused by development of sense organs in front of animal which leads to development of nervous tissue

this nervous tissue leads to development of head and brain

1. Turbellaria-Dugesia or planarians are free living(not parasites)
2. Trematoda-parasitic flukes
3. Monogenea-single host
4. Cestoda-tape worms

1. Muscular
2. Digestive (incomplete due to only one opening which acts as mouth and anus)
3. Nervous System (have anterior ganglia or bundles of nerves with nerve cords running down body) also have sensory and motor neurons for information and movement(some have eyespots)
4. Excretory (canals with flame cells that pump excretions through canals with flagella

Platyhelmenths lack respiratory,circulatory,and skeletal systems

Free living worms (don't need a host to survive): have simple life cycles and reproduce asexually by literally breaking themselves in half or sexually by internal fertilization (female and male organs in same animal)

Parasitic worms (need a host to survive) have more complex life cycles-reduction in body parts (lose organs you don't need)-high reproductive output

Endoparasite-forms on the inside of other/host organisms

subclass: Digenea

mollusk (snail) intermediate host,vertebrate definitive host reproductive organs are half the body

example is fluke: lives in tropical areas, has separate, males and females that live attached to one another. Causes a disease called schistomonaisis (200 million people affected)

tapeworm-has head with suckers

has segments (proglotlid) that are smaller near the head and get larger and more mature as the worm grows

Proglotlid-are full of eggs and sperm the progltlid at the end of the worm snaps off to form new worm

Coelomate animals

Protosomes

Have metameres or segments or somites

Setae or hairs

closed circulatory system or blood always stays within a vessel

Nephridia-excretory mechanism (primitive kidneys)

Further cephalization-more development of sense organs and brain

Hermaphroditic

have spiral cleavage and not all cells are the same size

have mosaic embryo-cells are already committed to becoming something

Schizocoeous development-blastospheres first opening is mouth and second is the anus

Radial cleavage all cells are same size

regulative embryo-no cell has made a decision about what it will become (stem cells)

Entrecoelous development blastospheres first opening is anus and second is the mouth

Polychaeta

Oligochaeta

Hirudinea

include blood worm, fan worns,feather duster worms, christmas tree worms (filter feeder with radiole)

are marine animals that burrow tunnels in sediment

has parapoda (legs)

no permanent sex organs

indirect development ( larvae look nothing like adult)

include earthworms, aquatic worms

few setae

direct development (larvae look like adult)

ecological benefits

includes leeches

no setae

no septa

parasites or carnivores that have anticoagulant saliva Leeches have a reduces coelom-filled with a tissue. Drinks and fills itself with blood (external parasite). Attaches with suckers that are near mouth to correct host. Salivary glands secrete saliva into the wound, made by the proboscis, that contains an anticoagulant that stops the blood from clotting creating a steady flow of blood to the parasite. Blood is digested very slowly over 6 months. The ceca are sections off the digestive track that hold the blood. the leeches will become twice its size when full. They are hermaphroditic.

Disease was thought to be caused by an in-balance of fluids in your body called humors.

Consist of blood,phlegm, black bile, and yellow bile. Being sick was the blood balance was to high in comparison to the others. In order to cure the sickness it was thought to let them bleed or to apply a leech. There was a huge market industry for leeches in the medical industry

Organisms need oxygen from air and organic nutrients from the soil. Worms decompose organic material into nutrients for plants. 

In northern forests soils were not inhabited by worms. Therefore their is no breakdown of organic material so the ground is made up of duff or organic material. Plants have adapted to live of off the organic material. Earthworms are now being introduced via fishing and will break down organic material killing the native plants that can grow in duff.