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107 Cards in this Set

  • Front
  • Back
genetic change over time from a common ancestor
What is the persentage of inverts in the world?
How many phyla are there?
Cambrian Explosion
510-540 million years ago.
No new species has been created since then, they all have evolved
What does evolution produce?
biodiversity & complexity
over time a group becomes dissimilar from eachother over time
Adaptive radiation
multiple divergence from a common ancestor (Cambrian Explosion)
Example of Adaptive Radiation
Burgess Shale- a lot of sedimentary rock examples of animals that evolved during the cambrian explosion. 25 groups are present here and 22 went extenct

Arthropoda- three main groups. Chelicerates, Crustaceans, and Insects
lineages with different ancestors that over time gained similar characteristics (Mussles and Barnicles)
What is the relationship between complexity of animals, recent evolution and success
Recent animals are more complex but more complex animals are not always the most sucessful
Approaches to classifying animals
Traditional approach- Linnaean systematics (things that look alike). Binomial nomenclature, either italics or underline. Cap first letter of first name, name of person who first described it comes next. (K,P,C,O,F,G,S) (Issues- based on beliefe and not actual scientific research, similarity)

Phylogenetic systematics- Cladistics, evolution rather than guessing. Willi Hennig.
Apmorphic Characteristic
characteristics in clatogram which clatogram is based on, unique characteristic
Monophyletic taxon
a clade consisting of a common ancestor and all of the decendents
Paraphyletic taxon
a group or a clade in which member species and all decendents of a common ancestor, but does not contain all species decended from that ancestor
Plesimorphic Characteristic
characteristic shared by all ancestor and all decendents
- 5500 living species
- Prefer to live in 30 m or less
- Sessile
- Simplest metezoan animals
- Skeleton made of spicules
- They are made either of Calcium carbionate or silicon dioxide
- No tissue and no organs
Cells that cover the outer surface of the sponge, they make up the pinicoderm (a one cell thick layer that covers the outer surface and produce a sticky substance on bottom)
Donought shaped cells scatterd among pinicoderm. Water enter the sponge through each ostium, which is though this layer.
Flagillated cells living in spongocil
- generate currents to maintain water circulation
- help capture food particles
- capture incoming sperm
Collar of microvilli
extenction of cytoplasm that encircles the beginning part of the flagellum
Amoeba shaped cells
Create spicules
Amoebid shaped, typically in mesohyl, they digest food, also store food, can produce eggs and sperm. They are also todipotent
can become any cell needed but can not change back
Five major characteristics of Porefera
1. Are sessle

2. Organized around a system of porus passageways and chambers through which H20 can flow through

3. Sponges have a skeleton made of spicules

4. Posess specialized cells that perform various functions

5. Sponges are todipotent
What makes sponges flexable
Spongin fibers, they are taken out in bath sponges
What makes spongin?
Reasons why sponges are colorful
1. They have symbiotic algae and bacteria

2. Pigment granules in amoeboid cells
Why are sponges sucessful?
- Very simple animals
- Morphological simplicity
- Have all specialized cells they need
- No selective pressure on them to change
- High sapasity to regenerate
- Cell agrigation- causes regeneration
Mecical purposes of sponges
- biochemical active agents (determines preditors in natural environment and they compete for space on reef)

- Maoris- indeginious people use sponges to promote whound healing
Potassium Flurosilicate
Makes up 10% if sponges dry weight, anti-inflamitory agent
Morphological types of sponges
- Asconoid sponges

- Synconoid sponges

- Leuconoid sponges
Asconoid Sponges
- simplest body structre with a large central cavity (Spongoceal)

- Pinocoderm (outer layer) has no folds at all

- Water flow: enters ostia of porocytes then moves through flagilated spongocil then exits through the ostium

- Limitation because of its simpliciy- size (increase in volume does not come with increase of size)
Synconoid Sponges
- more complex

- pinicoderm is pushed out into hundreds of flingerlike projections

- choanocyte layer is no longer limited to spongocyl

- water enters incurrent canals and enters ostium of porocyte, thenwater enters flagillated radical canals then goes through reduced spongocyl and exits through ostia
Leuconoid Sponges
- Highest degree of folding in pinicoderm

- incurrent canals become more internal and branched

- spongocil is reduced

- water glow- water enters through ostia of porocytes then gas to branched incurrent canals, after it does through another pore then glagillated chambers then excurrent canals join more canals and water exits through ostium

- most common sponge type
Regulation of water flow
Flagella- account for significant amount of water flow, they feed on bacteria

Water flow is at its highest velosity in flagillated chambers, fastest in osculum

take advantage of currents around them
asexual reproduction- no eggs or sperm necessary. They use gemmites or fragmentation. Gemmites are not common in marine sponges.

Some are broadcast spawners, reproduce sexually

sperm arrises from choanocytes and eggs come from choanocytes or archeaocytes (depends on species)

internal and external fertilization
These are made when there is a drying out (decicration) and can survive rough conditions due to outer layer
Sponges relationship to other animals
believed all metezoa came from flagillated protozoa (all metezoa have flagellum and ancestor with it gave rise to animals with it)

Evidence points to choanoflagellates- protozoa that looks like choanocyte (ancestor to all animals)

Choanoflagilites are sister group to metezoa
Distinguishing characteristics of cnidarians
1. Process 2 embriotic tissue layers
2. Mesoglea
3. All have radial symmetry
4. 2 morphological forms
5. All have tenticles and one single opening to the gastrovascular cavity
6. All have cnidoblasts
2 embriotic tissue layers
ectoderm and endoderm

Ectoderm- cells of the outermost layer, compose body wall of gastrula, gives rie to surface epithilla and nervous system

Endoderm- cells of the innermost layer and they live in the archinteron, gives rise to gut lining digestive organs
Cell layer cnidarians dont have
mesoderm- cells of the middle layer, give rise to many other structiures such as mscles, bones and circulatory system (triploblastic- if all three layers are present)
If only endoderm and ectoderm are present
provides form and shape, bouyancy in free swimming forms, mostly water, non-living, contains cells that store nutrients and help with transport
2 morphological forms
sessle (polyp)

free swimming (medusa)
- attached to substraight by the aboral surface

- has cylindrical shape, cylinder with tenticles around the mouth

- thin layer of mesoglea

- hard skeleton
- free swimming with oral surface facing down

- bell shaped with tenticles near the margin of the bell

- thick layer of mesoglea

- never has hard skeleton
- stinging cells

- most common in neumatocysts

- cnidocyte is round in hydroids and jellyfish and contains cnidocil which coral and anemonies lack
capsule with stinging cells
Cnidocyte discharge mechonism
rappid change in osmotic pressude due to increase in calcium in capsle (cnidocyl gets triggered and calcium enters sapsule- change in pressure- water rushes in and the pressure increases and fources thread out of capsle and into prey)
How do cnidarians feed?
- carnivores

- most feed on zooplankton

- digestion begins in GVC- extracellular digestion (outside the cells)

- GVC is lined with cillia and assures adiquare mixing

- Some have intracellular digestion
- reduce body dencity and become more bouyant in the water

- muscles contract to move

- cillia or glagella are used to move

- some animals elongate and shorten body muscles

- related to skeletal system
and structure that maintains shape and supports and protects body
(endoskeleton and exoskeleton)
Hydrostatic Skeleton

(In polyp and medusa)
- fluid filled space that reatins a constant volume in which muscles can operate agains

- the body is supported slightly by the pressurized water within

- the fluid is imcompressable and localized pressures as a result of muscular contracion will be transmitted uniformally in all drections

- GVC is hydrostatic skeleton is polyp

- Mesoglea is hydrostatic skeleton in medusa
Class Hydrozoa
- Hydroids
- smallest of cnidarians
- miniature plants- sessle
- colonial (majority)
Types of polyps
feeding on microscopic plankton and share partially digested food with other members
reproductive non feeding, they lack a mouth and tenticles. Make medusa and eventually break off
defence- made of may cnidocytes
Class Scyphozoa
- "cup"
- all marine
- medusa stage is dominant
- manaubrium- with frilly arms= oral arms loaded with stinging cells
Life Cycle of Cnidarian (Scyphozoa)
1. Externam fertilizaton
2. Zygote
3. Planuea
4. Scyphistoma polyp
5. Strobilization (transverse assion)
6. Free-swimming ephyra released
7. Develops into medusa
Class Cubozoa
- sea wasps, box jellies, tentilces in groups of 4
- Found in tropical/subtropical and indopacific
Class Anthozoa
- "flower animals"
- sea anemonies, coral, sea whips
- anemonies- solitary
- coral- colonial
- Symbiotic relationship with zooxanthellae
symbiotic dinoflagellates in gastroderm, gives color to sea anemonies
- only polyp that lays down calcium carbonate
- most of polyps are in Anthazoa
- some coral are in Hydrozoan class
- most are colonial- physically connected and shared GVC
- have sclerosepta but lack syconogliphs (anemonies have)
- most have zooxanthallae
sheets of calcium carbionate (CaCo3) that project into polyp
- lack sclerosepta
- firecoral
Food for Corals
- carbohydrates provided by zooxanthallae
- eat from ocean
White tips
growing coral without bacteria, it has not had time to grow
How are coral reefs formed?
- Simbiosis facilitates deposition of CaCo3 because the zooxanthallae take it up
- contributors are hermatypic corals with zooxanthallae, and calcareous algae that have caco3
- destruction phase- boreing organisms bore into reef and it turns into rubble and animals that live in it get smothered (biological errosion)
- deposition- larval will settle down and undergo a sexual reproduction. Over time the pile of rubble is taken by the live coral
Main types of coral reefs
Fringing Reed- Projected deaward along the shore- Hawaii

Barrior Reef- further from shore, seperated by lagoon, Australia and Belize (reasons for lagoon- 1. island can be sinking and 2. there can be an increase in sea level)

Atoll Reef- reef that rests on sumits of submerged volcanoes, circular and has a lagoon in the middle, Indopacific

Patch Reed- lare piece of reef breaks off, land in soft sediment habitats and over time becomes its own reef (FL Keys)
Where are reefs found?
Highest concentration is in the indopacific (micronesia to Indonesia to Australia to Thailand to Asia)

Western Atlantic- FL and Carribean

(23-29 C)
30 meters deep
Rainforests of the sea
High economical value
any named group of organisms that is sufficietly distinct to be assigned to a ctatgory
all the members of any particular phylum are presumed to have evolved from a single ancestral form.
share a common evolutionary origin
shared characteristics derived from a common ancestor in which the characteristecs originated
a group of orgnisms that includes the most recent common ancestor of all its members and all descendants of that sncestor; every valid clade forms a "monophyletic" group.
the pictoral representation of branching sequences that are characterized by particular changes in key mrphological or molecular characteristics
Homologous Characters, Homology
characters that have the same evolutionary origin from a common ancestor, often coded for by the same genes. Homology is the basis for all decisions about evolutionary relationships among species
Monophyletic Toxon
a group of species that evolved from a single ancestor and includes all descendants of that ancestor. By definition, every valid clade forms a monophyletic taxon.
Any derived or specialized character
any ancestral or primitive character
a derived (advanced) character that is shared by the most recent common ancestor and by 2 or more species are more closely related to eachother. Essentially, synapomorphies are homologous characteristics that define clades
Paraphyletic grouping
a group of species sharing an immediate ancestor but not including all descendants of that ancestor.
a branching point on a clatogram
When there is a shortage of water fresh water sponges produce gemmule which is a small ball of cell with a hard outer cover. Inside is the archaeocytes surrounded by spicules with a site for future opening
Importance of waterflow in Sponges
food, gas exchange, waste removal, and the dissemination and collection of sperm
How water flow occours
Water flows into the ostium into the spongocoel and exits through the oscula. Water with food slows down within the choanocyte chanbers for digestion and speeds up on the way out of the sponge to dissipate wastes
Class Calcarea
- spicules composed only of caco3
- only living asconoid forms are found in this class
Class Demospongiae
- Contains around 80% of sponge species
- Almost all leuconoid in construction
- spicules composed of spongin and/or spicules
- all freshwater sponges are in this class
- no ostia and no internal canal system
- no choanocytes
- feed as carnavors
Class Hexactinellida
- bodies supported by 6 rayed siliceous spicules
- glass sponges
- live in sediment and anchored by tufts of spicules
- no pinicoderm layer
Defining characteristics of phylum cnidarian
1. Secretion of complex intravellular organells called snidae (nemutocysts)

2. planula larvae in the life cycle
Stinging nettle
Each consist of a rounded capsule with an opening. Inside is a long hollowed coiled tube which shoots out during discharge
Food collection, defence, and locomotion
3 main cnidarian classes
scyphozoa, hydrozoz, and anthozoa
Class Scyphozoa
- Defining characteristic: asexual replication by strobilation
- thick mesoglea layer
- swim actively but contracting muscles
- some obtain nutrients from zooxanthallae
- non feeding planula larva
Class Cubozoa
- sea wasps and box jellies
- defining characteristic- medusa with boxlike body and rhoplia comples, lensed eyes
- 4 tenticles or 4 clusters of tenticles
- plauna buds off many polyps and all develope into medusa
Class Hydrozoa
- neumadocysts found only in epidermus
- no cells are found within the mesoglea
- 3 major orders (Hydroia, Siphonophora, and Hydrocorals)
Class Anthozoa
- Sea anemonies and coral
- Absence of medusa
- Absence of operculum
- DNA is circular
- Ciliated gorrve in the wall leading to the mouth
- Coelenteron seperated by distinct sheets of tissue
- some can "swim" for short distances
How cnidarians swim
Muscles contract and the fluid in the bell gets pushed out and the cnidarian is propelled in the opposite direction. When the muscles are relazed water re-enters the bell and it pulles the cnidarian backwards
Class Hydrozoa- Order Hydroia
- thick medusa
- sence organs at base of tenticles or between tenticles
- either male or fem but never both
- very small
- zoochlorellae in tissues (green algae)
- fingerlike modules for defence
Class Hydrozoa- Order Siphonophora
- can have gas filled bubbles
- man of war
Class Hydrozoa- Hydrocorals
- colonial
- secrete calcareous skeleton
- warm waters
- fire coral
Class Anthozoa- Subclass Hexacorallia
- many tenticles around the mouth
- solitary
- hermatypic- reef building
- ahermatypic- non-reef building
- corals restricted to warm clear waters
- zooxanthallae
Class Anthozoa- Subclass Octocorallia
- pimmate- numerous outer foldings of the pinnules
- have 8 tenticles and are subdivided by 8 complete measenteries
- found in indopacific and atlantic
- sea anemonies are closest relatives
- sexual reporduction-broadcast
- can form large calcarous skeleton
- zooxanthallae conduct photosynthesis
Reef Architecture
- hundreds of encrusted organisms live on coral framework binding it together
- relationship between extention of coral framework and deteriation of detritus
- Gravitational flow exports sediments
- biological erosion and submarine lithification help grow corals
- Boreing organisms provide caco3 for reefs to build off of