Midterm 1 Flashcards
Chondrichthyes characteristics
1)Cartilaginous skeleton
2)Claspers (in males) for reproduction
3)Placoid scales
4)Teeth in replacement families
5)Variation in jaw suspension
6)Sensory systems
7)Spiracle
8)Series of gill openings
9)Lipid-filled liver; no air bladder
Amniotic Egg
- Defined by embryonic development in a multi-membrane egg
- Chorion forms the Outer membrane (ancestral), Encloses the yolk, amnion, allantois, & embryo
- Amnion Inner-most membrane surrounding the embryo
- Allantois Membrane creates a sac which stores waste& aids in respiration
- Yolk enclosed in a vitalin membrane (aka yolk membrane)
Characteristics of Holocephali
1)Holostylic jaw suspension, Most rigid jaw suspension
2)Palatine plate
3)Oviparous
4)Single gill opening (with 4 gills inside), covered by an operculum; no spiracle.
Gained Features of Vertebrates over the Chordates
1)Vertebrae
2)Cranium
3)Brain
4)Pituitary
5)Multi-chambered heart
6)Mineralized tissues
7)HOX gene duplication
1st branchial arch develops into
Becomes the platoquadrante and madible
Modifications of Lissamphibia for land
Pelvic girdle attached to the vertebral column and the Pectoral girdle had to dissociate from the cranium
Sub Phylum Urochordata
Although they may look very different from other chordates, they all have chordate features (e.g. as larvae).
Respiration path of Hagfish
Median Nostril->Velum->Pharynx-> Gill arches->out of body
Evidence to support the theory that the gill arches evolved into jaws
1)Jaws,hyroid and gill arches share similar developmental origin
2)Nerves and blood vessel overlap for gill arches and jaw
3)Nerve and blood vessel match for spiracles and gill slits
4)Muscles that support jaws are related to muscles that support gill arches
Thelodonti
Jawless fish
Poorly arranged but durable scales
derived cranium
notable stomach
acellular bones
Earliest Brain segments
1)Procephalon
2)Mesencephalon
3)Rhombencephalon
Changes made to overcome gravity on land
- Limb arrangement must change
- Cost energy to move now
- Dragging to walking
General Lissamphibia
Typically have aquatic and terrestrial life stages, with eggs laid in water,
Skin is permeable and substantially involved in respiration. They retain the lateral line and some species retain electroreception.
Reason for paired fin development
As swimming speed increases there is an increase instability along the rotary axis
Mineralized tissue
Combination of organic components and inorganic minerals using chemicals like sillica or CaCo3
Origin of the three inner ear bones
1)Palatoquadrate > quadrate > incus
2)Meckel’s cartilage >malleus
3)Hyomandibula > stapes
5 paired cranial bones
Lateral tooth-bearing series:Premaxilla & maxilla
Median series:Nasal, frontal, parietal, & postparietal
Circumorbital series:Lacrimal, jugal, prefrontal, postfrontal, postorbital
Temporal series: Supratemporal & tabular
Cheek series:Squmosal & quadratojugal
Upper jaw attached by ligament (ant.) and sup. by hyoid pos.
Amphistylic
Identify structures A-C
A)Canal of lorenzi
B)Nerve fiber
C)Ampula of Lorenzi
List the Vertebral regions from anterior to posterior
- Cervical-neck
- Thoraxic-upper back
- Lumbar-lower back
- Sacrum-pelvis
- Coccyx- tail
Label structures A-I
A)Developed inner ear
B)Olfactory bulb
C)Jaws
D)Gill Skeletons
E)Pectoral fins
F)Pelvic fins
G)Anal fin
H)Caudal fin
I)Dorsal fin
New features of Gnathostomes
1)Shared HOX gene duplication
2)Jointed Gill arches
3)Jaws with teeth
4)Paired Fins
5)More developed vertebrae
The first Terrestrial tetrapod, similar to amphibians
Pederpes
Requirements to breath water
1)Gills
The respiratory (=gas exchange) surface is where O2 diffuses from water to blood through counter current exchange.
2) Flowing water
Fishes ventilate (=move water over) their gills.
3)Flowing blood
The heart pumps blood through the gills.
Identify this jaw type
Amphistylic
Cellular bone
Embedded cells remodel bone over time leading to complex microstructre ex. osteocytes
Characteristics of Elasmobranchs
Amphistylic jaw suspension: The upper jaw is attached to the chondrocranium anteriorly by ligaments and the posterior is supported by the hyoid arch (now called the hyomandibula).
Note the location of the mouth
Note the spines
Predecessor for the modern shark
Cranium
Feature found in vertebrates which is formed of cartilage or bone and protects the brain
What creates the pumping motion in Hagfish and Lamprey
Water is sucked or pushed through the oral cavity creating pressure changes that allow for water movement into the gills
Changes to bones in gnathostomes
1)Visceral arch become jointed
2)1st gill slit becomes a spiracle
3)Speicalization of the 1st and 2nd gill arch
Endostyle
Cilliated glandular groove on the floor of the pharynx, homologous to the thyroid and metabolizes iodine
Ventilation Hypothesis
1)Reduction in premadibular oral cavity, reorganization of mandibular arch, changes in hypobrachial musculature combined to increase gill ventilation
2)allows suction of prey
3)Jaws allowed for more forceful opening and closing of mouth
Conodonts
Feeding structures that suggest a shift from suspension feeding to predation and mineralized elements of tissues (Cambrain)
Actinopterygii traits
1)Ossified skeleton
2)Primitive Lung
3)Gas Bladder
4)Poikilothermic
5)Ovoparitous
6)Sensory Systems- development of second nostril
7)Fins-fin rays extend from radials
8)Scales
Gill Arch Theory
Fins are homologous with gill rays and girdles are homologous with gill arches
Identify these scale types
A)Cycloid
B)Ctenoid
C)Ganoid
D)Placoid
Acellular bone
Bone that has no cells embedded within and is deposited as is ex.Fish scales
Outside of a cartilaginous bone gets ossified
Perichondral bone
two connection points between upper jaw & chondrocranium; lower jaw connected to upper jaw
Autodiastylic
Clusters of specialized cells allow sharks (and other fish) to detect vibrations and pressure gradients in the water. This helps them to detect the movement of prey.
Lateral line
Unique structures of Lissamphibia
- Columella= Derived from the hyoid arc and used to transmit high frequency sounds
- Operculum=Coonnects to the ear capsule and Opercularis muscle links it to shoulder girdle to transmit vibration from ground
- Levator Bulbi Muscle=Pushes eyes outward, increasing buccal cavity volume
- Pedicillate Teeth=Dentine crown and base, Separated by uncalcified dentine or fibrous connective tissue
- Poison Gland=Mucous gland to maintain skin moisture
Viviparity
live birth’. In animals, vivipary is where offspring grow and develop in the womb and are birthed live
The 5 Chordate features
1)Notochord
2)Dorsal neural tube
3)Pharyngeal slits
4)Endostyle
5)Post anal tail
Walks on the tip of their toe ex.horse
Unguligrade
Placoderms
The ‘armoured jawed fishes’
Headshield with fused plates of dermal bone
Hinge at the junction of the head and trunk
Jaws, with bony teeth
Some ossification of vertebrae
without fenestrae
Anapsid
Characteristics of modern sharks
- Hyostylic jaw suspension: The upper jaw is attached anteriorly by ligaments to the chondrocranium. It is also hinged posteriorly by the hyomandibula.
- viviparity
Galeaspida
Significant morphological variations
single dorsal opening for respiration
large # of gill slits
paired appendages
Examples of mienralized tissue
1)Mineralized cartilidge
2)bone
3)Dentine
4)Enamel
Cladograms
Nodes that show where species branched from a common ancestor but the branches themselves provide no information
Adaptations of Hagfish
1)Skeins of fibers that react with seawater to create slime
2)Tying themselves into knots to create leverage
Identify this jaw type
Holostylic
Gas bladder which has become separated from the gut using the circulatory system. Has a rete mirable which secretes lactic acid to help in loading and unloading of the CO2 and O2
Physoclistous
Draw the Lungfish lung
Pharyngeal Slits
Openings in the pharynx that allow for one way flow of water, similar to gills but are not used in respiration
Mineral %
Higher mineral % gives you more support but decreases the flexibility and shatter resistance
Post Anal Tail
The anus is not terminal, i.e., the body (including notochord and musculature) continues past the anus to form a tail.
Respiratory system of Cephlochordata
Respiration is through the surface.
Pharyngeal slits are not yet gill slits; not specialized for gas exchange.
Arcualia
resemble an evolutionarily early form of the vertebral column made of cartilage
Full foot on the ground from heel to toe, most stable ex.human
Plantigrade
One fenestra
Synapsid
Anaspida
Lack armour
dorsal spines
related to cyclostomes
4 shark categories and their jaws
1)Holocephali-Holostylic jaw suspension, Most rigid jaw suspension
2)Elasmobranchs-Amphistylic jaw suspension
3)Modern Sharks-Hyostylic jaw suspension
4)Batoidea-Modified hyostylic jaw suspension allows for greater suction feeding. Modified teeth are used for crushing shelled invertebrates.
Feeding path of Cephalochordata
Pharynx-> Mucus of endostyle->gut->anus
Anura (Frogs) characteristics
Vertebrae fused with ilium
*
Posterior vert. Fused into urostyle
*
Elongated limbs w/ fused bones
Identify this jaw type
Hyostylic
Characteristics of Batoidea
- Enlarged pectoral fins; eyes and spiracles on the top, and multiple gill slits on the underside.
- Oviparous: females lay egg cases
- Modified hyostylic jaw suspension allows for greater suction feeding. Modified teeth are used for crushing shelled invertebrates.
Ostracoderms
1)Bony head shield and smaller bony scales
2)Adapted to open swimming and shifting of sediment to avoid predation
Amniote skin
- Less permeable but more resistant to abrasion skin accomplished with Fewer glands, Thicker epidermis, including a thicker stratum corneum,More keratin,Higher hydrophobic lipid content
- Scales form through thickening and folding of the epidermis layer with thick keratin sections followed by thin keratin sections
- Molting:The outer layer of epidermis separates at the separation zone. The newly exposed layer of cells dies and forms a new stratum corneum.
Chronograms
Nodes show where species branched from a common ancestor with branches that are proportional to the time since the group diverged from the last node
Odontodes
First mineralized tooth like elements that formed within the skin evolving into teeth armour bone and scales. Forms under a dermal layer and minerals are deposited over time
Pituitary gland
Produces and regulates hormones like the thyroid
Features of Sarcopterygii
Two dorsal fins
Dual lobed tail
Fleshy fin stalks
Retention of lungs that feed oxygenated blood to the heart
Circulation in vertebrates
Closed circulatory system with hemoglobin containing RBC and Gill slits for respiration
Water intake path of Cephalochordata
Pharynx-> pharyngeal slits-> atrium->atriopore
Chondrocranium
- Contains the ethmoid and basal plates under the brain, Forms the posterior wall and foramen magnum, around the sensory organs and made of cartlidge
- In agnathans it encapsulates the brain but for us it only makes the bottoms of our skull
Benefits of mineralized tissue
1)protection
2)structural support
3)mineral storage
Ventilation of gills in sharks vs fish
In sharks, water enters the mouth and/or spiracles, flows over the gills, and exits through the gill slits.
In fish, water enters the mouth, flows over the gills, and exits through the operculum.
Circulatory system of Cephlochordata
1)Closed circulatory system with blood vessels.
2)Blood is plasma-like; no pigments or blood cells.
3)No heart; contractile blood vessels.
4)Blood vessels resemble vertebrate pattern (i.e., blood flows forward ventrally and towards the posterior dorsally).
oviparity
expulsion of undeveloped eggs rather than live young
Multichambered heart
2 chambers that pump blood with the Sinus venousus and Atrium
Notochord
Flexible rod that can be bent laterally but not axially and is composed of fluid filled cells in a sheath which muscles will contract allowing for the swimming motion
Novel Ostracoderm features
1)Pectoral fins
2)Claudial fins
3)Bony armour mineralization
4)Internal cartilaginous skeletons
Identify this jaw type
Autodiastylic
Brain
Feature found in vertebrates which is anterior of the dorsal neural tubes. The tube swells to form the 3 segment brain which processes sensory information
Acanthodii traits
1)Rhomboid scales
2)Spines reinforce fins
3)Possibly first appearance of operculum
4) Dentated jaw (varies widely in type of dentition)
Ovoviviparity
Ovoviviparous animals possess embryos that develop inside eggs that remain in the mother’s body until they are ready to hatch.
Two fenestrae
Diapsid
Buccal pump ventilation
Suction phase: The buccal chamber expands, creating negative pressure that draws water in through the mouth. The operculum or gill slits prevent water from entering over the gills and flowing backwards.
Force phase: The mouth closes, creating positive pressure that forces water out through the gills (via gill slits or operculum).
Used by: some sharks, and most fish.
Role of cartilage structures in Lamprey and Hagfish
Supports the respiration from the gill arches
Meckel’s cartilage
Arising in Placoderm jaws and continuing into Sharks, a piece of cartilage from which the mandibles (lower jaws) of vertebrates evolved.
Dermatocranium
These make up the dorsal covering of the brain & sensory organs containing the Premaxilla, maxilla, mandible/dentary, Palate and opercule
Changes to feeding on land
- change from suction feeding to biting, leading to changes in width of head
Actinopterygii major groups
1)Polypteriformes ex. Saddle birchir
2)Acipenseriformes ex. Sturgeon
3)Lepisosteiforms ex.gar
4)Amiiforms
5)Teleosts
a chemosensory system located at the base of the septum on the vomer bone, involved in perceiving and processing stimuli related to social and reproductive behaviors in vertebrates
Vomeronasal Organ
Lissamphibia orders
1)Gymnophiona(Caecillians)
2)Caudata(Salamanders)
3)Anura (Frogs)
The upper jaw is fused with the chondrocranium. This arrangement gives high strength and low flexibility
Holostylic jaw suspension
Chorionic Eggs
- Chorion Encloses the entire egg
- Yolk Enclosed by a vitalin membrane
Splanchnocramium
Includes gill arches and their derivatives
Gill arch I (mandibular arch) becomes Quadropalate (dorsal) and Meckel’s caratilage (ventral)
Gill arch II (hyoid arch) becomes the Hyoid (plus ceratohyal, & basihyal)
Over time this was reduced and became the connection point of the jaw and our inner ear bones incus,malleus, and stapes
Two diffrences between Actinopterygii and Sarcopterygii that allowed for the transition to land in Sarcopterygii but not actinopterygii
1) Loss of primitive lung in actinopterygii
2)Addition of the Ulna Bone and more robust radials
- Membranous bone
- No cartilage necessary
Dermal bones
Path of blood through the sarcopterygii circulation system
Two Atria, Partially divided ventricle, Bulbus arteriosus spiral valve, a split occurs, Ductus arterious will change the blood flow allowing a bypass from the lung. When Oxygen is high it will go to the gills, when oxygen is low it will go to the lungs
Hox Gene Duplication
Genes that regulate development are duplicated and exon regions are shuffled or mutated to produce new functions or developmental patterns
Mineralized cartilaginous pieces that form the shark skeleton
Tesserae
Hydroxyapatite
Composed of calcium and phosphate which helps store phosphate and is more stable in acidic environments than CaCo3
organisms that are able to maintain different temperature “zones” in different regions of the body
Regional homothermy
Changes for respiration on land
- With aspirational breathing, air is pulled into the lungs, instead of being pushed into the lungs.
- Adaptation of the incurrent and movement of the excurrent nostril into the buccal cavity allowing us to breath through the nostril allowing chewing and breathing
shunts blood towards the lungs when oxygen is low, oxygenated blood is shunted to the gills and body
Bulbus arteriosus Spiral valve
Path of Blood from gills to body in sharks/fish
Blood flows from the heart, through the gills where it is oxygenated, to the body. Veins bring deoxygenated blood back to the heart.
Ram ventilation
The fish/shark swims with it’s mouth open, forcing water over the gills.
Used by: many sharks, and some large & fast fish.
Evolution of bones pathway
1)Dermal bone
2)Dermal acellular bone
3)Dermal cellular bone
Cambrain Period
No life yet on land
Protists an animals lived in the ocean along the continental shelf
Ordovician and Sylvanian Era
1)First land plants, vascular plants, and fungi
2)Arthorpods begin to colonize land
3)Diversification of jawless fishes and mineralization of tissue
Flow of blood in Lissamphibia body with lungs
Pulmonary vein takes blood from the lungs to heart->goes to body. Deoxygenated blood comes from hepatic vein (body)-> heart and then to the skin for respiration
Organization of gills
Each side of the pharynx (L&R) has 9 hemibranchs.
An interbranchial septum (= septum between chambers) has gills on both sides; together with the gills it is called a holobranch.
A simple septum (=chamber on only one side) has a single hemibranch.
Defined by the presence of an amniotic membrane in their eggs
Amniotes
a physiological term for animals that vary between self-regulating their
body temperature, and allowing the surrounding environment to affect it
Heterothermy
Challenges of adapting to land
1)Respiration
2)Gravity
3)Support
4)Sensory changes
5)Headshape
Identify structures A-J
A)Nerual Tube
B)Notochord
C) V-shaped Myomeres
D)Anus
E)Atriopore
F) Pulsating blood
G)Atrium
H)Pharyngeal slit
I)Pharynx
J)Endostyle
Sensory Systems changes in amniotes
- Loss of the ooliths
- introduction of the staples,incus, and malleus derived from the spiricle
- Organ of Corti:Tectorial membrane is vital for conduction of sound waves with Hair cells causing nerve signals upon deflection
Gas bladder which retains a connection to the gut. This allows for gulping or burping of air
Physostomus
Jaw suspension types
1)Hyostylic
2)Autodiastylic
3)Amphistylic
4)Holostylic
Spongy bone Replaces existing cartilage
Endochondral bone
Metaspriggina
1)Development of eyes and nasal sac
2)Possible craniums and arculalia
3)No bones or mineralized tissues
(Cambrain)
Osterostraci
Paired pectoral fins
calcified skeleton with three layered bones
electric organs
Upper jaw attached by ligament (ant.); significant support to both upper & lower jaw from hyoid
Hyostylic jaw suspension
Euphaneropids
Calcification of endosekeltal elements, anal tail. and 30 gill pans for more active lifestyle
(Cambrain)
Piturriaspida
Large number of rostal projections
well paired fins
Bone types
1)Dermal bones form armour/exoskeletons
2)Internal cartilage
3)Internal chondral bones
How to identify Hagfish vs Lamprey
Top=Hag fish, 12 gill slits set further back, tentacles, slime glands
Bottom=Lamprey, seven pairs of gill slits set forward
Label this diagram
A)Neural Spine and Arc
B)Prezygoprophysis
C)Spinal cord
D)Notochord
E)Rib
F)Centum elements
G)Postzygoprophysis
Sensory systems in sharks
-1)Vision:Sharks have good vision, even at low light levels.
2)Chemoreception: Sharks are highly sensitive to smell. Differences in smell between the left and right nares provide information about the direction of a smell’s source.
3)Electroreception: Ampullae of Lorenzini are small organs that are found on the shark’s rostrum. These detect electrical fields, including those given off by the muscle activity of potential prey.
4)Lateral line system: Clusters of specialized cells allow sharks (and other fish) to detect vibrations and pressure gradients in the water. This helps them to detect the movement of prey.
3-7 branchial arch
visceral arches
Gymnophiona(Caecillians) characteristics
- Highly derived species with unique mandibular abductors that forcefully shut the jaw
- Make the milk
Myllokunmingia/Haikouichthys
Oldest known craniates with skulls formed from cartilage. Early example of gills (Cambrain)
Phylograms
Nodes show where species deviated from a common ancestor with branches lengths that equate to changes in the defining features
Caudata(Salamanders) characteristics
- Body plan usually informative about habitat / locomotion
- Both external and internal fertilization
-Eggs layed in mass covered in gelatinous material
P. Chordata
Composed of the chordates and vertebrates this phylum is multicellular, bilateral symmetry, deuterostome development. sister phylum to echinoderms
Fin Fold theory
the paired limbs are derived from the local persistence of parts of a continuous fold that in ancestral vertebrates passed along each side of the trunk and fused behind the anus into a single fin.
an organism with a variable body temperature that tends to fluctuate with and is similar to or slightly higher than the temperature of its environment
Poikilothermic
Changes in the skeleton of Actinopterygii
- Formation of the Premaxilla, Maxilla, and Dentery
- Development of the Operculum and loss of interbrachial septa
Vertebrae
Structure found in Vertebrates that are made of cartilage or bone and protect the neural tube and Notochord which help to anchor structures such as the ribs
Identify structures A-K
A)Support spine
B)Dorsal Neurochord
c)Notochord
D)Myomeres
E)Epipharyngeal groove
F)Endostyle
G) Pharyngeal slit
H)Pharyngeal rod
I)Pharyngeal lumen
J)Metapleural fold
K)Epidermis
Dorsal Neural Tube
Forms during the development of the embryo via in folding of the ectoderm and acts as the central nervous system. Sits just above the notochord
Label the egg
A)Yolk
B)Chorion
C)Allantois
D)Amnion
E)Embryo
Flow of blood in the Lissamphibia body with gills
Heart->body and gills mixed together. Gills get oxygenated but mixes with the body deoxygenated blood
Walks with toes on ground and heel raised,quick and quiet movements ex.cat
Digitgrade
Scale shapes in Actinopterygii
cycloid,ctenoid,placoid and ganoid
Ostracoderm groups
1)Arandaspida and Astrapida
2)Herterostaci
3)Anaspida
4)Thelodonti
5)Galeaspida
6)Pituriaspida
7)Osterostraci
2nd branchial arch
Becomes the hyoid arch
Changes to sensory processing on land
- loss of the lateral line and Electroreception as your in air
- Spiracle developed into a tube and the hyomandibula turns into Stapes allowing the formation of the Ear
Label the strucutres 1-10
1)Barbel
2)Median Nostril
3)Mouth
4)Oral cavity
5)Pharynx
6)Velum
7)Nasopharyngeal duct
8)Brain
9)Adenohypophysis
10)Nasal Sac