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