Midterm Flashcards

Dermal Bone

Membrane bone - Ossifies directly and is phylogenetically older

Exoskeleton

Made of dermal bone - External armor

Perichondral bone

Bone on surface of cartilage

Endochondral bone

Cartilage bone - Ossifies by replacing cartilage and is phylogenetically younger

Endoskeleton

Internal skeleton

Notochord

Flexible primitive structure found in Hagfish and Lamprey (Jawless Fishes)

Ancestral trend in bony fishes

More vertebrae and more intermuscular bones

Derived trend in bony fishes

Fewer vertebrae and fewer intermuscular bones

Mandibular arch

Becomes jaws

Hyoid arch

Supports jaws

Branchial arches

Supports gills

Amphistylic

Hyoid arch supports both jaws

Basal sharks

Hyostylic

No otic process

More flexible

Found in sharks and rays

Autostylic

Hyoid arch is not involved

Found in lungfishes and tetrapods

Holostylic

Found in ratfishes

Upper jaw fused with chondrocranium

Ancestral Jaws

Skull is more hard + bony

Both maxilla and premaxilla have teeth

No ascending process

Small premaxilla

Maxilla attached to opercular apparatus

Derived Jaws

Only premaxilla has teeth

Longer premaxilla

More articulate skull

Has ascending process

Rotates downwards and forwards

Ancestral pectoral fin placement

Ventral

Derived pectoral fin placement

Lateral

Ancestral pelvic fin placement

Posterior

Derived pelvic fin placement

Anterior

Ancestral dorsal and body spines

Dorsal - absent

Body - absent or few

Derived dorsal and body spines

Dorsal - present

Body - present on head or operculum

Ancestral body shape

Elongated or fusiform

Derived body shape

Laterally compressed

Ancestral size

Large

Derived size

Small

Hyoid coupling

Creates suction

Opercular coupling

No suction

Hyoid apparatus is not involved

Hyoid coupling process

Epaxial musculature - pulls head back

Hypaxial musculature - causes rotation of pectoral girdle

Hyoid apparatus is pulled back, then down - creates suction

Opercular coupling process

Levator operculi lifts opercular apparatus

Then pulls back on lower jaw via interopercular articular ligament

Process of closing mouth

Adductor mandibulae pulls on the primordial ligament

Ligament is connected to upper and lower jaws - pulls them back

Mouth snaps closed

Advantages of no suction

Nipping

Crushing

Pharygneal jaws

Modified gill arches

Angulliform

Eels

Most of body

Undulation

Can move backwards - slow

Low Re

Ancestral

Subcarangiform/Carangiform/Thunniform

Salmon + Jacks + Tuna

Posterior half of body

Undulation

Higher Re

Inertia is more important

Swims fast

Ostraciliform

Boxfish

Caudal region

Oscillation

Tetradontiform/Balistiform/Diodontiform

Triggerfish + Sunfish + Porcupinefish

Median fins

Oscillation

Rajiform/Amiiform/Gymnotiform

Rays + Bowfin + Knifefishes

Pectoral fins and median fins

Undulation

Swims with anal fin

Labriform

Wrasses

Pectoral fins

Oscillation

Unpaired fins

Dorsal and anal fins

Helps with stabilizing

Can be used for propulsion

Roll

Right or left on vertical axis

Yaw

Head movement (left or right)

Pitch

Nose down or up

Paired fins

Control direction and breaking

Non-swimming

Modified fins

Frog fishes

Walking on land

Modified fins

Mudskippers

Flying

Extended pectoral and pelvic fins

Flying fishes

High Re

Fish that are large and fast

Inertia is more important

Tuna and sharks

Low Re

Fish that are small and slow

Viscosity is more important

Mucus

Reduces friction and maintains laminar flow

Scales

Create microturbulance along skin

Maintain laminar flow

Reduce boundary layer separation

Streamlined body + Narrow peduncle

Reduced boundary layer separation

Reduce turbulent wake

Reduce drag

Low density compounds

Sharks

Do not have a gas filled bladder

Liver is high in lipids and oils

Maintains buoyancy

Low density compounds - Bony fishes

Rockfish

Have oils in bones

Oilfishes

Have high oil and wax concentrations in muscle

Open ocean fishes

Generate lift

No lift if not swimming forward

Like an airplane

Reduced tissues

Deep oceanic fishes

Controls buoyancy

Cartilage is lighter than bone

Gas filled spaces

Sand tiger sharks

Swallow air into their stomach

No gas bladder

Shallow hydrostatic organ

Buoyancy increases as fish swim up

Gas bladder expands

Deep hydrostatic organ

Buoyancy decreases as fish swim down

Gas bladder compresses

Physostomous swimbladder

Connected to esophagus

Live near surface

Ancestral

Can gulp to go deeper

Pro - less susceptible to barotrauma

Cons - need to go to the surface to get air in order to go down deep

Physoclistous swimbladder

Can’t gulp

Live deep in ocean

Derived

Pro - they don’t need to go up to surface

Con - barotrauma and slow changes

Rete mirable

Countercurrent exchange system

Short rete mirable

Less pressure

Fish that live in shallow water

Need less oxygen

Long rete mirable

More pressure

Fish that live in deep water

Need more oxygen

Stridulation

Friction of teeth - pharyngeal

Fin spines

Bones

Swimbladder sounds

Swimbladder is amplifier

Produced by stridulation of bones

Sonic muscles

Rubs on gas bladder

Placoid scales

Do not grow with age

Dentine middle layer

Hard enamel coating

Not flexible

Cartilaginous fishes

Cycloid and ctenoid scales

Bony fishes

Most common

No enamel

Flexible - collagen

Can be used for aging

Ganoid scales

Ganoin coating

Dentine middle layer

Scales interlock

Cosmoid scales

Similar to ganoid scales

Cosmine middle layer

Shark scales

Placoid - reduce boundary layer separation

Biochromes

Red + orange + yellow

Absorb light, longer wavelength colors

Controlled by hormones

Chemical colors (pigment)

Schemochromes

Structural colors (crystals)

Blue + green + iridescent

Reflect and scatter light

Shorter wavelength colors

Color changes by hormones

Melanophores are dispersed throughout cell, then are contracted to the middle, making the cell change from dark to light

Melanophores

Black and brown

Xanthrophores

Yellow

Erythrophores

Red

Cyanophores

Blue

Leucophores

White

Iridophores

Iridescent

Countershading

Dark back

Light belly

Disruptive coloration

Hide body outline

Eyespots - makes head difficult to spot

Scares predators

Fish breathing

Buccal cavity

Opercular cavity

Ram ventilation

Actively move water through their mouth

Fast swimmers

Fish that don’t move do not use this

Gill structure

More lamella - fish that move around a lot

Less lamella - fish that are still and don’t move much

Cocurrent system

Blood and water flow same direction

Reaches equilibrium

No more oxygen - bad

Countercurrent system

Blood and water flow in opposite directions

More oxygen extracted from water

Does not reach equilibrium

Blood circulation

Single atrium

Only pumps deoxygenated blood

Lower pH

Hemoglobin carries less oxygen

Has lower affinity to oxygen

Higher pH

Hemoglobin carries more oxygen

Has higher affinity to oxygen

Metabolic rate

The higher the temperature, the higher the metabolic rate

There is less oxygen at higher temps

Fish need more oxygen at higher temps

Air breathing fish

Adapted to low oxygen environments

Catfish and mudskipper

Modified gills

Hypotonic

More salt inside fish than outside - cell ruptures

Hyperhydration

Salt loss

Drink little water

Always peeing diluted pee with water

Hypertonic

More salt outside fish than inside - cell shrivels

Dehydration

Excess salt

Drinks lots of water

Extremely concentrated urine

Chloride cells

Ions are transferred from the inside to the outside

Isotonic

There is same amount of salt inside the cell and outside the cell

Urea osmoconformers

Freshwater sharks

Produce TMAO - protects proteins in cells from toxic urea

Sharks have trouble keeping urea in their kidneys - lose it through their skin

Have huge livers

No small sharkies