Exam 2 Flashcards
(52 cards)
1
Q
Jaw Origins
A
Gill arches (respiration/foraging/gill support) migrated toward mouth opening and became associated with holding on to prey.
Derman bone migrated to teeth for gripping.
2
Q
Earliest Jawed Species
A
Placoderms
Devonian period (Age of Fishes)
- Freshwater and marine
- cartilagenous skeletons
- increased muscle size/complexity
- paired lateral fins (movement)
3
Q
Arthrodira
A
50cm - 12m long
Open-water predators
Teeth came from dermal bone (part of jaw)
Dominant predators during Devonian
4
Q
Teeth from Dermal Bone
A
Part of jaw
Gone once broken
5
Q
Antiarchi
A
Benthic
Feeding on crustaceans (flattened grinding plates)
Heavily armored
Primarily freshwater
(Devonian)
6
Q
Benthic
A
bottom feeder
7
Q
Acanthodians
A
Spiny Sharks
- Oldest jawed fishes (Silurian)
- Each fin preceded by sping anchored in body
- Cartilaginous
- Dominant freshwater predator
8
Q
Chondrichthyes
A
Cartilaginous Fishes
- Fossil Sharks
- Cladoselache (1-2m)
- Stethacanthus
- Hybodus (2m)
- Carcharodon megalodon (16-20m)
9
Q
Modern Day Chondrichthyes
A
Elasmobranchii & Holocephali
- Cartilaginous Skeleton
- Lack Swim Bladder (oil used for buoyancy. 90% of liver by weight)
- Placoid scales (reduces drag)
10
Q
Elasmobranchii
A
“Plate gills”
- Sharks, skates, rays
- Carniverous
- Suction/Filter/Attack
- Protrusible Jaw (hylostylic jaw suspension)
- Conveyor belt of teeth
11
Q
Elasmobranchii Reproduction
A
Universal Internal Fertilization
- Male claspers insert into female cloaca ‘groove’
- Seawater washes sperm into cloaca
- Fairly aggressive ritual (female skin 2-4x thicker than males)
- 30% oviparous, 70% viviparous
12
Q
Oviparity
A
Egg Laying
- Ancestral
- 2-7cm in length
- Nutrition from yolk
- Leathery shell gets tangled with kelp/coral/etc.
- 2-15 months
- Direct development into mini-adult due to yolk
13
Q
Ovoviparity
A
Eggs kept inside female
- Yolk nutrition (no placenta)
- Increased growth rates
- Stable environment
- Yolk runs out @ 3 months (some intrauterine cannibalism
14
Q
Oophagous Embryos
A
Feed on ovulating eggs
15
Q
Embryophagous Embryos
A
Feed on siblings, then eat eggs
16
Q
Viviparity
A
Live Birth
- Placental viviparity (65%) young attached to female through yolk sac placenta umbilical cord
- Little yolk, when gone, sac attaches to uterus
- Nutriens to young, wastes to mom
- Growths along cord absorb uterine milk (histotroph)
17
Q
Skates & Rays
A
- Durophagous (hard-bodied)
- Carnivorous (molluscs, crustaceans)
- Low reliance on vision
- Well developed olfaction & electrosensory
18
Q
Chimera
A
(Rat Fish)
- Derived from placoderms
- ~60 species @ 60-200cm in length
- Benthic (temperate marine)
- Grinding plates for hard-bodied organisms
- Oviparous (few, 10cm eggs)
- Female has no cloaca (urogenital opening)
- Scaleless
- Poisonous dorsal spine
19
Q
Chondrichthyes Conservation Status
A
Globally In Decline
- 30% of species are near extinction
- 47% lack data
- 73 millions of sharks killed anually
20
Q
Why it’s hard for Sharks, Skates, & Rays to Recover
A
- Reproduce late in life (6-18 years)
- Low fecundity (2 per event)
- Don’t reproduce yearly
- No parental care
- Long gestation
- Habitat loss
21
Q
Osteichthyes
A
Bony Fishes
- Sarcopterygii (lobed-fin fishes)
- Actinopterygii (ray-finned fishes)
22
Q
Sarcopterygii
A
Lobed-fin Fishes
- Fleshy, muscular pelvic/pectoral fins (single skeletal element)
- Cosmoid scales (dentine-based, dermal armoring)
- Fin joined to the body by a single bone; precursor to legs
- e.g. Lungfish
23
Q
Lungfish (Dipnoi)
A
6 living spp.
~18” - 6.5’
24
Q
Australian Lungfish
A
- Found in 3-4 rivers in Queensland.
- Retain functional gills as well as lungs
- Facultative air-breathers
25
**African Lungfish**
Protopterus spp.
* Obligate air-breathers (90% of air from lungs)
* Still/flowing water (rivers)
* Seasonal drought (6mo - 4yrs): greatly reduces heart rate, metabolism, metabolize body fats, waste is urea
* When rain comes: Metabolize glycogen, cannibolize young lungfish if no food, waste is ammonia
* Reproduction (early)
* Female builds burrow & lays eggs
* Internal fertilization
* Male guards and oxyginates eggs with tail lashing
26
**South American Lungfish** (Amazon)
Lepidosiren paradoxa
* Poorly known (recently derrived)
* Obligate air-breathers
* Hiburnate in burrows
* Reproduce like protopteris without tail-lashing (pelvic fins oxygenate burrow)
27
**Coelacanthimorpha**
* Devonian to Cretaceous
* Carnivorous
* 6 ft
* Oviviperous
* 40-65 years to maturity
* Use electrosensory abilities to forage
* Black market for specimens
28
**Osteolepimorphi**
Rhipidistians
* Ancestor to tetrapods/amphibians (no living species)
* Large predators (dentition)
* Shallow freshwater
* Decreased dermal bone thickness
* Well-muscled fins
29
**Actinopterygii**
Ray-Finned Fishes
* Individual fin rays (modified scales) line up in each fin
* Attached to adjacent body musculature
* Webs of skin supported by bony spines
* Unknown origins
30
**Paleonisciformes**
* Ancient Actinopterygii
* Cartilaginous (some ossification)
* New bond laid down on cartilage
* Devonian - Jurrasic
* 5-50cm
* Increased jaw, size, speed, strength
* Light/thin scales (increased energy savings, speed, flexibility)
* Evidence for swim bladder
* All Extinct
31
**Modern Actinopterygii**
* Chondrostei, Neopterygii, Telostei
32
**Sturgeons**
Acipenseridae
* Cartilagenous snout
* Benthic feeders (fish, crustaceans)
* Sensory barbels on snout (olfaction/chemosensory)
* Very Fecund (millions of small eggs per event, minimal investment)
33
**Paddlefish**
* Filter feeders
* Snout has electrosensory abilities
* 6-7'
* Fecund
34
**Neopterygii**
New Fins
* Most actinops
* Polypteriformes, Amiidae, Lepisosteidae (Gar)
35
**Polypteriformes**
* African wetlands, slow-moving rivers
* High tolerance to low O2
* Obligate air breathers (lungs)
* Predators
36
**Amiidae**
* Bowfin
* Wetlands, lakes, rivers
* Carnivores
* **Increased sexual based on color pattern (green) ; correlated with surplus energy**
37
**Lepisosteidae**
Gar
* 7 extant species
* Ambush predators
* Facultative air-breathers
* Takes air into swim bladder where O2/CO2 exchange occurs
38
**Placement & Function of Paired Fins**
* Strong musculature at base determines use
* Used for pitch and roll
39
**Advanced Teleost Movement**
* Decreased pitch & roll
* Increased braking and steering
* Increased thrust and propulsion
* Pectorals onto body sides
* Pelvics toward thoracic
40
**Undulation**
* Swim Speed: Around 2 body lengths per second
* Proportion of Body Involved: Increase along majority of body axis.
* Energy Required: Increased energy.
41
**Oscillation**
* Swim Speed: 10-20 body lengths per second
* Proportion of Body Involved: less than a third (often lower)
* Energy Required: lower energy used
42
**Symmetrical Caudal Fin**
Homocercal (equal)
Heterocercal (not equal)
43
**Swim/Air/Gas Bladder**
* Neutralize buoyancy
* Save Energy
* Pneumatic Duct (connection between swim bladder and gut)
* physostomes (salmids, eels, herring, minnows)
* Closed bladder (no duct)
* Physoclists
* Gas exchange driven by gas glad (ovale) with vascular system
* No bladder
* Benthic, Pelagic
44
**Pelagic**
Top feeders
45
**Decreased Dermal Armoring**
* Thinner/smaller scales
* Decreased weight
* Enhanced energy savings
* Increased streamlining
* Increased flexibility
46
**Why is Feeding More Complex in Water?**
* Water is 900 times more dense, 80 times more viscous
* Pushing water displaces/warns prey
* Pushing water is energetically expensive
47
**Attack & Grasp**
* Ambush foragers
* No suction involved
* Firm jaws lined with teeth for grasping
* Ancestral behavior
48
**Filter Feeders**
* No suction
* Swim with mouth open (gaping maw)
* Particles cought on gill rakers
49
**Projectile Feeders**
* Terrestrial prey
* Groove on roof of mouth for spitting
* Excellent vision (can correct for refraction)
50
**Suction Feeding**
* Involves buccal and opercular cavities/openings
* Inhalation (suction)
* Floors of both cavities drop and increase volume (draws in water & sucks in prey)
* Can extend upper jaw bones
* Exhalation (prey capture & removal of water)
* Close openings
* Raise floor of cavities
* Prey captured in gill rakers
* Maintains gill oxygenation during entire process
51
**Trophic Groups**
* herbivores (plant/protists)
* frugivores (fruits/berries)
* algivores (green algae)
* xylophagous (deadwood)
* coral eaters
* parasites
52
**Verts in the News**
* Viviparous Lizards
* On mountaintops. Increased extinction due to climate change.
* Leatherback Sea Turtles
* Seals sleep with half of brain active
* Amphibian Malformation
* biodiversity overcomes
* Stitchbird/Hihi
* Colors enhanced by diet
* Brookesia micra
* Adult smaller than fingertip
* Type 1 Diabetes Cured in Dogs
* Gene therapy for insulin and glucokinase (4 years)
