Fish: Natural History

Front 1

[ respiration ]

fish must be much more efficient in their...

Back 1

uptake of oxygen (water is oxygen-poor)

Front 2

[ respiration ]

gill arch

Back 2

• bony or cartilaginous arches in the throat of fish to which the filaments and rakers of the gills are attached
• provide support for gill filaments
  

Front 3

[ respiration ]

gill filaments

Back 3

a.k.a. primary lamellae

• finger-like projections that form a curtain through which water moves across
  
• fleshy part of the gills, through which oxygen is taken into the blood from the water passing through the gills...cartilaginous gas exchange
  
• possess secondary lamellae

Front 4

[ respiration ]

secondary lemellae

Back 4

• projections on the surface of each primary lamella
  
• increase surface area to gain efficiency...raised ridges

Front 5

[ respiration ]

countercurrent flow

Back 5

water flow and blood flow occurs in opposite directions creating concentration gradient from high to low pressure

Front 6

[ respiration ]

advantage of countercurrent flow

Back 6

oxygenated water is contacting poorly oxygenated blood, giving it more oxygen

Front 7

[ respiration ]

what are the 2 basic ways fish move water across gill membranes?

Back 7

1. gill pumping
2. ram ventilation
   

Front 8

[ respiration ]

gill pumping

Back 8

synchronized pressure changes in the buccaneers and opercular chambers

Front 9

[ respiration ]

ram ventilation

Back 9

keeping mouth open while swimming

Front 10

[ respiration ]

aerial respiration

Back 10

• receiving oxygen from atmosphere (supplemental form of getting oxygen)
  
• most are facultative air breathers
• some are obligate air breathers

Front 11

[ respiration ]

facultative vs. obligate aerial respiration

Back 11

• facultative → optional
• obligate → necessary to have access to atmosphere oxygen
  - e.g. South American lungfish

Front 12

[ buoyancy regulation ]

what is buoyancy regulation?

Back 12

maintaining a position in the water column

Front 13

[ buoyancy regulation ]

gas bladder

Back 13

• flexible gas-filled chamber in body cavity
  
• most Teleosts have these
• benthic species usually do not have them
• forms as out pocket of the esophagus during embryonic development

Front 14

[ buoyancy regulation ]

physostomous gas bladder

Back 14

retain the pneumatic duct

Front 15

[ buoyancy regulation ]

physoclistous gas bladder

Back 15

pneumatic duct is not retained (MOST fishes)

Front 16

[ buoyancy regulation ]

neutrally buoyant

Back 16

maintain position in water column without expending energy

Front 17

[ buoyancy regulation ]

most gas bladders have an oval body that is...

Back 17

highly vascularized

Front 18

[ buoyancy regulation ]

gas release in physostomes

Back 18

release gas through the esophagus and out of the mouth

Front 19

[ buoyancy regulation ]

gas release in physoclists

Back 19

release gas through the bloodstream

Front 20

[ buoyancy regulation ]

gas addition

Back 20

• moving gases from blood back into swim bladder
• uses gas gland on the bottom of the gas bladder
  

Front 21

[ buoyancy regulation ]

rete mirable (gas addition)

Back 21

• "wonderful net"
• bundle of capillaries where the arterial capillaries and venous capillaries lie adjacent but in opposite directions
  - countercurrent flow

Front 22

list the 3 functions of the gas bladder

Back 22

1. buoyancy regulation
   
2. respiration
3. sound reception

Front 23

[ locomotion ]

define locomotion

Back 23

how an organism moves through its environment

Front 24

[ locomotion ]

most efficient fish body type

Back 24

fusiform (torpedo-shaped)

Front 25

[ locomotion ]

myomeres

Back 25

• series of muscles along sides of body connected backbone to skin
• locomotion is accomplished by moving these from side to side
  

Front 26

[ feeding ]

pharyngeal jaws

Back 26

• "internal jaws"
  
• contain teeth that function in food processing

Front 27

[ feeding ]

jaw protrusion

Back 27

• major evolutionary advance
• jaws can be moved forward while feeding (independently of rest of body)
• major advantage → suction feeding
  

Front 28

[ feeding ]

suction feeding

Back 28

• accelerates speed of bite because they don't have to move whole body forward
  
• creates a low pressure area in front of the jaw and high pressure area inside the mouth which sucks in the water in front of it along with any prey
  
• major advantage of jaw protrusion

Front 29

[ feeding ]

Elasmobranchii jaw protrusion

Back 29

consist of a Palatoquadrate (upper jaw) that is not connected to the skull

Front 30

[ feeding ]

gill rakers

Back 30

• projections on gill (modification of gill arches) to aid in feeding

• as food becomes smaller, arches become longer and tighter together (and vice versa with larger food)

Front 31

[ reproduction and development ]

what are the 2 defining, important characteristics of reproduction and development?

Back 31

1. larval stage
2. indeterminate growth

Front 32

[ reproduction and development ]

larval stage

Back 32

• first stage after hatching in which specimen does not represent juvenile or adult stage
  
• most fish have this

Front 33

[ reproduction and development ]

fish life stages

Back 33

fertilized egg → larvae → juvenile → adult

Front 34

[ reproduction and development ]

indeterminate growth

Back 34

increase in size throughout life (rapid in early growth and slows down as specimen gets older

Front 35

[ reproduction and development ]

list the 3 influences of indeterminate growth

Back 35

1. reproduction
   - reproductive success increases with size
2. predator avoidance
   - less susceptible to predators when larger
3. feeding
   - feeding opportunities increase with size

Front 36

[ reproduction and development ]

influences of indeterminate growth: reproduction

Back 36

reproductive success increases with size

• females produce more and/or larger eggs
  - increased survival
• select larger mates
  - adaptive because larger = survived longer
• can better defend breeding territories when larger

Front 37

[ reproduction and development ]

external fertilization

Back 37

• eggs fertilized outside the body
  
• most fish exhibit this kind of fertilization
• spawning

Front 38

[ reproduction and development ]

spawning

Back 38

females release eggs into water and male fertilizes them

Front 39

[ reproduction and development ]

internal fertilization

Back 39

• some fish exhibit this type of fertilization
  
• e.g. Elasmobranchs, Poeciliids, Gambusians
• some males may have claspers (i.e. Elasmobranchs)

Front 40

[ reproduction and development ]

clasper

Back 40

modified pelvic fins used in internal fertilization

Front 41

[ reproduction and development ]

Poeciliids have a ____________ for mating, which is....

Back 41

gonopodium, which is a modification of a clasper

Front 42

[ reproduction and development ]

oviparous

Back 42

• "egg-laying"
  
• eggs are laid outside body and nourishment comes from egg yolk
  
• can be applied to most bony fishes

Front 43

[ reproduction and development ]

viviparous

Back 43

• "live-bearing"
• young develop within mother and receive nourishment from her
  

Front 44

[ reproduction and development ]

list the 3 ways of getting nourishment in viviparous fishes

Back 44

1. "placental" connection: nourishment from the mother's bloodstream
   
2. secretions from the reproductive tract
3. nutritive eggs: food for the embryos

Front 45

[ reproduction and development ]

ovoviviparous

Back 45

• eggs are produced but are retained inside female until hatching or just before
• nourishment comes from egg yolk
  

Front 46

[ reproduction and development ]

the larval stage begins when...

Back 46

begins when they switch from egg yolk to feeding on an external food source (free swimming stage)

Front 47

[ reproduction and development ]

juvenile stage

Back 47

resemble miniature version of adult form

Front 48

[ reproduction and development ]

list 2 deviations from normal reproductive stages

Back 48

1. asymmetric development
   - e.g. flounders have symmetry as larvae but
   asymmetry as juveniles and adults)
   
2. smoltification of anadromous salmonids
   - in order to transition from fresh to salt water
   - egg → larvae → fry → parr → smolt → adult

Front 49

[ reproduction and development ]

adult stage

Back 49

attainment of sexual maturity

Front 50

sensory systems

list the 4 sensory systems

Back 50

1. hearing
2. lateral line system
3. vision
4. smell

Front 51

sensory systems: hearing

otoliths

Back 51

• "ear stones"
• sounds waves hit them and cause them to move
• different density than fish body that captures sound movement and converts to movement...also enhances hearing
  

Front 52

sensory systems: hearing

Weberian ossicles

Back 52

connect gas bladder to inner ear and otolith

Front 53

sensory systems: lateral line system

lateral line system

Back 53

• detects vibrations and changes in water pressure
  
• only works underwater

Front 54

sensory systems: lateral line system

neuromast cells

Back 54

provide spatial awareness and allow fish to navigate in space

Front 55

sensory systems: vision

a fish lens is ______, rather than ______ like it is in terrestrial vertebrates

Back 55

round, rather than oval

Front 56

sensory systems: vision

lens

Back 56

• rounded
• where refraction takes place...major focusing is done automatically because of underwater environment so LITTLE refraction is done
  

Front 57

sensory systems: vision

retina

Back 57

• mass of receptor cells at back of eye
• consists of rods and cones
  

Front 58

sensory systems: vision

list the 2 types of photoreceptors found in the retina and what types of reception they are responsible for

Back 58

1. rods → light reception
2. cones → color reception

Front 59

sensory systems: vision

tapetum lucidum

Back 59

• layer of guanine crystals behind receptor layer of retina
• reflect light back out
  
• increases night vision in nocturnal species
• rod cells stimulated twice

Front 60

sensory systems: smell

nasal sacs

Back 60

contain olfactory receptors

Front 61

sensory systems: smell

list the 4 functions of smell

Back 61

1. locating food
2. locating mates
3. returning to natal sites
4. avoiding predators
   - alarm system in schooling fish

Front 62

electroreception

what is electroreception?

Back 62

• the ability to detect minute electrical field
  - can detect prey
  - used in communication
  
• uses electrocytes

Front 63

electroreception

electrocytes

Back 63

• stacked cells that magnify impulses
  - electric ray → 20 to 50 volts
  - electric eel → 500 volts

Front 64

magnetic reception

what is magnetic reception?

Back 64

the ability to detect earth's magnetic field